AutoGen

This file documents AutoGen, a tool designed for generating program files that contain repetitive text with varied substitutions. This document is very long because it is intended as a reference document. For a quick start example, See section 1.2 A Simple Example. For a simple example of Automated Option processing, See section 7.3 Quick Start. For a full list of the Automated Option features, See section 7.1 AutoOpts Features.

This edition documents version 5.2, January 2002.

1. Introduction		AutoGen's Purpose
2. AutoGen Definitions File
3. AutoGen Template
4. Augmenting AutoGen
5. Invoking autogen		Invoking AutoGen
6. What Gets Installed Where
7. Automated Option Processing
8. Add-on packages for AutoGen
9. Hints, helps and FAQs
10. Some ideas for the future.
Concept Index		General index
Function Index		Function index

1. Introduction

AutoGen is a tool designed for generating program files that contain repetitive text with varied substitutions. Its goal is to simplify the maintenance of programs that contain large amounts of repetitious text. This is especially valuable if there are several blocks of such text that must be kept synchronized.

One common example is the problem of maintaining the code required for processing program options. Processing options requires a minimum of four different constructs be kept in proper order in different places in your program. You need at least:

1. The flag character in the flag string,
2. code to process the flag when it is encountered,
3. a global state variable or two, and
4. a line in the usage text.

You will need more things besides this if you choose to implement long option names, rc/ini file processing, environment variables and so on. All of this can be done mechanically; with the proper templates and this program. In fact, it has already been done and AutoGen itself uses it See section 7. Automated Option Processing. For a simple example of Automated Option processing, See section 7.3 Quick Start. For a full list of the Automated Option features, See section 7.1 AutoOpts Features.

1.1 The Purpose of AutoGen
1.2 A Simple Example
1.3 csh/zsh caveat
1.4 A User's Perspective

1.1 The Purpose of AutoGen

The idea of this program is to have a text file, a template if you will, that contains the general text of the desired output file. That file includes substitution expressions and sections of text that are replicated under the control of separate definition files.

AutoGen was designed with the following features:

1. The definitions are completely separate from the template. By completely isolating the definitions from the template it greatly increases the flexibility of the template implementation. A secondary goal is that a template user only needs to specify those data that are necessary to describe his application of a template.

2. Each datum in the definitions is named. Thus, the definitions can be rearranged, augmented and become obsolete without it being necessary to go back and clean up older definition files. Reduce incompatibilities!

3. Multiple values for a given name create an array of values. These arrays of values are used to control the replication of sections of the template.

4. There are named collections of definitions. They form a nested hierarchy. Associated values are collected and associated with a group name. These associated data are used collectively in sets of substitutions.

5. The template has special markers to indicate where substitutions are required, much like the ${VAR} construct in a shell here doc. These markers are not fixed strings. They are specified at the start of each template. Template designers know best what fits into their syntax and can avoid marker conflicts.

   We did this because it is burdensome and difficult to avoid conflicts using either M4 tokenizaion or C preprocessor substitution rules. It also makes it easier to specify expressions that transform the value. Of course, our expressions are less cryptic than the shell methods.

6. These same markers are used, in conjunction with enclosed keywords, to indicate sections of text that are to be skipped and for sections of text that are to be repeated. This is a major improvement over using C preprocessing macros. With the C preprocessor, you have no way of selecting output text because it is an unvarying, mechanical substitution process.

7. Finally, we supply methods for carefully controlling the output. Sometimes, it is just simply easier and clearer to compute some text or a value in one context when its application needs to be later. So, functions are available for saving text or values for later use.

1.2 A Simple Example

This is just one simple example that shows a few basic features. If you are interested, you also may run "make check" with the VERBOSE enviornment variable set and see a number of other examples in the `agen5/test/testdir' directory.

Assume you have an enumeration of names and you wish to associate some string with each name. Assume also, for the sake of this example, that it is either too complex or too large to maintain easily by hand. We will start by writing an abbreviated version of what the result is supposed to be. We will use that to construct our output templates.

In a header file, `list.h', you define the enumeration and the global array containing the associated strings:

typedef enum { IDX_ALPHA, IDX_BETA, IDX_OMEGA } list_enum; extern const char* az_name_list[ 3 ];

Then you also have `list.c' that defines the actual strings:

#include "list.h" const char* az_name_list[] = { "some alpha stuff", "more beta stuff", "final omega stuff" };

First, we will define the information that is unique for each enumeration name/string pair.

autogen definitions list; list = { list_element = alpha; list_info = "some alpha stuff"; }; list = { list_info = "more beta stuff"; list_element = beta; }; list = { list_element = omega; list_info = "final omega stuff"; };

The autogen definitions list; entry defines the file as an AutoGen definition file that uses a template named list. That is followed by three list entries that define the associations between the enumeration names and the strings. The order of the differently named elements inside of list is unimportant. They are reversed inside of the beta entry and the output is unaffected.

Now, to actually create the output, we need a template or two that can be expanded into the files you want. In this program, we use a single template that is capable of multiple output files.

It looks something like this. (For a full description, See section 3. AutoGen Template.)

[+ AutoGen5 template h c +] [+ CASE (suffix) +][+ == h +] typedef enum {[+ FOR list "," +] IDX_[+ (string-upcase! (get "list_element")) +][+ ENDFOR list +] } list_enum; extern const char* az_name_list[ [+ (count "list") +] ]; [+ == c +] #include "list.h" const char* az_name_list[] = {[+ FOR list "," +] "[+list_info+]"[+ ENDFOR list +] };[+ ESAC +]

The [+ AutoGen5 template h c +] text tells AutoGen that this is an AutoGen version 5 template file; that it is to be processed twice; that the start macro marker is [+; and the end marker is +]. The template will be processed first with a suffix value of h and then with c. Normally, the suffix values are appended to the `base-name' to create the output file name.

The [+ == h +] and [+ == c +] CASE selection clauses select different text for the two different passes. In this example, the output is nearly disjoint and could have been put in two separate templates. However, sometimes there are common sections and this is just an example.

The [+FOR list "," +] and [+ ENDFOR list +] clauses delimit a block of text that will be repeated for every definition of list. Inside of that block, the definition name-value pairs that are members of each list are available for substitutions.

The remainder of the macros are expressions. Some of these contain special expression functions that are dependent on AutoGen named values; others are simply Scheme expressions, the result of which will be inserted into the output text. Other expressions are names of AutoGen values. These values will be inserted into the output text. For example, [+list_info+] will result in the value associated with the name list_info being inserted between the double quotes and (string-upcase! (get "list_element")) will first "get" the value associated with the name list_element, then change the case of all the letters to upper case. The result will be inserted into the output document.

If you have compiled AutoGen, you can copy out the template and definitions, run `autogen' and produce exactly the hypothesized desired output.

One more point, too. Lets say you decided it was too much trouble to figure out how to use AutoGen, so you created this enumeration and string list with thousands of entries. Now, requirements have changed and it has become necessary to map a string containing the enumeration name into the enumeration number. With AutoGen, you just alter the template to emit the table of names. It will be guaranteed to be in the correct order, missing none of the entries. If you want to do that by hand, well, good luck.

1.3 csh/zsh caveat

AutoGen tries to use your normal shell so that you can supply shell code in a manner you are accustomed to using. If, however, you use csh or zsh, you cannot do this. Csh is sufficiently difficult to program that it is unsupported. Zsh, though largely programmable, also has some anomolies that make it incompatible with AutoGen usage. Therefore, when invoking AutoGen from these environments, you must be certain to set the SHELL environment variable to a Bourne-derived shell. e.g., sh, ksh or bash.

Any shell you choose for your own scripts need to follow these basic requirements:

1. It handles trap $sig ":" without output to standard out. This is done when the server shell is first started. If your shell does not handle this, then it may be able to by loading functions from its start up files.
2. At the beginning of each scriptlet, the command \\cd $PWD is inserted. This ensures that cd is not aliased to something peculiar and each scriptlet starts life in the execution directory.
3. At the end of each scriptlet, the command echo mumble is appended. The program you use as a shell must emit the single argument mumble on a line by itself.

1.4 A User's Perspective

Alexandre wrote: > > I'd appreciate opinions from others about advantages/disadvantages of > each of these macro packages.

I am using AutoGen in my pet project, and find one of its best points to be that it separates the operational data from the implementation.

Indulge me for a few paragraphs, and all will be revealed: In the manual, Bruce cites the example of maintaining command line flags inside the source code; traditionally spreading usage information, flag names, letters and processing across several functions (if not files). Investing the time in writing a sort of boiler plate (a template in AutoGen terminology) pays by moving all of the option details (usage, flags names etc.) into a well structured table (a definition file if you will), so that adding a new command line option becomes a simple matter of adding a set of details to the table.

So far so good! Of course, now that there is a template, writing all of that tedious optargs processing and usage functions is no longer an issue. Creating a table of the options needed for the new project and running AutoGen generates all of the option processing code in C automatically from just the tabular data. AutoGen in fact already ships with such a template... AutoOpts.

One final consequence of the good separation in the design of AutoGen is that it is retargetable to a greater extent. The egcs/gcc/fixinc/inclhack.def can equally be used (with different templates) to create a shell script (inclhack.sh) or a c program (fixincl.c).

This is just the tip of the iceberg. AutoGen is far more powerful than these examples might indicate, and has many other varied uses. I am certain Bruce or I could supply you with many and varied examples, and I would heartily recommend that you try it for your project and see for yourself how it compares to m4.

As an aside, I would be interested to see whether someone might be persuaded to rationalise autoconf with AutoGen in place of m4... Ben, are you listening? autoconf-3.0! `kay? =)O|

Sincerely, Gary V. Vaughan

2. AutoGen Definitions File

This chapter describes the syntax and semantics of the AutoGen definition file. In order to instantiate a template, you normally must provide a definitions file that identifies itself and contains some value definitions. Consequently, we keep it very simple. For "advanced" users, there are preprocessing directives and comments that may be used as well.

The definitions file is used to associate values with names. When multiple values are associated with a single name, an implicit array of values is formed. Values may be either simple strings or compound collections of name-value pairs. An array may not contain both simple and compound members. Fundamentally, it is as simple as:

prog_name = "autogen"; flag = { name = templ_dirs; value = L; descrip = "Template search directory list"; };

For purposes of commenting and controlling the processing of the definitions, C-style comments and most C preprocessing directives are honored. The major exception is that the #if directive is ignored, along with all following text through the matching #endif directive. The C preprocessor is not actually invoked, so C macro substitution is not performed.

2.1 The Identification Definition
2.2 Named Definitions
2.3 Dynamic Text
2.4 Controlling What Gets Processed
2.5 Pre-defined Names
2.6 Commenting Your Definitions
2.7 What it all looks like.
2.8 YACC Language Grammar
2.9 AutoGen without Definitions

2.1 The Identification Definition

The first definition in this file is used to identify it as a AutoGen file. It consists of the two keywords, `autogen' and `definitions' followed by the default template name and a terminating semi-colon (;). That is:

AutoGen Definitions template-name;

Note that, other than the name template-name, the words `AutoGen' and `Definitions' are searched for without case sensitivity. Most lookups in this program are case insensitive.

Also, if the input contains more identification definitions, they will be ignored. This is done so that you may include (see section 2.4 Controlling What Gets Processed) other definition files without an identification conflict.

AutoGen uses the name of the template to find the corresponding template file. It searches for the file in the following way, stopping when it finds the file:

1. It tries to open `./template-name'. If it fails,
2. it tries `./template-name.tpl'.
3. It searches for either of these files in the directories listed in the templ-dirs command line option.

If AutoGen fails to find the template file in one of these places, it prints an error message and exits.

2.2 Named Definitions

Any name may have multiple values associated with it in the definition file. If there is more than one instance, the only way to expand all of the copies of it is by using the FOR (see section 3.6.13 FOR - Emit a template block multiple times) text function on it, as described in the next chapter.

There are two kinds of definitions, `simple' and `compound'. They are defined thus (see section 2.8 YACC Language Grammar):

compound_name '=' '{' definition-list '}' ';' simple_name '=' string ';' no_text_name ';'

No_text_name is a simple definition with a shorthand empty string value. The string values for definitions may be specified in any of several formation rules.

2.2.1 Naming a Value
2.2.2 Definition List
2.2.3 Double Quote String
2.2.4 Single Quote String
2.2.6 An Unquoted String
2.2.5 Shell Output String
2.2.7 Scheme Result String
2.2.8 A Here String
2.2.9 Concatenated Strings

2.2.1 Naming a Value

The names may be a simple name taking the next available index, or may specify an index by name or number. For example:

txt_name txt_name[2] txt_name[ DEF_NAME ]

DEF_NAME must be defined to have a numeric value. If you do specify an index, you must take care not to cause conflicts.

2.2.2 Definition List

definition-list is a list of definitions that may or may not contain nested compound definitions. Any such definitions may only be expanded within a FOR block iterating over the containing compound definition. See section 3.6.13 FOR - Emit a template block multiple times.

Here is, again, the example definitions from the previous chapter, with three additional name value pairs. Two with an empty value assigned (first and last), and a "global" group_name.

autogen definitions list; group_name = example; list = { list_element = alpha; first; list_info = "some alpha stuff"; }; list = { list_info = "more beta stuff"; list_element = beta; }; list = { list_element = omega; last; list_info = "final omega stuff"; };

2.2.3 Double Quote String

The string follows the C-style escaping (\, \n, \f, \v, etc.), plus octal character numbers specified as \ooo. The difference from "C" is that the string may span multiple lines. Like ANSI "C", a series of these strings, possibly intermixed with single quote strings, will be concatenated together.

2.2.4 Single Quote String

This is similar to the shell single-quote string. However, escapes \ are honored before another escape, single quotes ' and hash characters #. This latter is done specifically to disambiguate lines starting with a hash character inside of a quoted string. In other words,

foo = ' #endif ';

could be misinterpreted by the definitions scanner, whereas this would not:

foo = ' \#endif ';

As with the double quote string, a series of these, even intermixed with double quote strings, will be concatenated together.

2.2.5 Shell Output String

This is assembled according to the same rules as the double quote string, except that there is no concatenation of strings and the resulting string is written to a shell server process. The definition takes on the value of the output string.

NB The text is interpreted by a server shell. There may be left over state from previous ` processing and it may leave state for subsequent processing. However, a cd to the original directory is always issued before the new command is issued.

2.2.6 An Unquoted String

A simple string that does not contain white space may be left unquoted. The string must not contain any of the characters special to the definition text (i.e. ", #, ', (, ), ,, ;, <, =, >, [, ], `, {, or }). This list is subject to change, but it will never contain underscore (_), period (.), slash (/), colon (:), hyphen (-) or backslash (\\). Basically, if the string looks like it is a normal DOS or UNIX file or variable name, and it is not one of two keywords (`autogen' or `definitions') then it is OK to not quote it, otherwise you should.

2.2.7 Scheme Result String

A scheme result string must begin with an open parenthesis (. The scheme expression will be evaluated by Guile and the value will be the result. The AutoGen expression functions are disabled at this stage, so do not use them.

2.2.8 A Here String

A `here string' is formed in much the same way as a shell here doc. It is denoted with a doubled less than character and, optionally, a hyphen. This is followed by optional horizontal white space and an ending marker-identifier. This marker must follow the syntax rules for identifiers. Unlike the shell version, however, you must not quote this marker. The resulting string will start with the first character on the next line and continue up to but not including the newline that precedes the line that begins with the marker token. No backslash or any other kind of processing is done on this string. The characters are copied directly into the result string.

Here are two examples:

str1 = <<- STR_END $quotes = " ' ` STR_END; str2 = << STR_END $quotes = " ' ` STR_END; STR_END;

The first string contains no new line characters. The first character is the dollar sign, the last the back quote.

The second string contains one new line character. The first character is the tab character preceeding the dollar sign. The last character is the semicolon after the STR_END. That STR_END does not end the string because it is not at the beginning of the line. In the preceeding case, the leading tab was stripped.

2.2.9 Concatenated Strings

If single or double quote characters are used, then you also have the option, a la ANSI-C syntax, of implicitly concatenating a series of them together, with intervening white space ignored.

NB You cannot use directives to alter the string content. That is,

str = "foo" #ifdef LATER "bar" #endif ;

will result in a syntax error. The preprocessing directives are not carried out by the C preprocessor. However,

str = '"foo\n" #ifdef LATER " bar\n" #endif ';

Will work. It will enclose the `#ifdef LATER' and `#endif' in the string. But it may also wreak havoc with the definition processing directives. The hash characters in the first column should be disambiguated with an escape \ or join them with previous lines: "foo\n#ifdef LATER....

2.3 Dynamic Text

There are several methods for including dynamic content inside a definitions file. Three of them are mentioned above (2.2.5 Shell Output String and see section 2.2.7 Scheme Result String) in the discussion of string formation rules. Another method uses the #shell processing directive. It will be discussed in the next section (see section 2.4 Controlling What Gets Processed). Guile/Scheme may also be used to yield to create definitions.

When the Scheme expression is preceeded by a backslash and single quote, then the expression is expected to be an alist of names and values that will be used to create AutoGen definitions.

This method can be be used as follows:

\'( (name (value-expression)) (name2 (another-expr)) )

This is entirely equivalent to:

name = (value-expression); name2 = (another-expr);

Under the covers, the expression gets handed off to a Guile function named alist->autogen-def in an expression that looks like this:

(alist->autogen-def ( (name (value-expression)) (name2 (another-expr)) ) )

2.4 Controlling What Gets Processed

Definition processing directives can only be processed if the '#' character is the first character on a line. Also, if you want a '#' as the first character of a line in one of your string assignments, you should either escape it by preceding it with a backslash `\', or by embedding it in the string as in "\n#".

All of the normal C preprocessing directives are recognized, though several are ignored. There is also an additional #shell - #endshell pair. Another minor difference is that AutoGen directives must have the hash character (#) in column 1.

The ignored directives are: `#assert', `#ident', `#pragma', and `#if'. Note that when ignoring the #if directive, all intervening text through its matching #endif is also ignored, including the #else clause.

The AutoGen directives that affect the processing of definitions are:

#define name [ <text> ]

Will add the name to the define list as if it were a DEFINE program argument. Its value will be the first non-whitespace token following the name. Quotes are not processed.

After the definitions file has been processed, any remaining entries in the define list will be added to the environment.

#elif

This must follow an #if otherwise it will generate an error. It will be ignored.

#else

This must follow an #if, #ifdef or #ifndef. If it follows the #if, then it will be ignored. Otherwise, it will change the processing state to the reverse of what it was.

#endif

This must follow an #if, #ifdef or #ifndef. In all cases, this will resume normal processing of text.

#endshell

Ends the text processed by a command shell into autogen definitions.

#error [ <descriptive text> ]

This directive will cause AutoGen to stop processing and exit with a status of EXIT_FAILURE.

#if [ <ignored conditional expression> ]

#if expressions are not analyzed. Everything from here to the matching #endif is skipped.

#ifdef name-to-test

The definitions that follow, up to the matching #endif will be processed only if there is a corresponding -Dname command line option.

#ifndef name-to-test

The definitions that follow, up to the matching #endif will be processed only if there is not a corresponding -Dname command line option or there was a canceling -Uname option.

#include unadorned-file-name

This directive will insert definitions from another file into the current collection. If the file name is adorned with double quotes or angle brackets (as in a C program), then the include is ignored.

#line

Alters the current line number and/or file name. You may wish to use this directive if you extract definition source from other files. getdefs uses this mechanism so AutoGen will report the correct file and approximate line number of any errors found in extracted definitions.

#shell

Invokes $SHELL or `/bin/sh' on a script that should generate AutoGen definitions. It does this using the same server process that handles the back-quoted ` text. CAUTION let not your $SHELL be csh.

#undef name-to-undefine

Will remove any entries from the define list that match the undef name pattern.

2.5 Pre-defined Names

When AutoGen starts, it tries to determine several names from the operating environment and put them into environment variables for use in both #ifdef tests in the definitions files and in shell scripts with environment variable tests. __autogen__ is always defined. For other names, AutoGen will first try to use the POSIX version of the sysinfo(2) system call. Failing that, it will try for the POSIX uname(2) call. If neither is available, then only "__autogen__" will be inserted into the environment.

If sysinfo(2) is available, the strings associated with

• SI_SYSNAME (e.g., "__sunos__")
• SI_HOSTNAME (e.g., "__ellen__")
• SI_ARCHITECTURE (e.g., "__sparc__")
• SI_HW_PROVIDER (e.g., "__sun_microsystems__")
• SI_PLATFORM (e.g., "__sun_ultra_5_10__")
• SI_MACHINE (e.g., "__sun4u__")

For Linux and other operating systems that only support the uname(2) call, AutoGen will use these values:

• sysname (e.g., "__linux__")
• machine (e.g., "__i586__")
• nodename (e.g., "__bach__")

By testing these pre-defines in my definitions, you can select pieces of the definitions without resorting to writing shell scripts that parse the output of uname(1). You can also segregate real C code from autogen definitions by testing for "__autogen__".

#ifdef __bach__ location = home; #else location = work; #endif

2.6 Commenting Your Definitions

The definitions file may contain C and C++ style comments.

/* * This is a comment. It continues for several lines and closes * when the characters '*' and '/' appear together. */ // this comment is a single line comment

2.7 What it all looks like.

This is an extended example:

autogen definitions `template-name'; /* * This is a comment that describes what these * definitions are all about. */ global = "value for a global text definition."; /* * Include a standard set of definitions */ #include standards.def a_block = { a_field; a_subblock = { sub_name = first; sub_field = "sub value."; }; #ifdef FEATURE a_subblock = { sub_name = second; }; #endif };

2.8 YACC Language Grammar

The processing directives and comments are not part of the grammar. They are handled by the scanner/lexer. The following was extracted directly from the defParse.y source file:

definitions : identity def_list TK_END { $$ = (YYSTYPE)(rootDefCtx.pDefs = (tDefEntry*)$2); } ; def_list : definition { $$ = $1; } | definition def_list { $$ = addSibMacro( $1, $2 ); } | identity def_list { $$ = $2; } ; identity : TK_AUTOGEN TK_DEFINITIONS anyname ';' { $$ = identify( $3 ); } ; definition : value_name ';' { $$ = makeMacro( $1, (YYSTYPE)"", VALTYP_TEXT ); } | value_name '=' text_list ';' { $$ = makeMacroList( $1, $3, VALTYP_TEXT ); } | value_name '=' block_list ';' { $$ = makeMacroList( $1, $3, VALTYP_BLOCK ); } ; text_list : anystring { $$ = startList( $1 ); } | anystring ',' text_list { $$ = appendList( $1, $3 ); } ; block_list : def_block { $$ = startList( $1 ); } | def_block ',' block_list { $$ = appendList( $1, $3 ); } ; def_block : '{' def_list '}' { $$ = $2; } ; anystring : anyname { $$ = $1; } | TK_STRING { $$ = $1; } | TK_NUMBER { $$ = $1; } ; anyname : TK_OTHER_NAME { $$ = $1; } | TK_VAR_NAME { $$ = $1; } ; value_name : TK_VAR_NAME { $$ = findPlace( $1, (YYSTYPE)NULL ); } | TK_VAR_NAME '[' TK_NUMBER ']' { $$ = findPlace( $1, $3 ); } | TK_VAR_NAME '[' TK_VAR_NAME ']' { $$ = findPlace( $1, $3 ); } ;

2.9 AutoGen without Definitions

It is entirely possible to write a template that does not depend upon external definitions. Such a template would likely have an unvarying output, but be convenient nonetheless because of an external library of either AutoGen or Scheme functions, or both. This can be accommodated by providing the --override-tpl and --no-definitions options on the command line. See section 5. Invoking autogen.

3. AutoGen Template

The AutoGen template file defines the content of the output text. It is composed of two parts. The first part consists of a pseudo macro invocation and commentary. It is followed by the template proper.

This pseudo macro is special. It is used to identify the file as a AutoGen template file, fixing the starting and ending marks for the macro invocations in the rest of the file, specifying the list of suffixes to be generated by the template and, optionally, the shell to use for processing shell commands embedded in the template.

AutoGen-ing a file consists of copying text from the template to the output file until a start macro marker is found. The text from the start marker to the end marker constitutes the macro text. AutoGen macros may cause sections of the template to be skipped or processed several times. The process continues until the end of the template is reached. The process is repeated once for each suffix specified in the pseudo macro.

This chapter describes the format of the AutoGen template macros and the usage of the AutoGen native macros. Users may augment these by defining their own macros. See section 3.6.4 DEFINE - Define a user AutoGen macro.

3.1 Format of the Pseudo Macro
3.2 Naming a value
3.3 Macro Expression Syntax
3.4 AutoGen Scheme Functions
3.5 Common Scheme Functions
3.6 AutoGen Native Macros
3.7 Redirecting Output

3.1 Format of the Pseudo Macro

The pseudo-macro starts with up to seven (7) punctuation characters used for the template start-macro marker, followed by the autogen magic marker (autogen5), the template marker (template), zero or more suffix specifications, scheme expressions and the end-macro marker. It may also consist of up to seven (7) punctuation characters. Interspersed may be comment lines (blank lines or lines starting with a hash mark [#]) and edit mode markers (text between pairs of -*- characters).

As an example, assume we want to use [+ and +] as the start and end macro markers, and we wish to produce a `.c' and a `.h' file, then the first macro invocation will look something like this:

[+ AutoGen5 template -*- Mode: emacs-mode-of-choice -*- h=chk-%s.h c # make sure we don't use csh: (setenv "SHELL" "/bin/sh") +]

Note It is generally a good idea to use some sort of opening bracket in the starting macro and closing bracket in the ending macro (e.g. {, (, [, or even < in the starting macro). It helps both visually and with editors capable of finding a balancing parenthesis. The closing marker may not begin with an open parenthesis, as that is used to enclose a scheme expression.

It is also helpful to avoid using the comment marker (#); the POSIXly acceptable file name characters period (.), hyphen (-) and underscore (_); and finally, it is advisable to avoid using any of the quote characters double, single or back-quote. But there is no special check for any of these advisories.

Detailed description:

The starting macro marker must be the first non-white space characters encountered in the file. The marker consists of all the contiguous ASCII punctuation characters found there. With optional intervening white space, this marker must be immediately followed by the keywords, "autogen5" and "template". Capitalization of these words is not important. This is followed by zero, one or more suffix specifications and, possibly, a scheme expression.

Suffix specifications consist of a sequence of POSIX compliant file name characters and, optionally, an equal sign and a file name "printf"-style formatting string. Two string arguments are allowed for that string: the base name of the definition file and the current suffix (that being the text to the left of the equal sign). (Note "POSIX compliant file name characters" consist of alphanumerics plus the period (.), hyphen (-) and underscore (_) characters.) If there are no suffix specifications, then the generated file will be written to the stdout file descriptor.

The scheme expression is intended to allow the template writer to specify the shell program that must be used to interpret the shell commands in the template. It can have no effect on any shell commands in the definitions file, as that file will have been processed by the time the pseudo macro is interpreted. You can specify the shell as follows:

(setenv "SHELL" "/bin/sh")

This works because AutoGen examines the value of the SHELL environment variable in order to select the shell to run. If that shell is allowed to be csh, AutoGen will break. If it is allowed to be zsh, AutoGen may break. Your milage may vary.

The pseudo macro ends with an end macro marker. Like the starting macro marker, it consists of a contiguous sequence of arbitrary punctuation characters. However, additionally, it may not begin with any of the POSIX file name characters and it may not contain the start macro marker.

This pseudo macro may appear on one or several lines of text. Intermixed may be comment lines (completely blank or starting with the hash character # in column 1), and file content markers (text between -*- pairs on a single line). This may be used to establish editing "modes" for the file. These are ignored by AutoGen.

The template proper starts after the pseudo-macro. The starting character is either the first non-whitespace character or the first character after the new-line that follows the end macro marker.

3.2 Naming a value

When an AutoGen value is specified in a template, it is specified by name. The name may be a simple name, or a compound name of several components. Since each named value in AutoGen is implicitly an array of one or more values, each component may have an index associated with it.

It looks like this:

comp-name-1 . comp-name-2 [ 2 ]

Note that if there are multiple components to a name, each component name is separated by a dot (.). Indexes follow a component name, enclosed in square brackets ([ and ]). The index may be either an integer or an integer-valued define name. The first component of the name is searched for in the current definition level. If not found, higher levels will be searched until either a value is found, or there are no more definition levels. Subsequent components of the name must be found within the context of the newly-current definition level. Also, if the named value is prefixed by a dot (.), then the value search is started in the current context only. No higher levels are searched.

If someone rewrites this, I'll incorporate it. :-)

3.3 Macro Expression Syntax

AutoGen has two types of expressions: full expressions and basic ones. A full AutoGen expression can appear by itself, or as the argument to certain AutoGen built-in macros: CASE, IF, ELIF, INCLUDE, INVOKE (explicit invocation, see section 3.6.16 INVOKE - Invoke a User Defined Macro), and WHILE. If it appears by itself, the result is inserted into the output. If it is an argument to one of these macros, the macro code will act on it sensibly.

You are constrained to basic expressions only when passing arguments to user defined macros, See section 3.6.4 DEFINE - Define a user AutoGen macro.

The syntax of a full AutoGen expression is:

[[ <apply-code> ] <value-name> ] [ <basic-expr-1> [ <basic-expr-2> ]]

How the expression is evaluated depends upon the presence or absence of the apply code and value name. The "value name" is the name of an AutoGen defined value, or not. If it does not name such a value, the expression result is generally the empty string. All expressions must contain either a value-name or a basic-expr.

3.3.1 Apply Code
3.3.2 Basic Expression

3.3.1 Apply Code

The "apply code" selected determines the method of evaluating the expression. There are five apply codes, including the non-use of an apply code.

`no apply code'

This is the most common expression type. Expressions of this sort come in three flavors:

`<value-name>'

The result is the value of value-name, if defined. Otherwise it is the empty string.

`<basic-expr>'

The result of the basic expression is the result of the full expression, See section 3.3.2 Basic Expression.

`<value-name> <basic-expr>'

If there is a defined value for value-name, then the basic-expr is evaluated. Otherwise, the result is the empty string.

`% <value-name> <basic-expr>'

If value-name is defined, use basic-expr as a format string for sprintf. Then, if the basic-expr is either a back-quoted string or a parenthesized expression, then hand the result to the appropriate interpreter for further evaluation. Otherwise, for single and double quote strings, the result is the result of the sprintf operation. Naturally, if value-name is not defined, the result is the empty string.

For example, assume that foo had the string value, bar:

[+ % foo `printf '%%x\\n' $%s` +]

This would cause the shell to evaluate "printf '%x\n' $bar". Assuming that the shell variable bar had a numeric value, the expression result would be that number, in hex. Note the need for doubled percent characters and backslashes.

`? <value-name> <basic-expr-1> <basic-expr-2>'

Two basic-expr-s are required. If the value-name is defined, then the first basic-expr-1 is evaluated, otherwise basic-expr-2 is.

`- <value-name> <basic-expr>'

Evaluate basic-expr only if value-name is not defined.

`?% <value-name> <basic-expr-1> <basic-expr-2>'

This combines the functions of `?' and `%'. If value-name is defined, it behaves exactly like `%', above, using basic-expr-1. If not defined, then basic-expr-2 is evaluated.

For example, assume again that foo had the string value, bar:

[+ ?% foo `cat $%s` `pwd` +]

This would cause the shell to evaluate "cat $bar". If foo were not defined, then the result would be the name of our current directory.

3.3.2 Basic Expression

A basic expression can have one of the following forms:

`'STRING''

A single quoted string. Backslashes can be used to protect single quotes ('), hash characters (#), or backslashes (\) in the string. All other characters of STRING are output as-is when the single quoted string is evaluated. Backslashes are processed before the hash character for consistency with the definition syntax. It is needed there to avoid preprocessing conflicts.

`"STRING"'

A double quoted string. This is a cooked text string as in C, except that they are not concatenated with adjacent strings. Evaluating "STRING" will output STRING with all backslash sequences interpreted.

``STRING`'

A back quoted string. When this expression is evaluated, STRING is first interpreted as a cooked string (as in `"STRING"') and evaluated as a shell expression by the AutoGen server shell. This expression is replaced by the stdout output of the shell.

`(STRING)'

A parenthesized expression. It will be passed to the Guile interpreter for evaluation and replaced by the resulting value.

Additionally, other than in the % and ?% expressions, the Guile expressions may be introduced with the Guile comment character (;) and you may put a series of Guile expressions within a single macro. They will be implicitly evaluated as if they were arguments to the (begin ...) expression. The result will be the the result of the last Guile expression evaluated.

3.4 AutoGen Scheme Functions

AutoGen uses Guile to interpret Scheme expressions within AutoGen macros. All of the normal Guile functions are available, plus several extensions (see section 3.5 Common Scheme Functions) have been added to augment the repertoire of string manipulation functions and manage the state of AutoGen processing.

This section describes those functions that are specific to AutoGen. Please take note that these AutoGen specific functions are not loaded and thus not made available until after the command line options have been processed and the AutoGen definitions have been loaded. They may, of course, be used in Scheme functions that get defined at those times, but they cannot be invoked.

3.4.1 `ag-function?' - test for function
3.4.2 `base-name' - base output name
3.4.3 `count' - definition count
3.4.4 `def-file' - definitions file name
3.4.5 `dne' - "Do Not Edit" warning
3.4.6 `error' - display message and exit
3.4.7 `error-source-line' - display of file & line
3.4.8 `exist?' - test for value name
3.4.9 `first-for?' - detect first iteration
3.4.10 `for-by' - set iteration step
3.4.11 `for-from' - set initial index
3.4.12 `for-index' - get current loop index
3.4.13 `for-sep' - set loop separation string
3.4.14 `for-to' - set ending index
3.4.15 `get' - get named value
3.4.16 `high-lim' - get highest value index
3.4.17 `last-for?' - detect last iteration
3.4.18 `len' - get count of values
3.4.19 `low-lim' - get lowest value index
3.4.20 `match-value?' - test for matching value
3.4.21 `out-delete' - delete current output file
3.4.22 `out-depth' - output file stack depth
3.4.23 `out-move' - change name of output file
3.4.24 `out-name' - current output file name
3.4.25 `out-pop' - close current output file
3.4.26 `out-push-add' - append output to file
3.4.27 `out-push-new' - purge and create output file
3.4.28 `out-resume' - resume current output file
3.4.29 `out-suspend' - suspend current output file
3.4.30 `out-switch' - close and create new output
3.4.31 `set-writable' - Make the output file be writable
3.4.32 `stack' - make list of AutoGen values
3.4.33 `suffix' - get the current suffix
3.4.34 `tpl-file' - get the template file name
3.4.35 `tpl-file-line' - get the template file and line number

3.4.1 `ag-function?' - test for function

Arguments:
ag-name - name of AutoGen macro

3.4.2 `base-name' - base output name

This Scheme function takes no arguments.

3.4.3 `count' - definition count

Arguments:
ag-name - name of AutoGen value

3.4.4 `def-file' - definitions file name

This Scheme function takes no arguments.

3.4.5 `dne' - "Do Not Edit" warning

-*- buffer-read-only: t -*- vi: set ro:

Arguments:
prefix - string for starting each output line
first_prefix - Optional - for the first output line

3.4.6 `error' - display message and exit

DEFINITIONS ERROR in %s line %d for %s: %s\n

The first three arguments to this format are provided by the routine and are: The name of the template file, the line within the template where the error was found, and the current output file name.

After displaying the message, the current output file is removed and autogen exits with the EXIT_FAILURE error code. IF, however, the argument begins with the number 0 (zero), or the string is the empty string, then processing continues with the next suffix.

Arguments:
message - message to display before exiting

3.4.7 `error-source-line' - display of file & line

This Scheme function takes no arguments.

3.4.8 `exist?' - test for value name

(exist? "foo[3].bar.baz")

Arguments:
ag-name - name of AutoGen value

3.4.9 `first-for?' - detect first iteration

Arguments:
for_var - Optional - which for loop

3.4.10 `for-by' - set iteration step

Arguments:
by - the iteration increment for the AutoGen FOR macro

3.4.11 `for-from' - set initial index

Arguments:
from - the initial index for the AutoGen FOR macro

3.4.12 `for-index' - get current loop index

Arguments:
for_var - Optional - which for loop

3.4.13 `for-sep' - set loop separation string

Arguments:
separator - the text to insert between the output of each FOR iteration

3.4.14 `for-to' - set ending index

Arguments:
to - the final index for the AutoGen FOR macro

3.4.15 `get' - get named value

Arguments:
ag-name - name of AutoGen value

3.4.16 `high-lim' - get highest value index

This is very useful for specifying the size of a zero-based array of values where not all values are present. For example:

tMyStruct myVals[ [+ (+ 1 (high-lim "my-val-list")) +] ];

Arguments:
ag-name - name of AutoGen value

3.4.17 `last-for?' - detect last iteration

Arguments:
for_var - Optional - which for loop

3.4.18 `len' - get count of values

Arguments:
ag-name - name of AutoGen value

3.4.19 `low-lim' - get lowest value index

Arguments:
ag-name - name of AutoGen value

3.4.20 `match-value?' - test for matching value

Arguments:
op - boolean result operator
ag-name - name of AutoGen value
test-str - string to test against

3.4.21 `out-delete' - delete current output file

This Scheme function takes no arguments.

3.4.22 `out-depth' - output file stack depth

This Scheme function takes no arguments.

3.4.23 `out-move' - change name of output file

Arguments:
new-name - new name for the current output file

3.4.24 `out-name' - current output file name

This Scheme function takes no arguments.

3.4.25 `out-pop' - close current output file

If there is no argument, no further action is taken. Otherwise, the argument should be #t and the contents of the file are returned by the function.

Arguments:
disp - Optional - return contents of the file

3.4.26 `out-push-add' - append output to file

Arguments:
file-name - name of the file to append text to

3.4.27 `out-push-new' - purge and create output file

Arguments:
file-name - Optional - name of the file to create

3.4.28 `out-resume' - resume current output file

Arguments:
suspName - A name tag for reactivating

3.4.29 `out-suspend' - suspend current output file

Arguments:
suspName - A name tag for reactivating

3.4.30 `out-switch' - close and create new output

Arguments:
file-name - name of the file to create

3.4.31 `set-writable' - Make the output file be writable

Arguments:
set? - Optional - boolean arg, false to make output non-writable

3.4.32 `stack' - make list of AutoGen values

Arguments:
ag-name - AutoGen value name

3.4.33 `suffix' - get the current suffix

This Scheme function takes no arguments.

3.4.34 `tpl-file' - get the template file name

This Scheme function takes no arguments.

3.4.35 `tpl-file-line' - get the template file and line number

Arguments:
msg-fmt - Optional - formatting for line message

3.5 Common Scheme Functions

This section describes a number of general purpose functions that make the kind of string processing that AutoGen does a little easier. Unlike the AutoGen specific functions (see section 3.4 AutoGen Scheme Functions), these functions are available for direct use during definition load time.

3.5.1 `bsd' - Free BSD public license
3.5.2 `c-string' - emit string for ANSI C
3.5.3 `extract' - extract text from another file
3.5.4 `find-file' - locate a file in the search path
3.5.5 `fprintf' - format to a file
3.5.6 `gperf' - perform a perfect hash function
3.5.7 `gpl' - GNU public license
3.5.8 `in?' - test for string in list
3.5.9 `join' - join string list with separator
3.5.10 `kr-string' - emit string for K&R C
3.5.11 `lgpl' - GNU lib public license
3.5.12 `license' - an arbitrary license
3.5.13 `make-gperf' - build a perfect hash function program
3.5.14 `max' - maximum value in list
3.5.15 `min' - minimum value in list
3.5.16 `prefix' - prefix lines with a string
3.5.17 `printf' - format to stdout
3.5.18 `raw-shell-str' - single quote shell string
3.5.19 `shell' - invoke a shell script
3.5.20 `shell-str' - double quote shell string
3.5.21 `shellf' - format a string, run shell
3.5.22 `sprintf' - format a string
3.5.23 `string-capitalize' - make a new string be capitalized
3.5.24 `string-capitalize!' - capitalize a string
3.5.25 `string-contains-eqv?' - caseless substring
3.5.26 `string-contains?' - substring match
3.5.27 `string-downcase' - make a new string be lower case
3.5.28 `string-downcase!' - make a string be lower case
3.5.29 `string-end-eqv-match?' - caseless regex ending
3.5.30 `string-end-match?' - regex match end
3.5.31 `string-ends-eqv?' - caseless string ending
3.5.32 `string-ends-with?' - string ending
3.5.33 `string-equals?' - string matching
3.5.34 `string-eqv-match?' - caseless regex match
3.5.35 `string-eqv?' - caseless string match
3.5.36 `string-has-eqv-match?' - caseless regex contains
3.5.37 `string-has-match?' - contained regex match
3.5.38 `string-match?' - regex match
3.5.39 `string-start-eqv-match?' - caseless regex start
3.5.40 `string-start-match?' - regex match start
3.5.41 `string-starts-eqv?' - caseless string start
3.5.42 `string-starts-with?' - string starting
3.5.43 `string->c-name!' - map non-name chars to underscore
3.5.44 `string-tr!' - convert characters
3.5.45 `string-upcase' - make a new string be upper case
3.5.46 `string-upcase!' - make a string be upper case
3.5.47 `sub-shell-str' - back quoted (sub-)shell string
3.5.48 `sum' - sum of values in list

3.5.1 `bsd' - Free BSD public license

Arguments:
prog_name - name of the program under the BSD
owner - Grantor of the BSD License
prefix - String for starting each output line

3.5.2 `c-string' - emit string for ANSI C

A K&R compiler will choke. Use kr-string for that compiler.

Arguments:
string - string to reformat

3.5.3 `extract' - extract text from another file

The first two arguments are required, the second are optional:

• The file-name argument is used to name the file that contains the demarcated text.
• The marker-fmt is a formatting string that is used to construct the starting and ending demarcation strings. The sprintf function is given the marker-fmt with two arguments. The first is either "START" or "END". The second is either "DO NOT CHANGE THIS COMMENT" or the optional caveat argument.
• caveat is presumed to be absent if it is the empty string (""). If absent, "DO NOT CHANGE THIS COMMENT" is used as the second string argument to the marker-fmt.
• When a default argument is supplied and no pre-existing text is found, then this text will be inserted between the START and END markers.

[+ (extract "fname" "// %s - SOMETHING - %s" "" "example default") +]

will result in the following text being inserted into the output:

// START - SOMETHING - DO NOT CHANGE THIS COMMENT example default // END - SOMETHING - DO NOT CHANGE THIS COMMENT

The "example default" string can then be carried forward to the next generation of the output, provided the output is not named "fname" and the old output is renamed to "fname" before AutoGen-eration begins.

NOTE:

You can set aside previously generated source files inside the pseudo macro with a Guile/scheme function, extract the text you want to keep with this extract function. Just remember you should delete it at the end, too. Here is an example from my Finite State Machine generator:

[+ AutoGen5 Template -*- Mode: text -*- h=%s-fsm.h c=%s-fsm.c (shellf "[ -f %1$s-fsm.h ] && mv -f %1$s-fsm.h .fsm.head [ -f %1$s-fsm.c ] && mv -f %1$s-fsm.c .fsm.code" (base-name)) +]

This code will move the two output files name, ".fsm.head" and ".fsm.code". At the end of the 'c' output processing, I delete them.

Arguments:
file-name - name of file with text
marker-fmt - format for marker text
caveat - Optional - warn about changing marker
default - Optional - default initial text

3.5.4 `find-file' - locate a file in the search path

Arguments:
file-name - name of file with text
suffix - Optional - file suffix to try, too

3.5.5 `fprintf' - format to a file

Arguments:
port - Guile-scheme output port
format - formatting string
format-arg - Optional - list of arguments to formatting string

3.5.6 `gperf' - perform a perfect hash function

See the documentation for gperf(1GNU) for more details.

Arguments:
name - name of hash list
str - string to hash

3.5.7 `gpl' - GNU public license

Arguments:
prog-name - name of the program under the GPL
prefix - String for starting each output line

3.5.8 `in?' - test for string in list

Arguments:
test-string - string to look for
string-list - list of strings to check

3.5.9 `join' - join string list with separator

Arguments:
separator - string to insert between entries
list - list of strings to join

3.5.10 `kr-string' - emit string for K&R C

Arguments:
string - string to reformat

3.5.11 `lgpl' - GNU lib public license

Arguments:
prog_name - name of the program under the LGPL
owner - Grantor of the LGPL (obsolete)
prefix - String for starting each output line

3.5.12 `license' - an arbitrary license

Arguments:
lic_name - file name of the license
prog_name - name of the licensed program or library
owner - Grantor of the License
prefix - String for starting each output line

3.5.13 `make-gperf' - build a perfect hash function program

This program will be obliterated within a few seconds after AutoGen exits.

Arguments:
name - name of hash list
strings - list of strings to hash

3.5.14 `max' - maximum value in list

Arguments:
list - list of values. Strings are converted to numbers

3.5.15 `min' - minimum value in list

Arguments:
list - list of values. Strings are converted to numbers

3.5.16 `prefix' - prefix lines with a string

For example, if the first string is "# " and the second contains:

two lines

The result string will contain:

# two # lines

Arguments:
prefix - string to insert at start of each line
text - multi-line block of text

3.5.17 `printf' - format to stdout

Arguments:
format - formatting string
format-arg - Optional - list of arguments to formatting string

3.5.18 `raw-shell-str' - single quote shell string

NOTE: some shells will not correctly handle unusual non-printing characters. This routine works for most reasonably conventional ASCII strings.

Arguments:
string - string to transform

3.5.19 `shell' - invoke a shell script

Arguments:
command - shell command - the result value is stdout

3.5.20 `shell-str' - double quote shell string

NOTE: some shells will not correctly handle unusual non-printing characters. This routine works for most reasonably conventional ASCII strings.

WARNING:
This function omits the extra backslash in front of a backslash, however, if it is followed by either a backquote or a dollar sign. It must do this because otherwise it would be impossible to protect the dollar sign or backquote from shell evaluation. Consequently, it is not possible to render the strings "\\$" or "\\`". The lesser of two evils.

All others characters are copied directly into the output.

The sub-shell-str variation of this routine behaves identically, except that the extra backslash is omitted in front of " instead of `. You have to think about it. I'm open to suggestions.

Meanwhile, the best way to document is with a detailed output example. If the backslashes make it through the texinfo processing correctly, below you will see what happens with three example strings. The first example string contains a list of quoted foos, the second is the same with a single backslash before the quote characters and the last is with two backslash escapes. Below each is the result of the raw-shell-str, shell-str and sub-shell-str functions.

foo[0] = 'foo' "foo" `foo` $foo raw-shell-str: ''\''foo'\'' "foo" `foo` $foo' shell-str: "'foo' \"foo\" `foo` $foo" sub-shell-str: `'foo' "foo" \`foo\` $foo` foo[1] = \'bar\' \"bar\" \`bar\` \$bar raw-shell-str: '\'\''bar\'\'' \"bar\" \`bar\` \$bar' shell-str: "\\'bar\\' \\"bar\\" \`bar\` \$bar" sub-shell-str: `\\'bar\\' \"bar\" \\`bar\\` \$bar` foo[2] = \\'BAZ\\' \\"BAZ\\" \\`BAZ\\` \\$BAZ raw-shell-str: '\\'\''BAZ\\'\'' \\"BAZ\\" \\`BAZ\\` \\$BAZ' shell-str: "\\\\'BAZ\\\\' \\\\"BAZ\\\\" \\\`BAZ\\\` \\\$BAZ" sub-shell-str: `\\\\'BAZ\\\\' \\\"BAZ\\\" \\\\`BAZ\\\\` \\\$BAZ`

There should be triple and quadruple backslashes in the last two lines of the example. If this was not accurately reproduced, take a look at the agen5/test/shell.test test. Notice the backslashes in front of the dollar signs. It goes from zero to one to three for the "cooked" string examples.

Arguments:
string - string to transform

3.5.21 `shellf' - format a string, run shell

Arguments:
format - formatting string
format-arg - Optional - list of arguments to formatting string

3.5.22 `sprintf' - format a string

Arguments:
format - formatting string
format-arg - Optional - list of arguments to formatting string

3.5.23 `string-capitalize' - make a new string be capitalized

Arguments:
str - input string

3.5.24 `string-capitalize!' - capitalize a string

Arguments:
str - input/output string

3.5.25 `string-contains-eqv?' - caseless substring

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.26 `string-contains?' - substring match

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.27 `string-downcase' - make a new string be lower case

Arguments:
str - input string

3.5.28 `string-downcase!' - make a string be lower case

Arguments:
str - input/output string

3.5.29 `string-end-eqv-match?' - caseless regex ending

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.30 `string-end-match?' - regex match end

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.31 `string-ends-eqv?' - caseless string ending

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.32 `string-ends-with?' - string ending

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.33 `string-equals?' - string matching

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.34 `string-eqv-match?' - caseless regex match

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.35 `string-eqv?' - caseless string match

This is an overloaded operation. If the arguments are not both strings, then the query is passed through to scm_num_eq_p().

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.36 `string-has-eqv-match?' - caseless regex contains

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.37 `string-has-match?' - contained regex match

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.38 `string-match?' - regex match

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.39 `string-start-eqv-match?' - caseless regex start

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.40 `string-start-match?' - regex match start

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.41 `string-starts-eqv?' - caseless string start

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.42 `string-starts-with?' - string starting

Arguments:
text - text to test for pattern
match - pattern/substring to search for

3.5.43 `string->c-name!' - map non-name chars to underscore

Arguments:
str - input/output string

3.5.44 `string-tr!' - convert characters

It is too bad this little program has so many different and incompatible implementations!

Arguments:
source - string to transform
match - characters to be converted
translation - conversion list

3.5.45 `string-upcase' - make a new string be upper case

Arguments:
str - input string

3.5.46 `string-upcase!' - make a string be upper case

Arguments:
str - input/output string

3.5.47 `sub-shell-str' - back quoted (sub-)shell string

Arguments:
string - string to transform

3.5.48 `sum' - sum of values in list

Arguments:
list - list of values. Strings are converted to numbers

3.6 AutoGen Native Macros

This section describes the various AutoGen natively defined macros. Unlike the Scheme functions, some of these macros are "block macros" with a scope that extends through a terminating macro. Block macros must not overlap. That is to say, a block macro started within the scope of an encompassing block macro must have its matching end macro appear before the encompassing block macro is either ended or subdivided.

The block macros are these:

CASE

This macro has scope through the ESAC macro. The scope is subdivided by SELECT macros. You must have at least one SELECT macro.

DEFINE

This macro has scope through the ENDDEF macro. The defined user macro can never be a block macro.

FOR

This macro has scope through the ENDFOR macro.

IF

This macro has scope through the ENDIF macro. The scope may be subdivided by ELIF and ELSE macros. Obviously, there may be only one ELSE macro and it must be the last of these subdivisions.

INCLUDE

This macro has the scope of the included file. It is a block macro in the sense that the included file must not contain any incomplete block macros.

WHILE

This macro has scope through the ENDWHILE macro.

3.6.1 AutoGen Macro Syntax
3.6.2 CASE - Select one of several template blocks
3.6.3 COMMENT - A block of comment to be ignored
3.6.4 DEFINE - Define a user AutoGen macro
3.6.5 ELIF - Alternate Conditional Template Block
3.6.6 ELSE - Alternate Template Block
3.6.7 ENDDEF - Ends a macro definition.
3.6.8 ENDFOR - Terminates the FOR function template block
3.6.9 ENDIF - Terminate the IF Template Block
3.6.10 ENDWHILE - Terminate the WHILE Template Block
3.6.11 ESAC - Terminate the CASE Template Block
3.6.12 EXPR - Evaluate and emit an Expression
3.6.13 FOR - Emit a template block multiple times
3.6.14 IF - Conditionally Emit a Template Block
3.6.15 INCLUDE - Read in and emit a template block
3.6.16 INVOKE - Invoke a User Defined Macro
3.6.17 SELECT - Selection block for CASE function
3.6.18 UNKNOWN - Either a user macro or a value name.
3.6.19 WHILE - Conditionally loop over a Template Block

3.6.1 AutoGen Macro Syntax

The general syntax is:

[ { <native-macro-name> | <user-defined-name> } ] [ <arg> ... ]

The syntax for <arg> depends on the particular macro, but is generally a full expression (see section 3.3 Macro Expression Syntax). Here are the exceptions to that general rule:

1. INVOKE macros, implicit or explicit, must be followed by a list of name/string value pairs. The string values are simple expressions, as described above.

   That is, the INVOKE syntax is either:

   <user-macro-name> [ <name> [ = <expression> ] ... ]

   or

   INVOKE <name-expression> [ <name> [ = <expression> ] ... ]

2. AutoGen FOR macros must be in one of two forms:

   FOR <name> [ <separator-string> ]

   or

   FOR <name> (...Scheme expression list)

   where <name> must be a simple name and the Scheme expression list is expected to contain one or more of the for-from, for-to, for-by, and for-sep functions. (See section 3.6.13 FOR - Emit a template block multiple times, and 3.4 AutoGen Scheme Functions)

3. AutoGen DEFINE macros must be followed by a simple name. Anything after that is ignored. See section 3.6.4 DEFINE - Define a user AutoGen macro.

4. The AutoGen COMMENT, ELSE, ESAC and the END* macros take no arguments and ignore everything after the macro name (e.g. see 3.6.3 COMMENT - A block of comment to be ignored)

3.6.2 CASE - Select one of several template blocks

The arguments are evaluated and converted to a string, if necessary. (see section 3.6.12 EXPR - Evaluate and emit an Expression) The scope of the macro is up to the matching ESAC function. Within the scope of a CASE, this string is matched against case selection macros. There are sixteen match macros that are derived from four different ways the test may be performed, plus an "always true" match. The code for each selection expression is formed as follows:

1. Must the match start matching from the beginning of the string? If not, then the match macro code starts with an asterisk (*).
2. Must the match finish matching at the end of the string? If not, then the match macro code ends with an asterisk (*).
3. Is the match a pattern match or a string comparison? If a comparison, use an equal sign (=). If a pattern match, use a tilde (~).
4. Is the match case sensitive? If alphabetic case is important, double the tilde or equal sign.
5. Do you need a default match when none of the others match? Use a single asterisk (*).

For example:

[+ CASE <full-expression> +] [+ ~~* "[Tt]est" +]reg exp must match at start, not at end [+ == "TeSt" +]a full-string, case sensitive compare [+ = "TEST" +]a full-string, case insensitive compare [+ * +]always match - no testing [+ ESAC +]

<full-expression> (see section 3.3 Macro Expression Syntax) may be any expression, including the use of apply-codes and value-names. If the expression yields a number, it is converted to a decimal string.

These case selection codes have also been implemented as Scheme expression functions using the same codes (see section 3.5 Common Scheme Functions).

3.6.3 COMMENT - A block of comment to be ignored

If the native macro name code is #, then the entire macro function is treated as a comment and ignored.

3.6.4 DEFINE - Define a user AutoGen macro

This function will define a new macro. You must provide a name for the macro. You do not specify any arguments, though the invocation may specify a set of name/value pairs that are to be active during the processing of the macro.

[+ define foo +] ... macro body with macro functions ... [+ enddef +] ... [+ foo bar='raw text' baz=<<text expression>> +]

Once the macro has been defined, this new macro can be invoked by specifying the macro name as the first token after the start macro marker. Alternatively, you may make the invocation explicitly invoke a defined macro by specifying INVOKE in the macro invocation. If you do that, the macro name can be computed with an expression that gets evaluated every time the INVOKE macro is encountered. See section 3.6.16 INVOKE - Invoke a User Defined Macro.

Any remaining text in the macro invocation will be used to create new name/value pairs that only persist for the duration of the processing of the macro. The expressions are evaluated the same way basic expressions are evaluated. See section 3.3 Macro Expression Syntax.

The resulting definitions are handled much like regular definitions, except:

1. The values may not be compound. That is, they may not contain nested name/value pairs.
2. The bindings go away when the macro is complete.
3. The name/value pairs are separated by whitespace instead of semi-colons.
4. Sequences of strings are not concatenated.

3.6.5 ELIF - Alternate Conditional Template Block

This macro must only appear after an IF function, and before any associated ELSE or ENDIF functions. It denotes the start of an alternate template block for the IF function. Its expression argument is evaluated as are the arguments to IF. For a complete description See section 3.6.14 IF - Conditionally Emit a Template Block.

3.6.6 ELSE - Alternate Template Block

This macro must only appear after an IF function, and before the associated ENDIF function. It denotes the start of an alternate template block for the IF function. For a complete description See section 3.6.14 IF - Conditionally Emit a Template Block.

3.6.7 ENDDEF - Ends a macro definition.

This macro ends the DEFINE function template block. For a complete description See section 3.6.4 DEFINE - Define a user AutoGen macro.

3.6.8 ENDFOR - Terminates the FOR function template block

This macro ends the FOR function template block. For a complete description See section 3.6.13 FOR - Emit a template block multiple times.

3.6.9 ENDIF - Terminate the IF Template Block

This macro ends the IF function template block. For a complete description See section 3.6.14 IF - Conditionally Emit a Template Block.

3.6.10 ENDWHILE - Terminate the WHILE Template Block

This macro ends the WHILE function template block. For a complete description See section 3.6.19 WHILE - Conditionally loop over a Template Block.

3.6.11 ESAC - Terminate the CASE Template Block

This macro ends the CASE function template block. For a complete description, See section 3.6.2 CASE - Select one of several template blocks.

3.6.12 EXPR - Evaluate and emit an Expression

This macro does not have a name to cause it to be invoked explicitly, though if a macro starts with one of the apply codes or one of the simple expression markers, then an expression macro is inferred. The result of the expression evaluation (see section 3.3 Macro Expression Syntax) is written to the current output.

3.6.13 FOR - Emit a template block multiple times

This macro has a slight variation on the standard syntax:

FOR <value-name> [ <separator-string> ]

or

FOR <value-name> (...Scheme expression list

The first argument must be the name of an AutoGen value. If there is no value associated with the name, the FOR loop block is skipped entirely. The scope of the FOR function extends to the corresponding ENDFOR macro.

If there are any further arguments, if the first character is either a semi-colon (;) or an opening parenthesis ((), then it is presumed to be a Scheme expression containing the FOR macro specific functions for-from, for-by, for-to, and/or for-sep. See section 3.4 AutoGen Scheme Functions. Otherwise, the remaining text is presumed to be a string for inserting between each iteration of the loop. This string will be emitted one time less than the number of iterations of the loop. That is, it is emitted after each loop, excepting for the last iteration.

If the from/by/to functions are invoked, they will specify which copies of the named value are to be processed. If there is no copy of the named value associated with a particular index, the FOR template block will be instantiated anyway. The template must use methods for detecting missing definitions and emitting default text. In this fashion, you can insert entries from a sparse or non-zero based array into a dense, zero based array.

NB: the for-from, for-to, for-by and for-sep functions are disabled outside of the context of the FOR macro. Likewise, the first-for, last-for and for-index functions are disabled outside of the range of a FOR block.

[+FOR var (for-from 0) (for-to <number>) (for-sep ",") +] ... text with various substitutions ...[+ ENDFOR var+]

this will repeat the ... text with various substitutions ... <number>+1 times. Each repetition, except for the last, will have a comma , after it.

[+FOR var ",\n" +] ... text with various substitutions ...[+ ENDFOR var +]

This will do the same thing, but only for the index values of var that have actually been defined.

3.6.14 IF - Conditionally Emit a Template Block

Conditional block. Its arguments are evaluated (see section 3.6.12 EXPR - Evaluate and emit an Expression) and if the result is non-zero or a string with one or more bytes, then the condition is true and the text from that point until a matched ELIF, ELSE or ENDIF is emitted. ELIF introduces a conditional alternative if the IF clause evaluated FALSE and ELSE introduces an unconditional alternative.

[+IF <full-expression> +] emit things that are for the true condition[+ ELIF <full-expression-2> +] emit things that are true maybe[+ ELSE "This may be a comment" +] emit this if all but else fails[+ ENDIF "This may *also* be a comment" +]

<full-expression> may be any expression described in the EXPR expression function, including the use of apply-codes and value-names. If the expression yields an empty string, it is interpreted as false.

3.6.15 INCLUDE - Read in and emit a template block

The entire contents of the named file is inserted at this point. The contents of the file are processed for macro expansion. The arguments are eval-ed, so you may compute the name of the file to be included. The included file must not contain any incomplete function blocks. Function blocks are template text beginning with any of the macro functions `IF', `FOR', `WHILE', and `CASE' and extending through the respective terminating macro functions.

3.6.16 INVOKE - Invoke a User Defined Macro

User defined macros may be invoked explicitly or implicitly. If you invoke one implicitly, the macro must begin with the name of the defined macro. Consequently, this may not be a computed value. If you explicitly invoke a user defined macro, the macro begins with the macro name INVOKE followed by a basic expression that must yield a known user defined macro. A macro name _must_ be found, or AutoGen will issue a diagnostic and exit.

Arguments are passed to the invoked macro by name. The text following the macro name must consist of a series of names each of which is followed by an equal sign (=) and a basic expression that yields a string.

The string values may contain template macros that are parsed the first time the macro is processed and evaluated again every time the macro is evaluated.

3.6.17 SELECT - Selection block for CASE function

This macro selects a block of text by matching an expression against the sample text expression evaluated in the CASE macro. See section 3.6.2 CASE - Select one of several template blocks.

You do not specify a SELECT macro with the word "select". Instead, you must use one of the 17 match operators described in the CASE macro description.

3.6.18 UNKNOWN - Either a user macro or a value name.

The macro text has started with a name not known to AutoGen. If, at run time, it turns out to be the name of a defined macro, then that macro is invoked. If it is not, then it is a conditional expression that is evaluated only if the name is defined at the time the macro is invoked.

You may not specify UNKNOWN explicitly.

3.6.19 WHILE - Conditionally loop over a Template Block

Conditionally repeated block. Its arguments are evaluated (see section 3.6.12 EXPR - Evaluate and emit an Expression) and as long as the result is non-zero or a string with one or more bytes, then the condition is true and the text from that point until a matched ENDWHILE is emitted.

[+WHILE <full-expression> +] emit things that are for the true condition[+ ENDWHILE +]

<full-expression> may be any expression described in the EXPR expression function, including the use of apply-codes and value-names. If the expression yields an empty string, it is interpreted as false.

3.7 Redirecting Output

AutoGen provides a means for redirecting the template output to different files. It is accomplished by providing a set of Scheme functions named out-* (see section 3.4 AutoGen Scheme Functions).

These functions allow you to logically "push" output files onto a stack and return to previous files by "pop"ing them back off. At the end of processing the template for a particular suffix (see section 3.1 Format of the Pseudo Macro), all the files in the output stack are closed and popped off. Consequently, at the start of the processing of a template, there is only one output file on the stack. That file cannot be popped off.

There are also several functions for determining the output status. See section 3.4 AutoGen Scheme Functions.

4. Augmenting AutoGen

AutoGen was designed to be simple to enhance. You can do it by providing shell commands, Guile/Scheme macros or callout functions that can be invoked as a Guile macro. Here is how you do these.

4.1 Shell Output Commands
4.2 Guile Macros
4.3 Guile Callout Functions
4.4 AutoGen Macros

4.1 Shell Output Commands

Shell commands are run inside of a server process. This means that, unlike `make', context is kept from one command to the next. Consequently, you can define a shell function in one place inside of your template and invoke it in another. You may also store values in shell variables for later reference. If you load functions from a file containing shell functions, they will remain until AutoGen exits.

If your shell script should determine that AutoGen should stop processing, the recommended method for stopping AutoGen is:

echo "some error text" >&2 kill -2 ${AG_pid}

4.2 Guile Macros

Guile also maintains context from one command to the next. This means you may define functions and variables in one place and reference them elsewhere. You also may load Guile macro definitions from a Scheme file by using the --load-scheme command line option (see section 5.7 load-scheme option (-S)). Beware, however, that the AutoGen specific scheme functions have not been loaded at this time, so though you may define functions that reference them, do not invoke the AutoGen functions at this time.

If your Scheme script should determine that AutoGen should stop processing, the recommended method for stopping AutoGen is:

(error "some error text")

4.3 Guile Callout Functions

Callout functions must be registered with Guile to work. This can be accomplished either by putting your routines into a shared library that contains a void scm_init( void ) routine that registers these routines, or by building them into AutoGen.

To build them into AutoGen, you must place your routines in the source directory and name the files `exp*.c'. You also must have a stylized comment that `getdefs' can find that conforms to the following:

/*=gfunc <function-name> * * what: <short one-liner> * general_use: * string: <invocation-name-string> * exparg: <name>, <description> [, ['optional'] [, 'list']] * doc: A long description telling people how to use * this function. =*/ SCM ag_scm_<function-name>( SCM arg_name[, ...] ) { <code> }

`gfunc'

You must have this exactly thus.

`<function-name>'

This must follow C syntax for variable names

`<short one-liner>'

This should be about a half a line long. It is used as a subsection title in this document.

`general_use:'

You must supply this unless you are an AutoGen maintainer and are writing a function that queries or modifies the state of AutoGen.

`<invocation-name-string>'

Normally, the function-name string will be transformed into a reasonable invocation name. However, that is not always true. If the result does not suit your needs, then supply an alternate string.

`exparg:'

You must supply one for each argument to your function. All optional arguments must be last. The last of the optional arguments may be a list, if you choose.

`doc:'

Please say something meaningful.

`[, ...]'

Do not actually specify an ANSI ellipsis here. You must provide for all the arguments you specified with exparg.

See the Guile documentation for more details. More information is also available in a large comment at the beginning of the `agen5/snarf.tpl' template file.

4.4 AutoGen Macros

There are two kinds those you define yourself and AutoGen native. The user-defined macros may be defined in your templates or loaded with the --lib-template option (See 3.6.4 DEFINE - Define a user AutoGen macro and 5.4 lib-template option (-l)).

As for AutoGen native macros, do not add any. It is easy to do, but I won't like it. The basic functions needed to accomplish looping over and selecting blocks of text have proven to be sufficient over a period of several years. New text transformations can be easily added via any of the AutoGen extension methods, as discussed above.

5. Invoking autogen

This chapter was generated by AutoGen, the aginfo template and the option descriptions for the autogen program. It documents the autogen usage text and option meanings.

This software is released under the GNU General Public License.

5.1 autogen usage help (-?)
5.5 base-name option (-b)
5.20 define option (-D)
5.6 definitions option
5.12 equate option
5.4 lib-template option (-l)
5.8 load-functions option (-F)
5.7 load-scheme option (-S)
5.14 loop-limit option
5.3 override-tpl option (-T)
5.10 select-suffix option (-o)
5.18 show-defs option
5.19 show-shell option
5.9 skip-suffix option (-s)
5.11 source-time option
5.2 templ-dirs option (-L)
5.15 timeout option (-t)
5.17 trace-out option
5.16 trace option
5.21 undefine option (-U)
5.13 writable option

5.1 autogen usage help (-?)

This is the automatically generated usage text for autogen:

@exampleindent 0

autogen - The Automated Program Generator - Ver. 5.2.14 USAGE: autogen [ -<flag> [<val>] | --<name>[{=| }<val>] ]... [ <def-file> ] Flg Arg Option-Name Description -L YES templ-dirs Template search directory list - may appear multiple times -T YES override-tpl Override template file - may not be preset -l YES lib-template Library template file - may appear multiple times -b YES base-name Base name for output file(s) - may not be preset YES definitions Definitions input file - disabled as --no-definitions - enabled by default - may not be preset -S YES load-scheme Scheme code file to load -F YES load-functions Load scheme callout library -s YES skip-suffix Omit the file with this suffix - may not be preset - may appear multiple times -o opt select-suffix specify this output suffix - may not be preset - may appear multiple times no source-time set mod times to latest source - disabled as --no-source-time YES equate characters considered equivalent no writable Allow output files to be writable - disabled as --not-writable - may not be preset The following options are often useful while debugging new templates: Flg Arg Option-Name Description Num loop-limit Limit on increment loops -t Num timeout Time limit for servers - must lie within the range: 0 to 3600 KWd trace tracing level of detail YES trace-out tracing output file or filter These options can be used to control what gets processed in the definitions files and template files. Flg Arg Option-Name Description -D YES define name to add to definition list - may appear multiple times -U YES undefine definition list removal pattern - an alternate for define Auto-supported Options: Flg Arg Option-Name Description -v opt version Output version information and exit -? no help Display usage information and exit -! no more-help Extended usage information passed thru pager -> opt save-opts Save the option state to an rc file -< YES load-opts Load options from an rc file - disabled as --no-load-opts - may appear multiple times Options may be specified by doubled hyphens and their name or by a single hyphen and the flag character (option value). AutoGen creates text files from templates using external definitions. The following option preset mechanisms are supported: - reading file $HOME/.autogenrc - reading file ./.autogenrc - examining environment variables named AUTOGEN_* The valid trace option keywords are: nothing templates block-macros expressions everything The definitions file (`<def-file>') can be specified with the `definitions' option or as the command argument, but not both. Omitting it or specifying `-' will result in reading definitions from standard input. The output file names are based on the template, but generally use the base name of the definition file. If standard in is read for the definitions, then `stdin' will be used for that base name. The suffixes to the base name are gotten from the template. However, the template file may specify the entire output file name. The generated files are always created in the current directory. If you need to place output in an alternate directory, `cd' to that directory and use the `--templ_dirs' option to search the original directory. `loop-limit' is used in debugging to stop runaway expansions.

@exampleindent 4

5.2 templ-dirs option (-L)

This is the "template search directory list" option.

This option has some usage constraints. It:

• may appear an unlimited number of times.

Add a directory to the list of directories to search when opening a template, either as the primary template or an included one. The last entry has the highest priority in the search list. That is to say, they are searched in reverse order.

5.3 override-tpl option (-T)

This is the "override template file" option.

This option has some usage constraints. It:

• may not be preset with environment variables or in initialization (rc) files.

Definition files specify the standard template that is to be expanded. This option will override that name and expand a different template.

5.4 lib-template option (-l)

This is the "library template file" option.

This option has some usage constraints. It:

• may appear an unlimited number of times.

DEFINE macros are saved from this template file for use in processing the main macro file. Template text aside from the DEFINE macros is is ignored.

5.5 base-name option (-b)

This is the "base name for output file(s)" option.

This option has some usage constraints. It:

• may not be preset with environment variables or in initialization (rc) files.

A template may specify the exact name of the output file. Normally, it does not. Instead, the name is composed of the base name of the definitions file with suffixes appended. This option will override the base name derived from the definitions file name. This is required if there is no definitions file and advisable if definitions are being read from stdin. If the definitions are being read from standard in, the base name defaults to `stdin'.

5.6 definitions option

This is the "definitions input file" option.

This option has some usage constraints. It:

• is enabled by default.
• may not be preset with environment variables or in initialization (rc) files.

Use this argument to specify the input definitions file with a command line option. If you do not specify this option, then there must be a command line argument that specifies the file, even if only to specify stdin with a hyphen (-). Specify, --no-definitions when you wish to process a template without any active AutoGen definitions.

5.7 load-scheme option (-S)

This is the "scheme code file to load" option. Use this option to pre-load Scheme scripts into the Guile interpreter before template processing begins. Please note that the AutoGen specific functions are not loaded until after argument processing. So, though they may be specified in lambda functions you define, they may not be invoked until after option processing is complete.

5.8 load-functions option (-F)

This is the "load scheme callout library" option. This option is used to load Guile-scheme callout functions. The automatically called initialization routine scm_init must be used to register these routines or data. This routine can be generated by using the following command and the `snarf.tpl' template. Read the introductory comment in `snarf.tpl' to see what the `getdefs(1AG)' comment must contain.

GRP_NAME=whateveryoulike eopt="subblock=exparg=arg_name,arg_desc,arg_optional,arg_list" eopt="$eopt defs=gfunc templ=snarf srcfile" eopt="assign=group=${GRP_NAME} assign=init=_init $eopt" eopt="$eopt autogen=${AG} base-name=expr" getdefs $eopt <<source-file-list>>

Note, however, that your functions must be named:

whateveryoulike_scm_<<function_name>>(...)

so you may wish to use a shorter group name.

5.9 skip-suffix option (-s)

This is the "omit the file with this suffix" option.

This option has some usage constraints. It:

• may appear an unlimited number of times.
• may not be preset with environment variables or in initialization (rc) files.

Occasionally, it may not be desirable to produce all of the output files specified in the template. (For example, only the `.h' header file, but not the `.c' program text.) To do this specify --skip-suffix=c on the command line.

5.10 select-suffix option (-o)

This is the "specify this output suffix" option.

This option has some usage constraints. It:

• may appear an unlimited number of times.
• may not be preset with environment variables or in initialization (rc) files.

If you wish to override the suffix specifications in the template, you can use one or more copies of this option. See the suffix specification in the 3.1 Format of the Pseudo Macro section of the info doc.

5.11 source-time option

This is the "set mod times to latest source" option. If you stamp your output files with the `DNE' macro output, then your output files will always be different, even if the content has not really changed. If you use this option, then the modification time of the output files will change only if the input files change. This will help reduce unneeded builds.

5.12 equate option

This is the "characters considered equivalent" option. This option will alter the list of characters considered equivalent. The default are the three characters, "_-^". (The latter is conventional on a Tandem, and I do a lot of work on the Tandem.)

5.13 writable option

This is the "allow output files to be writable" option.

This option has some usage constraints. It:

• may not be preset with environment variables or in initialization (rc) files.

This option will leave output files writable.Normally, output files are read-only.

5.14 loop-limit option

This is the "limit on increment loops" option. This option prevents runaway loops. For example, if you accidentally specify, "FOR x (for-from 1) (for-to -1) (for-by 1)", it will take a long time to finish. If you do have more than 256 entries in tables, you will need to specify a new limit with this option.

5.15 timeout option (-t)

This is the "time limit for servers" option. AutoGen works with a shell server process. Most normal commands will complete in less than 10 seconds. If, however, your commands need more time than this, use this option.

The valid range is 0 to 3600 seconds (1 hour). Zero will disable the server time limit.

5.16 trace option

This is the "tracing level of detail" option. This option will cause AutoGen to display a trace of its template processing. There are five levels:

`nothing'

Does no tracing at all (default)

`templates'

Traces the invocation of DEFINEd macros and INCLUDEs

`block-macros'

Traces all block macros. The above, plus IF, FOR, CASE and WHILE.

`expressions'

Displays the results of expression evaluations

`everything'

Displays the invocation of every AutoGen macro, even TEXT macros.

5.17 trace-out option

This is the "tracing output file or filter" option. The output specified may be either a file name, or, if the option argument begins with the pipe operator (|), a command that will receive the tracing output as standard in. For example, --traceout='| less' will run the trace output through the less program.

5.18 show-defs option

This is the "show the definition tree" option.

This option has some usage constraints. It:

• must be compiled in by defining DEBUG during the compilation.
• may not be preset with environment variables or in initialization (rc) files.

This will print out the complete definition tree before processing the template.

5.19 show-shell option

This is the "show shell commands" option.

This option has some usage constraints. It:

• must be compiled in by defining DEBUG during the compilation.
• may not be preset with environment variables or in initialization (rc) files.

This will cause set -x to be executed in the shell, with the resultant output printed to /dev/tty.

5.20 define option (-D)

This is the "name to add to definition list" option.

This option has some usage constraints. It:

• may appear an unlimited number of times.
• is a member of the define class of options.

The AutoGen define names are used for the following purposes:

1. Sections of the AutoGen definitions may be enabled or disabled by using C-style #ifdef and #ifndef directives.
2. When defining a value for a name, you may specify the index for a particular value. That index may be a literal value, a define option or a value #define-d in the definitions themselves.
3. The name of a file may be prefixed with $NAME. That part of the name string will be replaced with the define-d value for NAME.
4. While processing a template, you may specify an index to retrieve a specific value. That index may also be a define-d value.

5.21 undefine option (-U)

This is the "definition list removal pattern" option.

This option has some usage constraints. It:

• may appear an unlimited number of times.
• may not be preset with environment variables or in initialization (rc) files.
• is a member of the define class of options.

Just like 'C', AutoGen uses #ifdef/#ifndef preprocessing directives. This option will cause the matching names to be removed from the list of defined values.

6. What Gets Installed Where

There are several files that get installed. The number depend whether or not both shared and archive libraries are to be installed. The following assumes that everything is installed relative to $prefix. You can, of course, use configure to place these files where you wish.

NB AutoGen does not contain any compiled-in path names. All support directories are located via option processing and the environment variable HOME.

The installed files are:

1. The executables in `bin' (autogen, getdefs and columns).

2. The AutoOpts link libraries as `lib/libopts.*'.

3. An include file in `include/options.h', needed for Automated Option Processing (see next chapter).

4. Several template files and a scheme script in `share/autogen', needed for Automated Option Processing (see section 7. Automated Option Processing), parsing definitions written with scheme syntax (see section 2.3 Dynamic Text), the templates for producing documentation for your program (see section 7.4.3 Man and Info doc Attributes), and AutoFSM.

5. Info-style help files as `info/autogen.info*'. These files document AutoGen, the option processing library AutoOpts, and several add-on components.

6. The three man pages for the three executables are installed in man/man1.

This program, library and supporting files can be installed with three commands:

• <src-dir>/configure [ <configure-options> ]
• make
• make install

However, you may wish to insert make check before the make install command.

If you do perform a make check and there are any failures, you will find the results in tests/FAILURES. Needless to say, I would be interested in seeing the contents of those files and any associated messages. If you choose to go on and analyze one of these failures, you will need to invoke the test scripts individually. You may do so by specifying the test (or list of test) in the TESTS make variable, thus:

gmake TESTS=test-name.test check

I specify gmake because most makes will not let you override internal definitions with command line arguments. gmake does.

All of the AutoGen tests are written to honor the contents of the VERBOSE environment variable. Normally, any commentary generated during a test run is discarded unless the VERBOSE environment variable is set. So, to see what is happening during the test, you might invoke the following with bash or ksh:

VERBOSE=1 gmake TESTS="for.test forcomma.test" check

Or equivalently with csh:

env VERBOSE=1 gmake TESTS="for.test forcomma.test" check

7. Automated Option Processing

AutoOpts 11.0 is bundled with AutoGen. It is a tool that virtually eliminates the hassle of processing options and keeping man pages, info docs and usage text up to date. This package allows you to specify several program attributes, up to a hundred option types and many option attributes. From this, it then produces all the code necessary to parse and handle the command line and initialization file options, and the documentation that should go with your program as well.

AutoOpts is distributed under The GNU General Public License with the Library extentions (LGPL). It is in no way a "lesser" license. You have greater license with it.

7.1 AutoOpts Features
7.2 Competitive Feature Analysis
7.3 Quick Start
7.4 Option Definitions
7.5 Programmatic Interface
7.6 Option Descriptor File
7.7 Using AutoOpts
7.8 AutoOpts for Shell Scripts
7.9 Automated `Invoking Info' Doc
7.10 Automated Man Pages