2:unlink

From Linux Man Pages

      unlink - delete a name and possibly the file it refers to
      

Contents 1 SYNOPSIS 2 DESCRIPTION 3 RETURN VALUE 4 ERRORS 5 CONFORMING TO 6 BUGS 7 RELATED 8 CATEGORY

SYNOPSIS

      #include <unistd.h>
 
      int unlink(const char *pathname);

DESCRIPTION

      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  exis-
      tence 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 it.

RETURN VALUE

      On success, zero is returned.  On error, -1 is returned, and errno is set appropriately.

ERRORS

      EACCES Write access to the directory containing pathname is not allowed for the process's effective UID,  or  one
             of the directories in pathname did not allow search permission.  (See also path_resolution(2).)
 
      EBUSY (not on Linux)
             The  file  pathname  cannot  be unlinked because it is being used by the system or another process and the
             implementation considers this an error.
 
      EFAULT pathname points outside your accessible address space.
 
      EIO    An I/O error occurred.
 
      EISDIR pathname refers to a directory.  (This is the non-POSIX value returned by Linux since 2.1.132.)
 
      ELOOP  Too many symbolic links were encountered in translating pathname.
 
      ENAMETOOLONG
             pathname was too long.
 
      ENOENT A component in pathname does not exist or is a dangling symbolic link, or pathname is empty.
 
      ENOMEM Insufficient kernel memory was available.
 
      ENOTDIR
             A component used as a directory in pathname is not, in fact, a directory.
 
      EPERM  The system does not allow unlinking of directories, or unlinking of directories requires  privileges  that
             the  current  process  doesn't  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 process's effective UID is nei-
             ther  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 CAP_FOWNER capability).
 
      EROFS  pathname refers to a file on a read-only filesystem.

CONFORMING TO

      SVr4, 4.3BSD, POSIX.1-2001.

BUGS

      Infelicities in the protocol underlying NFS can cause the unexpected disappearance of files which are still being
      used.

RELATED

      rm(1),  chmod(2),  link(2),  mknod(2),  open(2), path_resolution(2), rename(2), rmdir(2), unlinkat(2), mkfifo(3),
      remove(3)

CATEGORY