port to c + reduce flicker + use timerfd

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 304 insertions, 0 deletions

diff --git a/src/mongoclock.c b/src/mongoclock.c
new file mode 100644
index 0000000..781b7b4
--- /dev/null
+++ b/src/mongoclock.c
@@ -0,0 +1,304 @@
+/**
+ * Copyright © 2013, 2015  Mattias Andrée  (maandree@member.fsf.org)
+ * 
+ * Copying and distribution of this file, with or without modification,
+ * are permitted in any medium without royalty provided the copyright
+ * notice and this notice are preserved.  This file is offered as-is,
+ * without any warranty.  [GNU All Permissive License]
+ */
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <time.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <sys/timerfd.h>
+
+$<
+d() {
+  echo '"'"$(echo "$1" | sed -e 's/X/ /g' -e 's/\[/\\033\[7m /g' -e 's/\]/\\033\[m /g')"'"'
+}
+$>
+
+#define DX  16
+#define DY  12
+static const char* mongo_0[] = {$(d '    [XXXX]      '),
+				$(d '  [XX]  [XX]    '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]  []  [XX]  '),
+				$(d '[XX]  []  [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '  [XX]  [XX]    '),
+				$(d '    [XXXX]      ')};
+
+static const char* mongo_1[] = {$(d '      [XX]      '),
+				$(d '    [XXXX]      '),
+				$(d '  [XXXXXX]      '),
+				$(d '      [XX]      '),
+				$(d '      [XX]      '),
+				$(d '      [XX]      '),
+				$(d '      [XX]      '),
+				$(d '      [XX]      '),
+				$(d '      [XX]      '),
+				$(d '      [XX]      '),
+				$(d '      [XX]      '),
+				$(d '  [XXXXXXXXXX]  ')};
+
+static const char* mongo_2[] = {$(d '  [XXXXXXXX]    '),
+				$(d '[XX]      [XX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '        [XX]    '),
+				$(d '      [XX]      '),
+				$(d '    [XX]        '),
+				$(d '  [XX]          '),
+				$(d '[XX]            '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XXXXXXXXXXXX]  ')};
+
+static const char* mongo_3[] = {$(d '  [XXXXXXXX]    '),
+				$(d '[XX]      [XX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '    [XXXXXX]    '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '  [XXXXXXXX]    ')};
+
+static const char* mongo_4[] = {$(d '        [XX]    '),
+				$(d '      [XXXX]    '),
+				$(d '    [XXXXXX]    '),
+				$(d '  [XX]  [XX]    '),
+				$(d '[XX]    [XX]    '),
+				$(d '[XXXXXXXXXXXX]  '),
+				$(d '        [XX]    '),
+				$(d '        [XX]    '),
+				$(d '        [XX]    '),
+				$(d '        [XX]    '),
+				$(d '        [XX]    '),
+				$(d '      [XXXXXX]  ')};
+
+static const char* mongo_5[] = {$(d '[XXXXXXXXXXXX]  '),
+				$(d '[XX]            '),
+				$(d '[XX]            '),
+				$(d '[XX]            '),
+				$(d '[XX]            '),
+				$(d '[XXXXXXXXXX]    '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '  [XXXXXXXX]    ')};
+
+static const char* mongo_6[] = {$(d '      [XXXX]    '),
+				$(d '    [XX]        '),
+				$(d '  [XX]          '),
+				$(d '[XX]            '),
+				$(d '[XX]            '),
+				$(d '[XXXXXXXXXX]    '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '  [XXXXXXXX]    ')};
+
+static const char* mongo_7[] = {$(d '[XXXXXXXXXXXX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '        [XX]    '),
+				$(d '      [XX]      '),
+				$(d '    [XX]        '),
+				$(d '    [XX]        '),
+				$(d '    [XX]        '),
+				$(d '    [XX]        '),
+				$(d '    [XX]        '),
+				$(d '    [XX]        ')};
+
+static const char* mongo_8[] = {$(d '  [XXXXXXXX]    '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '  [XXXXXXXX]    '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '  [XXXXXXXX]    ')};
+
+static const char* mongo_9[] = {$(d '  [XXXXXXXX]    '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '[XX]      [XX]  '),
+				$(d '  [XXXXXXXXXX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '          [XX]  '),
+				$(d '        [XX]    '),
+				$(d '      [XX]      '),
+				$(d '  [XXXX]        ')};
+
+#define DC  16
+static const char* mongo_c[] = {$(d '                '),
+				$(d '                '),
+				$(d '      [XX]      '),
+				$(d '      [XX]      '),
+				$(d '                '),
+				$(d '                '),
+				$(d '                '),
+				$(d '                '),
+				$(d '      [XX]      '),
+				$(d '      [XX]      '),
+				$(d '                '),
+				$(d '                ')};
+
+static const char** mongo_ds[] = {
+  mongo_0, mongo_1, mongo_2, mongo_3, mongo_4,
+  mongo_5, mongo_6, mongo_7, mongo_8, mongo_9};
+
+
+static volatile sig_atomic_t caught_sigterm = 0;
+static volatile sig_atomic_t caught_sigwinch = 1;
+
+
+#define t(...)  do if ((__VA_ARGS__) < 0) goto fail; while (0)
+
+
+static void sigterm(int signo)
+{
+  caught_sigterm = 1;
+  (void) signo;
+}
+
+static void sigwinch(int signo)
+{
+  caught_sigwinch = 1;
+  (void) signo;
+}
+
+
+static void print_time(const char*** str, size_t y, size_t x)
+{
+  size_t r, c;
+  
+  fprintf(stdout, "\033[%zu;1H\033[1J", y + 1);
+  
+  for (r = 0; r < DY; r++)
+    {
+      fprintf(stdout, "\033[%zu;%zuH\033[1K", y + r + 1, x + 1);
+      for (c = 0; str[c] != NULL; c++)
+	fprintf(stdout, "%s", str[c][r]);
+      fprintf(stdout, "\033[0K");
+    }
+  
+  fprintf(stdout, "\033[0J");
+  fflush(stdout);
+}
+
+
+int main(int argc, char* argv[])
+{
+  time_t now_;
+  struct tm* now;
+  const char** digits[9];
+  size_t x = 0, y = 0;
+  struct winsize winsize;
+  int small = 0, fd;
+  struct itimerspec itimerspec;
+  char _buf[8];
+  
+  fprintf(stdout, "\033[?1049h\033[?25l");
+  
+  t (clock_gettime(CLOCK_REALTIME, &(itimerspec.it_value)));
+  itimerspec.it_interval.tv_sec = 1;
+  itimerspec.it_interval.tv_nsec = 0;
+  itimerspec.it_value.tv_sec += 1;
+  itimerspec.it_value.tv_nsec = 0;
+  t (fd = timerfd_create(CLOCK_REALTIME, 0));
+  t (timerfd_settime(fd, TFD_TIMER_ABSTIME, &itimerspec, NULL));
+  
+  signal(SIGTERM, sigterm);
+  signal(SIGQUIT, sigterm);
+  signal(SIGINT, sigterm);
+  signal(SIGWINCH, sigwinch);
+  
+  while (!caught_sigterm)
+    {
+      if (caught_sigwinch)
+	{
+	  caught_sigwinch = 0;
+	  t (TEMP_FAILURE_RETRY(ioctl(STDOUT_FILENO, TIOCGWINSZ, &winsize)));
+	  y = winsize.ws_row;
+	  x = winsize.ws_col;
+	  if      (y < DY)               small = 2;
+	  else if (x < 4 * DX + DC)      small = 2;
+	  else if (x < 6 * DX + 2 * DC)  small = 1;
+	  else                           small = 0;
+	  y -= DY;
+	  x -= 4 * DX + DC;
+	  if (!small)
+	    x -= 2 * DX + DC;
+	  y /= 2;
+	  x /= 2;
+	}
+      
+      if (small == 2)
+	{
+	  fprintf(stdout, "\033[H\033[2J%s\n", "Screen is too small");
+	  fflush(stdout);
+	  pause();
+	  continue;
+	}
+      
+      now_ = time(NULL);
+      if (now_ == -1)  goto fail;
+      now = localtime(&now_);
+      if (now == NULL)  goto fail;
+      
+      digits[0] = mongo_ds[now->tm_hour / 10];
+      digits[1] = mongo_ds[now->tm_hour % 10];
+      digits[2] = mongo_c;
+      digits[3] = mongo_ds[now->tm_min / 10];
+      digits[4] = mongo_ds[now->tm_min % 10];
+      digits[5] = small ? NULL : mongo_c;
+      digits[6] = mongo_ds[now->tm_sec / 10];
+      digits[7] = mongo_ds[now->tm_sec % 10];
+      digits[8] = NULL;
+      
+      print_time(digits, y, x);
+      
+      if (read(fd, _buf, 8) < 0)
+	if (errno != EINTR)
+	  goto fail;
+    }
+  
+  fprintf(stdout, "\033[?25h\n\033[?1049l");
+  fflush(stdout);
+  TEMP_FAILURE_RETRY(close(fd));
+  return 0;
+  
+ fail:
+  perror(*argv);
+  fprintf(stdout, "\033[?25h\n\033[?1049l");
+  fflush(stdout);
+  TEMP_FAILURE_RETRY(close(fd));
+  return 1;
+  (void) argc;
+}
+