package handle_configs;

# $Id$

use diagnostics;
use strict;

use common;

sub searchstr {
    # Preceed all characters which are special characters in regexps with
    # a backslash, so that the returned string used in a regexp searches
    # a literal occurence of the original string. White space is replaced
    # by "\s+"
    # "quotemeta()" does not serve for this, as it also quotes some regular
    # characters, as the space
    my ($s) = @_;
    $s =~ s/([\\\/\(\)\[\]\{\}\|\.\$\@\%\*\?\#\+\-])/\\$1/g;
    return $s;
}

sub read_directives {

    # Read one or more occurences of a directive

    my ($lines_ptr, $directive) = @_;

    my @result = ();
    my $searchdirective = searchstr($directive);
    ($_ =~ /^\s*$searchdirective\s+(\S.*)$/ and push(@result, $1)) 
	foreach @{$lines_ptr};
    (chomp) foreach @result;
    return @result;
}

sub read_unique_directive {

    # Read a directive, if the directive appears more than once, use
    # the last occurence and remove all the others, if it does not
    # occur, return the default value

    my ($lines_ptr, $directive, $default) = @_;

    if ((my @d = read_directives($lines_ptr, $directive)) > 0) {
	my $value = $d[$#d];
	set_directive($lines_ptr, "$directive $value");
	return $value;
    } else {
        return $default;
    }
}

sub insert_directive {

    # Insert a directive only if it is not already there

    my ($lines_ptr, $directive) = @_;

    my $searchdirective = searchstr($directive);
    ($_ =~ /^\s*$searchdirective$/ and return 0) foreach @{$lines_ptr};
    push(@{$lines_ptr}, "$directive\n");
    return 1;
}

sub remove_directive {

    # Remove a directive

    my ($lines_ptr, $directive) = @_;

    my $success = 0;