IO::File(3pm)

💖 NAME 💖

Okay so bestie, this is the IO::File(3pm) page from the Perl Programmers Reference Guide, and its whole thing is: supply object methods for filehandles. That’s the vibe. 💅

---

✨ SYNOPSIS ✨

No cap, here’s the whole mood in code:

use IO::File;

my $fh = IO::File->new();
if ($fh->open("< file")) {
    print <$fh>;
    $fh->close;
}

my $fh = IO::File->new("> file");
if (defined $fh) {
    print $fh "bar\n";
    $fh->close;
}

my $fh = IO::File->new("file", "r");
if (defined $fh) {
    print <$fh>;
    undef $fh;       # automatically closes the file
}

my $fh = IO::File->new("file", O_WRONLY|O_APPEND);
if (defined $fh) {
    print $fh "corge\n";

    my $pos = $fh->getpos;
    $fh->setpos($pos);

    undef $fh;       # automatically closes the file
}

autoflush STDOUT 1;

---

🦋 DESCRIPTION 🦋

IO::File inherits from IO::Handle and IO::Seekable. It extends these classes with methods that are specific to file handles. It’s giving “filehandle glow-up,” lowkey. ✨

---

🎀 CONSTRUCTOR 🎀

🧚 new ( FILENAME [,MODE [,PERMS]] )

Creates an IO::File. If it receives any parameters, they are passed to the method open; if the open fails, the object is destroyed. Otherwise, it is returned to the caller. Simple as that, bestie. 🫶

🦋 new_tmpfile

Creates an IO::File opened for read/write on a newly created temporary file. On systems where this is possible, the temporary file is anonymous (i.e. it is unlinked after creation, but held open). If the temporary file cannot be created or opened, the IO::File object is destroyed. Otherwise, it is returned to the caller. Temporary-file main character energy, honestly. 💫

---

🧚 METHODS 🧚

🍓 the open signatures 🍓

open( FILENAME [,MODE [,PERMS]] )
open( FILENAME, IOLAYERS )

open accepts one, two or three parameters. With one parameter, it is just a front end for the built-in open function. With two or three parameters, the first parameter is a filename that may include whitespace or other special characters, and the second parameter is the open mode, optionally followed by a file permission value. Periodt. 💅

If IO::File::open receives a Perl mode string (">", "+<", etc.) or an ANSI C fopen() mode string ("w", "r+", etc.), it uses the basic Perl open operator (but protects any special characters). Iconic behavior. 👑

If IO::File::open is given a numeric mode, it passes that mode and the optional permissions value to the Perl sysopen operator. The permissions default to 0666. Ngl, that default matters. 🫡

If IO::File::open is given a mode that includes the ":" character, it passes all the three arguments to the three-argument open operator. Love that for us. ✨

For convenience, IO::File exports the O_XXX constants from the Fcntl module, if this module is available. Free constants, no cap. 🎁

---

🙈 NOTE 🙈

Some operating systems may perform IO::File::new() or IO::File::open() on a directory without errors. This behavior is not portable and not suggested for use. Using opendir() and readdir() or IO::Dir are suggested instead. So like… don’t do the directory thing, bestie. It’s giving undefined behavior adjacent. 💀

---

🌈 SEE ALSO 🌈

• perlfunc
• "I/O Operators" in perlop
• IO::Handle
• IO::Seekable
• IO::Dir

---

📜 HISTORY 📜

Derived from FileHandle.pm by Graham Barr <gbarr@pobox.com>. Respect the ancestry. 🫶

---

mwah 💋 — this page is from perl v5.42.3, dated 2026-11-03. bye bestie! 🎀🦋💖