1.\" Copyright (c) 1980, 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.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)getpid.2 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD$ 30.\" 31.Dd November 2, 2006 32.Dt GETPID 2 33.Os 34.Sh NAME 35.Nm getpid , 36.Nm getppid 37.Nd get parent or calling process identification 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In sys/types.h 42.In unistd.h 43.Ft pid_t 44.Fn getpid void 45.Ft pid_t 46.Fn getppid void 47.Sh DESCRIPTION 48The 49.Fn getpid 50system call 51returns 52the process ID of 53the calling process. 54Though the ID is guaranteed to be unique, it should 55.Em NOT 56be used for constructing temporary file names, for 57security reasons; see 58.Xr mkstemp 3 59instead. 60.Pp 61The 62.Fn getppid 63system call 64returns the process ID of the parent 65of the calling process. 66.Sh ERRORS 67The 68.Fn getpid 69and 70.Fn getppid 71system calls are always successful, and no return value is reserved to 72indicate an error. 73.Sh SEE ALSO 74.Xr fork 2 , 75.Xr getpgrp 2 , 76.Xr kill 2 , 77.Xr setpgid 2 , 78.Xr setsid 2 , 79.Xr exec 3 80.Sh STANDARDS 81The 82.Fn getpid 83and 84.Fn getppid 85system calls are expected to conform to 86.St -p1003.1-90 . 87.Sh HISTORY 88The 89.Fn getpid 90function appeared in 91.At v7 . 92