upkg: Print usage info on stdout/stderr as appropriate.

diff --git a/src/upkg.c b/src/upkg.c
index 12dc09ea024eec77d3c79ed8a4457090e8db8662..62f99365dcc28e5c2747e4f580a69d8a93fa8703 100644 (file)
--- a/src/upkg.c
+++ b/src/upkg.c
@@ -57,14 +57,14 @@ There is NO WARRANTY, to the extent permitted by law."
        );
 }
 
-void print_usage(void)
+void print_usage(FILE *f)
 {
-       printf("Usage: %s [options] package\n", progname);
+       fprintf(f, "Usage: %s [options] package\n", progname);
 }
 
 void print_help(void)
 {
-       print_usage();
+       print_usage(stdout);
        puts("Detailed help coming soon.  Until then, I'll just list my options.");
        for (unsigned i = 0; lopts[i].name; i++) {
                const struct option *o = &lopts[i];
@@ -175,13 +175,13 @@ int main(int argc, char **argv)
                        print_help();
                        return EXIT_SUCCESS;
                default:
-                       print_usage();
+                       print_usage(stderr);
                        return EXIT_FAILURE;
                }
        }
 
        if (argv[optind] == NULL) {
-               print_usage();
+               print_usage(stderr);
                return EXIT_FAILURE;
        }