From: PerlFAQ Server on 9 May 2010 18:00 This is an excerpt from the latest version perlfaq5.pod, which comes with the standard Perl distribution. These postings aim to reduce the number of repeated questions as well as allow the community to review and update the answers. The latest version of the complete perlfaq is at http://faq.perl.org . -------------------------------------------------------------------- 5.7: How do I make a temporary file name? If you don't need to know the name of the file, you can use "open()" with "undef" in place of the file name. In Perl 5.8 or later, the "open()" function creates an anonymous temporary file: open my $tmp, '+>', undef or die $!; Otherwise, you can use the File::Temp module. use File::Temp qw/ tempfile tempdir /; my $dir = tempdir( CLEANUP => 1 ); ($fh, $filename) = tempfile( DIR => $dir ); # or if you don't need to know the filename my $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; my $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 + $1)/e; # O_EXCL is required for security reasons. sysopen my($fh), $base_name, O_WRONLY|O_EXCL|O_CREAT; } if( defined fileno($fh) ) { return ($fh, $base_name); } else { return (); } } } -------------------------------------------------------------------- The perlfaq-workers, a group of volunteers, maintain the perlfaq. They are not necessarily experts in every domain where Perl might show up, so please include as much information as possible and relevant in any corrections. The perlfaq-workers also don't have access to every operating system or platform, so please include relevant details for corrections to examples that do not work on particular platforms. Working code is greatly appreciated. If you'd like to help maintain the perlfaq, see the details in perlfaq.pod.
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