AX_SYS_PERLSHARPBANG
Determine how the perl interpreter is located by the OS kernel and make substitution variable PERL_SHEBANG available. Does AC_PATH_PROG to find the path to perl. As a side-effect, that sets PERLINTERP and makes it available as a substitution variable.
Note: The macro allows for the possibility (expected to be seldom used) of an explicit user override (the "user" being the operator executing the final ’configure’ script, in this context) by making the option argument like:
--with-perl-shebang='#! /my/funky/perlpath' # OR
--with-perl-shebang='/my/funky/perlpath' # we just throw away the #! anyway
# as it must not appear in Makefile
Rationale: The are various ways of starting an interpreter on different *nix-like systems. Many use the simple
#!/usr/bin/perl
but it could be instead
#!/usr/local/bin/perl
and there is even the possibility that the user wants
#!/usr/bin/env perl
to find whichever perl comes first in the current $PATH. This is preferred by some of us because we run multiple perl installations on the same box. Adjusting our $PATH then allows us to set precedence over other perls, even whatever the "house" version is.
Users on very non-unix systems like MS Windows do not have a kernel that does this kind of thing from the first line of script files, but instead the perl on their machine is started and merely notices whatever comes after the interpreter path on this first line of the script (options like "-w").
Acknowledgement: this macro was in part inspired by Dean Povey’s AC_PROG_PERL_VERSION.
Download the latest version of ax_sys_perlsharpbang.m4 or browse the macro’s revision history.
Copyright © 2009 Soren Andersen somian@pobox.com
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