renice: rewrite usage()

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/renice.c b/sys-utils/renice.c
index e45c5aed8076af22065a6edf1d68bd86db5a28b9..4af6f04b31436d6c74220d9d4df9c92e87812e7a 100644 (file)
--- a/sys-utils/renice.c
+++ b/sys-utils/renice.c
@@ -49,16 +49,27 @@
 
 static int donice(int,int,int);
 
-static void usage(int rc)
+static int __attribute__((__noreturn__)) usage(FILE *out)
 {
-       printf( _("\nUsage:\n"
-               " renice [-n] priority [-p|--pid] pid  [... pid]\n"
-               " renice [-n] priority  -g|--pgrp pgrp [... pgrp]\n"
-               " renice [-n] priority  -u|--user user [... user]\n"
-               " renice -h | --help\n"
-               " renice -v | --version\n\n"));
-
-       exit(rc);
+       fprintf(out, _(
+               "\nUsage:\n"
+               " %1$s [-n] <priority> [-p] <pid> [<pid>  ...]\n"
+               " %1$s [-n] <priority>  -g <pgrp> [<pgrp> ...]\n"
+               " %1$s [-n] <priority>  -u <user> [<user> ...]\n"),
+               program_invocation_short_name);
+
+       fprintf(out, _(
+               "\nOptions:\n"
+               " -g, --pgrp <id>        interpret as process group ID\n"
+               " -h, --help             print help\n"
+               " -n, --priority <num>   set the nice increment value\n"
+               " -p, --pid <id>         force to be interpreted as process ID\n"
+               " -u, --user <name|id>   interpret as username or user ID\n"
+               " -v, --version          print version\n"));
+
+       fprintf(out, _("\nFor more information see renice(1).\n"));
+
+       exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
 }
 
 /*
@@ -83,7 +94,7 @@ main(int argc, char **argv)
        if (argc == 1) {
                if (strcmp(*argv, "-h") == 0 ||
                    strcmp(*argv, "--help") == 0)
-                       usage(EXIT_SUCCESS);
+                       usage(stdout);
 
                if (strcmp(*argv, "-v") == 0 ||
                    strcmp(*argv, "--version") == 0) {
@@ -93,7 +104,7 @@ main(int argc, char **argv)
        }
 
        if (argc < 2)
-               usage(EXIT_FAILURE);
+               usage(stderr);
 
        if (strcmp(*argv, "-n") == 0 || strcmp(*argv, "--priority") == 0) {
                argc--;
@@ -102,7 +113,7 @@ main(int argc, char **argv)
 
        prio = strtol(*argv, &endptr, 10);
        if (*endptr)
-               usage(EXIT_FAILURE);
+               usage(stderr);
 
        argc--;
        argv++;