Implement colored logging for para_server.

[paraslash.git] / color.c

diff --git a/color.c b/color.c
new file mode 100644 (file)
index 0000000..bd09446
--- /dev/null
+++ b/color.c
@@ -0,0 +1,132 @@
+/** \file color.c Functions for printing colored messages. */
+
+/*
+ * Mostly taken from the git source tree, version 1.6.1.76, January 2008.
+ */
+
+#include "para.h"
+#include "color.h"
+
+static int parse_color(const char *name, int len)
+{
+       static const char * const color_names[] = {
+               "normal", "black", "red", "green", "yellow",
+               "blue", "magenta", "cyan", "white"
+       };
+       char *end;
+       int i;
+       for (i = 0; i < ARRAY_SIZE(color_names); i++) {
+               const char *str = color_names[i];
+               if (!strncasecmp(name, str, len) && !str[len])
+                       return i - 1;
+       }
+       i = strtol(name, &end, 10);
+       if (end - name == len && i >= -1 && i <= 255)
+               return i;
+       return -2;
+}
+
+static int parse_attr(const char *name, int len)
+{
+       static const int attr_values[] = { 1, 2, 4, 5, 7 };
+       static const char * const attr_names[] = {
+               "bold", "dim", "ul", "blink", "reverse"
+       };
+       int i;
+       for (i = 0; i < ARRAY_SIZE(attr_names); i++) {
+               const char *str = attr_names[i];
+               if (!strncasecmp(name, str, len) && !str[len])
+                       return attr_values[i];
+       }
+       return -1;
+}
+
+/**
+ * Create an escape sequence for colored output.
+ *
+ * \param value Human-readable color spec.
+ * \param dst Result pointer for the escape sequence.
+ *
+ * \return -1 on errors, 1 on success.
+ *
+ * Format of \a value: [fg [bg]] [attr].
+ */
+int color_parse(const char *value, char *dst)
+{
+       const char *ptr = value;
+       int attr = -1;
+       int fg = -2;
+       int bg = -2;
+
+       if (!strcasecmp(value, "reset")) {
+               strcpy(dst, COLOR_RESET);
+               return 1;
+       }
+
+       /* [fg [bg]] [attr] */
+       while (*ptr) {
+               const char *word = ptr;
+               int val, len = 0;
+
+               while (word[len] && !isspace(word[len]))
+                       len++;
+
+               ptr = word + len;
+               while (*ptr && isspace(*ptr))
+                       ptr++;
+
+               val = parse_color(word, len);
+               if (val >= -1) {
+                       if (fg == -2) {
+                               fg = val;
+                               continue;
+                       }
+                       if (bg == -2) {
+                               bg = val;
+                               continue;
+                       }
+                       goto bad;
+               }
+               val = parse_attr(word, len);
+               if (val < 0 || attr != -1)
+                       goto bad;
+               attr = val;
+       }
+
+       if (attr >= 0 || fg >= 0 || bg >= 0) {
+               int sep = 0;
+
+               *dst++ = '\033';
+               *dst++ = '[';
+               if (attr >= 0) {
+                       *dst++ = '0' + attr;
+                       sep++;
+               }
+               if (fg >= 0) {
+                       if (sep++)
+                               *dst++ = ';';
+                       if (fg < 8) {
+                               *dst++ = '3';
+                               *dst++ = '0' + fg;
+                       } else {
+                               dst += sprintf(dst, "38;5;%d", fg);
+                       }
+               }
+               if (bg >= 0) {
+                       if (sep++)
+                               *dst++ = ';';
+                       if (bg < 8) {
+                               *dst++ = '4';
+                               *dst++ = '0' + bg;
+                       } else {
+                               dst += sprintf(dst, "48;5;%d", bg);
+                       }
+               }
+               *dst++ = 'm';
+       }
+       *dst = 0;
+       return 1;
+bad:
+       PARA_ERROR_LOG("bad color value '%s'\n", value);
+       return -1;
+}