CHGRP(1P)                                           POSIX Programmer's Manual                                          CHGRP(1P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       chgrp - change the file group ownership

SYNOPSIS
       chgrp [-hR] group file ...

       chgrp -R [-H | -L | -P ] group file ...


DESCRIPTION
       The  chgrp  utility  shall set the group ID of the file named by each file operand to the group ID specified by the group
       operand.

       For each file operand, or, if the -R option is used, each file encountered while walking the directory trees specified by
       the  file  operands,  the  chgrp  utility  shall perform actions equivalent to the chown() function defined in the System
       Interfaces volume of IEEE Std 1003.1-2001, called with the following arguments:

        * The file operand shall be used as the path argument.

        * The user ID of the file shall be used as the owner argument.

        * The specified group ID shall be used as the group argument.

       Unless chgrp is invoked by a process with appropriate privileges, the set-user-ID and set-group-ID bits of a regular file
       shall be cleared upon successful completion; the set-user-ID and set-group-ID bits of other file types may be cleared.

OPTIONS
       The  chgrp  utility  shall  conform  to the Base Definitions volume of IEEE Std 1003.1-2001, Section 12.2, Utility Syntax
       Guidelines.

       The following options shall be supported by the implementation:

       -h     If the system supports group IDs for symbolic links, for each file operand that names  a  file  of  type  symbolic
              link,  chgrp shall attempt to set the group ID of the symbolic link instead of the file referenced by the symbolic
              link. If the system does not support group IDs for symbolic links, for each file operand that names a file of type
              symbolic link, chgrp shall do nothing more with the current file and shall go on to any remaining files.

       -H     If the -R option is specified and a symbolic link referencing a file of type directory is specified on the command
              line, chgrp shall change the group of the directory referenced by the symbolic link and  all  files  in  the  file
              hierarchy below it.

       -L     If the -R option is specified and a symbolic link referencing a file of type directory is specified on the command
              line or encountered during the traversal of a file hierarchy, chgrp shall change the group of the directory refer-
              enced by the symbolic link and all files in the file hierarchy below it.

       -P     If  the -R option is specified and a symbolic link is specified on the command line or encountered during the tra-
              versal of a file hierarchy, chgrp shall change the group ID of the symbolic link if the system supports this oper-
              ation. The chgrp utility shall not follow the symbolic link to any other part of the file hierarchy.

       -R     Recursively  change  file group IDs. For each file operand that names a directory, chgrp shall change the group of
              the directory and all files in the file hierarchy below it. Unless a -H, -L, or -P  option  is  specified,  it  is
              unspecified which of these options will be used as the default.


       Specifying  more  than  one  of the mutually-exclusive options -H, -L, and -P shall not be considered an error.  The last
       option specified shall determine the behavior of the utility.

OPERANDS
       The following operands shall be supported:

       group  A group name from the group database or a numeric group ID. Either specifies a group ID to be given to  each  file
              named  by  one  of the file operands. If a numeric group operand exists in the group database as a group name, the
              group ID number associated with that group name is used as the group ID.

       file   A pathname of a file whose group ID is to be modified.


STDIN
       Not used.

INPUT FILES
       None.

ENVIRONMENT VARIABLES
       The following environment variables shall affect the execution of chgrp:

       LANG   Provide a default value for the internationalization variables that are unset or null. (See the  Base  Definitions
              volume  of  IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for the precedence of international-
              ization variables used to determine the values of locale categories.)

       LC_ALL If set to a non-empty string value, override the values of all the other internationalization variables.

       LC_CTYPE
              Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-
              byte as opposed to multi-byte characters in arguments).

       LC_MESSAGES
              Determine the locale that should be used to affect the format and contents of diagnostic messages written to stan-
              dard error.

       NLSPATH
              Determine the location of message catalogs for the processing of LC_MESSAGES .


ASYNCHRONOUS EVENTS
       Default.

STDOUT
       Not used.

STDERR
       The standard error shall be used only for diagnostic messages.

OUTPUT FILES
       None.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       The following exit values shall be returned:

        0     The utility executed successfully and all requested changes were made.

       >0     An error occurred.


CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       Only the owner of a file or the user with appropriate privileges may change the owner or group of a file.

       Some implementations restrict the use of chgrp to a user with appropriate privileges when the group specified is not  the
       effective group ID or one of the supplementary group IDs of the calling process.

EXAMPLES
       None.

RATIONALE
       The  System  V  and BSD versions use different exit status codes. Some implementations used the exit status as a count of
       the number of errors that occurred; this practice is unworkable since it can overflow the range of valid exit status val-
       ues. The standard developers chose to mask these by specifying only 0 and >0 as exit values.

       The functionality of chgrp is described substantially through references to chown(). In this way, there is no duplication
       of effort required for describing the interactions of permissions, multiple groups, and so on.

FUTURE DIRECTIONS
       None.

SEE ALSO
       chmod(), chown(), the System Interfaces volume of IEEE Std 1003.1-2001, chown()

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy  between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard  is  the  referee   document.   The   original   Standard   can   be   obtained   online   at   http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                     CHGRP(1P)