Number & Date Validation Query

Hi all,
Do you have any pointers how to validate numbers (not to contain alphabets and special characters) and date(MM/DD/YYYY) format.

I used following regular expression to validate integer, which is not working in the default shell:

nodigits="$(echo $testvalue | sed 's/[[:digit:]]//g')"

if [ ! -z $nodigits ] ; then
echo "Invalid number format! Only digits, no commas, spaces, etc." >&2
return 1
fi


Alok

why not simply use (old and) powerfull tools ?

case x$input in x[0-9]*[0-9]) ;; *) print an error mssg and exit ;; esac
do the rest
exit 0

NOTA: this works w/ ALL shells (only csh needs switch instead of case, but csh
never was a good scripting shell, so don't use csh for scripts)

regular expressions don't do much for dates. You can either write a simple C module
that calls getdate() which does validate dates, or use another module that already does it. For example, touch validates dates.

Here is a primitive example that validates a full date and time in YYYYMMDDhhmmss format.

Try this to check the date string:

:
[ $# -eq 1 ] || {
echo "$0: usage: $0 MM/DD/YYYY" >&2
exit 2
}

case $1 in
[0-9][0-9]/[0-9][0-9]/[0-9][0-9][0-9][0-9]) : ;;
*) echo invalid
exit 1 ;;
esac

IFS=/ # redefine internal field separators
set $1 # separate the fields into $1, $2, $3

# touch does not check for 31st of February.
# If necessary, write a better check
if touch -ct $3$2$10000 x
then
echo valid
else
echo invalid
exit 1
fi


Regads

The test for integer from guggach

"
case x$input in x[0-9]*[0-9]) ;; *) print an error mssg and exit ;; esac
do the rest
exit 0
"

is not OK, because it evaluates "1XXX2" as valid.

In Korn shell you can use:

case $1 in
+([0-9])) echo valid ;;
*) echo invalid ;;
esac

In Bourne shell you can count all characters and all digits. If the counts are equal, the input is an integer:

C=`expr $1 : ".*"`
D=`expr $1 : "[0-9][0-9]*"`
[ $C -eq $D ] && {
echo valid
}

Regards

None of those methods does much for validating that the date is a valid date. Feb 32 is validated as Mar 3. I took it and used cal, sed , and grep to validate a recovery date in CCYY/MM/DD:

#Validate that the cycle date is a real date
MM=$(expr substr "$recovery" 6 2)
DD=$(expr substr "$recovery" 9 4)
YYYY=$(expr substr "$recovery" 1 4)
D=`echo $DD|sed s/^0//`
cal $MM $YYYY|tail +3|grep $D>/dev/null
if [ ${?} -ne 0 ]; then
echo "ERROR: Invalid recovery date. Process end."
exit 1
fi


The heart of this is a one-liner:
cal $MM $YYYY|tail +3|grep $D>/dev/null

Everything else is window dressing.

prouve it