/* $OpenBSD: fcntl_dup.c,v 1.2 2003/07/31 21:48:08 deraadt Exp $ */ /* * Written by Artur Grabowski 2002 Public Domain. */ #include #include #include #include #include int main(int argc, char *argv[]) { int orgfd, fd1, fd2; char temp[] = "/tmp/dup2XXXXXXXXX"; if ((orgfd = mkstemp(temp)) < 0) err(1, "mkstemp"); remove(temp); if (ftruncate(orgfd, 1024) != 0) err(1, "ftruncate"); if ((fd1 = dup(orgfd)) < 0) err(1, "dup"); /* Set close-on-exec */ if (fcntl(fd1, F_SETFD, 1) != 0) err(1, "fcntl(F_SETFD)"); if ((fd2 = fcntl(fd1, F_DUPFD)) < 0) err(1, "fcntl(F_DUPFD)"); /* Test 2: Was close-on-exec cleared? */ if (fcntl(fd2, F_GETFD) != 0) errx(1, "fcntl(F_DUPFD) didn't clear close-on-exec"); return 0; }