Implementation status: to be implemented


#include <unistd.h>

int fchown(int fildes, uid_t owner, gid_t group);


The function changes the owner and the group of the file.


fildes - the file descriptor.
owner - the new owner of a file.
group - the new group of a file.

The fchown() function is equivalent to chown() except that the file whose owner and group are changed is specified by the file descriptor fildes.

Return value

Upon successful completion, fchown() returns 0. Otherwise, -1 is returned and errno set to indicate the error.


[EBADF] The fildes argument is not a valid open file descriptor.
[EPERM] The effective user ID does not match the owner of the file or the process does not have appropriate privileges and _POSIX_CHOWN_RESTRICTED indicates that such privilege is required.
[EROFS] The file referred to by fildes resides on a read-only file system.

[EINTR] The fchown() function was interrupted by a signal.
[EINVAL] The owner or group ID is not a value supported by the implementation. The fildes argument refers to a pipe or socket or an fattach()-ed STREAM and the implementation disallows execution of fchown() on a pipe.
[EIO] A physical I/O error has occurred.

Implementation tasks

  • Implement fchown() function