unlink(2)							System Calls Manual							 unlink(2)

NAME

       unlink - Removes a directory entry

SYNOPSIS

       #include <unistd.h>

       int unlink (	 const char *path );

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       unlink():  XSH5.0

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS

       Specifies the directory entry to be removed.

DESCRIPTION

       When the directory entry is a hard link, the unlink() function removes it and decrements the link count of the file referenced by the link.
       When the directory entry is a symbolic link, the unlink() function removes the symbolic link and does not  affect  any  file  or  directory
       named by the contents of the symbolic link.

       When  all links to a file are removed and no process has the file open or mapped, all resources associated with the file are reclaimed, and
       the file is no longer accessible. If one or more processes have the file open or mapped when the last link is removed, the link is  removed
       before  the  unlink()  function returns, but the removal of the file contents is postponed until all open or map references to the file are
       removed.

       A hard link to a directory cannot be unlinked.

       A process must have write access to the parent directory of the file to be unlinked with respect to all access policies.

       Upon successful completion, the unlink() function marks for update the st_ctime and st_mtime fields of the directory  which  contained  the
       link.  If the file's link count is not 0 (zero), the st_ctime field of the file is also marked for update.

   System V Compatibility
       [Tru64  UNIX]  Any  attempt  to	unlink	non-empty  directories in the System V habitat will cause the unlink call to fail and set errno to
       ENOTEMPTY, even if the process has superuser privileges.  This error behavior is provided in the System V habitat to comply with the SVID-2
       industry standard.

RETURN VALUES

       Upon  successful  completion, a value of 0 (zero) is returned. If the unlink() function fails, a value of -1 is returned, the named file is
       not changed, and errno is set to indicate the error.

ERRORS

       If the unlink() function fails, the named file is not unlinked and errno may be set to one of the following values:  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.  The S_ISVTX
       flag is set on the directory containing the file referred to by the path argument and the caller is not the file owner, nor is  the  caller
       the  directory owner, nor does the caller have appropriate priviliges.  The entry to be unlinked is the mount point for a mounted file sys-
       tem.  The file named by path is a named STREAM.	The path parameter is an invalid address.  Too many symbolic  links  were  encountered	in
       translating  path.  The length of the path parameter exceeds PATH_MAX or a pathname component is longer than NAME_MAX.  Pathname resolution
       of a symbolic link produced an intermediate result whose length exceeds PATH_MAX.  The named file does not  exist  or  the  path  parameter
       points to an empty string.  A component of the path prefix is not a directory.  The named file is a directory.

	      The  S_ISVTX flag is set on the directory containing the file referred to by the path argument and the caller is not the file owner,
	      nor is the caller the directory owner, nor does the caller have appropriate priviliges.  The entry to be unlinked is part of a read-
	      only  file  system.   The entry to be unlinked is the last directory entry to a pure procedure (shared text) file that is being exe-
	      cuted.

       [Tru64 UNIX]  For NFS file access, if the link() function fails, errno may also be set to one of the  following	values:  Indicates  either
       that  the  request was for a write access to a file but the specified filename was actually a directory, or that the function was trying to
       rename a directory as a file.  Indicates either that the system file table is full, or that there are too many files currently open in  the
       system.	Indicates a stale NFS file handle.  A client cannot delete a link because the server has unmounted or unexported the remote direc-
       tory; or the directory that contains an file was either unmounted or unexported by the server.

RELATED INFORMATION

       Commands: link(1), unlink(1), rm(1)

       Functions: close(2), link(2), open(2), rmdir(2)

       Standards: standards(5) delim off

																	 unlink(2)