PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

FCHMOD(3P)                POSIX Programmer's Manual               FCHMOD(3P)

PROLOG         top

       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         top

       fchmod — change mode of a file

SYNOPSIS         top

       #include <sys/stat.h>

       int fchmod(int fildes, mode_t mode);

DESCRIPTION         top

       The fchmod() function shall be equivalent to chmod() except that the
       file whose permissions are changed is specified by the file
       descriptor fildes.

       If fildes references a shared memory object, the fchmod() function
       need only affect the S_IRUSR, S_IWUSR, S_IRGRP, S_IWGRP, S_IROTH, and
       S_IWOTH file permission bits.

       If fildes references a typed memory object, the behavior of fchmod()
       is unspecified.

       If fildes refers to a socket, the behavior of fchmod() is
       unspecified.

       If fildes refers to a STREAM (which is fattach()-ed into the file
       system name space) the call returns successfully, doing nothing.

RETURN VALUE         top

       Upon successful completion, fchmod() shall return 0. Otherwise, it
       shall return −1 and set errno to indicate the error.

ERRORS         top

       The fchmod() function shall fail if:

       EBADF  The fildes argument is not an open file descriptor.

       EPERM  The effective user ID does not match the owner of the file and
              the process does not have appropriate privileges.

       EROFS  The file referred to by fildes resides on a read-only file
              system.

       The fchmod() function may fail if:

       EINTR  The fchmod() function was interrupted by a signal.

       EINVAL The value of the mode argument is invalid.

       EINVAL The fildes argument refers to a pipe and the implementation
              disallows execution of fchmod() on a pipe.

       The following sections are informative.

EXAMPLES         top

   Changing the Current Permissions for a File
       The following example shows how to change the permissions for a file
       named /home/cnd/mod1 so that the owner and group have
       read/write/execute permissions, but the world only has read/write
       permissions.

           #include <sys/stat.h>
           #include <fcntl.h>

           mode_t mode;
           int    fildes;
           ...
           fildes = open("/home/cnd/mod1", O_RDWR);
           fchmod(fildes, S_IRWXU | S_IRWXG | S_IROTH | S_IWOTH);

APPLICATION USAGE         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       chmod(3p), chown(3p), creat(3p), fcntl(3p), fstatat(3p),
       fstatvfs(3p), mknod(3p), open(3p), read(3p), write(3p)

       The Base Definitions volume of POSIX.1‐2008, sys_stat.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/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 .

IEEE/The Open Group                 2013                          FCHMOD(3P)

Pages that refer to this page: sys_stat.h(0p)