man8/nscd.8

   1 .\" -*- nroff -*-
   2 .\" Copyright 1999 SuSE GmbH Nuernberg, Germany
   3 .\" Author: Thorsten Kukuk <kukuk@suse.de>
   4 .\"
   5 .\" This program is free software; you can redistribute it and/or
   6 .\" modify it under the terms of the GNU General Public License as
   7 .\" published by the Free Software Foundation; either version 2 of the
   8 .\" License, or (at your option) any later version.
   9 .\"
  10 .\" This program is distributed in the hope that it will be useful,
  11 .\" but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 .\" General Public License for more details.
  14 .\"
  15 .\" You should have received a copy of the GNU General Public
  16 .\" License along with this program; see the file COPYING.  If not,
  17 .\" write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18 .\" Boston, MA 02111-1307, USA.
  19 .\"
  20 .\" 2008-12-05 Petr Baudis <pasky@suse.cz>
  21 .\"     Rewrite the NOTES section to reflect modern reality
  22 .\"
  23 .TH NSCD 8 2008-12-05 "GNU" "Linux Programmer's Manual"
  24 .SH NAME
  25 /usr/sbin/nscd \- name service cache daemon
  26 .SH DESCRIPTION
  27 Nscd is a daemon that provides a cache for the most common name service
  28 requests.
  29 The default configuration file,
  30 .IR /etc/nscd.conf ,
  31 determines the behavior of the cache daemon.
  32 See
  33 .BR nscd.conf (5).
  34
  35 Nscd provides caching for accesses of the
  36 .BR passwd (5),
  37 .BR group (5),
  38 and
  39 .BR hosts (5)
  40 databases through standard libc interfaces, such as
  41 .BR getpwnam (3),
  42 .BR getpwuid (3),
  43 .BR getgrnam (3),
  44 .BR getgrgid (3),
  45 .BR gethostbyname (3),
  46 and others.
  47
  48 There are two caches for each database:
  49 a positive one for items found, and a negative one
  50 for items not found.
  51 Each cache has a separate TTL (time-to-live)
  52 period for its data.
  53 Note that the shadow file is specifically not cached.
  54 .BR getspnam (3)
  55 calls remain uncached as a result.
  56 .SH OPTIONS
  57 .TP
  58 .B "\-\-help"
  59 will give you a list with all options and what they do.
  60 .SH NOTES
  61 The daemon will try to watch for changes in configuration files
  62 appropriate for each database (e.g.
  63 .I /etc/passwd
  64 for the
  65 .I passwd
  66 database or
  67 .IR "/etc/hosts " and " /etc/resolv.conf"
  68 for the
  69 .I hosts
  70 database), and flush the cache when these are changed.
  71 However, this will happen only after a short delay (unless the
  72 .BR inotify (7)
  73 mechanism is available and glibc 2.9 or later is available),
  74 and this auto-detection does not cover configuration files
  75 required by non-standard NSS modules, if any are specified in
  76 .IR /etc/nsswitch.conf .
  77 In that case, you need to run the following command
  78 after changing the configuration file of the database so that
  79 .B nscd
  80 invalidates its cache:
  81
  82     $ \fBnscd -i \fI<database>\fP
  83 .SH "SEE ALSO"
  84 .BR nscd.conf (5),
  85 .BR nsswitch.conf (5)
  86 .\" .SH AUTHOR
  87 .\" .B nscd
  88 .\" was written by Thorsten Kukuk and Ulrich Drepper.