From 7192610528651f538496d3f85326f703556329ec Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Sun, 23 Jul 2006 01:27:27 +0000 Subject: Update to reflect recent changes to coreutils.texi. --- man/chmod.x | 84 +++++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 48 insertions(+), 36 deletions(-) (limited to 'man/chmod.x') diff --git a/man/chmod.x b/man/chmod.x index ab5c88492..c504872a3 100644 --- a/man/chmod.x +++ b/man/chmod.x @@ -1,42 +1,55 @@ [NAME] -chmod \- change file access permissions +chmod \- change file mode bits [DESCRIPTION] This manual page documents the GNU version of .BR chmod . .B chmod -changes the permissions of each given file according to +changes the file mode bits of each given file according to .IR mode , which can be either a symbolic representation of changes to make, or -an octal number representing the bit pattern for the new permissions. +an octal number representing the bit pattern for the new mode bits. .PP -The format of a symbolic mode is -`[ugoa...][[+-=][rwxXstugo...]...][,...]'. Multiple symbolic -operations can be given, separated by commas. +The format of a symbolic mode is [\c +\fBugoa\fP.\|.\|.][[\fB+-=\fP][\fIperms\fP.\|.\|.].\|.\|.], +where +.I "perms" +is either zero or more letters from the set +\fBrwxXst\fP, or a single letter from the set \fBugo\fP. +Multiple symbolic +modes can be given, separated by commas. .PP -A combination of the letters `ugoa' controls which users' access to -the file will be changed: the user who owns it (u), other users in the -file's group (g), other users not in the file's group (o), or all -users (a). If none of these are given, the effect is as if `a' were +A combination of the letters \fBugoa\fP controls which users' access +to the file will be changed: the user who owns it (\fBu\fP), other +users in the file's group (\fBg\fP), other users not in the file's +group (\fBo\fP), or all users (\fBa\fP). If none of these are given, +the effect is as if \fBa\fP were given, but bits that are set in the umask are not affected. .PP -The operator `+' causes the permissions selected to be added to the -existing permissions of each file; `-' causes them to be removed; and -`=' causes them to be the only permissions that the file has. +The operator \fB+\fP causes the selected file mode bits to be added to +the existing file mode bits of each file; \fB-\fP causes them to be +removed; and \fB=\fP causes them to be added and causes unmentioned +bits to be removed except that a directory's unmentioned set user and +group ID bits are not affected. .PP -The letters `rwxXstugo' select the new permissions for the affected -users: read (r), write (w), execute (or access for directories) (x), -execute only if the file is a directory or already has execute -permission for some user (X), set user or group ID on execution (s), -sticky (t), the permissions granted to the user who owns the file (u), -the permissions granted to other users who are members of the file's group (g), +The letters \fBrwxXst\fP select file mode bits for the affected users: +read (\fBr\fP), write (\fBw\fP), execute (or search for directories) +(\fBx\fP), execute/search only if the file is a directory or already +has execute permission for some user (\fBX\fP), set user or group ID +on execution (\fBs\fP), restricted deletion flag or sticky bit +(\fBt\fP). Instead of one or more of these letters, you can specify +exactly one of the letters \fBugo\fP: the permissions granted to the +user who owns the file (\fBu\fP), the permissions granted to other +users who are members of the file's group (\fBg\fP), and the permissions granted to users that are in neither of the two preceding -categories (o). +categories (\fBo\fP). .PP -A numeric mode is from one to four octal digits (0-7), derived by -adding up the bits with values 4, 2, and 1. Any omitted digits are -assumed to be leading zeros. The first digit selects the set user ID -(4) and set group ID (2) and sticky (1) attributes. The second digit +A numeric mode is from one to four octal digits (0\-7), derived by +adding up the bits with values 4, 2, and 1. Omitted digits are +assumed to be leading zeros, except that if the first digit is +omitted, a directory's set user and group ID bits are not affected. +The first digit selects the set user ID (4) and set group ID (2) and +restricted deletion or sticky (1) attributes. The second digit selects permissions for the user who owns the file: read (4), write (2), and execute (1); the third selects permissions for other users in the file's group, with the same values; and the fourth for other users not @@ -54,18 +67,17 @@ In contrast, .B chmod ignores symbolic links encountered during recursive directory traversals. -.SH STICKY FILES -On older Unix systems, the sticky bit caused executable files to be -hoarded in swap space. This feature is not useful on modern VM -systems, and the Linux kernel ignores the sticky bit on files. Other -kernels may use the sticky bit on files for system-defined purposes. -On some systems, only the superuser can set the sticky bit on files. -.SH STICKY DIRECTORIES -When the sticky bit is set on a directory, a file in that directory may -be unlinked or renamed only by the directory owner, the file owner, or root. -Without the sticky bit, anyone able to write to the -directory can delete or rename files. The sticky bit is commonly found -on directories, such as /tmp, that are world-writable. +.SH "RESTRICTED DELETION FLAG OR STICKY BIT" +The restricted deletion flag or sticky bit is a single bit, whose +interpretation depends on the file type. For directories, it prevents +unprivileged users from removing or renaming a file in the directory +unless they own the file or the directory; this is called the +.I "restricted deletion flag" +for the directory, and is commonly found on world-writable directories +like \fB/tmp\fP. For regular files on some older systems, the bit +saves the program's text image on the swap device so it will load more +quickly when run; this is called the +.IR "sticky bit" . .SH OPTIONS [SEE ALSO] chmod(2) -- cgit v1.2.3-54-g00ecf