pi-blaster.c: handle dont-daemonize long flag

The help text for pi-blaster indicates that `-D` is equivalent to
`--daemon`, however there is no option handling for the long flag
version. This commit adds a `--foreground` flag and deprecates the
confusing `-D` option.

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>

Dockerfile

@@ -8,4 +8,4 @@ RUN make
 
 FROM arm32v6/alpine
 COPY --from=builder /pi-blaster/pi-blaster .
-CMD ["./pi-blaster", "-D"]
+CMD ["./pi-blaster", "--foreground"]

README.md

@@ -210,7 +210,7 @@ active-low signal.
 
 To keep pi-blaster running in the foreground without running as a daemon use:
 
-    -D
+    --foreground
 
 To view help or version information, use:
 
@@ -258,6 +258,7 @@ about this project on [our blog][blog].
 * Thomas McVay (https://github.com/ThomasMcVay)
 * Pavle Petrovic (https://github.com/pavlecc)
 * arendruni (https://github.com/arendruni)
+* Lucas Servén Marín (https://github.com/squat)
 
 ## Want to support this project?
 

pi-blaster.c

@@ -928,6 +928,7 @@ void parseargs(int argc, char **argv)
   static struct option longopts[] =
   {
     {"help", no_argument, 0, 'h'},
+    {"foreground", no_argument, 0, 'f'},
     {"gpio", required_argument, 0, 'g'},
     {"invert", no_argument, 0, 'i'},
     {"pcm", no_argument, 0, 'p'},
@@ -938,7 +939,7 @@ void parseargs(int argc, char **argv)
   while (1)
   {
     index = 0;
-    c = getopt_long(argc, argv, "Dg:hipv", longopts, &index);
+    c = getopt_long(argc, argv, "Dfg:hipv", longopts, &index);
 
     if (c == -1)
       break;
@@ -952,17 +953,19 @@ void parseargs(int argc, char **argv)
     case 'h':
       fprintf(stderr, "%s version %s\n", argv[0], VERSION);
       fprintf(stderr, "Usage: %s [-hDgipv]\n"
-        "-h (--help)    - this information\n"
-        "-D (--daemon)  - Don't daemonize\n"
-        "-g (--gpio)    - comma separated list of GPIOs to use\n"
-        "                 If omitted, default is \"4,17,18,27,21,22,23,24,25\"\n"
-        "-i (--invert)  - invert pin output (pulse LOW)\n"
-        "-p (--pcm)     - use pcm for dmascheduling\n"
-        "-v (--version) - version information\n"
+        "-h (--help)       - this information\n"
+        "-D                - Don't daemonize (deprecated: use --foreground instead)\n"
+        "-f (--foreground) - run in the foreground\n"
+        "-g (--gpio)       - comma separated list of GPIOs to use\n"
+        "                    If omitted, default is \"4,17,18,27,21,22,23,24,25\"\n"
+        "-i (--invert)     - invert pin output (pulse LOW)\n"
+        "-p (--pcm)        - use pcm for dmascheduling\n"
+        "-v (--version)    - version information\n"
         , argv[0]);
       exit(-1);
 
     case 'D':
+    case 'f':
       daemonize = 0;
       break;
 
@@ -1103,4 +1106,4 @@ int main(int argc, char **argv) {
   go_go_go();
 
   return 0;
-}
+}