---
name: "execveat"
section: "2"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/execveat"
---

# execveat(2)

execute program relative to a directory file descriptor

## NAME

execveat - execute program relative to a directory file descriptor

## LIBRARY

Standard C library (*libc*, *-lc*)

## SYNOPSIS

```
#include <linux/fcntl.h>      /* Definition of AT_* constants */
#include <unistd.h>
```

**int execveat(int** *dirfd***, const char \****path***,**              **char \*const \_Nullable** *argv***\[\],**              **char \*const \_Nullable** *envp***\[\],**              **int** *flags***);**

## DESCRIPTION

The **execveat**() system call executes the program referred to by the combination of *dirfd* and *path*. It operates in exactly the same way as [**execve**(2)](/execve/2.md), except for the differences described in this manual page.

If *path* is relative, then it is interpreted relative to the directory referred to by the file descriptor *dirfd* (rather than relative to the current working directory of the calling process, as is done by [**execve**(2)](/execve/2.md) for a relative pathname).

If *path* is relative and *dirfd* is the special value **AT\_FDCWD**, then *path* is interpreted relative to the current working directory of the calling process (like [**execve**(2)](/execve/2.md)).

If *path* is absolute, then *dirfd* is ignored.

If *path* is an empty string and the **AT\_EMPTY\_PATH** flag is specified, then the file descriptor *dirfd* specifies the file to be executed (i.e., *dirfd* refers to an executable file, rather than a directory).

The *flags* argument is a bit mask that can include zero or more of the following flags:

- **AT\_EMPTY\_PATH**

  If *path* is an empty string, operate on the file referred to by *dirfd* (which may have been obtained using the [**open**(2)](/open/2.md) **O\_PATH** flag).

- **AT\_SYMLINK\_NOFOLLOW**

  If the file identified by *dirfd* and a non-NULL *path* is a symbolic link, then the call fails with the error **ELOOP**.

## RETURN VALUE

On success, **execveat**() does not return. On error, -1 is returned, and *errno* is set to indicate the error.

## ERRORS

The same errors that occur for [**execve**(2)](/execve/2.md) can also occur for **execveat**(). The following additional errors can occur for **execveat**():

- *path*

  is relative but *dirfd* is neither **AT\_FDCWD** nor a valid file descriptor.

- **EINVAL**

  Invalid flag specified in *flags*.

- **ELOOP**

  *flags* includes **AT\_SYMLINK\_NOFOLLOW** and the file identified by *dirfd* and a non-NULL *path* is a symbolic link.

- **ENOENT**

  The program identified by *dirfd* and *path* requires the use of an interpreter program (such as a script starting with "#!"), but the file descriptor *dirfd* was opened with the **O\_CLOEXEC** flag, with the result that the program file is inaccessible to the launched interpreter. See BUGS.

- **ENOTDIR**

  *path* is relative and *dirfd* is a file descriptor referring to a file other than a directory.

## STANDARDS

Linux.

## HISTORY

Linux 3.19, glibc 2.34.

## NOTES

In addition to the reasons explained in [**openat**(2)](/openat/2.md), the **execveat**() system call is also needed to allow [**fexecve**(3)](/fexecve/3.md) to be implemented on systems that do not have the */proc* filesystem mounted.

When asked to execute a script file, the *argv\[0\]* that is passed to the script interpreter is a string of the form */dev/fd/N* or */dev/fd/N/P*, where *N* is the number of the file descriptor passed via the *dirfd* argument. A string of the first form occurs when **AT\_EMPTY\_PATH** is employed. A string of the second form occurs when the script is specified via both *dirfd* and *path*; in this case, *P* is the value given in *path*.

For the same reasons described in [**fexecve**(3)](/fexecve/3.md), the natural idiom when using **execveat**() is to set the close-on-exec flag on *dirfd*. (But see BUGS.)

## BUGS

The **ENOENT** error described above means that it is not possible to set the close-on-exec flag on the file descriptor given to a call of the form:

```
execveat(fd, "", argv, envp, AT_EMPTY_PATH);
```

However, the inability to set the close-on-exec flag means that a file descriptor referring to the script leaks through to the script itself. As well as wasting a file descriptor, this leakage can lead to file-descriptor exhaustion in scenarios where scripts recursively employ **execveat**().

## SEE ALSO

[**execve**(2)](/execve/2.md), [**openat**(2)](/openat/2.md), [**fexecve**(3)](/fexecve/3.md)