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unlink() - Unix, Linux System Call
unlink - delete a name and possibly the file it refers to
int unlink(const char *pathname);
unlink() deletes a name from the filesystem. If that name was the
last link to a file and no processes have the file open the file is
deleted and the space it was using is made available for reuse.
If the name was the last link to a file but any processes still have
the file open the file will remain in existence until the last file
descriptor referring to it is closed.
If the name referred to a symbolic link the link is removed.
If the name referred to a socket, fifo or device the name for it is
removed but processes which have the object open may continue to use
On success, zero is returned. On error, -1 is returned, and errno is set appropriately.
Write access to the directory containing
pathname is not allowed for the processs effective UID, or one of the
pathname did not allow search permission.
EBUSY (not on Linux) ||
pathname cannot be unlinked because it is being used by the system
or another process and the implementation considers this an error.
pathname points outside your accessible address space.
An I/O error occurred.
pathname refers to a directory.
(This is the non-POSIX value returned by Linux since 2.1.132.)
Too many symbolic links were encountered in translating
pathname was too long. |
A component in
pathname does not exist or is a dangling symbolic link, or
pathname is empty.
Insufficient kernel memory was available.
A component used as a directory in
pathname is not, in fact, a directory.
The system does not allow unlinking of directories,
or unlinking of directories requires privileges that the
current process doesnt have.
(This is the POSIX prescribed error return;
as noted above, Linux returns
EISDIR for this case.)
EPERM (Linux only) ||
The filesystem does not allow unlinking of files.
EPERM or EACCES ||
The directory containing
pathname has the sticky bit
(S_ISVTX) set and the processs effective UID is neither the UID of the file to
be deleted nor that of the directory containing it, and
the process is not privileged (Linux: does not have the
pathname refers to a file on a read-only filesystem.
SVr4, 4.3BSD, POSIX.1-2001.
Infelicities in the protocol underlying NFS can cause the unexpected
disappearance of files which are still being used.