Question

I’m trying to print a CSV file using certain column widths. I think there’s an off by one error with i that’s causing the first column not to print. As you will see, I’m new to bash and desperately trying to make it act like C.

CSV='./test.csv'
column_width=(20 6 5 10 10 10 10 8 30)

IFS=","
        while read LINE
        do
                set -- $LINE
                arg=($@)
                for (( i = 0 ; i < ${#arg[@]} ; i++))
                do
                        case $i in
                                1) printf "%-20s"   ${arg[$i]} ;;
                                2) printf "%-6s"    ${arg[$i]} ;;
                                3) printf "%-5s"    ${arg[$i]} ;;
                                4) printf "%-10s"   ${arg[$i]} ;;
                                5) printf "%-10s"   ${arg[$i]} ;;
                                6) printf "%-10s"   ${arg[$i]} ;;
                                7) printf "%-10s"   ${arg[$i]} ;;
                                8) printf "%-8s"    ${arg[$i]} ;;
                                9) printf "%-30s\n" ${arg[$i]} ;;
                        esac
                done
        done < $CSV
        unset IFS

I’m also having trouble turning the case statement into a loop. To no avail, I tried replacing the entire C-style for-loop with:

for i in "${arg[@]}"; do
        printf "%-${column_width[$i]}s" ${arg[$i]}
done

I’m sure there’s a better way to accomplish this. I’m trying to learn about sed/awk but I’d like to know how to do it without them for now.

Answer 1

#!/usr/bin/env bash

csv=./test.csv
column_width=(20 6 5 10 10 10 10 8 30)

while n=0; IFS=, read -ra x; do
    printf '%-*s' {,,,,,,,,}{"${column_width[n]}","${x[n++]}"} 1 $'\n'
done <"$csv"