Shell Programming and Scripting

test=a
valeur=`printf %u "'$test"`
char=`expr $valeur + 1`
printf %c $char

$ cat nextchar
#! /usr/bin/ksh

while : ; do
        printf "enter a character - "
        read char
        printf "this char is %c \n" $char
        val=$(printf "%c" $char | od -An -td1)
        printf "decimal value is %d \n" $val
        printf "octal value is %o \n" $val
        ((val=val+1))
        octal=$(printf "0%o" $val)
        nextchar=$(echo \\${octal})
        printf "next char is %c \n" $nextchar
done
$ ./nextchar
enter a character - a
this char is a
decimal value is 97
octal value is 141
next char is b
enter a character - A
this char is A
decimal value is 65
octal value is 101
next char is B
enter a character - 1
this char is 1
decimal value is 49
octal value is 61
next char is 2
enter a character - !
this char is !
decimal value is 33
octal value is 41
next char is "
enter a character - ^C
$