UNLINK(2) | System Calls Manual | UNLINK(2) |
unlink
, unlinkat
— remove directory entry
#include
<unistd.h>
int
unlink
(const
char *path);
#include <fcntl.h>
#include <unistd.h>
int
unlinkat
(int
fd, const char
*path, int
flag);
The
unlink
()
function removes the link named by path from its
directory and decrements the link count of the file which was referenced by
the link. If that decrement reduces the link count of the file to zero, and
no process has the file open, then all resources associated with the file
are reclaimed. If one or more processes have the file open when the last
link is removed, the link is removed, but the removal of the file is delayed
until all references to it have been closed.
The
unlinkat
()
function is equivalent to either the unlink
() or
rmdir(2) function depending on the value
of flag (see below), except that where
path specifies a relative path, the directory entry to
be removed is determined relative to the directory associated with file
descriptor fd instead of the current working
directory.
If
unlinkat
()
is passed the special value AT_FDCWD
(defined in
<fcntl.h>
) in the
fd parameter, the current working directory is used
and the behavior is identical to a call to unlink
()
or rmdir(2), depending on whether or not
the AT_REMOVEDIR
bit is set in
flag.
The flag argument is the bitwise OR of zero or more of the following values:
AT_REMOVEDIR
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.
The unlink
() and
unlinkat
() functions will fail if:
ENOTDIR
]ENAMETOOLONG
]NAME_MAX
characters, or an entire pathname (including the terminating NUL) exceeded
PATH_MAX
bytes.ENOENT
]EACCES
]EACCES
]ELOOP
]EPERM
]unlink
() on a directory.EPERM
]EPERM
]EBUSY
]EIO
]EROFS
]EFAULT
]Additionally, unlinkat
() will fail if:
ENOTDIR
]AT_REMOVEDIR
flag bit is set and
path does not name a directory.ENOTEMPTY
]AT_REMOVEDIR
flag bit is set and the named
directory contains files other than
‘.
’ and
‘..
’ in it.EINVAL
]AT_REMOVEDIR
.EINVAL
]AT_REMOVEDIR
and the last element of
path consists of
‘.
’.EBADF
]AT_FDCWD
nor a valid file descriptor.ENOTDIR
]EACCES
]The unlink
() and
unlinkat
() functions conform to
IEEE Std 1003.1-2008 (“POSIX.1”).
The unlink
() system call first appeared in
Version 1 AT&T UNIX. The
unlinkat
() function appeared in
OpenBSD 5.0.
June 30, 2021 | OpenBSD-current |