You can specify the coding system for a specific operation by binding
the variables coding-system-for-read and/or
coding-system-for-write.
nil, it specifies the coding system to
use for reading a file, or for input from a synchronous subprocess.
It also applies to any asynchronous subprocess or network stream, but in
a different way: the value of coding-system-for-read when you
start the subprocess or open the network stream specifies the input
decoding method for that subprocess or network stream. It remains in
use for that subprocess or network stream unless and until overridden.
The right way to use this variable is to bind it with let for a
specific I/O operation. Its global value is normally nil, and
you should not globally set it to any other value. Here is an example
of the right way to use the variable:
;; Read the file with no character code conversion. ;; Assume CRLF represents end-of-line. (let ((coding-system-for-write 'emacs-mule-dos)) (insert-file-contents filename))
When its value is non-nil, coding-system-for-read takes
precedence over all other methods of specifying a coding system to use for
input, including file-coding-system-alist,
process-coding-system-alist and
network-coding-system-alist.
coding-system-for-read, except that it
applies to output rather than input. It affects writing to files,
subprocesses, and net connections.
When a single operation does both input and output, as do
call-process-region and start-process, both
coding-system-for-read and coding-system-for-write
affect it.
nil, no end-of-line conversion is done,
no matter which coding system is specified. This applies to all the
Emacs I/O and subprocess primitives, and to the explicit encoding and
decoding functions (see section Explicit Encoding and Decoding).
Go to the first, previous, next, last section, table of contents.