/ 
File-Stat-Bits-0.18
River stage zero No dependents
/ File::Stat::Bits

NAME

File::Stat::Bits - stat(2) bit mask constants

SYNOPSIS

 use File::stat;
 use File::Stat::Bits;

 my $st = stat($file) or die "Can't stat $file: $!";

 if ( S_ISCHR($st->mode) ) {
	my ($major, $minor) = dev_split( $st->rdev );

	print "$file is character device $major:$minor\n";
 }

 printf "Permissions are %04o\n", $st->mode & ALLPERMS;

(Too many S_IF* constants to example)

DESCRIPTION

Lots of Perl modules use the Unix file permissions and type bits directly in binary form with risk of non-portability for some exotic bits. Note that the POSIX module does not provides all needed constants and I can't wait when the POSIX module will be updated.

This separate module provides file type/mode bit and more constants from sys/stat.ph and sys/sysmacros.ph without pollution caller's namespace by other unneeded symbols from these headers. Most of these constants exported by this module are Constant Functions (see perlsub).

Since some of Perl builds does not include these converted headers, the build procedure will generate it for itself in the its own lib directory.

This module also should concentrate all portability and compatibility issues.

CONSTANTS

File type bit masks (for the st_mode field):

S_IFMT		bitmask for the file type bitfields
S_IFDIR	directory
S_IFCHR	character device
S_IFBLK	block device
S_IFREG	regular file
S_IFIFO	fifo (named pipe)
S_IFLNK	symbolic link
S_IFSOCK	socket

File access permission bit masks (for the st_mode field):

S_IRWXU	mask for file owner permissions
S_IRUSR	owner has read permission
S_IWUSR	owner has write permission
S_IXUSR	owner has execute permission
S_ISUID	set UID bit

S_IRWXG	mask for group permissions
S_IRGRP	group has read permission
S_IWGRP	group has write permission
S_IXGRP	group has execute permission
S_ISGID	set GID bit

S_IRWXO	mask for permissions for others
S_IROTH	others have read permission
S_IWOTH	others have write permisson
S_IXOTH	others have execute permission
S_ISVTX	sticky bit

Common mode bit masks:

ACCESSPERMS	 0777
   ALLPERMS	07777
DEFFILEMODE	 0666

FUNCTIONS

File type test macros (for the st_mode field):

S_ISDIR ( mode )	directory?
S_ISCHR ( mode )	character device?
S_ISBLK ( mode )	block device?
S_ISREG ( mode )	regular file?
S_ISFIFO( mode )	fifo (named pipe)?
S_ISLNK ( mode )	is it a symbolic link?
S_ISSOCK( mode )	socket?

All returns boolean value.

$major = major( $st_rdev )

Returns major device number of st_rdev

$minor = minor( $st_rdev )

Returns minor device number of st_rdev

($major, $minor) = dev_split( $st_rdev )

Splits st_rdev to major and minor device numbers

$st_rdev = dev_join( $major, $minor )

Makes st_rdev from major and minor device numbers (makedev())

NOTE

If major/minor definitions absent in reasonable set of system C headers all major/minor related functions returns undef.

SEE ALSO

stat(2)

File::stat(3)

AUTHOR

Dmitry Fedorov <fedorov@inp.nsk.su>

COPYRIGHT

Copyright (C) 2003 Dmitry Fedorov <fedorov@inp.nsk.su>

LICENSE

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

DISCLAIMER

The author disclaims any responsibility for any mangling of your system etc, that this script may cause.