tree-wide: add clickable man page link to all --help texts

This is a bit like the info link in most of GNU's --help texts, but we
don't do info but man pages, and we make them properly clickable on
terminal supporting that, because awesome.

I think it's generally advisable to link up our (brief) --help texts and
our (more comprehensive) man pages a bit, so this should be an easy and
straight-forward way to do it.

1 files changed, 17 insertions, 5 deletions

diff --git a/src/journal-remote/journal-gatewayd.c b/src/journal-remote/journal-gatewayd.c
index 9e77e314ff..88e65ed905 100644
--- a/src/journal-remote/journal-gatewayd.c
+++ b/src/journal-remote/journal-gatewayd.c
@@ -22,6 +22,7 @@
 #include "os-util.h"
 #include "parse-util.h"
 #include "sigbus.h"
+#include "terminal-util.h"
 #include "util.h"
 
 #define JOURNAL_WAIT_TIMEOUT (10*USEC_PER_SEC)
@@ -859,7 +860,14 @@ static int request_handler(
         return mhd_respond(connection, MHD_HTTP_NOT_FOUND, "Not found.");
 }
 
-static void help(void) {
+static int help(void) {
+        _cleanup_free_ char *link = NULL;
+        int r;
+
+        r = terminal_urlify_man("systemd-journal-gatewayd.service", "8", &link);
+        if (r < 0)
+                return log_oom();
+
         printf("%s [OPTIONS...] ...\n\n"
                "HTTP server for journal events.\n\n"
                "  -h --help           Show this help\n"
@@ -867,8 +875,13 @@ static void help(void) {
                "     --cert=CERT.PEM  Server certificate in PEM format\n"
                "     --key=KEY.PEM    Server key in PEM format\n"
                "     --trust=CERT.PEM Certificate authority certificate in PEM format\n"
-               "  -D --directory=PATH Serve journal files in directory\n",
-               program_invocation_short_name);
+               "  -D --directory=PATH Serve journal files in directory\n"
+               "\nSee the %s for details.\n"
+               , program_invocation_short_name
+               , link
+        );
+
+        return 0;
 }
 
 static int parse_argv(int argc, char *argv[]) {
@@ -899,8 +912,7 @@ static int parse_argv(int argc, char *argv[]) {
                 switch(c) {
 
                 case 'h':
-                        help();
-                        return 0;
+                        return help();
 
                 case ARG_VERSION:
                         return version();