| 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. |
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| 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 |
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| 20 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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| 32 | .\" @(#)exit.3 8.1 (Berkeley) 6/4/93 |
| 33 | .\" $FreeBSD: src/lib/libc/stdlib/exit.3,v 1.16 2007/01/09 00:28:09 imp Exp $ |
| 34 | .\" |
| 35 | .Dd June 15, 2007 |
| 36 | .Dt EXIT 3 |
| 37 | .Os |
| 38 | .Sh NAME |
| 39 | .Nm exit , |
| 40 | .Nm _Exit |
| 41 | .Nd perform normal program termination |
| 42 | .Sh LIBRARY |
| 43 | .Lb libc |
| 44 | .Sh SYNOPSIS |
| 45 | .In stdlib.h |
| 46 | .Ft void |
| 47 | .Fn exit "int status" |
| 48 | .Ft void |
| 49 | .Fn _Exit "int status" |
| 50 | .Sh DESCRIPTION |
| 51 | The |
| 52 | .Fn exit |
| 53 | and |
| 54 | .Fn _Exit |
| 55 | functions terminate a process. |
| 56 | .Pp |
| 57 | Before termination, |
| 58 | .Fn exit |
| 59 | performs the following functions in the order listed: |
| 60 | .Bl -enum -offset indent |
| 61 | .It |
| 62 | Call the functions registered with the |
| 63 | .Xr atexit 3 |
| 64 | function, in the reverse order of their registration. |
| 65 | .It |
| 66 | Flush all open output streams. |
| 67 | .It |
| 68 | Close all open streams. |
| 69 | .It |
| 70 | Unlink all files created with the |
| 71 | .Xr tmpfile 3 |
| 72 | function. |
| 73 | .El |
| 74 | .Pp |
| 75 | The |
| 76 | .Fn _Exit |
| 77 | function terminates without calling the functions registered with the |
| 78 | .Xr atexit 3 |
| 79 | function, and may or may not perform the other actions listed. |
| 80 | Both functions make the low-order eight bits of the |
| 81 | .Fa status |
| 82 | argument available to a parent process which has called a |
| 83 | .Xr wait 2 Ns -family |
| 84 | function. |
| 85 | .Pp |
| 86 | The C Standard |
| 87 | .Pq St -isoC-99 |
| 88 | defines the values |
| 89 | .Li 0 , |
| 90 | .Dv EXIT_SUCCESS , |
| 91 | and |
| 92 | .Dv EXIT_FAILURE |
| 93 | as possible values of |
| 94 | .Fa status . |
| 95 | Cooperating processes may use other values; |
| 96 | in a program which might be called by a mail transfer agent, the |
| 97 | values described in |
| 98 | .Xr sysexits 3 |
| 99 | may be used to provide more information to the parent process. |
| 100 | .Pp |
| 101 | Note that |
| 102 | .Fn exit |
| 103 | does nothing to prevent bottomless recursion should a function registered |
| 104 | using |
| 105 | .Xr atexit 3 |
| 106 | itself call |
| 107 | .Fn exit . |
| 108 | Such functions must call |
| 109 | .Fn _Exit |
| 110 | instead (although this has other effects as well which may not be desired). |
| 111 | .Sh RETURN VALUES |
| 112 | The |
| 113 | .Fn exit |
| 114 | and |
| 115 | .Fn _Exit |
| 116 | functions |
| 117 | never return. |
| 118 | .Sh SEE ALSO |
| 119 | .Xr _exit 2 , |
| 120 | .Xr wait 2 , |
| 121 | .Xr atexit 3 , |
| 122 | .Xr at_quick_exit 3 , |
| 123 | .Xr intro 3 , |
| 124 | .Xr sysexits 3 , |
| 125 | .Xr tmpfile 3 |
| 126 | .Sh STANDARDS |
| 127 | The |
| 128 | .Fn exit |
| 129 | and |
| 130 | .Fn _Exit |
| 131 | functions conform to |
| 132 | .St -isoC-99 . |