Add basic ls

src/user/app/ls/ls.c

@@ -0,0 +1,43 @@
+#include "src/lib/string.h"
+#include "src/user/syscall.h"
+
+#define WRITE_S(s) write(1, s, sizeof(s) - 1);
+#define WRITE_D(s) write(1, s, string_length(s));
+
+uint64_t ls(const char *path) {
+  uint64_t i = 0;
+  while (1) {
+    char out[100];
+    uint64_t s = readdir(path, i, 100, out);
+    if (!s) {
+      return 0;
+    }
+    if (s == (uint64_t)-1) {
+      WRITE_S("ls: path does not exist\n");
+      return (uint64_t)-1;
+    }
+    WRITE_D(out);
+    WRITE_S("\n");
+    i++;
+  }
+}
+
+uint64_t main(uint64_t argc, const char **argv) {
+  if (argc == 1) {
+    return ls(".");
+  }
+
+  uint64_t code = 0;
+  for (uint64_t i = 1; i < argc; i++) {
+    if (argc > 2) {
+      WRITE_S("\n");
+      WRITE_D(argv[i]);
+      WRITE_S(":\n");
+    }
+    if (ls(argv[i]) == (uint64_t)-1) {
+      code = (uint64_t)-1;
+    }
+  }
+
+  return code;
+}