Tag: code browsing

If you are a Linux developer, there is no alternative to the deadly combination of ctags and cscope when it comes to source code browsing and editing. I remember years back, out of mere curiosity I started learning them one evening and ended up in practicing throughout the night to get accustomed. I am a fan of ctags and cscope since then. They are much much lighter and faster than any other IDE I have laid my hands on.

ctags and cscope are the solutions to all your code browsing needs

Installation

To install on Ubuntu:

$ sudo apt-get install exuberant-ctags cscope

Usage

I added the following in my .bashrc to generate the tags and cscope file data:

function ta ()
{
    #clean older info
    rm -rf tags
    rm -rf cscope.files
    rm -rf cscope.out
    # generate new info
    find $PWD | egrep -i "\.(c|h|cpp)$" > cscope.files
    ctags -R . *.c *.h *.cpp --tag-relative=yes ./
}

To generate tags and cscope file information, navigate to the root directory of your project and run

$ ta

Troubleshooting on SuSE

I got the following error repeatedly on SuSE while trying to open tag search results (though it worked well on Ubuntu):

E429: File "/path/to/file.c" does not exist

Here are the steps I followed to fix it:

1. Generate cscope.files with absolute path

   $ find /path/to/project/files | egrep -i "\.(c|h|cpp)$" > cscope.files

2. Generate the tags file

   $ ctags -R . *.c *.h *.cpp --tag-relative=yes ./

A list of excellent tutorials, tips etc. to learn ctags & cscope:

• Browsing programs with tags
• The Vim/Cscope tutorial
• Jumping to the declaration of a local/global variable
• Vi and Vim Editor: 12 Powerful Find and Replace Examples
• ctags and cscope
• Ctags and Taglist
• Jumping to previously visited locations

The only plug-ins I use:

• MiniBufExplorer
  NOTE: Add ‘set hidden‘ in your ~/.vimrc not to lose syntax highlighting when you close a buffer. This hides the buffer instead of closing them. vim has a bug which causes loss of syntax highlighting on a buffer quit.
• Taglist
• CScope maps
• a.vim

Some pointers:

• search word under cursor: <Shift-#>
• find file with pattern in cscope: cs f fe file //check cscope_maps.vim for other switches
• to list all possibilities: type :ts IPPR and then press <Ctrl-d>
• <Ctrl-]> jumps to definition while <Ctrl-o> returns to previous location (double <'> does the same too). <Ctrl-i> jumps forward.

Some handy .vimrc entries to enjoy your mug of vi:

set ai //leads to scattered code when pasting in remote terminal (like PuTTY) on Windows,
//run set noai first to avoid.
set cindent //c like indentation
set ic //ignore case while searching
set incsearch //incremental search during typing
set hlsearch //highlight search matches
set ts=4 //tab length
set sw=4 //shift width, amount on shift you want in new lines
set nu //show line numbers

Happy coding! 🙂