Converter from IRC escape codes to ANSI ones

Makefile

@@ -1,5 +1,5 @@
 CFLAGS = -Wall -Werror
-TARGETS = dispatch irc-filter
+TARGETS = dispatch irc-filter irc-esc
 
 all: $(TARGETS)
 

irc-esc.c

@@ -0,0 +1,118 @@
+#include <stdio.h>
+
+enum {
+  RESET,
+  COLOR,
+  NOCOLOR,
+  BOLD,
+  UNDERLINE,
+  INVERSE
+};
+
+int color_map[] = {7, 0, 4, 2, 1, 1, 5, 3, 3, 2, 6, 6, 4, 5, 0, 7};
+
+void
+change_state(int what, int foreground, int background)
+{
+  static int bf = 0;
+  static int ul = 0;
+  static int rv = 0;
+  static int fg = -1;
+  static int bg = -1;
+
+  switch (what) {
+    case RESET:
+      fg = -1;
+      bg = -1;
+      bf = 0;
+      ul = 0;
+      rv = 0;
+      break;
+    case COLOR:
+      fg = (foreground<16)?color_map[foreground]:-1;
+      bg = (background<16)?color_map[background]:-1;
+      break;
+    case NOCOLOR:
+      fg = -1;
+      bg = -1;
+      break;
+    case BOLD:
+      bf = !bf;
+      break;
+    case UNDERLINE:
+      ul = !ul;
+      break;
+    case INVERSE:
+      rv = !rv;
+      break;
+  }
+
+  printf("\033[0");
+  if (bf) printf(";1");
+  if (ul) printf(";4");
+  if (rv) printf(";7");
+  if (0 <= fg) printf(";3%d", fg);
+  if (0 <= bg) printf(";4%d", bg);
+  printf("m");
+}
+
+int
+read_num()
+{
+  int acc = 0;
+  int fail = 1;
+
+  while (1) {
+    int c = getchar();
+
+    if ((c >= '0') && (c <= '9')) {
+      acc = (acc * 10) + (c - '0');
+    } else {
+      ungetc(c, stdin);
+      break;
+    }
+    fail = 0;
+  }
+  return fail?-1:acc;
+}
+
+int
+main(int argc, char *argv[])
+{
+  while (! feof(stdin)) {
+    int c = getchar();
+
+    if (EOF == c) {
+      break;
+    } else if (0 == c) {
+      printf("\\0");
+    } else if (3 == c) {  /* mIRC color */
+      int fg = read_num();
+      int bg = -1;
+      
+      c = getchar();
+      if (',' == c) {
+        bg = read_num();
+      } else {
+        ungetc(c, stdin);
+      }
+      change_state(COLOR, fg, bg);
+    } else if (2 == c) {
+      change_state(BOLD, 0, 0);
+    } else if (22 == c) {
+      change_state(INVERSE, 0, 0);
+    } else if (31 == c) {
+      change_state(UNDERLINE, 0, 0);
+    } else if (15 == c) { /* mIRC reset everything */
+      change_state(RESET, 0, 0);
+    } else if ('\n' == c) {
+      change_state(RESET, 0, 0);
+      putchar(c);
+    } else if (32 > c) {
+      printf("^%c", c + 'A' - 1);
+    } else {
+      putchar(c);
+    }
+  }
+  change_state(RESET, 0, 0);
+}