7.8 AutoOpts for Shell Scripts

AutoOpts may be used with shell scripts by automatically creating a complete program that will process command line options and pass back the results to the invoking shell by issuing shell variable assignment commands. It may also be used to generate portable shell code that can be inserted into your script.

The functionality of these features, of course, is somewhat constrained compared with the normal program facilities. Specifically, you cannot invoke callout procedures with either of these methods. Additionally, if you generate a shell script:

1. You cannot obtain options from RC/INI files.
2. You cannot obtain options from environment variables.
3. You cannot save the option state to an option file.
4. Option conflict/requirement verification is disabled.

Both of these methods are enabled by running AutoGen on the definitions file with the additional global attribute:

test-main [ = proc-to-call ] ;

If you do not supply a proc-to-call, it will default to putBourneShell. That will produce a program that will process the options and generate shell text for the invoking shell to interpret. If you supply the name, putShellParse, then you will have a program that will generate a shell script that can parse the options. If you supply a different procedure name, you will have to provide that routine and it may do whatever you like.

In summary, you will need to issue approximately the following two commands to have a working program:

autogen -L <opt-template-dir> program.def cc -o progopts -L <opt-lib-dir> -I <opt-include-dir> \ -DTEST_program_OPTS program.c -lopts

The resulting program can be used within your shell script as follows:

eval `./progopts $@` if [ -z "${OPTION_CT}" ] ; then exit 1 ; fi shift ${OPTION_CT}

If you had used "test-main = putShellParse" instead, then you can, at this point, merely run the program and it will write the parsing script to standard out. You may also provide this program with command line options to specify the shell script file to create or edit, and you may specify the shell program to use on the first shell script line. That program's usage text would look something like this:

genshellopt - Generate Shell Option Processing Script - Ver. 1 USAGE: genshellopt [ -<flag> [<val>] | --<name>[{=| }<val>] ]... Flg Arg Option-Name Description -o YES script Output Script File -s YES shell Shell name (follows "#!" magic) - disabled as --no-shell - enabled by default -v opt version Output version information and exit -? no help Display usage information and exit -! no more-help Extended usage information passed thru pager Options may be specified by doubled hyphens and their name or by a single hyphen and the flag character (option value). Note that `shell' is only useful if the output file does not already exist. If it does, then the shell name and optional first argument will be extracted from the script file. If the script file already exists and contains Automated Option Processing text, the second line of the file through the ending tag will be replaced by the newly generated text. The first `#!' line will be regenerated. = = = = = = = = This incarnation of genshell will produce a shell script to parse the options for getdefs: getdefs - AutoGen Definition Extraction Tool - Ver. 1.3 USAGE: getdefs { <option-name>[{=| }<val>] }... Arg Option-Name Req? Description YES defs-to-get opt Regexp to look for after the "/*=" opt ordering opt Alphabetize or use named file Num first-index opt The first index to apply to groups YES input YES Input file to search for defs YES subblock opt subblock definition names YES listattr opt attribute with list of values opt filelist opt Insert source file names into defs YES assign opt Global assignments YES common-assign opt Assignments common to all blocks YES copy opt File(s) to copy into definitions opt srcfile opt Insert source file name into each def opt linenum opt Insert source line number into each def YES output opt Output file to open opt autogen opt Invoke AutoGen with defs YES template opt Template Name YES agarg opt AutoGen Argument YES base-name opt Base name for output file(s) opt version opt Output version information and exit no help opt Display usage information and exit no more-help opt Extended usage information passed thru pager opt save-opts opt Save the option state to an rc file YES load-opts opt Load options from an rc file All arguments are named options.