man pages section 2: System Calls
    
U
 
 uadmin -- administrative control ( Index Term Link )
 
 ulimit -- get and set process limits ( Index Term Link )
 
 umount -- unmount a file system ( Index Term Link )
 
 unlink -- remove directory entry ( Index Term Link )
 
 unmount a file system -- umount ( Index Term Link )
 
 user audit identity, get process audit information -- getaudit ( Index Term Link )
 
 user IDs
  set -- setuid ( Index Term Link )
  set real and effective -- setreuid ( Index Term Link )
 
 utimes -- set file access and modification times ( Index Term Link )