lsfd: introduce -H, --list-columns option for making help messages short

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/misc-utils/lsfd.1.adoc b/misc-utils/lsfd.1.adoc
index 0f866f4cc207137454ce9939dc1fe5bd29653d74..b2a6aa5322f732bcffc7d26010e0159fdb07d95d 100644 (file)
--- a/misc-utils/lsfd.1.adoc
+++ b/misc-utils/lsfd.1.adoc
@@ -110,6 +110,9 @@ only for *lsfd* developers.
 *--dump-counters*::
 Dump the definition of counters used in *--summary* output.
 
+*-H*, *--list-columns*::
+List available columns that you can specify at *--output* option.
+
 include::man-common/help-version.adoc[]
 
 == OUTPUT COLUMNS

diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index 4c19f7e499f39b8c17de89639e1ab9dbc07e91ef..49f5863e07f06755164986e031be7a7e224df54d 100644 (file)
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -1578,10 +1578,23 @@ static void collect_processes(struct lsfd_control *ctl, const pid_t pids[], int
        ul_unref_path(pc);
 }
 
+static void __attribute__((__noreturn__)) list_colunms(FILE *out)
+{
+       fprintf(out, USAGE_COLUMNS);
+       for (size_t i = 0; i < ARRAY_SIZE(infos); i++)
+               fprintf(out, " %20s  %-10s%s\n", infos[i].name,
+                       infos[i].json_type == SCOLS_JSON_STRING?  "<string>":
+                       infos[i].json_type == SCOLS_JSON_ARRAY_STRING?  "<string>":
+                       infos[i].json_type == SCOLS_JSON_ARRAY_NUMBER?  "<string>":
+                       infos[i].json_type == SCOLS_JSON_NUMBER?  "<number>":
+                       "<boolean>",
+                       _(infos[i].help));
+       exit(EXIT_SUCCESS);
+}
+
 static void __attribute__((__noreturn__)) usage(void)
 {
        FILE *out = stdout;
-       size_t i;
 
        fputs(USAGE_HEADER, out);
        fprintf(out, _(" %s [options]\n"), program_invocation_short_name);
@@ -1602,19 +1615,9 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(_("     --summary[=<when>]       print summary information (only, append, or never)\n"), out);
 
        fputs(USAGE_SEPARATOR, out);
+       fputs(_(" -H, --list-columns           list the available columns\n"), out);
        fprintf(out, USAGE_HELP_OPTIONS(30));
 
-       fprintf(out, USAGE_COLUMNS);
-
-       for (i = 0; i < ARRAY_SIZE(infos); i++)
-               fprintf(out, " %16s  %-10s%s\n", infos[i].name,
-                       infos[i].json_type == SCOLS_JSON_STRING?  "<string>":
-                       infos[i].json_type == SCOLS_JSON_ARRAY_STRING?  "<string>":
-                       infos[i].json_type == SCOLS_JSON_ARRAY_NUMBER?  "<string>":
-                       infos[i].json_type == SCOLS_JSON_NUMBER?  "<number>":
-                       "<boolean>",
-                       _(infos[i].help));
-
        fprintf(out, USAGE_MAN_TAIL("lsfd(1)"));
 
        exit(EXIT_SUCCESS);
@@ -1926,6 +1929,7 @@ int main(int argc, char *argv[])
                { "summary",    optional_argument, NULL,  OPT_SUMMARY },
                { "counter",    required_argument, NULL, 'C' },
                { "dump-counters",no_argument, NULL, OPT_DUMP_COUNTERS },
+               { "list-columns",no_argument, NULL, 'H' },
                { NULL, 0, NULL, 0 },
        };
 
@@ -1934,7 +1938,7 @@ int main(int argc, char *argv[])
        textdomain(PACKAGE);
        close_stdout_atexit();
 
-       while ((c = getopt_long(argc, argv, "no:JrVhluQ:p:i::C:s", longopts, NULL)) != -1) {
+       while ((c = getopt_long(argc, argv, "no:JrVhluQ:p:i::C:sH", longopts, NULL)) != -1) {
                switch (c) {
                case 'n':
                        ctl.noheadings = 1;
@@ -2006,6 +2010,8 @@ int main(int argc, char *argv[])
                        print_version(EXIT_SUCCESS);
                case 'h':
                        usage();
+               case 'H':
+                       list_colunms(stdout);
                default:
                        errtryhelp(EXIT_FAILURE);
                }