/* * File: keyboard-leds-trayicons.c * Location: https://bgstack15.ddns.net/cgit/keyboard-leds-trayicons/ * Author: bgstack15 * Startdate: 2022-09-28-4 13:30 * SPDX-License-Identifier: GPL-3.0 * 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: * Usage: * References: * https://github.com/Cairo-Dock/cairo-dock-plug-ins/blob/master/keyboard-indicator/src/applet-xklavier.c#L124 * https://github.com/oco2000/xfce4-kbdleds-plugin/blob/fe753d9d0f8a720a35a32f5f556b8fbead798d20/panel-plugin/xkbleds.c * https://stackoverflow.com/questions/60897833/programmatically-calling-mainint-argc-char-argv-in-c * https://stackoverflow.com/questions/18649547/how-to-find-the-length-of-argv-in-c * https://www.geeksforgeeks.org/fork-system-call/ * 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 * https://qnaplus.com/c-program-to-sleep-in-milliseconds/ * 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 #include #include #include #include #include #include #include #include #include #include #include #include /* 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 */ char *strncpy_esc(char *dest, const char *src, size_t n) { size_t i = 0; size_t index = 0; while (i < n && src[i] != '\0') { if (src[i] == '\\' && src[i + 1] != '\0') { dest[index] = src[i + 1]; index++; i += 2; } else { dest[index] = src[i]; index++; i++; } } for (; index < n; index++) { dest[index] = '\0'; } return dest; } char *save_word(char *src, int i_del, int last) { char *dest = malloc((i_del - last) * sizeof(char)); strncpy_esc(dest, src + last + 1, i_del - last - 1); dest[i_del - last - 1] = '\0'; return dest; } /* * Struct that stores the label names on the menu and * their corresponding actions when the user selects them */ struct item { char *name; char *action; } * onmenu; char *onscrollup = NULL; char *onscrolldown = NULL; char *onmiddleclick = NULL; int menusize = 0; // number of menu entries GtkWidget *menu = NULL; GtkStatusIcon *icon; char *onclick = NULL; void tray_icon_on_click(GtkStatusIcon *status_icon, gpointer user_data) { if (onclick != NULL && fork() == 0) { execl("/bin/sh", "sh", "-c", onclick, (char *)NULL); } } void tray_icon_on_middleclick(GtkStatusIcon *status_icon, GdkEventButton *event, gpointer user_data) { if (2 == event->button) { if (onmiddleclick == NULL) { #ifdef DEBUG printf("middleclick, but no command specified\n"); #endif } else { #ifdef DEBUG printf("middleclick\n"); #endif if (onmiddleclick != NULL && fork() == 0) { execl("/bin/sh", "sh", "-c", onmiddleclick, (char *)NULL); } } } } /* * Callback function for when an entry is selected from the menu * We loop over all entry names to find what action to execute */ void click_menu_item(GtkMenuItem *menuitem, gpointer user_data) { const char *label = gtk_menu_item_get_label(menuitem); for (int i = 0; i < menusize; i++) { if (strcmp(label, onmenu[i].name) == 0 && fork() == 0) { execl("/bin/sh", "sh", "-c", onmenu[i].action, (char *)NULL); } } } void tray_icon_on_menu(GtkStatusIcon *status_icon, guint button, guint activate_time, gpointer user_data) { #ifdef DEBUG printf("Popup menu\n"); #endif if (menusize) { gtk_menu_popup_at_pointer((GtkMenu *)menu, NULL); } } void tray_icon_on_scroll(GtkStatusIcon *status_icon, GdkEventScroll *event, gpointer user_data) { char *i = NULL; switch (event->direction) { case GDK_SCROLL_UP: i = "up"; if (onscrollup != NULL && fork() == 0) execl("/bin/sh", "sh", "-c", onscrollup, (char *)NULL); break; case GDK_SCROLL_DOWN: i = "down"; if (onscrolldown != NULL && fork() == 0) execl("/bin/sh", "sh", "-c", onscrolldown, (char *)NULL); break; } if (i != NULL) { #ifdef DEBUG printf("scroll %s\n",i); #endif } } gboolean set_tooltip(gpointer data) { char *p = (char *)data; if (*p == '\0') { #ifdef DEBUG printf("Removing tooltip\n"); #endif gtk_status_icon_set_has_tooltip(icon, FALSE); return FALSE; } #ifdef DEBUG printf("Setting tooltip to '%s'\n", p); #endif gtk_status_icon_set_tooltip_text(icon, p); free(data); return FALSE; } gboolean set_icon(gpointer data) { char *p = (char *)data; #ifdef DEBUG printf("Setting icon to '%s'\n", p); #endif if (strchr(p, '/')) { gtk_status_icon_set_from_file(icon, p); } else { gtk_status_icon_set_from_icon_name(icon, p); } free(data); return FALSE; } gboolean set_visible(gpointer data) { gtk_status_icon_set_visible(icon, data == 0 ? FALSE : TRUE); return FALSE; } gboolean do_quit(gpointer data) { gtk_main_quit(); return FALSE; } gpointer watch_fifo(gpointer argv) { char *buf = malloc(1024 * sizeof(char)); char cmd; char quote; char *param; char *tmp = malloc(1024 * sizeof(char)); char *read; size_t len, i; char *fifo_path = (char *)argv; FILE *fifo; struct stat fifo_st; /* outer is for open */ outer: while (1) { if (stat(fifo_path, &fifo_st) != 0) { perror("FIFO does not exist, exiting\n"); gdk_threads_add_idle(do_quit, fifo); return NULL; } fifo = fopen(fifo_path, "r"); if (fifo == NULL) { perror("FIFO went away, exiting\n"); gdk_threads_add_idle(do_quit, fifo); return NULL; } /* inner is for read */ while (1) { read = fgets(buf, 1024 * sizeof(char), fifo); if (read == NULL) { /* no more data in pipe, reopen and block */ fclose(fifo); goto outer; } /* trim string */ while ((*read == '\n' || *read == ' ' || *read == '\t') && *read != '\0') { read++; } if (*read == '\0') { /* empty command */ continue; } cmd = *read; len = strlen(read); if (len < 3) { param = NULL; } else if (*(read + 2) != '\'' && *(read + 2) != '"') { // unquoted string read += 2; len -= 2; // trim trailing whitespace i = len - 1; while (i > 0) { if (!isspace(read[i])) { len = i + 1; read[len] = '\0'; break; } i -= 1; } param = malloc((len + 1) * sizeof(char)); strncpy(param, read, len + 1); } else { // quoted string quote = *(read + 2); read += 3; len -= 3; *tmp = '\0'; *(tmp + 1024 - 1) = '\0'; // keep track of what we have so far strncpy(tmp, read, 1023); // now keep reading until we have the end quote while (1) { // check for terminating ' if (len != 0) { // search backwards past whitespace i = len - 1; while (i > 0) { if (!isspace(tmp[i])) { break; } i -= 1; } if (tmp[i] == quote) { // maybe the end! // let's make sure it isn't escaped if (i >= 2 && tmp[i - 2] == '\\') { } else { // it's not! // we're done. // trim off the ' and // any whitespace we walked past len = i; tmp[len] = '\0'; break; } } } if (len == 1023) { // we can't read any more // but also haven't found the end // forcibly terminate the string fprintf(stderr, "Quoted string too long (max 1023 chars)\n"); break; } // we don't have the end of the string yet read = fgets(buf, 1024 * sizeof(char), fifo); if (read == NULL) { /* no more data in pipe, reopen and block */ fclose(fifo); goto outer; } // note that we don't trim here, because we're // in a quoted string. strncpy(tmp + len, read, 1023 - len); len += strlen(tmp + len); } // quoted string is now in param[0:len] param = malloc((len + 1) * sizeof(char)); strncpy(param, tmp, len + 1); } switch (cmd) { case 'q': gdk_threads_add_idle(do_quit, param); if (param != NULL) { free(param); } break; case 't': /* tooltip */ gdk_threads_add_idle(set_tooltip, param); break; case 'i': /* icon */ gdk_threads_add_idle(set_icon, param); break; case 'h': /* hide */ gdk_threads_add_idle(set_visible, (void *)0); if (param != NULL) { free(param); } break; case 's': /* show */ gdk_threads_add_idle(set_visible, (void *)1); if (param != NULL) { free(param); } break; case 'c': /* click */ if (onclick != NULL) { free(onclick); onclick = NULL; } if (param != NULL && *param == '\0') { #ifdef DEBUG printf("Removing onclick handler\n"); #endif free(param); break; } onclick = param; #ifdef DEBUG printf("Setting onclick handler to '%s'\n", onclick); #endif break; case 'm': /* menu */ if (onmenu != NULL) { // destroy the previous menu for (int i = 0; i < menusize; i++) { free(onmenu[i].name); free(onmenu[i].action); onmenu[i].name = NULL; onmenu[i].action = NULL; } free(onmenu); onmenu = NULL; gtk_widget_destroy(menu); menu = NULL; } menusize = 0; if (!param) { break; } else if (*param == '\0') { #ifdef DEBUG printf("Removing onmenu handler\n"); #endif free(param); break; } // This block makes sure that the parameter after 'm' is ready to be // processed We can't accept 2 straight commas, as it becomes ambiguous int straight = 0; int bars = 0; for (int i = 0; i < len; i++) { if (param[i] == ',' && param[i - 1] != '\\') { straight++; if (straight == 2) { break; } } else if (param[i] == '|' && param[i - 1] != '\\') { straight = 0; bars++; } } if (straight == 2) { printf("Two straight ',' found. Use '\\' to escape\n"); free(param); break; } // End of block that checks the parameter // Create the onmenu array which stores structs with name, action // properties menusize = bars + 1; onmenu = malloc(menusize * sizeof(struct item)); menu = gtk_menu_new(); int last = -1; int item = 0; char lastFound = '|'; // what was the last delimiter processed for (int i = 0; i < len; i++) { if (param[i] == ',' && param[i - 1] != '\\') { onmenu[item].name = save_word(param, i, last); last = i; lastFound = ','; } else if (param[i] == '|' && param[i - 1] != '\\') { if (lastFound == ',') { // we have found a ',' so we read an action onmenu[item].action = save_word(param, i, last); } else { // this is a label-only entry onmenu[item].name = save_word(param, i, last); onmenu[item].action = malloc(1); // pointer has to be freeable *onmenu[item].action = '\0'; } last = i; lastFound = '|'; item++; } } if (item < menusize) { // haven't read all actions because last one // didn't end with a '|' if (lastFound == ',') { onmenu[item].action = save_word(param, len, last); } else { onmenu[item].name = save_word(param, len, last); onmenu[item].action = malloc(1); *onmenu[item].action = '\0'; } } // Now create the menu item widgets and attach them on the menu for (int i = 0; i < menusize; i++) { GtkWidget *w; if (0 == strlen(onmenu[i].name) || (!strncmp(onmenu[i].name, "-----", 5))) { w = gtk_separator_menu_item_new() ; } else { w = gtk_menu_item_new_with_label(onmenu[i].name); g_signal_connect(G_OBJECT(w), "activate", G_CALLBACK(click_menu_item), NULL); } gtk_menu_shell_append(GTK_MENU_SHELL(menu), w); } gtk_widget_show_all(menu); free(param); break; case 'R': /* mouse scroll up */ if (onscrollup != NULL) { free(onscrollup); } if (!param || (*param == '\0')) { #ifdef DEBUG printf("Removing scrollup command\n"); onscrollup = NULL; #endif } else { #ifdef DEBUG printf("Setting scrollup command\n"); #endif onscrollup = malloc(strlen(param)); strncpy(onscrollup, param, len + 1); } break; case 'r': /* mouse scroll down */ if (onscrolldown != NULL) { free(onscrolldown); } if (!param || (*param == '\0')) { #ifdef DEBUG printf("Removing scrolldown command\n"); onscrolldown = NULL; #endif } else { #ifdef DEBUG printf("Setting scrolldown command\n"); #endif onscrolldown = malloc(strlen(param)); strncpy(onscrolldown, param, len + 1); } break; case 'S': /* mouse middle click */ if (onmiddleclick != NULL) { free(onmiddleclick); } if (!param || (*param == '\0')) { #ifdef DEBUG printf("Removing middle click command\n"); onmiddleclick = NULL; #endif } else { #ifdef DEBUG printf("Setting middleclick command\n"); #endif onmiddleclick = malloc(strlen(param)); strncpy(onmiddleclick, param, len + 1); } break; default: fprintf(stderr, "Unknown command: '%c'\n", *buf); if (param != NULL) { free(param); } } gdk_flush(); } } return NULL; } static GtkStatusIcon *create_tray_icon(char *start_icon) { GtkStatusIcon *tray_icon; if (strchr(start_icon, '/')) { tray_icon = gtk_status_icon_new_from_file(start_icon); } else { tray_icon = gtk_status_icon_new_from_icon_name(start_icon); } g_signal_connect(G_OBJECT(tray_icon), "activate", G_CALLBACK(tray_icon_on_click), NULL); g_signal_connect(G_OBJECT(tray_icon), "popup-menu", G_CALLBACK(tray_icon_on_menu), NULL); g_signal_connect(G_OBJECT(tray_icon), "scroll-event", G_CALLBACK(tray_icon_on_scroll), NULL); g_signal_connect(G_OBJECT(tray_icon), "button-release-event", G_CALLBACK(tray_icon_on_middleclick), NULL); gtk_status_icon_set_visible(tray_icon, TRUE); return tray_icon; } int print_usage(char **argv) { printf("Usage: %s [-i ICON] [-t TOOLTIP] [-h] [FIFO]\n", *argv); printf("Create a system tray icon as specified\n"); printf("\n"); printf(" -i ICON\tUse the specified ICON when initializing\n"); printf(" -t TOOLTIP\tUse the specified TOOLTIP when initializing\n"); printf(" -h \t\tDisplay this help message\n"); printf("\n"); printf("If a FIFO is not provided, mktrayicon will run until killed\n"); printf("Report bugs at https://github.com/jonhoo/mktrayicon\n"); return 0; } int fmain(int argc, char **argv) { char *start_icon = "none"; char *tooltip = NULL; char *pipe = NULL; GThread *reader; XInitThreads(); /* see http://stackoverflow.com/a/18690540/472927 */ gtk_init(&argc, &argv); if (argc == 1) { return print_usage(argv); } int c; while ((c = getopt(argc, argv, "i:t:h")) != -1) switch (c) { case 'i': start_icon = optarg; break; case 't': tooltip = optarg; break; case 'h': return print_usage(argv); case '?': fprintf(stderr, "Unknown option: %c\n", optopt); return 1; } icon = create_tray_icon(start_icon); if (tooltip) { gtk_status_icon_set_tooltip_text(icon, tooltip); } /* optind holds the index of the next argument to be parsed */ /* getopt moved positional arguments (if there were any) to the end of the * argv array, without parsing them */ /* so if there were only non-positional arguments, all arguments have been * parsed and optind will be equal to argc */ if (optind < argc) { pipe = argv[optind]; reader = g_thread_new("watch_fifo", watch_fifo, pipe); } gtk_main(); return 0; } /* STOP inclusion of mktrayicon.c */ Display* dpy; int get_indicator(Display* dpy, char* indicator) { // where indicator is one of ["Num Lock", "Caps Lock"] Atom lockIndicator = XInternAtom(dpy, indicator, False); int st; XkbGetNamedIndicator(dpy, lockIndicator, NULL, &st, NULL, NULL); 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) { // 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"); 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; while (_argv_C[++count_C]); while (_argv_N[++count_N]); 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 fmain(count_C,_argv_C); kill(pid, SIGUSR1); _exit(0); } else { // parent 1 if ((pid_N = fork()) == 0) { // parent1->child2 fmain(count_N,_argv_N); kill(pid, SIGUSR1); _exit(0); } else { // parent 1 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) { send_fifo_icon_message(stream_C, config.caps_off); printf("capslock off\n"); } else { send_fifo_icon_message(stream_C, config.caps_on); printf("capslock on\n"); }; status_caps_old = status_capslock; }; if(status_numlock != status_num_old) { if(0 == status_numlock) { send_fifo_icon_message(stream_N, config.num_off); printf("numlock off\n"); } else { send_fifo_icon_message(stream_N, config.num_on); printf("numlock on\n"); }; status_num_old = status_numlock; }; }; // 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; }