gen/FreeBSD/setmode.3

   1 .\" Copyright (c) 1989, 1991, 1993
   2 .\"     The Regents of the University of California.  All rights reserved.
   3 .\"
   4 .\" Redistribution and use in source and binary forms, with or without
   5 .\" modification, are permitted provided that the following conditions
   6 .\" are met:
   7 .\" 1. Redistributions of source code must retain the above copyright
   8 .\"    notice, this list of conditions and the following disclaimer.
   9 .\" 2. Redistributions in binary form must reproduce the above copyright
  10 .\"    notice, this list of conditions and the following disclaimer in the
  11 .\"    documentation and/or other materials provided with the distribution.
  12 .\" 3. All advertising materials mentioning features or use of this software
  13 .\"    must display the following acknowledgement:
  14 .\"     This product includes software developed by the University of
  15 .\"     California, Berkeley and its contributors.
  16 .\" 4. Neither the name of the University nor the names of its contributors
  17 .\"    may be used to endorse or promote products derived from this software
  18 .\"    without specific prior written permission.
  19 .\"
  20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30 .\" SUCH DAMAGE.
  31 .\"
  32 .\"     @(#)setmode.3   8.2 (Berkeley) 4/28/95
  33 .\" $FreeBSD: src/lib/libc/gen/setmode.3,v 1.11 2001/10/01 16:08:51 ru Exp $
  34 .\"
  35 .Dd April 28, 1995
  36 .Dt SETMODE 3
  37 .Os
  38 .Sh NAME
  39 .Nm getmode ,
  40 .Nm setmode
  41 .Nd modify mode bits
  42 .Sh LIBRARY
  43 .Lb libc
  44 .Sh SYNOPSIS
  45 .In unistd.h
  46 .Ft mode_t
  47 .Fn getmode "const void *set" "mode_t mode"
  48 .Ft void *
  49 .Fn setmode "const char *mode_str"
  50 .Sh DESCRIPTION
  51 The
  52 .Fn getmode
  53 function
  54 returns a copy of the file permission bits
  55 .Fa mode
  56 as altered by the values pointed to by
  57 .Fa set .
  58 While only the mode bits are altered, other parts of the file mode
  59 may be examined.
  60 .Pp
  61 The
  62 .Fn setmode
  63 function
  64 takes an absolute (octal) or symbolic value, as described in
  65 .Xr chmod 1 ,
  66 as an argument
  67 and returns a pointer to mode values to be supplied to
  68 .Fn getmode .
  69 Because some of the symbolic values are relative to the file
  70 creation mask,
  71 .Fn setmode
  72 may call
  73 .Xr umask 2 .
  74 If this occurs, the file creation mask will be restored before
  75 .Fn setmode
  76 returns.
  77 If the calling program changes the value of its file creation mask
  78 after calling
  79 .Fn setmode ,
  80 .Fn setmode
  81 must be called again if
  82 .Fn getmode
  83 is to modify future file modes correctly.
  84 .Pp
  85 If the mode passed to
  86 .Fn setmode
  87 is invalid or if memory cannot be allocated for the return value,
  88 .Fn setmode
  89 returns
  90 .Dv NULL .
  91 .Pp
  92 The value returned from
  93 .Fn setmode
  94 is obtained from
  95 .Fn malloc
  96 and should be returned to the system with
  97 .Fn free
  98 when the program is done with it, generally after a call to
  99 .Fn getmode .
 100 .Sh ERRORS
 101 The
 102 .Fn setmode
 103 function
 104 may fail and set errno for any of the errors specified for the library
 105 routine
 106 .Xr malloc 3 .
 107 .Sh SEE ALSO
 108 .Xr chmod 1 ,
 109 .Xr stat 2 ,
 110 .Xr umask 2 ,
 111 .Xr malloc 3
 112 .Sh HISTORY
 113 The
 114 .Fn getmode
 115 and
 116 .Fn setmode
 117 functions first appeared in
 118 .Bx 4.4 .