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.\" 3. 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.\" 30.Dd December 15, 2015 31.Dt GETPID 2 32.Os 33.Sh NAME 34.Nm getpid , 35.Nm getppid 36.Nd get parent or calling process identification 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In unistd.h 41.Ft pid_t 42.Fn getpid void 43.Ft pid_t 44.Fn getppid void 45.Sh DESCRIPTION 46The 47.Fn getpid 48system call 49returns 50the process ID of 51the calling process. 52Though the ID is guaranteed to be unique, it should 53.Em NOT 54be used for constructing temporary file names, for 55security reasons; see 56.Xr mkstemp 3 57instead. 58.Pp 59The 60.Fn getppid 61system call 62returns the process ID of the parent 63of the calling process. 64.Sh ERRORS 65The 66.Fn getpid 67and 68.Fn getppid 69system calls are always successful, and no return value is reserved to 70indicate an error. 71.Sh SEE ALSO 72.Xr fork 2 , 73.Xr getpgrp 2 , 74.Xr kill 2 , 75.Xr setpgid 2 , 76.Xr setsid 2 , 77.Xr exec 3 78.Sh STANDARDS 79The 80.Fn getpid 81and 82.Fn getppid 83system calls are expected to conform to 84.St -p1003.1-90 . 85.Sh HISTORY 86The 87.Fn getpid 88function appeared in 89.At v7 . 90