UNLINK

Section: System Calls (2)
Updated: August 1, 1992
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NAME

unlink - remove directory entry  

SYNOPSIS

int unlink(const char *path);
 

DESCRIPTION

The unlink function removes the link whose pathname is specified by path and decrement the link count of the file referenced by the link. If this entry was the last link to the file, and no process has the file open, then all resources associated with the file are reclaimed. If, however, the file was open in any process, the actual resource reclamation is delayed until it is closed, even though the directory entry has disappeared.

The path argument must not name a directory. Applications should use rmdir to remove a directory.

Upon successful completion, the unlink function marks for update the st_ctime and st_mtime fields of the parent directory of the entry to be removed. Furthermore, if the link count of the file is not zero, then the st_ctime field of the file is also marked for update.  

RETURN VALUE

Upon successful completion, a value of zero is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.  

ERRORS

If any of the following conditions occurs, the unlink function returns -1 and sets errno to the corresponding value:
[EACCES]
Search permission is denied for a component of the path prefix.
[EACCES]
Write permission is denied on the directory containing the link to be removed.
[EBUSY]
The entry to be unlinked is the mount point for a mounted file system.
[EFAULT]
The path argument points outside the process's allocated address space.
[EINVAL]
The pathname contains a character with the high-order bit set.
[EIO]
An I/O error occurred while deleting the directory entry or deallocating the inode.
[ELOOP]
Too many symbolic links were encountered in translating the pathname.
[ENAMETOOLONG]
A component of path exceeds 255 characters, or the entire pathname exceeds 1023 characters. For POSIX applications these values are given by the constants {NAME_MAX} and {PATH_MAX}, respectively.
[ENOENT]
The named file does not exist.
[ENOENT]
The path argument points to an empty string.
[ENOTDIR]
A component of the path prefix is not a directory.
[EPERM]
The named file is a directory.
[EPERM]
The directory containing the file is marked sticky, and neither the containing directory nor the file to be removed are owned by the effective user ID.
[EROFS]
The named file resides on a read-only file system.
 

SEE ALSO

close(2), link(2), open(2), rename(2), rmdir(2)

 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
SEE ALSO
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