[SOLVED] And condition usage on grep command

Issue

I have two regular expression, and trying to bind it into And condition

what I got

-grep -E "/[1-9]{4,}/" file
-grep -E '([0-9])(.*\1){3}' file

I tried to take a regular expression from each command, then bind it with multiple grep with pipe

cat file | grep pattern1 | grep patterns 

, but didn't work.

anyone can teach me way to use and condition for grep with these two patterns?

"/[1-9]{4,}/"   '([0-9])(.*\1){3}'

sample input

Q4HXD/7100525/+wg4C54V2I4mh4Xh
aaaa/123/422444qjem,,qewriiafa
!#@AVADFQWERASDFASDFQervzxcilh

expected output

Q4HXDa /7100525/+wg4C54V2I4mh4Xh

which satisfy both condition

Solution

You need to use [0-9] or [[:digit:]] to match any digit in a POSIX pattern and make sure both patterns are handled as POSIX ERE by passing -E option:

cat file | grep -E '/[0-9]{4,}/' | grep -E '([0-9])(.*\1){3}'

Else, you may use a PCRE pattern like

grep -P '^(?=.*/[0-9]{4,}/).*([0-9])(.*\1){3}' file

See an online grep demo

The latter pattern matches

• ^ - start of a string
• (?=.*/[0-9]{4,}/) - a positive lookahead that makes sure there is /, 4 or more digits, / after any 0+ chars other than line break chars
• .* - any 0+ chars other than line break chars, as many as possible
• ([0-9]) - Group 1: any digit
• (.*\1){3} - three occurrences of any 0+ chars other than line break chars, as many as possible, and then the Group 1 value.

Answered By - Wiktor Stribiżew