Use the File::Temp module, see File::Temp for more information.
use File::Temp qw/ tempfile tempdir /;
$dir = tempdir( CLEANUP => 1 ); ($fh, $filename) = tempfile( DIR => $dir );
# or if you don't need to know the filename
$fh = tempfile( DIR => $dir );The File::Temp has been a standard module since Perl 5.6.1. If you don't have a modern enough Perl installed, use the new_tmpfile class method from the IO::File module to get a filehandle opened for reading and writing. Use it if you don't need to know the file's name:
use IO::File; $fh = IO::File->new_tmpfile() or die "Unable to make new temporary file: $!";If you're committed to creating a temporary file by hand, use the process ID and/or the current time-value. If you need to have many temporary files in one process, use a counter:
BEGIN { use Fcntl; my $temp_dir = -d '/tmp' ? '/tmp' : $ENV{TMPDIR} || $ENV{TEMP}; my $base_name = sprintf("%s/%d-%d-0000", $temp_dir, $$, time()); sub temp_file { local *FH; my $count = 0; until (defined(fileno(FH)) || $count++ > 100) { $base_name =~ s/-(\d+)$/"-" . (1 + $1)/e; sysopen(FH, $base_name, O_WRONLY|O_EXCL|O_CREAT); } if (defined(fileno(FH)) return (*FH, $base_name); } else { return (); } } }