CHMOD(2)                                                 CHMOD(2)



     NAME
          chmod - change mode of file

     SYNOPSIS
          int chmod (path, mode)
          char *path;
          int mode;

     DESCRIPTION
          Path points to a path name naming a file.  chmod sets the
          access permission portion of the named file's mode according
          to the bit pattern contained in mode.

          Access permission bits are interpreted as follows:

         04000   Set user ID on execution.
         020#0   Set group ID on execution if # is 7, 5, 3, or 1
                 Enable mandatory file/record locking if # is 6, 4, 2, or 0
         01000   Save text image  after execution.
         00400   Read by owner.
         00200   Write by owner.
         00100   Execute (search if a directory) by owner.
         00070   Read, write, execute  (search) by group.
         00007   Read, write, execute  (search) by others.

          The effective user ID of the process must match the owner of
          the file or be super-user to change the mode of a file.

          If the effective user ID of the process is not super-user,
          mode bit 01000 (save text image on execution) is cleared.

          If the effective user ID of the process is not super-user
          and the effective group ID of the process does not match the
          group ID of the file, mode bit 02000 (set group ID on
          execution) is cleared.

          If a 410 executable file has the sticky bit (mode bit 01000)
          set, the operating system will not delete the program text
          from the swap area when the last user process terminates.
          If a 413 executable file has the sticky bit set, the
          operating system will not delete the memory mapping
          information for the program text portion of the file when
          the last user terminates.  Thus, when the next user of the
          file executes it, necessary tables need not be
          reestablished, and text itself can simply be faulted in as
          needed, saving some startup time.

          If the mode bit 02000 (set group ID on execution) is set and
          the mode bit 00010 (execute or search by group) is not set,
          mandatory file/record locking will exist on a regular file.
          This may effect future calls to open(2), creat(2),
           read(2), and write(2) on this file.



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     CHMOD(2)                                                 CHMOD(2)



          chmod will fail and the file mode will be unchanged if one
          or more of the following are true:

          [ENOTDIR]      A component of the path prefix is not a
                         directory.

          [ENOENT]       The named file does not exist.

          [EACCES]       Search permission is denied on a component of
                         the path prefix.

          [EPERM]        The effective user ID does not match the
                         owner of the file and the effective user ID
                         is not super-user.

          [EROFS]        The named file resides on a read-only file
                         system.

          [EFAULT]       Path points outside the allocated address
                         space of the process.

          [EINTR]        A signal was caught during the chmod system
                         call.

          [ENOLINK]      Path points to a remote machine and the link
                         to that machine is no longer active.

          [EMULTIHOP]    Components of path require hopping to
                         multiple remote machines.

     SEE ALSO
          chown(2), creat(2), fcntl(2), mknod(2), open(2), read(2),
          write(2).
          chmod(1) in the User's Reference Manual.

     DIAGNOSTICS
          Upon successful completion, a value of 0 is returned.
          Otherwise, a value of -1 is returned and errno is set to
          indicate the error.

     ORIGIN
          AT&T V.3













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