Linux shell script regex match

Question

I have a text file. I want to get lines starting with specific format. I just want to get lines that have x/x/x format. x is a number. But this regex is not working. It is always giving no match :

while read line           
do           
    regex="\d+\/\d+\/\d+"
    if [[ ${line} =~  ${regex} ]]; then 

        echo ${line}

    else

        echo "no match : ${line}"

    fi    
done <${textFileName}

File is :

Jeff Schaller · Accepted Answer · 2017-08-17 23:38:25Z

1

Don't use bash if you can use a better tool:

grep -E '^[[:digit:]]+/[[:digit:]]+/[[:digit:]]+' "${textFileName}"

But if you have to use bash:

while IFS= read -r line
do
  if [[ "$line}" =~ ^[[:digit:]]+/[[:digit:]]+/[[:digit:]]+ ]]; then
     echo -- "$line"
  else
    echo "no match: $line"
  fi
done < "$textFileName"

\d is not valid regex(3).

edited Aug 17, 2017 at 23:38

answered Aug 17, 2017 at 22:52

Jeff Schaller

2,6769 gold badges29 silver badges45 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

ivbtar Over a year ago

Hi i applied your code. But didnt work. while IFS= read -r line do if [[ "${line}" =~ '[[:digit:]]+/[[:digit:]]+/[[:digit:]]+' ]]; then echo -- "X:$line" else echo "no match: $line" fi done < "$textFileName"

Jeff Schaller Over a year ago

Don't quote the regex

Collectives™ on Stack Overflow

Linux shell script regex match

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related