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HP-UX Reference > Cchmod(1)HP-UX 11i Version 3: February 2007 |
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NAMEchmod — change file mode access permissions DESCRIPTIONThe chmod command changes the permissions of one or more files according to the value of symbolic_mode_list or numeric_mode. You can display the current permissions for a file with the ls -l command (see ls(1)). Only the owner of a file, or a user with appropriate privileges, can change its mode. Only a user having appropriate privileges can set (or retain, if previously set) the sticky bit of a regular file. If the sticky bit is set on a directory, files inside the directory may be renamed or removed only by the owner of the file, the owner of the directory, or the superuser (even if the modes of the directory would otherwise allow such an operation). In order to set the set-group-ID bit, the group of the file must correspond to your current group ID. If chmod is used on a symbolic link, the mode of the file referred to by the link is changed. OptionsThe chmod command recognizes the following options:
OperandsThe chmod command recognizes the following operands:
Symbolic Mode ListA symbolic_mode_list is a comma-separated list of operations in the following form. Whitespace is not permitted.
The variable fields can have the following values:
The operations are performed in the order specified, and can override preceding operations specified in the same command line. If who is omitted, the r, w, x, and X permissions are changed for all users if the changes are permitted by the current file mode creation mask (see umask(1)). The s and t permissions are changed as if a was specified in who. Omitting permission is useful only when used with = to delete all permissions. Numeric Mode (Obsolescent)Absolute permissions can be set by specifying a numeric_mode, an octal number constructed from the logical OR (sum) of the following mode bits: Miscellaneous mode bits: 4000 (= u=s) Set user ID on file execution (file only) 2000 (= g=s) Set group ID on file execution (file only) 1000 (= u=t) Set sticky bit; see below and chmod(2) Permission mode bits: 0400 (= u=r) Read by owner 0200 (= u=w) Write by owner 0100 (= u=x) Execute (search in directory) by owner 0040 (= g=r) Read by group 0020 (= g=w) Write by group 0010 (= g=x) Execute/search by group 0004 (= o=r) Read by others 0002 (= o=w) Write by others 0001 (= o=x) Execute/search by others EXTERNAL INFLUENCESEnvironment VariablesLC_MESSAGES determines the language in which messages are displayed. If LC_MESSAGES is not specified or is null, it defaults to the value of LANG. If LANG is not specified or is null, it defaults to C (see lang(5)). If any internationalization variable contains an invalid setting, all internationalization variables default to C. See environ(5). RETURN VALUEUpon completion, chmod returns one of the following values:
EXAMPLESDeny write permission to others: chmod o-w file Make a file executable by everybody: chmod a+x file Assign read and execute permission to everybody, and set the set-user-ID bit: chmod a=rx,u+s file Assign read and write permission to the file owner, and read permission to everybody else: chmod u=rw,go=r file or the obsolescent form: chmod 644 file Traverse a directory subtree making all regular files readable by user and group only, and all executables and directories executable (searchable) by everyone: chmod -R ug+r,o-r,a+X pathname If the current value of umask is 020 (umask -S displays u=rwx,g=rx,o=rwx; do not change write permission for group) and the current permissions for file mytest are 444 (a=r), displayed by ls -l as -r--r--r--, then the command chmod +w mytest sets the permissions to 646 (uo=rw,g=r), displayed by ls -l as -rw-r--rw-. If the current value of umask is 020 (umask -S displays u=rwx,g=rx,o=rwx; do not change write permission for group) and the current permissions for file mytest are 666 (a=rw), displayed by ls -l as -rw-rw-rw-, then the command chmod -w mytest sets the permissions to 464 (uo=r,g=rw), displayed by ls -l as -r--rw-r--. |
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