Contents | < Browse | Browse >
Executing simple commands
=========================
Any shell command can be executed, using `syscmd':
syscmd(SHELL-COMMAND)
which executes SHELL-COMMAND as a shell command.
The expansion of `syscmd' is void.
The expansion is *not* the output from the command! Instead the
standard input, output and error of the command are the same as those of
`m4'. This means that output or error messages from the commands are
not read by `m4', and might get mixed up with the normal output from
`m4'. This can produce unexpected results. It is therefore a good
habit to always redirect the input and output of shell commands used
with `syscmd'.