package util;

use strict;

use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
require Exporter;

@ISA = qw(Exporter);
@EXPORT = qw(append_file edit_file read_file replace_file);
@EXPORT_OK = qw();
%EXPORT_TAGS = ();

########################################################################
# append_file

sub append_file {
    my $filename = shift;
    my $function = shift;

    open(OUT, ">> $filename") || die "Can't open file '$filename'";
    my $result = &$function(\*OUT, @_);
    close(OUT);

    return $result;
}

########################################################################
# edit_file

sub edit_file {
    my $filename = shift;
    my $function = shift;

    open(IN, "< $filename") || die "Can't open file '$filename'";
    open(OUT, "> $filename.tmp") || die "Can't open file '$filename.tmp'";

    my $result = &$function(\*IN, \*OUT, @_);

    close(IN);
    close(OUT);

    if($result) {
        unlink("$filename");
        rename("$filename.tmp", "$filename");
    } else {
        unlink("$filename.tmp");
    }

    return $result;
}

########################################################################
# read_file

sub read_file {
    my $filename = shift;
    my $function = shift;

    open(IN, "< $filename") || die "Can't open file '$filename'";
    my $result = &$function(\*IN, @_);
    close(IN);

    return $result;
}

########################################################################
# replace_file

sub replace_file {
    my $filename = shift;
    my $function = shift;

    open(OUT, "> $filename.tmp") || die "Can't open file '$filename.tmp'";

    my $result = &$function(\*OUT, @_);

    close(OUT);

    if($result) {
        unlink("$filename");
        rename("$filename.tmp", "$filename");
    } else {
        unlink("$filename.tmp");
    }

    return $result;
}		   

1;