login-utils/need.8

   1 .\" Copyright (C) 2000  Richard Gooch
   2 .\"
   3 .\" This program is free software; you can redistribute it and/or modify
   4 .\" it under the terms of the GNU General Public License as published by
   5 .\" the Free Software Foundation; either version 2 of the License, or
   6 .\" (at your option) any later version.
   7 .\"
   8 .\" This program is distributed in the hope that it will be useful,
   9 .\" but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 .\" GNU General Public License for more details.
  12 .\"
  13 .\" You should have received a copy of the GNU General Public License
  14 .\" along with this program; if not, write to the Free Software
  15 .\" Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  16 .\"
  17 .\" Richard Gooch may be reached by email at  rgooch@atnf.csiro.au
  18 .\" The postal address is:
  19 .\"   Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia.
  20 .\"
  21 .\"     need.8          Richard Gooch   28-FEB-2000
  22 .\"
  23 .TH NEED 8 "28 Feb 2000" "Util-Linux Package"
  24 .SH NAME
  25 need \- utility to tell simpleinit(8) to start a service
  26 .SH SYNOPSIS
  27 .nf
  28 \fBneed\fP [\fB-r\fP] [\fBservice\fP]
  29 .BR display-services
  30 .fi
  31 .SH DESCRIPTION
  32 The \fBneed\fP programme is a utility that tells \fBsimpleinit\fP(8)
  33 to start a \fIservice\fP (usually a script in \fI/sbin/init.d\fP) and
  34 will wait for the service to become available. If the service is
  35 already available, it will not be started again.
  36
  37 When invoked as \fBdisplay-services\fP it will write the list of
  38 currently available services and the list of failed services to the
  39 standard output.
  40
  41 The \fB-r\fP option is used to tell \fBsimpleinit\fP(8) to "roll back"
  42 (stop) services up to (but not including) \fIservice\fP. If
  43 \fIservice\fP is not specified, all services are stopped. The \fB-r\fP
  44 option thus allows the system to be partially or wholly shut down in
  45 an orderly fashion. The \fBshutdown\fP(8) programme still needs to be
  46 run.
  47
  48 The \fBneed\fP programme is designed to help improve the robustness,
  49 scalability and readability of system boot scripts. It is now possible
  50 to write a modularised set of boot scripts without the complex and
  51 fragile numbered symlink scheme used in SysV-style boot scripts. Each
  52 script can simply declare, using \fBneed\fP(8), what must run before
  53 them.
  54 .SH EXIT CODE
  55 The exit code from \fBneed\fP is 0 if the service was successfully
  56 started, 1 if the service failed badly, and 2 if the service is
  57 unavailable (i.e. disabled in configuration files). These exit codes
  58 reflect the exit codes from the service startup scripts.
  59
  60 The exit code from \fBneed -r\fP is 0 if the service was successfully
  61 stopped, 1 if the service could not be stopped, and 2 if the service
  62 was not available to start with. The service shutdown scripts may only
  63 return 0 (for success) or 1 (for failure).
  64 .SH SIGNALS
  65 \fBneed\fP(8) uses \fBSIGUSR1\fP, \fBSIGUSR2\fP and \fBSIGPOLL\fP for
  66 communication with \fBsimpleinit\fP(8). Don't send these signals to
  67 it.
  68 .SH FILES
  69 .PD 0
  70 .TP 20
  71 .BI /dev/initctl
  72 This is the control FIFO, created by \fBsimpleinit\fP(8), which
  73 \fBneed\fP(8) writes commands to.
  74 .SH SEE ALSO
  75 .BR simpleinit (8),
  76 .BR init (8)
  77 .PP
  78 A more complete discussion of the new boot script system, based on
  79 \fBneed\fP(8), is available from:
  80 http://www.atnf.csiro.au/~rgooch/linux/boot-scripts/
  81 .SH AUTHOR
  82 Richard Gooch (rgooch@atnf.csiro.au)
  83 .SH AVAILABILITY
  84 The Util-Linux package is available from:
  85 ftp://ftp.??.kernel.org/pub/linux/utils/util-linux/