Unify parse_argv style

getopt is usually good at printing out a nice error message when
commandline options are invalid. It distinguishes between an unknown
option and a known option with a missing arg. It is better to let it
do its job and not use opterr=0 unless we actually want to suppress
messages. So remove opterr=0 in the few places where it wasn't really
useful.

When an error in options is encountered, we should not print a lengthy
help() and overwhelm the user, when we know precisely what is wrong
with the commandline. In addition, since help() prints to stdout, it
should not be used except when requested with -h or --help.

Also, simplify things here and there.

1 files changed, 19 insertions, 13 deletions

diff --git a/src/bootchart/bootchart.c b/src/bootchart/bootchart.c
index 5683025b19..c0e176da9b 100644
--- a/src/bootchart/bootchart.c
+++ b/src/bootchart/bootchart.c
@@ -163,7 +163,7 @@ static void help(void) {
                 DEFAULT_INIT);
 }
 
-static int parse_args(int argc, char *argv[]) {
+static int parse_argv(int argc, char *argv[]) {
         static const struct option options[] = {
                 {"rel",           no_argument,        NULL,  'r'},
                 {"freq",          required_argument,  NULL,  'f'},
@@ -180,12 +180,14 @@ static int parse_args(int argc, char *argv[]) {
                 {"entropy",       no_argument,        NULL,  'e'},
                 {}
         };
-        int c;
+        int c, r;
 
-        while ((c = getopt_long(argc, argv, "erpf:n:o:i:FCchx:y:", options, NULL)) >= 0) {
-                int r;
+        if (getpid() == 1)
+                opterr = 0;
 
+        while ((c = getopt_long(argc, argv, "erpf:n:o:i:FCchx:y:", options, NULL)) >= 0)
                 switch (c) {
+
                 case 'r':
                         arg_relative = true;
                         break;
@@ -238,18 +240,22 @@ static int parse_args(int argc, char *argv[]) {
                         break;
                 case 'h':
                         help();
-                        exit (EXIT_SUCCESS);
+                        return 0;
+                case '?':
+                        if (getpid() != 1)
+                                return -EINVAL;
+                        else
+                                return 0;
                 default:
-                        break;
+                        assert_not_reached("Unhandled option code.");
                 }
-        }
 
-        if (arg_hz <= 0.0) {
-                fprintf(stderr, "Error: Frequency needs to be > 0\n");
+        if (arg_hz <= 0) {
+                log_error("Frequency needs to be > 0");
                 return -EINVAL;
         }
 
-        return 0;
+        return 1;
 }
 
 static void do_journal_append(char *file) {
@@ -314,9 +320,9 @@ int main(int argc, char *argv[]) {
 
         parse_conf();
 
-        r = parse_args(argc, argv);
-        if (r < 0)
-                return EXIT_FAILURE;
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
 
         /*
          * If the kernel executed us through init=/usr/lib/systemd/systemd-bootchart, then