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Bash input validation

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Posted 01-11-2006 at 08:28 PM by unSpawn

Takes argument and stops when character outside restricted set is found.
Don't know how much slower, didn't run any timing tests with or without yet.

Code:

val_str() {
        declare -r str_allow="1234567890-_.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ "
        declare -r str_len="128"; str=( "$1" ); if [ -z "${str}" -o "${#str}" -gt "${str_len}" ]; then return 1; fi
        charLim=$[${#str}-1]; for charPos in $(seq 0 "$charLim"); do char="${str[0]:${charPos}:1}"
        expr index "${char/[\(\)]/!}" "${str_allow} " >/dev/null; case "$?" in 0) ;;*) return 1;; esac; done
 }

Should look for optimisation.

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Comments

Thank you, I've been searching for something like that!
I took a closer look and I want to make a suggestion considering expr's return value, cause I don't think it's nice sending it to /dev/null ...

Code:

# variables are labeled a bit different here ...
input=( "$1" )
charlimit=$[${#input}-1]

for charposition in $(seq 0 "$charlimit"); do
    char="${input[0]:${charposition}:1}"
        # the second for loop takes expr's output, ret_value;
        # if it's 0, the loop returns 1 and we're out
        for ret_value in $(expr index "$char" "${str_allow}"); do
            if [ ${ret_value} == 0 ]; then
                return 1
            fi
        done
done

# if the first loop returns 0, return 0;
# otherwise nothing would be returned
if [ "${?}" == 0 ]; then
    return 0
fi

Posted 12-31-1969 at 07:00 PM by unSpawn unSpawn is offline