+/** \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;
+}