unlink(2) - NetBSD Manual Pages

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UNLINK(2)                 NetBSD Programmer's Manual                 UNLINK(2)


NAME

     unlink - remove directory entry


SYNOPSIS

     #include <unistd.h>

     int
     unlink(const char *path);


DESCRIPTION

     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 process have the file open when the last
     link is removed, the link is removed, but the removal of the file is de-
     layed until all references to it have been closed.


RETURN VALUES

     Upon successful completion, a value of 0 is returned.  Otherwise, a value
     of -1 is returned and errno is set to indicate the error.


ERRORS

     The unlink() succeeds unless:

     [ENOTDIR]     A component of the path prefix is not a directory.

     [ENAMETOOLONG]
                   A component of a pathname exceeded {NAME_MAX} characters,
                   or an entire path name exceeded {PATH_MAX} characters.

     [ENOENT]      The named file does not exist.

     [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.

     [ELOOP]       Too many symbolic links were encountered in translating the
                   pathname.

     [EPERM]       The named file is a directory and the effective user ID of
                   the process is not the super-user, or the file system con-
                   taining the file does not permit the use of unlink() on 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.

     [EBUSY]       The entry to be unlinked is the mount point for a mounted
                   file system.

     [EIO]         An I/O error occurred while deleting the directory entry or
                   deallocating the inode.

     [EROFS]       The named file resides on a read-only file system.

     [EFAULT]      Path points outside the process's allocated address space.


SEE ALSO

     close(2),  link(2),  rmdir(2),  symlink(7)


STANDARDS

     The unlink() function conforms to IEEE Std1003.1-1990 (``POSIX'').


HISTORY

     An unlink() function call appeared in Version 6 AT&T UNIX.

4th Berkeley Distribution        June 4, 1993                                2