'\" t .\" Copyright (c) 2008 Linux Foundation, written by Michael Kerrisk .\" .\" .\" SPDX-License-Identifier: Linux-man-pages-copyleft .\" .TH pthread_equal 3 2023-10-31 "Linux man-pages 6.7" .SH NAME pthread_equal \- compare thread IDs .SH LIBRARY POSIX threads library .RI ( libpthread ", " \-lpthread ) .SH SYNOPSIS .nf .B #include .P .BI "int pthread_equal(pthread_t " t1 ", pthread_t " t2 ); .fi .SH DESCRIPTION The .BR pthread_equal () function compares two thread identifiers. .SH RETURN VALUE If the two thread IDs are equal, .BR pthread_equal () returns a nonzero value; otherwise, it returns 0. .SH ERRORS This function always succeeds. .SH ATTRIBUTES For an explanation of the terms used in this section, see .BR attributes (7). .TS allbox; lbx lb lb l l l. Interface Attribute Value T{ .na .nh .BR pthread_equal () T} Thread safety MT-Safe .TE .SH STANDARDS POSIX.1-2008. .SH HISTORY POSIX.1-2001. .SH NOTES The .BR pthread_equal () function is necessary because thread IDs should be considered opaque: there is no portable way for applications to directly compare two .I pthread_t values. .SH SEE ALSO .BR pthread_create (3), .BR pthread_self (3), .BR pthreads (7)