Shell Programming and Scripting

$ #cat with the sed to allow you to see my tab
$ cat foo.txt| sed 's/\t/;/g' 
a;1;x
b;;y

while read col1 col2 col3
do
 function1($col1)
 function2($col2)
 function3($col3)
done < foo.txt

sed -i 's/\t/;/g' foo.txt
IFS=';'
while read col1 col2 col3
do
 function1($col1)
 function2($col2)
 function3($col3)
done < foo.txt
sed -i 's/;/\t/g' foo.txt
IFS=' \t\n'

while IFS=$'\t' read col1 col2 col3
do
  ...
done < foo.txt

while IFS="     " read col1 col2 col3
do

while IFS=$(printf "\t") read col1 col2 col3
do

sed 's/\t/;/g' foo.txt | while IFS=';' read A B C; do echo "$A", "$B", "$C"; done

IFS=":" read A B <<<"A::B"
$ echo $A
A
$ echo $B
:B
$

IFS=":" read A B dummy <<<"A::B"
$ echo $A
A
$ echo $B

$