added major C improvements

   * use libinih to read config file
   * handle SIGPIPE gracefully (when a trayicon exits)
   * exit when both trayicons have exited

I wanted to try using libini-config5 but it was not documented at all,
and I need useful examples.

3 files changed, 204 insertions, 97 deletions

diff --git a/.gitignore b/.gitignore
index 1c3ea63..f63ec58 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,4 @@ debian
 status
 *.o
 old/
+keyboard-leds-trayicons
diff --git a/experimental/Makefile b/experimental/Makefile
index 2bb7fca..17c9660 100644
--- a/experimental/Makefile
+++ b/experimental/Makefile
@@ -20,39 +20,63 @@ CC = gcc
 CXXFLAGS = -g -std=c++17 -Wall -Weffc++ -Wextra -Wsign-conversion -Werror
 CCFLAGS = -g -Wno-deprecated-declarations \
 	`pkg-config --cflags x11` \
-	`pkg-config --cflags gtk+-3.0`
+	`pkg-config --cflags gtk+-3.0` \
+	`pkg-config --cflags inih` \
+	$(DEBUGFLAGS)
+CCFLAGS2 = -g -Wsign-conversion -Werror \
+	`pkg-config --cflags inih`
 
 # to remove all debug symbols: -s
 # to add full debug symbols: -g
 LDFLAGS = -g \
 	`pkg-config --libs x11` \
-	`pkg-config --libs gtk+-3.0`
+	`pkg-config --libs gtk+-3.0` \
+	`pkg-config --libs inih`
+LDFLAGS2 = -g \
+	`pkg-config --libs inih`
+
+ifneq (,$(DEBUG))
+CCFLAGS+=-DDEBUG=1
+endif
 
 src = $(wildcard *.c)
+src := $(filter-out readconf.c, $(src))
+#src2 = $(wildcard read*.c)
 obj = $(src:.c=.o)
+#obj2 = $(src2:.c=.o)
 
 BUILD_DIR ?= .
 
-OUTEXE = status
+OUTEXE = keyboard-leds-trayicons
+#OUTEXE2 = readconf
 
-all: $(OUTEXE)
+all: $(OUTEXE) $(OUTEXE2)
+#all: $(OUTEXE)
 
 $(obj):
 
+#$(obj2):
+
 $(BUILD_DIR)/%.o: %.c
 	$(CC) -c $(CCFLAGS) -o $@ $<
 
+#$(BUILD_DIR)/readconf.o: readconf.c
+#	$(CC) -c $(CCFLAGS2) -o $@ $<
+
 # link
 $(OUTEXE): $(obj)
 	$(CC) -o $@ $^ $(LDFLAGS)
 
+#$(OUTEXE2): $(obj2)
+#	$(CC) -o $@ $^ $(LDFLAGS2)
+
 .PHONY: clean cleanall list
 
 list:
 	@$(MAKE) -pRrq -f $(lastword $(MAKEFILE_LIST)) : 2>/dev/null | ${awkbin} -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' | ${sortbin} | ${grepbin} -E -v -e '^[^[:alnum:]]' -e '^$@$$' -e '\.(cp*|o)'
 
 clean:
-	rm -f $(obj)
+	rm -f $(obj) $(obj2)
 
 cleanall:
-	rm -f $(obj) $(OUTEXE)
+	rm -f $(obj) $(OUTEXE) $(obj2) $(OUTEXE2)
diff --git a/experimental/status.c b/experimental/keyboard-leds-trayicons.c
index f968af1..f2c6a4a 100644
--- a/experimental/status.c
+++ b/experimental/keyboard-leds-trayicons.c
@@ -1,5 +1,5 @@
 /*
- * File: status.c
+ * File: keyboard-leds-trayicons.c
  * Location: https://bgstack15.ddns.net/cgit/keyboard-leds-trayicons/
  * Author: bgstack15
  * Startdate: 2022-09-28-4 13:30
@@ -7,7 +7,6 @@
  * Title: Proof of Concept C utility for polling capslock and numlock
  * Purpose: Demonstrate these can be done in C, with the eventual goal of rewriting keyboard-leds-trayicons entirely in C to avoid the "sleep 0.75" in ps output
  * History:
- *    minimum viable product
  * Usage:
  * References:
  *    https://github.com/Cairo-Dock/cairo-dock-plug-ins/blob/master/keyboard-indicator/src/applet-xklavier.c#L124
@@ -18,15 +17,24 @@
  *    https://stackoverflow.com/questions/43326857/multiple-fork-in-c-program
  *    https://stackoverflow.com/questions/14173268/fifo-files-and-read-write
  *    https://ftp.gnu.org/old-gnu/Manuals/glibc-2.2.3/html_chapter/libc_15.html
- * Improvements:
- *    Write main keyboard-led-trayicons logic, which includes parsing config file (libconfig?)
- *    Write pipe connectivity to mktrayicon or integrate it entirely
  *    https://qnaplus.com/c-program-to-sleep-in-milliseconds/
- * Dependencies: libx11-dev
+ *    https://stackoverflow.com/questions/47107311/sending-signal-from-child-to-parent
+ *    https://stackoverflow.com/questions/108183/how-to-prevent-sigpipes-or-handle-them-properly
+ * Improvements:
+ *    Use getopts, -h, -c conffile, -d (debug)
+ *    fix all return values at end
+ * Dependencies: libx11-dev, libinih-dev, libgtk-3-dev
+ * Documentation:
+ *    features include:
+ *       operate when only one trayicon has exited
+ *       exit when both trayicons have exited
  */
+
 #include<ctype.h>
+#include<fcntl.h>
 #include<glib.h>
 #include<gtk/gtk.h>
+#include<ini.h>
 #include<stdio.h>
 #include<stdlib.h>
 #include<string.h>
@@ -34,8 +42,9 @@
 #include<unistd.h>
 #include<X11/XKBlib.h>
 #include<X11/Xlib.h>
-#include<fcntl.h>
+#include<signal.h>
 
+/* START inclusion of mktrayicon.c, 536 lines */
 /*
  * This function is made because it's needed to escape the '\' character
  * The basic code has been taken from the man pages of the strncpy function
@@ -620,6 +629,7 @@ int fmain(int argc, char **argv) {
   gtk_main();
   return 0;
 }
+/* STOP inclusion of mktrayicon.c */
 
 Display* dpy;
 
@@ -631,121 +641,193 @@ int get_indicator(Display* dpy, char* indicator) {
 	return st;
 }
 
+typedef struct {
+   const char* caps_on;
+   const char* caps_off;
+   const char* num_on;
+   const char* num_off;
+   int sleep_microseconds;
+   const char* caps_fifo;
+   const char* num_fifo;
+} configuration;
+
+// this should be configurable with -c parameter (getopts?)
+char* conffile = "/home/bgstack15/keyboard-leds-trayicons.conf";
+
+// slightly modified from example https://github.com/benhoyt/inih
+static int handler(void* user, const char* section, const char* name, const char* value) {
+   // KLT does not need section information at all.
+   configuration *pconfig = (configuration*)user;
+   #define MATCH(n, m, func) if (strcmp(name, n) == 0) { pconfig->m = func(value); }
+   MATCH("KLT_CAPS_ON_ICON", caps_on, strdup)
+   else MATCH("KLT_CAPS_OFF_ICON", caps_off, strdup)
+   else MATCH("KLT_NUM_ON_ICON", num_on, strdup)
+   else MATCH("KLT_NUM_OFF_ICON", num_off, strdup)
+   else MATCH("KLT_SLEEP_MICROSECONDS", sleep_microseconds, atoi)
+   else MATCH("KLT_CAPS_FIFO", caps_fifo, strdup)
+   else MATCH("KLT_NUM_FIFO", num_fifo, strdup)
+   else {
+      return 0; /* unknown section/name, error */
+   }
+   return 1;
+}
+
+char msg[1000];
+
+void *send_fifo_message(FILE *stream, const char *message) {
+#ifdef DEBUG
+   printf("Msg: %s", message);
+#endif
+   int response = fprintf(stream, message);
+#ifdef DEBUG
+   printf("response: %d\n", response);
+#endif
+   fflush(stream);
+}
+
+void *send_fifo_icon_message(FILE *stream, const char *iconfile) {
+   // msg is global buffer for messages to dump into a pipe
+   strcpy(msg, "i ");
+   strcat(msg, iconfile);
+   strcat(msg, "\n"); // very important for mktrayicon
+   send_fifo_message(stream, msg);
+}
+
+int closed_icons = 0;
+void sig_usr(int signo) {
+   if(signo == SIGUSR1) {
+      printf("an icon has exited!\n");
+      closed_icons++;
+   };
+   return;
+}
+
 int main(int argc, char **argv) {
-   FILE *stream;
+
+   // Step 1: load config
+   configuration config;
+   if (ini_parse(conffile, handler, &config) < 0) {
+      printf("Error: cannot load %s\n",conffile);
+      return 1;
+   }
+   #ifdef DEBUG
+   printf("Config loaded from %s.\n", conffile);
+   printf("caps_on=%s\n", config.caps_on);
+   printf("caps_off=%s\n", config.caps_off);
+   printf("num_on=%s\n", config.num_on);
+   printf("num_off=%s\n", config.num_off);
+   printf("sleep_us=%d\n", config.sleep_microseconds);
+   printf("caps_fifo=%s\n", config.caps_fifo);
+   printf("num_fifo=%s\n", config.num_fifo);
+   #endif
+
+   // Step 2: validate config
+   // hardcoded min/max for microseconds, 0 and 10 seconds
+   if (config.sleep_microseconds < 0 || config.sleep_microseconds >= 10000000) {
+      printf("Warning: invalid sleep_microseconds: %d\n", config.sleep_microseconds);
+   };
+
+   // Step 3: initialize variables
+   FILE *stream_N, *stream_C;
 	dpy = XOpenDisplay( NULL );
 	int status_capslock = get_indicator(dpy, "Caps Lock");
 	int status_numlock = get_indicator(dpy, "Num Lock");
-   printf("Capslock: %d\tNumlock: %d\n",status_capslock,status_numlock);
-   char *fifo_name_C = "/tmp/fifo1";
-   char *fifo_name_N = "/tmp/fifo2";
-   printf("done\n");
-   char *_argv_C[] = { "fmain", fifo_name_C, NULL };
-   char *_argv_N[] = { "fmain", fifo_name_N, NULL };
+   char *_argv_C[] = { "fmain", (char*)config.caps_fifo, NULL };
+   char *_argv_N[] = { "fmain", (char*)config.num_fifo, NULL };
    int count_C = 0;
    int count_N = 0;
-   int fd_C, fd_N;
-   struct stat st_C, st_N;
-   char *msg;
-   if (stat(fifo_name_C, &st_C) != 0)
-      mkfifo(fifo_name_C, 0666);
-   if (stat(fifo_name_N, &st_N) != 0)
-      mkfifo(fifo_name_N, 0666);
    while (_argv_C[++count_C]);
    while (_argv_N[++count_N]);
-   //fd_C = open(fifo_name_C, O_WRONLY);
-   if (fork() == 0) {
+   int fd_C, fd_N;
+   struct stat st_C, st_N;
+   pid_t pid, pid_C, pid_N;
+   printf("Capslock: %d\tNumlock: %d\n",status_capslock,status_numlock);
+
+   // Step 4: initiate fifo files
+   if (stat(config.caps_fifo, &st_C) != 0)
+      mkfifo(config.caps_fifo, 0666);
+   if (stat(config.num_fifo, &st_N) != 0)
+      mkfifo(config.num_fifo, 0666);
+
+   // Step 5: start child proceses (tray icons)
+   // parent 1
+   pid = getpid();
+   if ((pid_C = fork()) == 0) {
       // parent1->child 1
-      if (fork() == 0) {
-         // parent1->child1->child1
-         fmain(count_C,_argv_C);
-      }
-      else {
-         // parent1->child1
-         fd_C = open(fifo_name_C, O_WRONLY);
-         stream = fdopen(fd_C,"w");
-         msg = "m quit,echo 'q' > /tmp/fifo1\n";
-         printf("sending to fd_C %d message %s",fd_C,msg);
-         fprintf(stream,msg);
-         if (status_capslock)
-            msg = "i /home/bgstack15/dev/keyboard-leds-trayicons/src/usr/share/icons/hicolor/scalable/status/capslock-on.svg\n";
-         else
-            msg = "i /home/bgstack15/dev/keyboard-leds-trayicons/src/usr/share/icons/hicolor/scalable/status/capslock-off.svg\n";
-         printf("sending to fd_C %d message %s",fd_C,msg);
-         fprintf(stream,msg);
-         fclose(stream);
-      };
+      fmain(count_C,_argv_C);
+      kill(pid, SIGUSR1);
+      _exit(0);
    }
    else {
       // parent 1
-      if (fork() == 0) {
+      if ((pid_N = fork()) == 0) {
          // parent1->child2
          fmain(count_N,_argv_N);
+         kill(pid, SIGUSR1);
+         _exit(0);
       }
       else {
          // parent 1
-         fd_N = open(fifo_name_N, O_WRONLY);
-         stream = fdopen(fd_N,"w");
-         msg = "i battery\n";
-         printf("sending to fd_N %d message %s",fd_N,msg);
-         fprintf(stream,msg);
-         msg = "m say hello,yad 'hello'|quit,echo 'q' > /tmp/fifo2\n";
-         printf("sending to fd_N %d message %s",fd_N,msg);
-         fprintf(stream,msg);
-         fclose(stream);
-      };
-      // still parent 1
-      // main logic loop happens now
-      //while (access("/tmp/stop-keyboard-leds",F_OK) != 0) {
-      fd_C = open(fifo_name_C, O_WRONLY);
-      fd_N = open(fifo_name_N, O_WRONLY);
-      int status_caps_old = status_capslock;
-      int status_num_old = status_numlock;
-      while (1) {
-         //ueep(1000000); 1 second
-         //ueep(   1000); 1 millisecond
-         usleep( 100000); // WORKHERE: should be configurable
-         status_capslock = get_indicator(dpy, "Caps Lock");
-         status_numlock  = get_indicator(dpy, "Num Lock");
-         //printf("Capslock: %d\tNumlock: %d\n",status_capslock,status_numlock);
-         if(status_capslock != status_caps_old) {
-            stream = fdopen(fd_C,"w");
-            if (stream > 0) {
+         signal(SIGPIPE, SIG_IGN);
+         /* prevents breakage when C or N tray icon is closed.
+            However, now this daemon will never quit without the closed_icon counter!
+         */
+         fd_C = open(config.caps_fifo, O_WRONLY);
+         stream_C = fdopen(fd_C,"w");
+         fd_N = open(config.num_fifo, O_WRONLY);
+         stream_N = fdopen(fd_N,"w");
+         strcpy(msg, "m quit,echo 'q' > ");
+         strcat(msg, config.caps_fifo);
+         strcat(msg, "\n");
+         send_fifo_message(stream_C, msg);
+         strcpy(msg, "m say hello,yad 'hello'|quit,echo 'q' > ");
+         strcat(msg, config.num_fifo);
+         strcat(msg, "\n");
+         send_fifo_message(stream_N, msg);
+         // still parent 1
+         // Step 6: loop monitoring logic
+         int status_caps_old = -1;
+         int status_num_old = -1;
+         int kill_result = 500;
+         while (closed_icons < 2) {
+            //    (1000000); 1 second
+            //    (   1000); 1 millisecond
+            //    ( 100000); 0.1 seconds is a good number
+            usleep(config.sleep_microseconds);
+            status_capslock = get_indicator(dpy, "Caps Lock");
+            status_numlock  = get_indicator(dpy, "Num Lock");
+            //printf("Capslock: %d\tNumlock: %d\n",status_capslock,status_numlock);
+            if(signal(SIGUSR1,sig_usr) == SIG_ERR)
+               printf("Signal processed.");
+            if(status_capslock != status_caps_old) {
+               kill_result = kill(pid_C, 0);
+               printf("Checking for capslock change, pid %d, result %d\n", pid_C, kill_result);
                if(0 == status_capslock) {
-                  msg = "i /home/bgstack15/dev/keyboard-leds-trayicons/src/usr/share/icons/hicolor/scalable/status/capslock-off.svg\n";
-                  //printf("sending to fd_C %d message %s",fd_C,msg);
+                  send_fifo_icon_message(stream_C, config.caps_off);
                   printf("capslock off\n");
-                  fprintf(stream,msg);
                }
                else {
-                  msg = "i /home/bgstack15/dev/keyboard-leds-trayicons/src/usr/share/icons/hicolor/scalable/status/capslock-on.svg\n";
+                  send_fifo_icon_message(stream_C, config.caps_on);
                   printf("capslock on\n");
-                  fprintf(stream,msg);
                };
                status_caps_old = status_capslock;
-               fflush(stream);
-               //fclose(stream);
             };
-         };
-         if(status_numlock != status_num_old) {
-            stream = fdopen(fd_N,"w");
-            if (stream > 0) {
+            if(status_numlock != status_num_old) {
                if(0 == status_numlock) {
-                  msg = "i /home/bgstack15/dev/keyboard-leds-trayicons/src/usr/share/icons/hicolor/scalable/status/numlock-off.svg\n";
-                  //printf("sending to fd_N %d message %s",fd_N,msg);
+                  send_fifo_icon_message(stream_N, config.num_off);
                   printf("numlock off\n");
-                  fprintf(stream,msg);
                }
                else {
-                  msg = "i /home/bgstack15/dev/keyboard-leds-trayicons/src/usr/share/icons/hicolor/scalable/status/numlock-on.svg\n";
+                  send_fifo_icon_message(stream_N, config.num_on);
                   printf("numlock on\n");
-                  fprintf(stream,msg);
                };
                status_num_old = status_numlock;
-               fflush(stream);
             };
-         };
-      };
-   };
-   return 0;
+         }; // end while(1)
+         // Either CTRL+C was run twice, or both icons closed
+         return 15;
+      }; // end parent 1 loop
+      return 26;
+   }; // end parent 1 loop
+   return 37;
 }