Tip 110: Grep with Vim's Internal Search Engine

:vim[grep][!] /{pattern}/[g][j] {file} ...

When multiple matches are on the same line, the presence of the g flag creates a match for each one of them. Without it, only a single record is created for the entire line.
By default, Vim will jump straight to the first match, but you can prevent this by including the j flag.
The {file} argument must not be blank.
It can accept the same parameters as the :args command.
## is expanded to represent the names of each file in the argument list.

# If you open the file in vim,
# then you can \"ayy@a the next line to execute the vim command: 
:h :_##

Search in File, Then Search in Project

main advantage to using :vimgrep: it understands the same patterns as Vim’s search command

Example:

/\v'(([^']|'\w)+)'
:vim /<C-r>// **

If the pattern field is empty, the :vimgrep command matches every line in every file that it looks inside.