Finally use __progname, err(3) and warn(3).

That's more readable and less error-prone than fumbling around
with argv[0], fprintf(3), strerror(3), perror(3), and exit(3).

It's a bad idea to boycott good interfaces merely because standards
committees ignore them.  Instead, let's provide compatibility modules
for archaic systems (like commercial Solaris) that still don't have
them.  The compat module has an UCB Copyright (c) 1993...

1 files changed, 28 insertions, 0 deletions

diff --git a/test-err.c b/test-err.c
new file mode 100644
index 00000000..d17e0f0d
--- /dev/null
+++ b/test-err.c
@@ -0,0 +1,28 @@
+/*	$Id: test-err.c,v 1.1 2015/10/11 21:12:55 schwarze Exp $	*/
+/*
+ * Copyright (c) 2015 Ingo Schwarze <schwarze@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <err.h>
+
+int
+main(void)
+{
+	warnx("%d. warnx", 1);
+	warn("%d. warn", 2);
+	err(0, "%d. err", 3);
+	/* NOTREACHED */
+	return 1;
+}