From 89b7a51b52ca7c744d82a0b7c74549207cdc8387 Mon Sep 17 00:00:00 2001
From: Tulio A M Mendes <tadryanom@hotmail.com>
Date: Thu, 12 Feb 2026 00:10:44 -0300
Subject: [PATCH] =?utf8?q?feat:=20ulibc=20realpath()=20=E2=80=94=20resolve?=
 =?utf8?q?s=20'.',=20'..',=20relative=20paths=20via=20getcwd?=
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---
 user/ulibc/include/stdlib.h |  1 +
 user/ulibc/src/stdlib.c     | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/user/ulibc/include/stdlib.h b/user/ulibc/include/stdlib.h
index de433d7b..e52655c8 100644
--- a/user/ulibc/include/stdlib.h
+++ b/user/ulibc/include/stdlib.h
@@ -18,6 +18,7 @@ void*   calloc(size_t nmemb, size_t size);
 void*   realloc(void* ptr, size_t size);
 
 int     atoi(const char* s);
+char*   realpath(const char* path, char* resolved);
 void    exit(int status) __attribute__((noreturn));
 
 #ifndef NULL
diff --git a/user/ulibc/src/stdlib.c b/user/ulibc/src/stdlib.c
index 2234dff9..fc65f256 100644
--- a/user/ulibc/src/stdlib.c
+++ b/user/ulibc/src/stdlib.c
@@ -79,6 +79,42 @@ int atoi(const char* s) {
     return neg ? -n : n;
 }
 
+char* realpath(const char* path, char* resolved) {
+    if (!path || !resolved) return (void*)0;
+
+    char tmp[256];
+    int tpos = 0;
+
+    if (path[0] != '/') {
+        if (getcwd(tmp, sizeof(tmp)) < 0) return (void*)0;
+        tpos = (int)strlen(tmp);
+        if (tpos > 0 && tmp[tpos - 1] != '/') tmp[tpos++] = '/';
+    }
+
+    while (*path) {
+        if (*path == '/') { path++; continue; }
+        if (path[0] == '.' && (path[1] == '/' || path[1] == '\0')) {
+            path += 1; continue;
+        }
+        if (path[0] == '.' && path[1] == '.' && (path[2] == '/' || path[2] == '\0')) {
+            path += 2;
+            if (tpos > 1) {
+                tpos--;
+                while (tpos > 0 && tmp[tpos - 1] != '/') tpos--;
+            }
+            continue;
+        }
+        if (tpos > 0 && tmp[tpos - 1] != '/') tmp[tpos++] = '/';
+        while (*path && *path != '/' && tpos < 254) tmp[tpos++] = *path++;
+    }
+
+    if (tpos == 0) tmp[tpos++] = '/';
+    tmp[tpos] = '\0';
+
+    memcpy(resolved, tmp, (size_t)(tpos + 1));
+    return resolved;
+}
+
 void exit(int status) {
     _exit(status);
 }
-- 
2.43.0