Grep multiple bash parameters

Question

I\'m writing a bash script which shall search in multiple files.

The problem I\'m encountering is that I can\'t egrep an undetermined number of variables passed as param

Answer 1

A safe eval could be a good solution

#!/bin/bash

if [[ $# -gt 0 ]]; then
    TEMP=("grep" "-e" "\"\$1\"" "*")
    for (( I = 2; I <= $#; ++I )); do
        TEMP=("${TEMP[@]}" "|" "egrep" "-e" "\"\$${I}\"")
    done
    eval "${TEMP[@]}"
fi

To run it:

bash script.sh A B C

Answer 2

You can use recursion here to get required number of pipes:

#!/bin/bash

rec_egrep() {
    if [ $# -eq 0 ]; then
        exec cat
    elif [ $# -eq 1 ]; then
        exec egrep "$1"
    else
        local pat=$1
        shift
        egrep "$pat" | rec_egrep "$@"
    fi
}

first_arg="$1"
shift
grep "$first_arg" * | rec_egrep "$@"