read in bash on whitespace-delimited file without empty fields collapsing

Question

I\'m trying to read a multi-line tab-separated file in bash. The format is such that empty fields are expected. Unfortunately, the shell is collapsing together field separat

Answer 1

It's not necessary to use tr, but it is necessary that IFS is a non-whitespace character (otherwise multiples get collapsed to singles as you've seen).

$ IFS=, read -r one two three <<<'one,,three'
$ printf '<%s> ' "$one" "$two" "$three"; printf '\n'
 <> 

$ var=$'one\t\tthree'
$ var=${var//$'\t'/,}
$ IFS=, read -r one two three <<< "$var"
$ printf '<%s> ' "$one" "$two" "$three"; printf '\n'
 <> 

$ idel=$'\t' odel=','
$ var=$'one\t\tthree'
$ var=${var//$idel/$odel}
$ IFS=$odel read -r one two three <<< "$var"
$ printf '<%s> ' "$one" "$two" "$three"; printf '\n'
 <>