/*++ /* NAME /* fifo_open 1 /* SUMMARY /* fifo client test program /* SYNOPSIS /* fifo_open /* DESCRIPTION /* fifo_open creates a FIFO, then attempts to open it for writing /* with non-blocking mode enabled. According to the POSIX standard /* the open should succeed. /* DIAGNOSTICS /* Problems are reported to the standard error stream. /* LICENSE /* .ad /* .fi /* The Secure Mailer license must be distributed with this software. /* AUTHOR(S) /* Wietse Venema /* IBM T.J. Watson Research /* P.O. Box 704 /* Yorktown Heights, NY 10598, USA /*--*/ #include #include #include #include #include #include #define FIFO_PATH "test-fifo" #define perrorexit(s) { perror(s); exit(1); } static void cleanup(void) { printf("Removing fifo %s...\n", FIFO_PATH); if (unlink(FIFO_PATH)) perrorexit("unlink"); printf("Done.\n"); } static void stuck(int unused_sig) { printf("Non-blocking, write-only open of FIFO blocked\n"); cleanup(); exit(1); } int main(int unused_argc, char **unused_argv) { (void) unlink(FIFO_PATH); printf("Creating fifo %s...\n", FIFO_PATH); if (mkfifo(FIFO_PATH, 0600) < 0) perrorexit("mkfifo"); signal(SIGALRM, stuck); alarm(5); printf("Opening fifo %s, non-blocking, write-only mode...\n", FIFO_PATH); if (open(FIFO_PATH, O_WRONLY | O_NONBLOCK, 0) < 0) { perror("open"); cleanup(); exit(1); } printf("Non-blocking, write-only open of FIFO succeeded\n"); cleanup(); exit(0); }