Escaping slash "\" in grep

Question

I have file with line:

"H:\Check\WP_20140511_029.mp4"

along with other lines. I want to remove such lines indicating directory at H:\Check. I tried

grep -v ".*H:\\Check.*" testout.txt > testout2.txt

But it did not delete those lines. Whats wrong with my regex .*H:\\Check.*. regex101 shows that my regex correctly matches the line.

Answer 1

You can use:

grep -v 'H:\\Check' testout.txt > testout2.txt

It is important to use single quotes to avoid excessive escaping of backslash.

Using double quotes equivalent command will be this:

grep -v "H:\\\Check" testout.txt > testout2.txt

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EDIT:

\\ in double quotes is equivalent of a single backward slash due to shell expansion that happens in double quotes only. It is evident from these echo commands:

echo "H:\\Check"
H:\Check

echo 'H:\\Check'
H:\\Check