Add --help and --version command line switches

diff --git a/Makefile b/Makefile
index 0bd9893c2957d1125dc30e45ef5b89db4f2ba733..6c04adf52a3fd4acfe062a3ce187b6d5e2e19728 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-CFLAGS = -O2 -Wall -g
+CFLAGS = -O2 -Wall -g -DSTERM_VERSION='"$(shell git describe)"'
 
 ifneq ($(findstring HAVE_LOCKDEV,$(CFLAGS)),)
 LDLIBS = -llockdev

diff --git a/sterm.c b/sterm.c
index 368256c60da63160d927db43e833761392ad4269..13701e7a777acc6c59f49e5c51de29ea943f3819 100644 (file)
--- a/sterm.c
+++ b/sterm.c
@@ -1,7 +1,7 @@
 /*
  * Simple serial terminal
  *
- * Copyright 2014, 2015, 2016, 2017, 2019, 2020 Michal Sojka <sojkam1@fel.cvut.cz>
+ * Copyright 2014, 2015, 2016, 2017, 2019, 2020, 2021 Michal Sojka <sojkam1@fel.cvut.cz>
  *
  * This program is free software: you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -155,26 +155,29 @@ void exit_on_escapeseq(const char *buf, int len)
        }
 }
 
-void usage(const char* argv0)
+void print_usage_and_exit(const char* argv0, int exit_code)
 {
-       fprintf(stderr, "Usage: %s [options] <device>\n", argv0);
-       fprintf(stderr,
+       fprintf(exit_code == 0 ? stdout : stderr, "Usage: %s [options] <device>\n", argv0);
+       fprintf(exit_code == 0 ? stdout : stderr,
                "Options:\n"
                "  -b <duration> send break signal\n"
                "  -c        enter command mode\n"
                "  -d[PULSE] make pulse on DTR\n"
                "  -e        ignore '~.' escape sequence\n"
+               "  -h, --help  print help and exit\n"
                "  -n        do not switch stdin TTY to raw mode\n"
                "  -r[PULSE] make pulse on RTS\n"
                "  -s <baudrate>\n"
                "  -t <ms>   minimum delay between two transmitted characters\n"
                "  -v        verbose mode\n"
+               "  -V, --version  print version and exit\n"
                "\n"
                "PULSE is a number specifying the pulse. Absolute value defines the\n"
                "length of the pulse in milliseconds, sign determines the polarity of\n"
                "the pulse. Alternatively, PULSE can be either '+' or '-', which\n"
-               "corresponds to +1 or -1.\n"
+               "corresponds to '+1' or '-1'.\n"
                );
+       exit(exit_code);
 }
 
 void pulse(int fd, int dtr, int rts)
@@ -255,7 +258,14 @@ int main(int argc, char *argv[])
                atexit(restore_stdin_term);
        }
 
-       while ((opt = getopt(argc, argv, "b:cnd::er::s:vt:")) != -1) {
+       static struct option long_options[] = {
+               {"help",    no_argument,       0,  'h' },
+               {"version", no_argument,       0,  'V' },
+               {0,         0,                 0,  0   }
+       };
+
+       while ((opt = getopt_long(argc, argv, "b:cnd::er::s:vVt:h",
+                                 long_options, NULL)) != -1) {
                switch (opt) {
                case 'b': break_dur = atoi(optarg); break;
                case 'c': cmd = true; break;
@@ -311,9 +321,13 @@ int main(int argc, char *argv[])
                case 'v':
                        verbose = true;
                        break;
+               case 'V':
+                       printf("sterm version %s\n", strlen(STERM_VERSION) > 0 ? STERM_VERSION : "unknown");
+                       return 0;
+               case 'h':
+                       /* fallthrough */
                default: /* '?' */
-                       usage(argv[0]);
-                       exit(1);
+                       print_usage_and_exit(argv[0], opt == 'h' ? 0 : 1);
                }
        }
 
@@ -322,8 +336,7 @@ int main(int argc, char *argv[])
 
        if (!dev) {
                fprintf(stderr, "No device specified\n");
-               usage(argv[0]);
-               exit(1);
+               print_usage_and_exit(argv[0], 1);
        }
 
        signal(SIGINT, sighandler);