initial commit

.config/i3blocks/brightness/main.c

@@ -0,0 +1,199 @@
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <dirent.h>
+#include <stdint.h>
+#include <errno.h>
+#include <assert.h>
+#include <stdarg.h>
+#include <getopt.h>
+#include <sys/select.h>
+#include <sys/inotify.h>
+
+#define INOTIFY_EVENT_SIZE (sizeof (struct inotify_event))
+#define INOTIFY_BUFF_SIZE 64
+
+static bool get_float_value_from_file(const char *path,
+                                      float *dst_val);
+
+static void print_brightness_percent(const char *actual_path,
+                                     const char *max_path);
+
+static void usage(void) {
+  fprintf(stderr, "brightness %s - read actual brightness value in non-blocking style.\n\n", VERSION);
+  fprintf(stderr,
+          "Usage: brightness [options]\n\
+          \n\
+          Options:\n\
+          -a, --actual_brightness_path  \tpath to file with actual brightness string\n\
+          -m, --max_brightness_path     \tpath to file with max brightness string\n\
+          -h, --help                    \tprint this help.\n\
+          -V, --version                 \tprint version and exit.\n\
+          \n");
+}
+//////////////////////////////////////////////////////////////
+
+int
+main(int argc, char *argv[]) {
+  static const char *default_abp = "/sys/class/backlight/intel_backlight/actual_brightness";
+  static const char *default_mbp = "/sys/class/backlight/intel_backlight/max_brightness";
+  char *actual_brightness_path = default_abp;
+  char *max_brightness_path = default_mbp;
+
+  char buff[INOTIFY_BUFF_SIZE] = {0};
+  fd_set read_descriptors;
+  struct timeval time_to_wait;
+  int  ifd, wd, read_len, rc, opt_idx;
+  size_t opt_len;
+  // ifd - inotify_file_descriptor
+  // wd - inotify wait descriptor
+  // rc - result code
+
+  static const struct option lopts[] = {
+  {"actual_brightness_path", required_argument,  NULL, 'a'},
+  {"max_brightness_path", required_argument,  NULL, 'm'},
+  {"help", no_argument, NULL, 'h'},
+  {"version", no_argument, NULL, 'V'},
+  {NULL, 0, NULL, 0},
+};
+
+  while ((opt_idx = getopt_long(argc, argv, "a:m:hV", lopts, NULL)) != -1) {
+    switch (opt_idx) {
+      case 'a':
+        opt_len = strlen(optarg);
+        actual_brightness_path = malloc(opt_len + 1);
+        strcpy(actual_brightness_path, optarg);
+        break;
+      case 'm':
+        opt_len = strlen(optarg);
+        max_brightness_path = malloc(opt_len + 1);
+        strcpy(max_brightness_path, optarg);
+        break;
+      case 'h':
+        usage();
+        return 0;
+      case 'V':
+        printf("%s\n", VERSION);
+        return 0;
+      default:
+        printf("something bad is happened. option index is out of bounds (%d %c)\n", opt_idx, (char)opt_idx);
+        return -1;
+    }
+  }
+
+  print_brightness_percent(actual_brightness_path,
+                           max_brightness_path);
+
+  ifd = inotify_init();
+  if (ifd == -1) {
+    perror("inotify init failed");
+    return -1;
+  }
+
+  wd = inotify_add_watch(ifd, actual_brightness_path, IN_MODIFY);
+  FD_ZERO (&read_descriptors);
+  FD_SET (ifd, &read_descriptors);
+  time_to_wait.tv_sec = 10;
+  time_to_wait.tv_usec = 0;
+
+  while (1) {
+    fd_set tmp_set = read_descriptors;
+    rc = select(ifd+1, &tmp_set, NULL, NULL, &time_to_wait);
+    if (rc < 0) {
+      perror("select failed");
+      break;
+    }
+
+    if (rc == 0) { //timeout
+      continue;
+    }
+
+    if (!FD_ISSET(ifd, &read_descriptors)) {
+      continue;
+    }
+
+    read_len = read(ifd, (void*)buff, INOTIFY_BUFF_SIZE);
+    if (read_len < 0) {
+      perror("read failed");
+      continue;
+    }
+
+    for (int eix = 0; eix < read_len; ) {
+      struct inotify_event *event = (struct inotify_event*) &buff[eix];
+      eix += INOTIFY_EVENT_SIZE + event->len;
+      if (!(event->mask & IN_MODIFY)) {
+        continue;
+      }
+
+      print_brightness_percent(actual_brightness_path,
+                               max_brightness_path);
+    }
+  }
+
+  //actually when we receive some signal (like sigterm or something like that)
+  //we will be here.
+
+  inotify_rm_watch(ifd, wd);
+  close(ifd);
+
+  if (actual_brightness_path != default_abp)
+    free(actual_brightness_path);
+  if (max_brightness_path != default_mbp)
+    free(max_brightness_path);
+  return 0;
+}
+//////////////////////////////////////////////////////////////
+
+bool
+get_float_value_from_file(const char *path,
+                          float *dst_val) {
+#define BUFF_SIZE 16
+  char buff[BUFF_SIZE] = {0};
+  FILE *f = fopen(path, "r");
+  bool result = false;
+  if (f == NULL) {
+    perror("failed to open file");
+    return false;
+  }
+
+  do {
+    if (!(fread((void*) buff, 1, BUFF_SIZE, f))) {
+      perror("failed to read file");
+      break;
+    }
+
+    char *unused;
+    *dst_val = strtof(buff, &unused);
+    result = true;
+  } while (0);
+
+  fclose(f);
+  return result;
+}
+//////////////////////////////////////////////////////////////
+
+void
+print_brightness_percent(const char *actual_path,
+                         const char *max_path) {
+  float curr, max;
+  const char *parr[] = {actual_path, max_path};
+  float *farr[] = {&curr, &max};
+
+  for (size_t i = 0; i < 2; ++i) {
+    bool success = get_float_value_from_file(parr[i], farr[i]);\
+    if (!success) {
+      printf("\xF0\x9F\x94\x86"); //brightness symbol 🔆
+      printf(": NA\n");
+      fflush(stdout); // because we use select(), ant it blocks stdout
+      return;
+    }
+  }
+
+  printf("\xF0\x9F\x94\x86"); //brightness symbol 🔆
+  printf(": %02.f%%\n", (curr / max) * 100.f);
+  fflush(stdout); // because we use select(), ant it blocks stdout
+}
+//////////////////////////////////////////////////////////////