IO::File(3p) Perl Programmers Reference Guide IO::File(3p) #

IO::File(3p) Perl Programmers Reference Guide IO::File(3p)

NNAAMMEE #

 IO::File - supply object methods for filehandles

SSYYNNOOPPSSIISS #

     use IO::File;

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

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

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

     $fh = IO::File->new("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;

DDEESSCCRRIIPPTTIIOONN #

 "IO::File" inherits from "IO::Handle" and "IO::Seekable". It extends
 these classes with methods that are specific to file handles.

CCOONNSSTTRRUUCCTTOORR #

 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 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.

MMEETTHHOODDSS #

 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.

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

NNOOTTEE #

 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.

SSEEEE AALLSSOO #

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

HHIISSTTOORRYY #

 Derived from FileHandle.pm by Graham Barr <_g_b_a_r_r_@_p_o_b_o_x_._c_o_m>.

perl v5.36.3 2023-02-15 IO::File(3p)