| 1 | .\" Copyright (c) 1990, 1991, 1993 |
| 2 | .\" The Regents of the University of California. All rights reserved. |
| 3 | .\" |
| 4 | .\" This code is derived from software contributed to Berkeley by |
| 5 | .\" the American National Standards Committee X3, on Information |
| 6 | .\" Processing Systems. |
| 7 | .\" |
| 8 | .\" Redistribution and use in source and binary forms, with or without |
| 9 | .\" modification, are permitted provided that the following conditions |
| 10 | .\" are met: |
| 11 | .\" 1. Redistributions of source code must retain the above copyright |
| 12 | .\" notice, this list of conditions and the following disclaimer. |
| 13 | .\" 2. Redistributions in binary form must reproduce the above copyright |
| 14 | .\" notice, this list of conditions and the following disclaimer in the |
| 15 | .\" documentation and/or other materials provided with the distribution. |
| 16 | .\" 3. 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 | .\" @(#)system.3 8.1 (Berkeley) 6/4/93 |
| 33 | .\" $FreeBSD: src/lib/libc/stdlib/system.3,v 1.13 2008/06/26 08:24:59 danger Exp $ |
| 34 | .\" $DragonFly: src/lib/libc/stdlib/system.3,v 1.2 2003/06/17 04:26:46 dillon Exp $ |
| 35 | .\" |
| 36 | .Dd June 4, 1993 |
| 37 | .Dt SYSTEM 3 |
| 38 | .Os |
| 39 | .Sh NAME |
| 40 | .Nm system |
| 41 | .Nd pass a command to the shell |
| 42 | .Sh LIBRARY |
| 43 | .Lb libc |
| 44 | .Sh SYNOPSIS |
| 45 | .In stdlib.h |
| 46 | .Ft int |
| 47 | .Fn system "const char *string" |
| 48 | .Sh DESCRIPTION |
| 49 | The |
| 50 | .Fn system |
| 51 | function |
| 52 | hands the argument |
| 53 | .Fa string |
| 54 | to the command interpreter |
| 55 | .Xr sh 1 . |
| 56 | The calling process waits for the shell |
| 57 | to finish executing the command, |
| 58 | ignoring |
| 59 | .Dv SIGINT |
| 60 | and |
| 61 | .Dv SIGQUIT , |
| 62 | and blocking |
| 63 | .Dv SIGCHLD . |
| 64 | .Pp |
| 65 | If |
| 66 | .Fa string |
| 67 | is a |
| 68 | .Dv NULL |
| 69 | pointer, |
| 70 | .Fn system |
| 71 | will return non-zero if the command interpreter |
| 72 | .Xr sh 1 |
| 73 | is available, and zero if it is not. |
| 74 | .Sh RETURN VALUES |
| 75 | The |
| 76 | .Fn system |
| 77 | function |
| 78 | returns the exit status of the shell as returned by |
| 79 | .Xr waitpid 2 , |
| 80 | or \-1 if an error occurred when invoking |
| 81 | .Xr fork 2 |
| 82 | or |
| 83 | .Xr waitpid 2 . |
| 84 | A return value of 127 means the execution of the shell |
| 85 | failed. |
| 86 | .Sh SEE ALSO |
| 87 | .Xr sh 1 , |
| 88 | .Xr execve 2 , |
| 89 | .Xr fork 2 , |
| 90 | .Xr waitpid 2 , |
| 91 | .Xr popen 3 |
| 92 | .Sh STANDARDS |
| 93 | The |
| 94 | .Fn system |
| 95 | function |
| 96 | conforms to |
| 97 | .St -isoC |
| 98 | and is expected to be |
| 99 | .St -p1003.2 |
| 100 | compatible. |