@node sigprocmask @section @code{sigprocmask} @findex sigprocmask POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigprocmask.html} Gnulib module: sigprocmask Portability problems fixed by Gnulib: @itemize @item This function is missing on some platforms: mingw, MSVC 14. @end itemize Portability problems not fixed by Gnulib: @itemize @item In case of failure, the return value is wrong on some platforms: NetBSD 9.0 when libpthread is in use. @end itemize Note: Although @code{sigprocmask} officially has undefined behaviour in multi-threaded programs, in practice it is essentially equivalent to @code{pthread_sigmask}, with only a difference regarding the error return convention. It's simpler to use @code{sigprocmask}, since it does not require linking with @code{-lpthread} on some platforms: glibc, NetBSD, OpenBSD, AIX, IRIX.