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PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult 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 [-h] 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
       POSIX.1‐2017, 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 POSIX.1‐2017, Section
12.2, Utility Syntax Guidelines.

The following options shall be supported by the implementation:

-h 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.

-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 referenced 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 traversal of a file hierarchy, chgrp shall change
the group ID of the symbolic link. 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   POSIX.1‐2017,   Section   8.2,
                 Internationalization   Variables  for  the  precedence  of  internationalization
                 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 standard 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 values. 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.

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1-2017, Standard for Information Technology -- Portable  Operating  System  Interface
       (POSIX),  The  Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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.opengroup.org/unix/online.html .

       Any  typographical  or  formatting errors that appear in this page are most likely to have
       been introduced during the conversion of the source files to man page  format.  To  report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .