#include <stdlib.h>
#include <stdio.h>

int main( int argc, char **argv ) {
  char *arg = *++argv;
  printf( "%s is %s\n", arg, getenv(arg) );
  exit(0);
}
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which is named env-echo.c, which you should compile with cc -o env-echo env-echo.c. You can then use this script:

#! /usr/bin/perl -w

use strict;

my $var   = shift || 'FOO';
my $value = shift || 'bar';

$ENV{$var} = $value;
system "./env-echo $var";
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g r i n d e r
just another bofh

print@_{sort keys %_},$/if%_=split//,'= & *a?b:e\f/h^h!j+n,o@o;r$s-t%t#u';

Setting it in the current processes' environment should be enough, since any subprocesses inherit their parent's environment.

Although system() does, in fact open a new shell, that shell should inherit your perl script's environment like any other child process (and pass it on to its children).

Update: reasons why this may not be working:

• What shell are you using? bash, for instance, executes .bashrc everytime it starts a subshell (same as .csh does with .cshrc, .tcsh does with .tcshrc, etc.). Are you inadvertantly overwriting your desired environment variable(s) in some startup script?
• The SYBASE variable (and the like) is special, particularly when you are trying to use DBD::Sybase with DBI. You cannot set $ENV{SYBASE} (even in a BEGIN block) and expect DBD::Sybase/DBI to work. (on closer re-read, I realize this iss not your problem)
• There is probably another one, but I cannot at the moment think of it.

dmm

The SYBASE env. variable is special...

Actually, that's not the case. It's the LD_LIBRARY_PATH variable that needs to be set outside of the running process for it to have any effect.

The SYBASE env. variable can be set normally when using DBI/DBD::Sybase - it needs to be set before DBD::Sybase gets loaded, but as that only happens on the first DBI->connect() there is no need to use a BEGIN block.

Michael

Right you are! I stand corrected. Thanks, mpeppler. Good catch.

You would think with all of the times this particular thing has bitten me in the behind, I'd remember the difference between SYBASE and LD_LIBRARY_PATH. In my own defense, the environment where this was a problem bundled these two things together in one script for changing between production and development.

dmm

You can give a man a fish and feed him for a day ...
Or, you can teach him to fish and feed him for a lifetime

/\/\averick
perl -l -e "eval pack('h*','072796e6470272f2c5f2c5166756279636b672');"

`export LD_LIBRARY_PATH=/usr/local/lib`
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7.1 as in RedHat 7.1? system() should inherit your %ENV variables as said before. But if your C program requires that you input something and get something out of it then it might be more appropriate to use IPC::Open3.

use strict;
use IPC::Open3;

$ENV{'LD_LIBRARY_PATH'} = '/usr/local/lib';

$COMMAND = '/some/c/proggie -w -options';

my ($read,$write,$error);
my $pid = open3($read,$write,$error,$COMMAND);
if ($pid) {
    # do stuff
} else {
    # croak, bitch and complain
}
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BMaximus

Are you by any chance calling the Perl program from within a shell script and then hoping to change the environment variable?

If so then you are SoL. As Perl is a subprocess it cannot set its parent environment. You need to use export since export is a shell builtin and not a subprocess. The closest that you can come is something like this:

export foo=`perl script.pl`
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`export LD_LIBRARY_PATH=/usr/local/lib`
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