diff --git a/plugin/cscope.vim b/plugin/cscope.vim
index cdf923d..fed6f64 100755
--- a/plugin/cscope.vim
+++ b/plugin/cscope.vim
@@ -1,154 +1,125 @@
-" vim: tabstop=2 shiftwidth=2 softtabstop=2 expandtab foldmethod=marker
 "    Copyright: Copyright (C) 2012-2015 Brook Hong
 "    License: The MIT License
 "
+let s:cscope_vim_db_dir = substitute($HOME,'\\','/','g')."/.cscope.vim"
+let s:cscope_vim_db_index_file = s:cscope_vim_db_dir.'/index'
+let s:cscope_vim_db_current_prepend_path = ""
+let s:cscope_vim_db_entry_len = 5
+let s:cscope_vim_db_entry_idx_prepend_path = 0
+let s:cscope_vim_db_entry_idx_id = 1
+let s:cscope_vim_db_entry_idx_loadtimes = 2
+let s:cscope_vim_db_entry_idx_dirty = 3
+let s:cscope_vim_db_entry_idx_depedency = 4
+let s:cscope_vim_db_entry_key_id = 'id'
+let s:cscope_vim_db_entry_key_loadtimes = 'loadtimes'
+let s:cscope_vim_db_entry_key_dirty = 'dirty'
+let s:cscope_vim_db_entry_key_depedency = 'depedency'
 
-if !exists('g:cscope_silent')
-  let g:cscope_silent = 0
-endif
-
-if !exists('g:cscope_auto_update')
-  let g:cscope_auto_update = 1
-endif
+function! CscopeFind(action, word, ...)
+  let l:current_path = tolower(substitute(expand('%:p:h'), '\\', '/', 'g'))
+  let l:prepend_path = <SID>GetPrependPath(l:current_path)
+  let l:in_dependency = 0
 
-if !exists('g:cscope_open_location')
-  let g:cscope_open_location = 1
-endif
+  " possible reasons for empty prepend path
+  "   - DB not yet built
+  "   - we are in depedency files 
+  if l:prepend_path == "" && s:cscope_vim_db_current_prepend_path != ""
+    for l:d in split(s:dbs[s:cscope_vim_db_current_prepend_path][s:cscope_vim_db_entry_key_depedency], ';')
+      let l:d = substitute(l:d, "\/\\s*$", '', 'g')
 
-if !exists('g:cscope_split_threshold')
-  let g:cscope_split_threshold = 10000
-endif
+      if stridx(l:current_path, l:d) == 0
+        let l:in_dependency = 1
+        break
+      endif
+    endfor
+  endif
+  
+  " build a brand new db
+  if l:prepend_path == "" && l:in_dependency == 0 
+    let l:prepend_path = <SID>InitDB(l:current_path)
 
-function! ToggleLocationList()
-  let l:own = winnr()
-  lw
-  let l:cwn = winnr()
-  if(l:cwn == l:own)
-    if &buftype == 'quickfix'
-      lclose
-    elseif len(getloclist(winnr())) > 0
-      lclose
-    else
-      echohl WarningMsg | echo "No location list." | echohl None
+    if l:prepend_path != ""
+      call <SID>BuildDB(l:prepend_path, 1)
+      call <SID>LoadDB(l:prepend_path)
     endif
   endif
-endfunction
 
-if !exists('g:cscope_cmd')
-  if executable('cscope')
-    let g:cscope_cmd = 'cscope'
-  else
-    echo 'cscope: command not found'
-    finish
-  endif
-endif
+  if l:prepend_path != ""
+    let l:id = s:dbs[l:prepend_path][s:cscope_vim_db_entry_key_id]
 
-if !exists('g:cscope_interested_files')
-  let files = readfile(expand("<sfile>:p:h")."/interested.txt")
-  let g:cscope_interested_files = join(map(files, 'v:val."$"'), '\|')
-endif
+    if cscope_connection(2, s:cscope_vim_db_dir.'/'.l:id.'.db') == 0
+      call <SID>LoadDB(l:prepend_path)
+    endif
+  endif
 
-let s:cscope_vim_dir = substitute($HOME,'\\','/','g')."/.cscope.vim"
-let s:index_file = s:cscope_vim_dir.'/index'
+  try
+    if a:0 == 0 
+      exe 'cs f '.a:action.' '.a:word
+    elseif a:0 >= 1 && a:1 == 'horizontal'
+      exe 'scs f '.a:action.' '.a:word
+    elseif a:0 >= 1 && a:1 == 'vertical'
+      exe 'vert scs f '.a:action.' '.a:word
+    endif
 
-function! s:GetBestPath(dir)
-  let f = substitute(a:dir,'\\','/','g')
-  let bestDir = ""
-  for d in keys(s:dbs)
-    if stridx(f, d) == 0 && len(d) > len(bestDir)
-      let bestDir = d
+    if g:cscope_open_location == 1
+      cw
     endif
-  endfor
-  return bestDir
+  catch
+    echohl WarningMsg | echo 'Can not find '.a:word.' with querytype as '.a:action.'.' | echohl None
+  endtry
 endfunction
 
-function! s:ListFiles(dir)
-  let d = []
-  let f = []
-  let cwd = a:dir
-  let sl = &l:stl
-  while cwd != ''
-    let a = split(globpath(cwd, "*"), "\n")
-    for fn in a
-      if getftype(fn) == 'dir'
-        call add(d, fn)
-      elseif getftype(fn) != 'file'
-        continue
-      elseif fn !~? g:cscope_interested_files
-        continue
-      else
-        if stridx(fn, ' ') != -1
-          let fn = '"'.fn.'"'
-        endif
-        call add(f, fn)
-      endif
-    endfor
-    let cwd = len(d) ? remove(d, 0) : ''
-    sleep 1m | let &l:stl = 'Found '.len(f).' files, finding in '.cwd | redrawstatus
-  endwhile
-  sleep 1m | let &l:stl = sl | redrawstatus
-  return f
-endfunction
+function! CscopeFindInteractive(pat)
+  call inputsave()
 
-function! s:RmDBfiles()
-  let odbs = split(globpath(s:cscope_vim_dir, "*"), "\n")
-  for f in odbs
-    call delete(f)
-  endfor
+  let qt = input("\nChoose a querytype for '".a:pat."'(:help cscope-find)\n  c: functions calling this function\n  d: functions called by this function\n  e: this egrep pattern\n  f: this file\n  g: this definition\n  i: files #including this file\n  s: this C symbol\n  t: this text string\n\n  or\n  <querytype><pattern> to query `pattern` instead of '".a:pat."' as `querytype`, Ex. `smain` to query a C symbol named 'main'.\n> ")
+
+  call inputrestore()
+
+  if len(qt) > 1
+    call CscopeFind(qt[0], qt[1:])
+  elseif len(qt) > 0
+    call CscopeFind(qt, a:pat)
+  endif
 endfunction
 
-function! s:FlushIndex()
-  let lines = []
+function! s:CscopeUpdateAllDB()
   for d in keys(s:dbs)
-    call add(lines, d.'|'.s:dbs[d]['id'].'|'.s:dbs[d]['loadtimes'].'|'.s:dbs[d]['dirty'])
+    call <SID>BuildDB(d, 0)
   endfor
-  call writefile(lines, s:index_file)
 endfunction
 
-function! s:CheckNewFile(dir, newfile)
-  let id = s:dbs[a:dir]['id']
-  let cscope_files = s:cscope_vim_dir."/".id.".files"
-  let files = readfile(cscope_files)
-  if len(files) > g:cscope_split_threshold
-    let cscope_files = s:cscope_vim_dir."/".id."_inc.files"
-    if filereadable(cscope_files)
-      let files = readfile(cscope_files)
-    else
-      let files = []
+function! s:CscopeUpdateCurrentDB()
+  let l:current_path = expand('%:p:h')
+  let l:prepend_path = <SID>GetPrependPath(l:current_path)
+
+  if l:prepend_path != ""
+    call <SID>BuildDB(l:prepend_path, 0)
+  else
+    let l:prepend_path = <SID>InitDB(l:current_path)
+
+    if l:prepend_path != ""
+      call <SID>BuildDB(l:prepend_path, 1)
+      call <SID>LoadDB(l:prepend_path)
     endif
   endif
-  if count(files, a:newfile) == 0
-    call add(files, a:newfile)
-    call writefile(files, cscope_files)
-  endif
 endfunction
 
-function! s:_CreateDB(dir, init)
-  let id = s:dbs[a:dir]['id']
-  let cscope_files = s:cscope_vim_dir."/".id."_inc.files"
-  let cscope_db = s:cscope_vim_dir.'/'.id.'_inc.db'
-  if ! filereadable(cscope_files) || a:init
-    let cscope_files = s:cscope_vim_dir."/".id.".files"
-    let cscope_db = s:cscope_vim_dir.'/'.id.'.db'
-    if ! filereadable(cscope_files)
-      let files = <SID>ListFiles(a:dir)
-      call writefile(files, cscope_files)
-    endif
-  endif
-  exec 'cs kill '.cscope_db
-  redir @x
-  exec 'silent !'.g:cscope_cmd.' -b -i '.cscope_files.' -f'.cscope_db
-  redi END
-  if @x =~ "\nCommand terminated\n"
-    echohl WarningMsg | echo "Failed to create cscope database for ".a:dir.", please check if " | echohl None
-  else
-    let s:dbs[a:dir]['dirty'] = 0
-    exec 'cs add '.cscope_db
+function! s:CscopeRebuildCurrentDB()
+  call <SID>ClearDBs(0)
+
+  let l:current_path = expand('%:p:h')
+  let l:prepend_path = <SID>InitDB(l:current_path)
+
+  if l:prepend_path != ""
+    call <SID>BuildDB(l:prepend_path, 1)
+    call <SID>LoadDB(l:prepend_path)
   endif
 endfunction
 
 function! s:CheckAbsolutePath(dir, defaultPath)
   let d = a:dir
+
   while 1
     if !isdirectory(d)
       echohl WarningMsg | echo "Please input a valid path." | echohl None
@@ -160,109 +131,247 @@ function! s:CheckAbsolutePath(dir, defaultPath)
       break
     endif
   endwhile
+
   let d = substitute(d,'\\','/','g')
   let d = substitute(d,'/\+$','','')
-  return d
-endfunction
 
-function! s:InitDB(dir)
-  let id = localtime()
-  let s:dbs[a:dir] = {}
-  let s:dbs[a:dir]['id'] = id
-  let s:dbs[a:dir]['loadtimes'] = 0
-  let s:dbs[a:dir]['dirty'] = 0
-  call <SID>_CreateDB(a:dir, 1)
-  call <SID>FlushIndex()
+  return d
 endfunction
 
-function! s:LoadDB(dir)
+" @param clearWhich:  -1   all database
+"                      0   the current database
+function! s:ClearDBs(clearWhich)
   cs kill -1
-  exe 'cs add '.s:cscope_vim_dir.'/'.s:dbs[a:dir]['id'].'.db'
-  if filereadable(s:cscope_vim_dir.'/'.s:dbs[a:dir]['id'].'_inc.db')
-    exe 'cs add '.s:cscope_vim_dir.'/'.s:dbs[a:dir]['id'].'_inc.db'
+  
+  if a:clearWhich == -1
+    let s:dbs = {}
+    call <SID>RmDBfiles()
+    call writefile([], s:cscope_vim_db_index_file)
+  elseif a:clearWhich == 0
+    let l:current_path = expand('%:p:h')
+    let l:prepend_path = <SID>GetPrependPath(l:current_path)
+
+    if l:prepend_path != ""
+      let l:current_db_files = split(globpath(s:cscope_vim_db_dir, s:dbs[l:prepend_path][s:cscope_vim_db_entry_key_id]."*"), "\n")
+
+      for f in l:current_db_files
+        call delete(f)
+      endfor
+
+      unlet s:dbs[l:prepend_path]
+
+      call <SID>FlushIndex()
+    endif
   endif
-  let s:dbs[a:dir]['loadtimes'] = s:dbs[a:dir]['loadtimes']+1
-  call <SID>FlushIndex()
 endfunction
 
-function! s:AutoloadDB(dir)
-  let m_dir = <SID>GetBestPath(a:dir)
-  if m_dir == ""
-    echohl WarningMsg | echo "Can not find proper cscope db, please input a path to generate cscope db for." | echohl None
-    let m_dir = input("", a:dir, 'dir')
-    if m_dir != ''
-      let m_dir = <SID>CheckAbsolutePath(m_dir, a:dir)
-      call <SID>InitDB(m_dir)
-      call <SID>LoadDB(m_dir)
-    endif
+function! s:BuildDB(prepend_path, init)
+  let l:id = s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id]
+  let l:depedency = split(s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_depedency], ';')
+  let l:cscope_files = s:cscope_vim_db_dir."/".id."_inc.files"
+  let l:cscope_db = s:cscope_vim_db_dir.'/'.id.'_inc.db'
+
+  if ! filereadable(cscope_files) || a:init
+    let l:cscope_files = s:cscope_vim_db_dir."/".id.".files"
+    let l:cscope_db = s:cscope_vim_db_dir.'/'.id.'.db'
+  endif
+
+  " validate depedency
+  for i in range(len(l:depedency))
+    let l:depedency[i] = <SID>CheckAbsolutePath(l:depedency[i], "")
+  endfor
+
+  " force update file list
+  let files = []
+  for d in [a:prepend_path] + l:depedency
+    let files += <SID>ListFiles(d)
+  endfor
+  call writefile(files, cscope_files)
+
+  " build cscope database, must build in the 
+  " prepend path otherwise there might be error
+  " in generating database, e.g. invalid path for
+  " symbols.
+  exec 'chdir '.a:prepend_path
+  exec 'cs kill '.cscope_db
+  redir @x
+  exec 'silent !'.g:cscope_cmd.' -b -i '.cscope_files.' -f '.cscope_db
+  redir END
+
+  " check build result and add database
+  if @x =~ "\nCommand terminated\n"
+    echohl WarningMsg | echo "Failed to create cscope database for ".a:prepend_path.", please check if " | echohl None
   else
-    let id = s:dbs[m_dir]['id']
-    if cscope_connection(2, s:cscope_vim_dir.'/'.id.'.db') == 0
-      call <SID>LoadDB(m_dir)
-    endif
+    let s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_dirty] = 0
   endif
+
+  call <SID>FlushIndex()
 endfunction
 
-function! s:updateDBs(dirs)
-  for d in a:dirs
-    call <SID>_CreateDB(d, 0)
+function! s:FlushIndex()
+  let l:lines = []
+
+  for d in keys(s:dbs)
+    call add(l:lines, d.'|'.s:dbs[d][s:cscope_vim_db_entry_key_id].'|'.s:dbs[d][s:cscope_vim_db_entry_key_loadtimes].'|'.s:dbs[d][s:cscope_vim_db_entry_key_dirty].'|'.s:dbs[d][s:cscope_vim_db_entry_key_depedency].'|')
   endfor
-  call <SID>FlushIndex()
+
+  call writefile(l:lines, s:cscope_vim_db_index_file)
 endfunction
 
-function! s:echo(msg)
-  if g:cscope_silent == 0
-    echo a:msg
-  endif
+function! s:GetPrependPath(dir)
+  let f = tolower(substitute(a:dir,'\\','/','g'))
+  let bestDir = ""
+
+  for d in keys(s:dbs)
+    if stridx(f, d) == 0 && len(d) > len(bestDir)
+      let bestDir = d
+    endif
+  endfor
+
+  return bestDir
 endfunction
 
-function! s:clearDBs()
-  cs kill -1
-  let s:dbs = {}
-  call <SID>RmDBfiles()
-  call writefile([], s:index_file)
+function! s:InitDB(current_path)
+  echohl WarningMsg | echo "Please input a path to generate cscope database." | echohl None
+  let l:prepend_path = tolower(substitute(input("", a:current_path, 'dir'),'\\','/','g'))
+
+  if l:prepend_path != ''
+    let prepend_path = <SID>CheckAbsolutePath(l:prepend_path, a:current_path)
+
+    echohl WarningMsg | echo "\nPlease input depedency paths (separated with ';'), if any." | echohl None
+    let l:depedency_path = tolower(substitute(input("", "", 'dir'),'\\','/','g'))
+
+    let s:dbs[l:prepend_path] = {}
+    let s:dbs[l:prepend_path][s:cscope_vim_db_entry_key_id] = localtime()
+    let s:dbs[l:prepend_path][s:cscope_vim_db_entry_key_loadtimes] = 0
+    let s:dbs[l:prepend_path][s:cscope_vim_db_entry_key_dirty] = 0
+    let s:dbs[l:prepend_path][s:cscope_vim_db_entry_key_depedency] = l:depedency_path
+
+    call <SID>FlushIndex()
+
+    return l:prepend_path
+  else
+    echohl WarningMsg | echo "Error: path can not be empty." | echohl None
+  endif
 endfunction
 
-function! s:listDBs()
+function! s:ListDBs()
   let dirs = keys(s:dbs)
+
   if len(dirs) == 0
     echo "You have no cscope dbs now."
   else
     let s = [' ID                   LOADTIMES    PATH']
+
     for d in dirs
       let id = s:dbs[d]['id']
-      if cscope_connection(2, s:cscope_vim_dir.'/'.id.'.db') == 1
+
+      if cscope_connection(2, s:cscope_vim_db_dir.'/'.id.'.db') == 1
         let l = printf("*%d  %10d            %s", id, s:dbs[d]['loadtimes'], d)
       else
         let l = printf(" %d  %10d            %s", id, s:dbs[d]['loadtimes'], d)
       endif
+
       call add(s, l)
     endfor
+
     echo join(s, "\n")
   endif
 endfunction
 
-function! s:loadIndex()
+function! s:ListFiles(dir)
+  let d = []
+  let f = []
+  let cwd = a:dir
+  let sl = &l:stl
+
+  while cwd != ''
+    let a = split(globpath(cwd, "*"), "\n")
+
+    for fn in a
+      if getftype(fn) == 'dir'
+        call add(d, fn)
+      elseif getftype(fn) != 'file'
+        continue
+      elseif fn !~? g:cscope_interested_files
+        continue
+      else
+        if stridx(fn, ' ') != -1
+          let fn = '"'.fn.'"'
+        endif
+        call add(f, fn)
+      endif
+    endfor
+
+    let cwd = len(d) ? remove(d, 0) : ''
+
+    sleep 1m | let &l:stl = 'Found '.len(f).' files, finding in '.cwd | redrawstatus
+  endwhile
+
+  sleep 1m | let &l:stl = sl | redrawstatus
+  return f
+endfunction
+
+function! s:LoadDB(prepend_path)
+  cs kill -1
+
+  if g:cscope_search_case_insensitive == 1
+    exe 'cs add '.s:cscope_vim_db_dir.'/'.s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id].'.db '.a:prepend_path.' -C'
+    echo 'cscope db '.s:cscope_vim_db_dir.'/'.s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id].'.db added, searching case insensitively.'
+
+    if filereadable(s:cscope_vim_db_dir.'/'.s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id].'_inc.db')
+      exe 'cs add '.s:cscope_vim_db_dir.'/'.s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id].'_inc.db '.a:prepend_path.' -C'
+      echo 'cscope db '.s:cscope_vim_db_dir.'/'.s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id].'_inc.db added, searching case insensitively.'
+    endif
+  else
+    exe 'cs add '.s:cscope_vim_db_dir.'/'.s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id].'.db'
+    echo 'cscope db '.s:cscope_vim_db_dir.'/'.s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id].'.db added, searching case sensitively.'
+
+    if filereadable(s:cscope_vim_db_dir.'/'.s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id].'_inc.db')
+      exe 'cs add '.s:cscope_vim_db_dir.'/'.s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id].'_inc.db'
+      echo 'cscope db '.s:cscope_vim_db_dir.'/'.s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_id].'_inc.db added, searching case sensitively.'
+    endif
+  endif
+
+  let s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_loadtimes] = s:dbs[a:prepend_path][s:cscope_vim_db_entry_key_loadtimes] + 1
+  let s:cscope_vim_db_current_prepend_path = a:prepend_path
+
+  call <SID>FlushIndex()
+endfunction
+
+function! s:LoadIndex()
+  " s:dbs = { 'prepend1': {'id': '',
+  "                        'loadtimes': '',
+  "                        'dirty': 0|1,
+  "                        'depedency': '...;...'},
+  "           ...
+  "         }
   let s:dbs = {}
-  if ! isdirectory(s:cscope_vim_dir)
-    call mkdir(s:cscope_vim_dir)
-  elseif filereadable(s:index_file)
-    let idx = readfile(s:index_file)
+  
+  if ! isdirectory(s:cscope_vim_db_dir)
+    call mkdir(s:cscope_vim_db_dir)
+  elseif filereadable(s:cscope_vim_db_index_file)
+    let idx = readfile(s:cscope_vim_db_index_file)
+   
     for i in idx
       let e = split(i, '|')
-      if len(e) == 0
-        call delete(s:index_file)
+    
+      if len(e) != s:cscope_vim_db_entry_len
         call <SID>RmDBfiles()
       else
-        let db_file = s:cscope_vim_dir.'/'.e[1].'.db'
-        if filereadable(db_file)
-          if isdirectory(e[0])
-            let s:dbs[e[0]] = {}
-            let s:dbs[e[0]]['id'] = e[1]
-            let s:dbs[e[0]]['loadtimes'] = e[2]
-            let s:dbs[e[0]]['dirty'] = (len(e) > 3) ? e[3] :0
+        let l:db_file = s:cscope_vim_db_dir.'/'.e[s:cscope_vim_db_entry_idx_id].'.db'
+        let l:db_file_list = s:cscope_vim_db_dir.'/'.e[s:cscope_vim_db_entry_idx_id].'.files'
+       
+        if filereadable(l:db_file)
+          if isdirectory(e[s:cscope_vim_db_entry_idx_prepend_path])
+            let s:dbs[e[s:cscope_vim_db_entry_idx_prepend_path]] = {}
+            let s:dbs[e[s:cscope_vim_db_entry_idx_prepend_path]][s:cscope_vim_db_entry_key_id] = e[s:cscope_vim_db_entry_idx_id]
+            let s:dbs[e[s:cscope_vim_db_entry_idx_prepend_path]][s:cscope_vim_db_entry_key_loadtimes] = e[s:cscope_vim_db_entry_idx_loadtimes]
+            let s:dbs[e[s:cscope_vim_db_entry_idx_prepend_path]][s:cscope_vim_db_entry_key_dirty] = e[s:cscope_vim_db_entry_idx_dirty]
+            let s:dbs[e[s:cscope_vim_db_entry_idx_prepend_path]][s:cscope_vim_db_entry_key_depedency] = e[s:cscope_vim_db_entry_idx_depedency]
           else
-            call delete(db_file)
+            call delete(l:db_file)
+            call delete(l:db_file_list)
           endif
         endif
       endif
@@ -272,75 +381,43 @@ function! s:loadIndex()
   endif
 endfunction
 
-function! s:preloadDB()
-  let dirs = split(g:cscope_preload_path, ';')
-  for m_dir in dirs
-    let m_dir = <SID>CheckAbsolutePath(m_dir, m_dir)
-    if ! has_key(s:dbs, m_dir)
-      call <SID>InitDB(m_dir)
-    endif
-    call <SID>LoadDB(m_dir)
-  endfor
-endfunction
+function! s:RmDBfiles()
+  let odbs = split(globpath(s:cscope_vim_db_dir, "*"), "\n")
 
-function! CscopeFind(action, word)
-  let dirtyDirs = []
-  for d in keys(s:dbs)
-    if s:dbs[d]['dirty'] == 1
-      call add(dirtyDirs, d)
-    endif
+  for f in odbs
+    call delete(f)
   endfor
-  if len(dirtyDirs) > 0
-    call <SID>updateDBs(dirtyDirs)
-  endif
-  call <SID>AutoloadDB(expand('%:p:h'))
-  try
-    exe ':lcs f '.a:action.' '.a:word
-    if g:cscope_open_location == 1
-      lw
-    endif
-  catch
-    echohl WarningMsg | echo 'Can not find '.a:word.' with querytype as '.a:action.'.' | echohl None
-  endtry
 endfunction
 
-function! CscopeFindInteractive(pat)
-    call inputsave()
-    let qt = input("\nChoose a querytype for '".a:pat."'(:help cscope-find)\n  c: functions calling this function\n  d: functions called by this function\n  e: this egrep pattern\n  f: this file\n  g: this definition\n  i: files #including this file\n  s: this C symbol\n  t: this text string\n\n  or\n  <querytype><pattern> to query `pattern` instead of '".a:pat."' as `querytype`, Ex. `smain` to query a C symbol named 'main'.\n> ")
-    call inputrestore()
-    if len(qt) > 1
-        call CscopeFind(qt[0], qt[1:])
-    elseif len(qt) > 0
-        call CscopeFind(qt, a:pat)
-    endif
-    call feedkeys("\<CR>")
-endfunction
+if !exists('g:cscope_open_location')
+  let g:cscope_open_location = 1
+endif
 
-function! s:onChange()
-  if expand('%:t') =~? g:cscope_interested_files
-    let m_dir = <SID>GetBestPath(expand('%:p:h'))
-    if m_dir != ""
-      let s:dbs[m_dir]['dirty'] = 1
-      call <SID>FlushIndex()
-      call <SID>CheckNewFile(m_dir, expand('%:p'))
-      redraw
-      call <SID>echo('Your cscope db will be updated automatically, you can turn off this message by setting g:cscope_silent 1.')
-    endif
-  endif
-endfunction
+if !exists('g:cscope_search_case_insensitive')
+  let g:cscope_search_case_insensitive = 0
+endif
 
-function! CscopeUpdateDB()
-  call <SID>updateDBs(keys(s:dbs))
-endfunction
-if exists('g:cscope_preload_path')
-  call <SID>preloadDB()
+if !exists('g:cscope_cmd')
+  if executable('cscope')
+    let g:cscope_cmd = 'cscope'
+  else
+    echo 'cscope: command not found'
+    finish
+  endif
 endif
 
-if g:cscope_auto_update == 1
-  au BufWritePost * call <SID>onChange()
+if !exists('g:cscope_interested_files')
+  let files = readfile(expand("<sfile>:p:h")."/interested.txt")
+  let g:cscope_interested_files = join(map(files, 'v:val."$"'), '\|')
 endif
 
+command! -nargs=0 CscopeClearAllDB       call <SID>ClearDBs(-1)
+command! -nargs=0 CscopeClearCurrentDB   call <SID>ClearDBs(0)
+command! -nargs=0 CscopeList             call <SID>ListDBs()
+command! -nargs=0 CscopeRebuildCurrentDB call <SID>CscopeRebuildCurrentDB()
+command! -nargs=0 CscopeUpdateAllDB      call <SID>CscopeUpdateAllDB()
+command! -nargs=0 CscopeUpdateCurrentDB  call <SID>CscopeUpdateCurrentDB()
+
 set cscopequickfix=s-,g-,d-,c-,t-,e-,f-,i-
-com! -nargs=0 CscopeClear call <SID>clearDBs()
-com! -nargs=0 CscopeList call <SID>listDBs()
-call <SID>loadIndex()
+call <SID>LoadIndex()
+