unlink(2) [hpux man page]
unlink(2) System Calls Manual unlink(2) NAME
unlink - remove directory entry; delete file SYNOPSIS
DESCRIPTION
The system call removes the directory entry named by the path name pointed to by path. When all links to a file have been removed and no process has the file open, the space occupied by the file is freed and the file ceases to exist. If one or more processes have the file open when the last link is removed, only the directory entry is removed immediately so that processes that do not already have the file open cannot access the file. After all processes close their references to the file, if there are no more links to the file, the space occupied by the file is then freed and the file ceases to exist. RETURN VALUE
returns the following values: Successful completion. Failure. is set to indicate the error. ERRORS
If fails, is set to one of the following values: Search permission is denied for a component of the path prefix. Write permission is denied on the directory containing the link to be removed. The process does not have read/write access permission to the parent directory. The entry to be unlinked is the mount point for a mounted file system. path points outside the process's allocated address space. The reliable detection of this error is implementation dependent. Too many symbolic links were encountered in translating the path name. The length of the specified path name exceeds bytes, or the length of a component of the path name exceeds bytes while is in effect. The named file does not exist (for example, path is null or a component of path does not exist). A component of the path prefix is not a directory. The directory containing the file to be removed has the sticky bit set and neither the containing directory nor the file to be removed are owned by the effective user ID. The named file is a directory and the effective user ID is not a user with appropriate privileges. Some file systems return this error whenever the named file is a directory, regardless of the user ID. The directory entry to be unlinked is part of a read-only file system. The entry to be unlinked is the last link to a pure procedure (shared text) file that is being executed. WARNINGS
If is used on a directory that is not empty (contains files other than and the directory is unlinked, the files become orphans, and the directory link count is left with an inaccurate value unless they are linked by some other directory. If is used on a directory that is empty (contains only the files and the directory is unlinked, but the parent directory's link count is left with an inaccurate value. In either of the above cases, the file system should be checked using (see fsck(1M)). To avoid these types of problems, use instead (see rmdir(2)). SEE ALSO
rm(1), close(2), link(2), open(2), rmdir(2), remove(3C), privileges(5). STANDARDS CONFORMANCE
unlink(2)
Check Out this Related Man Page
unlink(2) System Calls unlink(2) NAME
unlink, unlinkat - remove directory entry SYNOPSIS
#include <unistd.h> int unlink(const char *path); int unlinkat(int dirfd, const char *path, int flag); DESCRIPTION
The unlink() function removes a link to a file. If path names a symbolic link, unlink() removes the symbolic link named by path and does not affect any file or directory named by the contents of the symbolic link. Otherwise, unlink() removes the link named by the pathname pointed to by path and decrements the link count of the file referenced by the link. The unlinkat() function also removes a link to a file. See fsattr(5). If the flag argument is 0, the behavior of unlinkat() is the same as unlink() except in the processing of its path argument. If path is absolute, unlinkat() behaves the same as unlink() and the dirfd argument is unused. If path is relative and dirfd has the value AT_FDCWD, defined in <fcntl.h>, unlinkat() also behaves the same as unlink(). Other- wise, path is resolved relative to the directory referenced by the dirfd argument. If the flag argument is set to the value AT_REMOVEDIR, defined in <fcntl.h>, unlinkat() behaves the same as rmdir(2) except in the process- ing of the path argument as described above. When the file's link count becomes 0 and no process has the file open, the space occupied by the file will be freed and the file is no longer accessible. If one or more processes have the file open when the last link is removed, the link is removed before unlink() or unlinkat() returns, but the removal of the file contents is postponed until all references to the file are closed. The path argument must not name a directory unless the process has appropriate privileges and the implementation supports using unlink() and unlinkat() on directories. Upon successful completion, unlink() and unlinkat() will mark for update the st_ctime and st_mtime fields of the parent directory. If the file's link count is not 0, the st_ctime field of the file will be marked for update. RETURN VALUES
Upon successful completion, 0 is returned. Otherwise, -1 is returned, errno is set to indicate the error, and the file is not unlinked. ERRORS
The unlink() and unlinkat() functions will fail if: EACCES Search permission is denied for a component of the path prefix, or write permission is denied on the directory containing the link to be removed. EACCES The parent directory has the sticky bit set and the file is not writable by the user, the user does not own the parent directory, the user does not own the file, and the user is not a privileged user. EBUSY The entry to be unlinked is the mount point for a mounted file system. EFAULT The path argument points to an illegal address. EINTR A signal was caught during the execution of the unlink() function. ELOOP Too many symbolic links were encountered in translating path. ENAMETOOLONG The length of the path argument exceeds PATH_MAX, or the length of a path component exceeds NAME_MAX while _POSIX_NO_TRUNC is in effect. ENOENT The named file does not exist or is a null pathname. ENOLINK The path argument points to a remote machine and the link to that machine is no longer active. ENOTDIR A component of the path prefix is not a directory or the provided directory descriptor for unlinkat() is not AT_FDCWD or does not reference a directory. EPERM The named file is a directory and {PRIV_SYS_LINKDIR} is not asserted in the effective set of the calling process. EROFS The directory entry to be unlinked is part of a read-only file system. The unlink() and unlinkat() functions may fail if: ENAMETOOLONG Pathname resolution of a symbolic link produced an intermediate result whose length exceeds {PATH_MAX}. ETXTBSY The entry to be unlinked is the last directory entry to a pure procedure (shared text) file that is being executed. USAGE
Applications should use rmdir(2) to remove a directory. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |unlink() is Standard; | | |unlinkat() is Evolving | +-----------------------------+-----------------------------+ |MT-Level |Async-Signal-Safe | +-----------------------------+-----------------------------+ SEE ALSO
rm(1), close(2), link(2), open(2), rmdir(2), remove(3C), attributes(5), privileges(5), fsattr(5) SunOS 5.10 1 Feb 2003 unlink(2)