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.Dd December 15, 2015 29.Dt GETPID 2 30.Os 31.Sh NAME 32.Nm getpid , 33.Nm getppid 34.Nd get parent or calling process identification 35.Sh LIBRARY 36.Lb libc 37.Sh SYNOPSIS 38.In unistd.h 39.Ft pid_t 40.Fn getpid void 41.Ft pid_t 42.Fn getppid void 43.Sh DESCRIPTION 44The 45.Fn getpid 46system call 47returns 48the process ID of 49the calling process. 50Though the ID is guaranteed to be unique, it should 51.Em NOT 52be used for constructing temporary file names, for 53security reasons; see 54.Xr mkstemp 3 55instead. 56.Pp 57The 58.Fn getppid 59system call 60returns the process ID of the parent 61of the calling process. 62.Sh ERRORS 63The 64.Fn getpid 65and 66.Fn getppid 67system calls are always successful, and no return value is reserved to 68indicate an error. 69.Sh SEE ALSO 70.Xr fork 2 , 71.Xr getpgrp 2 , 72.Xr kill 2 , 73.Xr setpgid 2 , 74.Xr setsid 2 , 75.Xr exec 3 76.Sh STANDARDS 77The 78.Fn getpid 79and 80.Fn getppid 81system calls are expected to conform to 82.St -p1003.1-90 . 83.Sh HISTORY 84The 85.Fn getpid 86function appeared in 87.At v7 . 88