From 38201cc1bb723a4c44648b86ee1b4bd8a4aedd87 Mon Sep 17 00:00:00 2001
From: Abdelrahman Said <said.abdelrahman89@gmail.com>
Date: Fri, 3 Nov 2023 22:47:42 +0000
Subject: [PATCH] Add path utilties

---
 include/cpath.h | 18 ++++++++++++
 src/cpath.c     | 76 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+)
 create mode 100644 include/cpath.h
 create mode 100644 src/cpath.c

diff --git a/include/cpath.h b/include/cpath.h
new file mode 100644
index 0000000..06f7018
--- /dev/null
+++ b/include/cpath.h
@@ -0,0 +1,18 @@
+#ifndef PATH_UTILS_H
+#define PATH_UTILS_H
+
+#include "aliases.h"
+
+#define NUMPARTS(...)                                                          \
+  (sizeof((const char *[]){"", __VA_ARGS__}) / sizeof(const char *) - 1)
+
+#define JOIN_PATH(DST, ...) join_path(DST, NUMPARTS(__VA_ARGS__), __VA_ARGS__)
+
+void join_path(char *dst, u64 count, ...);
+
+#define DIRNAME(DST, PATH) dirup(DST, 1, PATH)
+#define DIRUP(DST, COUNT, PATH) dirup(DST, COUNT, PATH)
+
+void dirup(char *dst, u64 levels, const char *path);
+
+#endif // !PATH_UTILS_H
diff --git a/src/cpath.c b/src/cpath.c
new file mode 100644
index 0000000..998523f
--- /dev/null
+++ b/src/cpath.c
@@ -0,0 +1,76 @@
+#include "cpath.h"
+#include "aliases.h"
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+#if defined(__unix__) || defined(__APPLE__) || defined(__ANDROID__)
+INTERNAL char path_sep = '/';
+#elif defined(_WIN32) || defined(_WIN64)
+INTERNAL char path_sep = '\';
+#endif
+
+void join_root_and_leaf(const char *root, const char *leaf, char *dst);
+
+void join_path(char *dst, u64 count, ...) {
+  va_list args;
+
+  va_start(args, count);
+
+  for (u64 i = 0; i < count; ++i) {
+    join_root_and_leaf(dst, va_arg(args, const char *), dst);
+  }
+
+  va_end(args);
+}
+
+void dirup(char *dst, u64 levels, const char *path) {
+  if (levels < 1) {
+    return;
+  }
+
+  u64 end_index = 0;
+  u64 sep_count = 0;
+
+  u64 length = strlen(path);
+  if (path[length - 1] == path_sep) {
+    --length;
+  }
+
+  for (u64 i = length - 1; i >= 0; --i) {
+    if (path[i] == path_sep) {
+      ++sep_count;
+      end_index = i;
+
+      if (sep_count == levels) {
+        break;
+      }
+    }
+  }
+
+  if (sep_count < levels) {
+    end_index = 0;
+  }
+
+  strncpy(dst, path, end_index);
+}
+
+void join_root_and_leaf(const char *root, const char *leaf, char *dst) {
+  u64 root_length = strlen(root);
+  u64 root_end = root_length - 1;
+
+  u64 leaf_length = strlen(leaf);
+  u64 leaf_start = 0;
+
+  if (root[root_end] == path_sep) {
+    --root_end;
+  }
+
+  if (leaf[leaf_start] == path_sep) {
+    ++leaf_start;
+  }
+
+  strncpy(dst, root, ++root_end);
+  dst[root_end] = path_sep;
+  strncpy(&(dst[++root_end]), &(leaf[leaf_start]), leaf_length - leaf_start);
+}