String Validation program

Shell Programming and Scripting
1

Hi

I want to validate the sting which one having only A-Z, a-z, *, . ,_ and 0-9 digits. Can anyone send me the program? I tried with following program but its taking all special characters like @ , # % and ^.

echo " Enter Text :"
read text
while [ ! $(echo "$text" | tr -dc '[A-za-z0-9]') ]
do
echo "Character is wrong"
done

2

Do you know about POSIX classes - maybe something using tr -<whatever> [:alnum:]

[A-z] lets some punctutation like ^ "through"

Plus, unless you turn off globbing, the * character will not come through as *, it will come through as a listing of files in the current directory.

3

I had this script for sometime. Check it out.

[/tmp]$ cat string.ksh 
#! /bin/ksh 

set -f

(($#)) && STR="$@" || STR="abcdefghijklmnopqrstuvwxyz1234567890!@#$%^&*()-=_+[]{}"
STRING="$STR"
typeset -R1 last
typeset -L1 first

while ((${#STR})) 
do
        first="${STR}"
        last="${STR}"

        [[ "$first" = [a-zA-Z0-9\.\_\*] ]] || { echo "Unwanted $first" ; exit 1 ; }
        [[ "$last" = [a-zA-Z0-9\.\_\*] ]] || { echo "Unwanted $last" ; exit 1 ; }

        STR="${STR%$last}"
        STR="${STR#$first}"

        ((${#STR} == 1)) && break;

done
        echo "$STRING looks fine."

Like jim has said, you need to turn off globbing or invoke the script as

sh -c 'set -f; ./string.ksh abcd@#$'

where abcd@#$ is the string you are trying to validate. All characters you wish to keep should go inside the [a-zA-Z0-9\.\_\*] construct.

4

Hi,
Thanx to all...

The given program is working fine but typeset -R and -L values are not working in linux machine. Is there any other variables to declare this typeset for string in linux?

Regards
mpk

5

Linux isn't the problem, it's your shell. Some linux distros use pdksh but this supports typeset -L and -R as well.