$ grep ‘’ your_file
</br>
</br>remember, vim would expand the tab to spaces we input, so the grep will fail us.
</br>
</br>$ grep expandtab ~/.vimrc
</br>“set noexpandtab
</br>
</br>in vim,
</br> if the character is a tab, the cursor would stop once;
</br>if they are spaces, the cursor will stop for a “tabstop” times.
</br>
</br>$ grep tabstop .vimrc
</br>“set tabstop=4
</br>
</br>with hexedit, or hexdump, or any hex editor,
</br> we can see the TAB is ascii 09,
</br>while we know space is ascii 20.
</br>