chdir (nr 80)

Linux Signature

int chdir(const char *path);

Description

Changes the current working directory to path.

Current Implementation

1. Reads a null-terminated path string from user space (max 4096 bytes). Returns -EFAULT (-14) if the pointer is invalid.
2. Resolves the path relative to the process’s current cwd. Normalises . and .. components.
3. Validates that the resolved path is an existing directory by calling devices::vfs::list_dir() (through osl::blocking::blocking()). This blocks the calling thread while the async VFS operation completes.
4. On success, updates the process’s cwd field to the resolved path and returns 0.
5. On failure, returns the error from the VFS (typically -ENOENT or -ENOTDIR).

Source: osl/src/syscalls/fs.rs — sys_chdir

Usage from C (musl)

#include <unistd.h>

if (chdir("/some/path") < 0) {
    /* error */
}

Errors

Future Work

• Support fchdir(fd) to change directory via an open directory fd.