Support for FreeBSD-style ls Coloring

If LSCOLORS is undefined or partially defined (missing some of the eleven expected
value pairs), the patch will automatically fill in those missing values with default
colors. However, if the LS_COLORS environment variable is already defined, the
application prefer the LS_COLORS approach, maintaining current working flow of the
program.

1 files changed, 76 insertions, 5 deletions

diff --git a/src/color.c b/src/color.c
index a026831..f77877d 100644
--- a/src/color.c
+++ b/src/color.c
@@ -607,6 +607,67 @@ fail:
 	return ret;
 }
 
+/** Parse the FreeBSD $LSCOLORS format. */
+static int parse_bsd_ls_colors(struct colors *colors, const char *lscolors) {
+	static const char *keys[] = {
+		"di", "ln", "so", "pi", "ex", "bd", "cd", "su", "sg", "tw", "ow"
+	};
+
+	static const char *fg_codes[256] = {
+		['a'] = "30", ['b'] = "31", ['c'] = "32", ['d'] = "33",
+		['e'] = "34", ['f'] = "35", ['g'] = "36", ['h'] = "37", ['x'] = "39",
+		['A'] = "1;30", ['B'] = "1;31", ['C'] = "1;32", ['D'] = "1;33",
+		['E'] = "1;34", ['F'] = "1;35", ['G'] = "1;36", ['H'] = "1;37", ['X'] = "1"
+	};
+
+	static const char *bg_codes[256] = {
+		['a'] = "40", ['b'] = "41", ['c'] = "42", ['d'] = "43",
+		['e'] = "44", ['f'] = "45", ['g'] = "46", ['h'] = "47", ['x'] = "49",
+		['A'] = "4;100", ['B'] = "4;101", ['C'] = "4;102", ['D'] = "4;103",
+		['E'] = "4;104", ['F'] = "4;105", ['G'] = "4;106", ['H'] = "4;107", ['X'] = "4;49"
+	};
+
+	// Please refer to https://man.freebsd.org/cgi/man.cgi?ls(1)#ENVIRONMENT
+	char complete_colors[] = "exfxcxdxbxegedabagacad";
+
+	size_t max = strlen(complete_colors);
+	size_t len = strnlen(lscolors, max + 1);
+	if (len == 0 || len % 2 != 0 || len > max) {
+		errno = EINVAL;
+		return -1;
+	}
+	memcpy(complete_colors, lscolors, len);
+
+	for (size_t i = 0; i < countof(keys); ++i) {
+		uint8_t fg = complete_colors[i * 2];
+		uint8_t bg = complete_colors[(i * 2) + 1];
+
+		const char *fg_code = fg_codes[fg];
+		const char *bg_code = bg_codes[bg];
+
+		if (!fg_code || !bg_code) {
+			continue;
+		}
+
+		dchar *esc = dstrprintf("%s;%s", fg_code, bg_code);
+		if (!esc) {
+			return -1;
+		}
+
+		int ret = set_esc(colors, keys[i], esc);
+		dstrfree(esc);
+		if (ret != 0) {
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static bool str_isset(const char *str) {
+    return str && *str;
+}
+
 struct colors *parse_colors(void) {
 	struct colors *colors = ALLOC(struct colors);
 	if (!colors) {
@@ -676,12 +737,22 @@ struct colors *parse_colors(void) {
 		goto fail;
 	}
 
-	if (parse_gnu_ls_colors(colors, getenv("LS_COLORS")) != 0) {
-		goto fail;
-	}
-	if (parse_gnu_ls_colors(colors, getenv("BFS_COLORS")) != 0) {
-		goto fail;
+	const char *gnu_colors = getenv("LS_COLORS");
+	const char *bfs_colors = getenv("BFS_COLORS");
+	const char *bsd_colors = getenv("LSCOLORS");
+	if (str_isset(gnu_colors) || str_isset(bfs_colors)) {
+		if (parse_gnu_ls_colors(colors, gnu_colors) != 0) {
+			goto fail;
+		}
+		if (parse_gnu_ls_colors(colors, bfs_colors) != 0) {
+			goto fail;
+		}
+	} else if (str_isset(bsd_colors)) {
+		if (parse_bsd_ls_colors(colors, bsd_colors) != 0) {
+			goto fail;
+		}
 	}
+
 	if (build_iext_trie(colors) != 0) {
 		goto fail;
 	}