How to grep including single quote in a file

Question

I have this line from file.php:

'user' => '',

What would be the appropriate command using grep to query the exact line?

Answer 1

Use double quotes to enclose your pattern:

grep "'user' => ''," your_file

I would also make use of some metacharacters to ensure the lookup is robust to the different spacing styles used by people:

grep "'user'\s*=>\s*''\s*," your_file

To add different keywords to your search, you need extended regular expressions. Supply the -E switch to grep:

grep -E "'(user|group|foo)'\s*=>\s*''\s*," your_file

The above will print lines matching 'user' => '', or 'group' => '', or 'foo' => '', (with different spacing variations). Modify as needed.