Extended ls with -aA options

1 files changed, 42 insertions, 6 deletions

diff --git a/ls.c b/ls.c
index c507523..fe6ae76 100644
--- a/ls.c
+++ b/ls.c
@@ -4,7 +4,20 @@
 #include <unistd.h>
 
 
-int ls(const char * path)
+struct options
+{
+	unsigned int skip_dots:1;
+	unsigned int skip_self_and_up:1;
+};
+
+
+struct options defaults = {
+	.skip_dots = 1,
+	.skip_self_and_up = 1,
+};
+
+
+int ls(const char * path, struct options opts)
 {
 	DIR * dir;
 	if (NULL == (dir = opendir(path))) {
@@ -12,8 +25,16 @@ int ls(const char * path)
 		return 1;
 	}
 	struct dirent * entry;
-	while (NULL != (entry = readdir(dir)))
+	while (NULL != (entry = readdir(dir))) {
+		const unsigned int is_dot = '.' == entry->d_name[0];
+		if (opts.skip_dots && is_dot)
+			continue;
+		const unsigned int is_self = is_dot && 0 == entry->d_name[1];
+		const unsigned int is_up = is_dot && '.' == entry->d_name[1];
+		if (opts.skip_self_and_up && (is_self || is_up))
+			continue;
 		printf("%s\n", entry->d_name);
+	}
 	closedir(dir);
 	return 0;
 }
@@ -21,10 +42,25 @@ int ls(const char * path)
 
 int main(int argc, char * argv[])
 {
+	int opt;
+	struct options opts = defaults;
+	while (-1 != (opt = getopt(argc, argv, "aA"))) {
+		switch (opt) {
+		case 'a':
+			opts.skip_self_and_up = 0;
+			// fall-through
+		case 'A':
+			opts.skip_dots = 0;
+			break;
+		default:
+			dprintf(2, "Usage: %s [-aA] [file...]\n", argv[0]);
+			return 1;
+		}
+	}
 	int res = 0;
-	if (argc == 1)
-		res |= ls(".");
-	for (int i = 1; i < argc; ++i)
-		res |= ls(argv[i]);
+	if (optind >= argc)
+		res |= ls(".", opts);
+	for (int i = optind; i < argc; ++i)
+		res |= ls(argv[i], opts);
 	return res;
 }