How to read character by character using awk

Either use fold -1 then pipe into awk, or loop through each character in awk, e.g....

$ cat file1
abc
$ fold -1 file1 | awk '{print $0}'
a
b
c
$ awk '{for(i=1;i<=length;i++) print substr($0, i, 1)}' file1
a
b
c

What shell? Bash has the `read` builtin where you can do:

while read -n1 char; do
 #do something with the byte in $char
done <input.file

could u explain what is "-n1" here in this syntax

So -n1 means reading character by character.

Regards,
Chella

what exactly the "number 1" do in the syntax

if i give 2 what will happen .... does it read 2 chars at a time

can u explain it little bit clear

regards
srikanth