Move color option parsing out of diff.c and into color.[ch]

The intent is to lib-ify colorizing code so it can be reused.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 176 insertions, 0 deletions

diff --git a/color.c b/color.c
new file mode 100644
index 0000000000..d8c8399d59
--- /dev/null
+++ b/color.c
@@ -0,0 +1,176 @@
+#include "color.h"
+#include "cache.h"
+#include "git-compat-util.h"
+
+#include <stdarg.h>
+
+#define COLOR_RESET "\033[m"
+
+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 (*name && !*end && 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;
+}
+
+void color_parse(const char *value, const char *var, char *dst)
+{
+	const char *ptr = value;
+	int attr = -1;
+	int fg = -2;
+	int bg = -2;
+
+	if (!strcasecmp(value, "reset")) {
+		strcpy(dst, "\033[m");
+		return;
+	}
+
+	/* [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;
+bad:
+	die("bad config value '%s' for variable '%s'", value, var);
+}
+
+int git_config_colorbool(const char *var, const char *value)
+{
+	if (!value)
+		return 1;
+	if (!strcasecmp(value, "auto")) {
+		if (isatty(1) || (pager_in_use && pager_use_color)) {
+			char *term = getenv("TERM");
+			if (term && strcmp(term, "dumb"))
+				return 1;
+		}
+		return 0;
+	}
+	if (!strcasecmp(value, "never"))
+		return 0;
+	if (!strcasecmp(value, "always"))
+		return 1;
+	return git_config_bool(var, value);
+}
+
+static int color_vprintf(const char *color, const char *fmt,
+		va_list args, const char *trail)
+{
+	int r = 0;
+
+	if (*color)
+		r += printf("%s", color);
+	r += vprintf(fmt, args);
+	if (*color)
+		r += printf("%s", COLOR_RESET);
+	if (trail)
+		r += printf("%s", trail);
+	return r;
+}
+
+
+
+int color_printf(const char *color, const char *fmt, ...)
+{
+	va_list args;
+	int r;
+	va_start(args, fmt);
+	r = color_vprintf(color, fmt, args, NULL);
+	va_end(args);
+	return r;
+}
+
+int color_printf_ln(const char *color, const char *fmt, ...)
+{
+	va_list args;
+	int r;
+	va_start(args, fmt);
+	r = color_vprintf(color, fmt, args, "\n");
+	va_end(args);
+	return r;
+}