aboutsummaryrefslogtreecommitdiffstats
path: root/tools/map
blob: 2862a62f1954a55fb702437f386b500b8ed197ca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
#!/bin/sh

set -e

if [ -z "$1" ]; then
    echo "Usage: $0 <expr>"
    echo ""
    echo "Give the given expression for each newline-separated line in stdin as an argument to echo (think map in many programming languages)."
    echo 'The iterator variable is called "$ELEM", and the index variable is called "$IDX".'
    exit 1
fi

i=0
while IFS=$'\n' read -r line; do
    j=0
    for item in $line; do
        eval "X${j}='$item'"
        j=$((j+1))
    done

    IDX=$i ELEM="$line" eval "echo $1"
    i=$((i+1))
done