1 files changed, 74 insertions, 0 deletions
diff --git a/42sh/src/builtins/cd.c b/42sh/src/builtins/cd.c
new file mode 100644
index 0000000..90fd9db
--- /dev/null
+++ b/42sh/src/builtins/cd.c
@@ -0,0 +1,74 @@
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "builtins.h"
+#include "utils/env.h"
+
+int cd_pointpoint(char *path, char *old)
+{
+    char *current = strrchr(path, '/');
+    size_t len = current - path;
+    if (len == 0)
+    {
+        fprintf(stderr, "cd: error with ..\n");
+        return 2;
+    }
+    char *parent = malloc(len + 1);
+    memcpy(parent, current, len);
+    parent[len] = '\0';
+    old = path;
+    path = parent;
+    env_set("OLDPWD", old);
+    env_set("PWD", path);
+    free(parent);
+
+    return 0;
+}
+
+int cd(struct string **args)
+{
+    if (args[0] == NULL || args[1] != NULL)
+    {
+        fprintf(stderr, "cd: error too many arguments\n");
+        fflush(stdout);
+        return 2;
+    }
+    if (strcmp(env_get("PWD"), "") == 0)
+    {
+        fprintf(stderr, "cd: error with PWD\n");
+        fflush(stdout);
+        return 2;
+    }
+    char *old = env_get("OLDPWD");
+    char *path = env_get("PWD");
+    char *tmp = old;
+    if (strcmp(args[0]->data, "-") == 0)
+    {
+        if (strcmp(old, "") == 0)
+        {
+            fprintf(stderr, "cd: error with OLDPWD\n");
+            fflush(stdout);
+            return 2;
+        }
+        printf("%s\n", old);
+        old = path;
+        path = tmp;
+    }
+    else if (strcmp(args[0]->data, "..") == 0)
+    {
+        int res = cd_pointpoint(path, old);
+        fflush(stdout);
+        return res;
+    }
+    else
+    {
+        old = path;
+        path = args[0]->data;
+    }
+    env_set("OLDPWD", old);
+    env_set("PWD", path);
+    fflush(stdout);
+    return 0;
+}