diff options
Diffstat (limited to 'man')
| -rw-r--r-- | man/chmod.x | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/man/chmod.x b/man/chmod.x index d581013f9..a2a88ac98 100644 --- a/man/chmod.x +++ b/man/chmod.x @@ -28,19 +28,19 @@ 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), -save program text on swap device (t), the permissions that the user -who owns the file currently has for it (u), the permissions that other -users in the file's group have for it (g), and the permissions that -other users not in the file's group have for it (o). +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), +and the permissions granted to users that are in neither of the two preceding +categories (o). .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 save text image (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 in the file's group, with the same values. +(4) and set group ID (2) and 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 +in the file's group, with the same values. .PP .B chmod never changes the permissions of symbolic links; the @@ -54,4 +54,16 @@ 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, files in that directory may +only be unlinked or renamed by root or their owner. (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, +which are world-writable. .SH OPTIONS |