IO::File(3p) Perl Programmers Reference Guide IO::File(3p)
IO::File - supply object methods for filehandles
use IO::File; $fh = new IO::File; if ($fh->open("< file")) { print <$fh>; $fh->close; } $fh = new IO::File "> file"; if (defined $fh) { print $fh "bar\n"; $fh->close; } $fh = new IO::File "file", "r"; if (defined $fh) { print <$fh>; undef $fh; # automatically closes the file } $fh = new IO::File "file", O_WRONLY|O_APPEND; if (defined $fh) { print $fh "corge\n"; $pos = $fh->getpos; $fh->setpos($pos); undef $fh; # automatically closes the file } autoflush STDOUT 1;
"IO::File" inherits from "IO::Handle" and "IO::Seekable". It extends these classes with methods that are specific to file handles.
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. new_tmpfile Creates an "IO::File" opened for read/write on a newly created temporary file. On systems where this is possi- ble, the temporary file is anonymous (i.e. it is perl v5.8.8 2005-02-05 1 IO::File(3p) Perl Programmers Reference Guide IO::File(3p) unlinked after creation, but held open). If the tem- porary file cannot be created or opened, the "IO::File" object is destroyed. Otherwise, it is returned to the caller.
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 whi- tespace or other special characters, and the second parameter is the open mode, optionally followed by a file permission value. 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 pro- tects any special characters). 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. If "IO::File::open" is given a mode that includes the ":" character, it passes all the three arguments to the three-argument "open" operator. For convenience, "IO::File" exports the O_XXX constants from the Fcntl module, if this module is available. binmode( [LAYER] ) "binmode" sets "binmode" on the underlying "IO" object, as documented in "perldoc -f binmode". "binmode" accepts one optional parameter, which is the layer to be passed on to the "binmode" call.
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.
perlfunc, "I/O Operators" in perlop, IO::Handle, IO::Seekable, IO::Dir
Derived from FileHandle.pm by Graham Barr <gbarr@pobox.com>. perl v5.8.8 2005-02-05 2