#!/usr/bin/env perl
# Try to locate best version of auto*
# By Michael Pyne <michael.pyne@kdemail.net>
#
# Copyright (c) 2005.
# This code is public domain. You may use it however you like (including
# relicensing).
# Emulate the 'which' program.
sub which
{
my $prog = shift;
my @paths = split(/:/, $ENV{'PATH'});
for $path (@paths)
{
return "$path/$prog" if -x "$path/$prog";
}
return "";
}
# Subroutine to determine the highest installed version of the given program,
# searching from the given paths.
sub findBest
{
my ($program, @paths) = @_;
my $best_version_found = '0'; # Deliberately a string.
my %versions;
my %minimumVersions = (
'autoconf' => '2.5',
'automake' => '1.6',
);
# Allow user to use environment variable to override search.
return $ENV{uc $program} if $ENV{uc $program};
for $prefix (@paths)
{
@files = glob "$prefix/$program*";
for $file (@files)
{
# Don't check non-executable scripts.
next unless -x $file;
($version) = $file =~ /$prefix\/$program-?(.*)$/;
$version =~ s/-|\.//g;
# Special case some programs to make sure it has a minimum version.
if (not $version and exists $minimumVersions{$program})
{
my $min_version = $minimumVersions{$program};
my $versionOutput = `$program --version 2>/dev/null | head -n 1`;
# If we can't run the script to get the version it likely won't work later.
next unless $versionOutput;
# Use number.number for version (we don't need the excess in general).
($versionOutput) = ($versionOutput =~ /(\d\.\d)/);
# Use lt to do lexicographical comparison of strings (which should be
# equivalent and doesn't involve issues with floating point conversions).
if (not $versionOutput or $versionOutput lt $min_version)
{
next;
}
}
# If no version suffix then use it in favor of a versioned autotool
# since the ever-popular WANT_AUTOFOO should then work (in theory).
return $file unless $version;
# Emulate 'which', and abort if we've already seen this version.
next if exists $versions{$version};
# Save filename of program.
$versions{$version} = $file;
# Use string comparison so that e.g. 253a will be > 253 but < 254.
if ($version gt $best_version_found)
{
$best_version_found = $version;
}
}
}
return $versions{$best_version_found};
}
# Find an appropriate "which" program for later use by the shell script calling
# us.
sub findWhich
{
for $candidate ('type -p', 'which', 'type')
{
$test = `$candidate sh 2>/dev/null`;
chomp $test;
return $candidate if -x $test;
}
}
# Uses which() to find a program unless the user provided its path in the
# environment (the upper case program name is searched).
sub findProgram
{
$suffix = ""; # For use if @_ has only one param.
my ($program, $suffix) = @_;
return $ENV{uc $program} if $ENV{uc $program};
return which("$program$suffix");
}
# SCRIPT STARTS.
# Search in path.
@paths = split(/:/, $ENV{'PATH'});
# Make sure at least /usr/bin and /usr/local/bin are in this search.
unshift @paths, '/usr/local/bin' unless grep $_ eq '/usr/local/bin', @paths;
unshift @paths, '/usr/bin' unless grep $_ eq '/usr/bin', @paths;
$autoconf = findBest('autoconf', @paths);
($autoconf_suffix) = $autoconf =~ /.*autoconf(.*)$/;
# Find matching autoconf companions.
$autoheader = findProgram('autoheader', $autoconf_suffix);
$autom4te = findProgram('autom4te', $autoconf_suffix);
# Get best automake, and look for unsermake to possibly override it.
$automake = findBest('automake', @paths);
$unsermake = "";
# backward compatible: if $UNSERMAKE points to a path, use it
$unsermake = findProgram('unsermake') if (defined($ENV{'UNSERMAKE'}) and $ENV{'UNSERMAKE'} =~ /\//);
# new compatible: if it says 'yes', use the one from path
$unsermake = which('unsermake') if ($ENV{'UNSERMAKE'} ne 'no');
($automake_suffix) = $automake =~ /.*automake(.*)$/;
# Use unsermake if we found it.
$automake = "$unsermake -c" if $unsermake;
# Find matching automake companions.
$aclocal = findProgram('aclocal', $automake_suffix);
$which = findWhich();
# Make sure we have all of the needed programs.
for $i (qw'autoconf autoheader autom4te automake aclocal')
{
unless(${$i})
{
print "# Unable to find $i!!\n";
exit 1;
}
}
# Print results in eval-able form.
print <<EOF;
AUTOCONF="$autoconf"
AUTOHEADER="$autoheader"
AUTOM4TE="$autom4te"
AUTOMAKE="$automake"
ACLOCAL="$aclocal"
WHICH="$which"
export AUTOCONF AUTOHEADER AUTOM4TE AUTOMAKE ACLOCAL WHICH
EOF
exit 0;