Assign fields to variables - Bash [duplicate]

Question

Suppose I have a string with pipe separator:

str="1|2|3|4"

I want them to be assigned to specific variables.

var_a=1
var_b=2
var_c=3
var_d=4

I am doing it in this way:

var_a="`echo $str | cut -d'|' -f1`"
var_b="`echo $str | cut -d'|' -f2`"
var_c="`echo $str | cut -d'|' -f3`"
var_d="`echo $str | cut -d'|' -f4`"

Can this be done in an efficient way? Please suggest.

Answer 1

It is better to use an array to store individual delimited values:

str="1|2|3|4"
IFS='|' read -ra arr <<< "$str"

#examine array values
declare -p arr

declare -a arr='([0]="1" [1]="2" [2]="3" [3]="4")' 

To loop through array, use:

for i in "${arr[@]}"; do echo "$i"; done

1
2
3
4

Answer 2

IFS='|' read -r var_a var_b var_c var_d rest <<<"$str"

rest is the variable that gets further columns after the first four, should any others exist. If you just want to discard them, the conventional name to use for a placeholder variable is _.

This is covered in detail in BashFAQ #1: How can I read a file (data stream, variable) line-by-line (and/or field-by-field)?