fchmod(3p) — Linux manual page


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

       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

       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

           #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);



RATIONALE         top




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.1‐2017, sys_stat.h(0p)

COPYRIGHT         top

       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 .

IEEE/The Open Group               2017                        FCHMOD(3P)

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