How can I assign the match of my regular expression to a variable?

Question

I have a text file with various entries in it. Each entry is ended with line containing all asterisks.

I\'d like to use shell commands to parse this file and assign each

Answer 1

I'm surprised to not see a native bash solution here. Yes, bash has regular expressions. You can find plenty of random documentation online, particularly if you include "bash_rematch" in your query, or just look at the man pages. Here's a silly example, taken from here and slightly modified, which prints the whole match, and each of the captured matches, for a regular expression.

if [[ $str =~ $regex ]]; then
    echo "$str matches"
    echo "matching substring: ${BASH_REMATCH[0]}"
    i=1
    n=${#BASH_REMATCH[*]}
    while [[ $i -lt $n ]]
    do
        echo "  capture[$i]: ${BASH_REMATCH[$i]}"
        let i++
    done
else
    echo "$str does not match"
fi

The important bit is that the extended test [[ ... ]] using its regex comparision =~ stores the entire match in ${BASH_REMATCH[0]} and the captured matches in ${BASH_REMATCH[i]}.