Search code examples
m4

Can m4 execute user defined bash scripts?

Can the m4 macro-expansion language execute user-defined bash scripts? consider the m4 file

define(`FOOBAR', `esyscmd(mycmd)') dnl
FOOBAR

where mycmd is a bash file defined in the same directory as the m4 file which looks like 

#!/bin/bash

echo "Hello World"

However, on executing m4 on the input file I get the error

sh: 1: mycmd: not found

Does that mean I need to modify some sort of variable containing a list of directories where m4 looks for particular commands?

I hope to be able to run awk (or even python) scripts and stick the output of those scripts in place of the corresponding macro name.

Solution

  • The m4 can execute external programs. You forgot only one thing: the PATH. Please try:

    define(`FOOBAR', `esyscmd(./mycmd)') dnl
FOOBAR

    Please note ./mycmd!