From: Matthew Booth <mbooth@redhat.com>
Date: Fri, 1 Oct 2010 16:23:11 +0000 (+0100)
Subject: Send usage output to stdout or stderr depending on context.
X-Git-Tag: 2.10~3
X-Git-Url: http://git.annexia.org/?p=febootstrap.git;a=commitdiff_plain;h=f6e12eccb65bef3eb57631e54199d8b1610e7c5c

Send usage output to stdout or stderr depending on context.

If usage information is displayed because of an error, it should go to stderr.
If it is displayed because the -h option was given it should go to stdout.
---

diff --git a/helper/main.c b/helper/main.c
index 4afcb24..f194008 100644
--- a/helper/main.c
+++ b/helper/main.c
@@ -51,9 +51,10 @@ static const struct option long_options[] = {
 };
 
 static void
-usage (const char *progname)
+usage (FILE *f, const char *progname)
 {
-  printf ("%s: build the supermin appliance on the fly\n"
+  fprintf (f,
+          "%s: build the supermin appliance on the fly\n"
           "\n"
           "Usage:\n"
           "  %s [-options] inputs [...] host_cpu kernel initrd\n"
@@ -99,7 +100,7 @@ main (int argc, char *argv[])
 
     switch (c) {
     case HELP_OPTION:
-      usage (argv[0]);
+      usage (stdout, argv[0]);
       exit (EXIT_SUCCESS);
 
     case 'f':
@@ -119,7 +120,7 @@ main (int argc, char *argv[])
       exit (EXIT_SUCCESS);
 
     default:
-      usage (argv[0]);
+      usage (stderr, argv[0]);
       exit (EXIT_FAILURE);
     }
   }