#!/usr/bin/perl -w =head1 NAME pam_getenv - get environment variables from /etc/environment =head1 SYNOPSIS pam_getenv B<[-l] [-s]> I<env_var> =head1 DESCRIPTION This tool will print out the value of I<env_var> from F</etc/environment>. It will attempt to expand environment variable references in the definition of I<env_var> but will fail if PAM items are expanded. The B<-l> option indicates the script should return an environment variable related to default locale information. The B<-s> option indicates that the script should return an system default environment variable. Currently neither the B<-l> or B<-s> options do anything. They are included because future versions of Debian may have a separate repository for the initial environment used by init scripts and for system locale information. These options will allow this script to be a stable interface even in that environment. =cut # Copyright 2004 by Sam Hartman # This script may be copied under the terms of the GNU GPL # version 2, or at your option any later version. use strict; use vars qw(*CONFIGFILE *ENVFILE); sub read_line($) { my $fh = shift; my $line; local $_; line: while (<$fh>) { chomp; s/^\s+//; s/\#.*$//; next if $_ eq ""; if (s/\\\s*$//) { $line .= $_; next line; } $line .= $_; last; } $line; } sub parse_line($) { my $var; my (%x, @x); local $_ = shift; return undef unless defined $_ and s/(\S+)\s//; $var->{Name} = $1; s/^\s*//; @x = split(/=([^"\s]\S*|"[^"]*")\s*/, $_); unless (scalar(@x)%2 == 0) { push @x, undef; } %x = @x; @{$var}{"Default", "Override"} = @x{"DEFAULT", "OVERRIDE"}; $var; } sub expand_val($) { my ($val) = @_; return undef unless $val; die "Cannot handle PAM items\n" if /(?<!\\)\@/; $val =~ s/(?<!\\)\$\{([^}]+)\}/$ENV{$1}||""/eg; return $val; } my $lookup; while ($_ = shift) { next if $_ eq "-s"; next if $_ eq "-l"; $lookup = $_; last; } unless (defined $lookup) { die "Usage: pam_getenv [-l] [-s] env_var\n"; } my %allvars; open (CONFIGFILE, "/etc/security/pam_env.conf") or die "Cannot open environment file: $!\n"; while (my $var = parse_line(read_line(\*CONFIGFILE))) { my $val; unless ($val = expand_val($var->{Override})) { $val = expand_val($var->{Default}); } $allvars{$var->{Name}} = $val; } if (open (ENVFILE, "/etc/environment")) { while (my $line = read_line(\*ENVFILE)) { $line =~ s/^export //; $line =~ /(.*?)=(.+)/ or next; my ($var, $val) = ($1, $2); # This is bizarre logic (" and ' match each other, quotes are only # significant at the start and end of the string, and the trailing quote # may be omitted), but it's what pam_env does. $val =~ s/^["'](.*?)["']?$/$1/; $allvars{$var} = $val; } } if (exists $allvars{$lookup}) { print $allvars{$lookup}, "\n"; exit(0); }