MINOR: halog: add some help on the command line

diff --git a/contrib/halog/halog.c b/contrib/halog/halog.c
index 40852aec0c3942df04987e98d24c00a528c8a5a2..250623d8275989fefd555df1e81259f8c8852931 100644 (file)
--- a/contrib/halog/halog.c
+++ b/contrib/halog/halog.c
@@ -123,19 +123,58 @@ void filter_graphs(const char *accept_field, const char *time_field, struct time
 void filter_output_line(const char *accept_field, const char *time_field, struct timer **tptr);
 void filter_accept_holes(const char *accept_field, const char *time_field, struct timer **tptr);
 
-void die(const char *msg)
+void usage(FILE *output, const char *msg)
 {
-       fprintf(stderr,
+       fprintf(output,
                "%s"
-               "Usage: halog [-q] [-c] [-v] {-gt|-pct|-st|-tc|-srv|-u|-uc|-ue|-ua|-ut|-uao|-uto}\n"
+               "Usage: halog [-h|--help] for long help\n"
+               "       halog [-q] [-c] [-v] {-gt|-pct|-st|-tc|-srv|-u|-uc|-ue|-ua|-ut|-uao|-uto}\n"
                "       [-s <skip>] [-e|-E] [-H] [-rt|-RT <time>] [-ad <delay>] [-ac <count>]\n"
                "       [-Q|-QS] [-tcn|-TCN <termcode>] [ -hs|-HS [min][:[max]] ] < log\n"
                "\n",
                msg ? msg : ""
                );
+}
+
+void die(const char *msg)
+{
+       usage(stderr, msg);
        exit(1);
 }
 
+void help()
+{
+       usage(stdout, NULL);
+       printf(
+              "Input filters (several filters may be combined) :\n"
+              " -H                      only match lines containing HTTP logs (ignore TCP)\n"
+              " -E                      only match lines without any error (no 5xx status)\n"
+              " -e                      only match lines with errors (status 5xx or negative)\n"
+              " -rt|-RT <time>          only match response times larger|smaller than <time>\n"
+              " -Q|-QS                  only match queued requests (any queue|server queue)\n"
+              " -tcn|-TCN <code>        only match requests with/without termination code <code>\n"
+              " -hs|-HS <[min][:][max]> only match requests with HTTP status codes within/not\n"
+              "                         within min..max. Any of them may be omitted. Exact\n"
+              "                         code is checked for if no ':' is specified.\n"
+              "Modifiers\n"
+              " -v                      invert the input filtering condition\n"
+              " -q                      don't report errors/warnings\n"
+              "\n"
+              "Output filters - only one may be used at a time\n"
+              " -c    only report the number of lines that would have been printed\n"
+              " -pct  output connect and response times percentiles\n"
+              " -st   output number of requests per HTTP status code\n"
+              " -tc   output number of requests per termination code (2 chars)\n"
+              " -srv  output statistics per server (time, requests, errors)\n"
+              " -u*   output statistics per URL (time, requests, errors)\n"
+              "       Additional characters indicate the output sorting key :\n"
+              "       -u : by URL, -uc : request count, -ue : error count\n"
+              "       -ua : average response time, -uto : average total time\n"
+              "       -uao, -uto: average times computed on valid ('OK') requests\n"
+              );
+       exit(0);
+}
+
 
 /* return pointer to first char not part of current field starting at <p>. */
 
@@ -600,6 +639,8 @@ int main(int argc, char **argv)
                                die("Fatal: missing output file name.\n");
                        output_file = argv[1];
                }
+               else if (strcmp(argv[0], "-h") == 0 || strcmp(argv[0], "--help") == 0)
+                       help();
                argc--;
                argv++;
        }