Shell Programming and Scripting

ASDF,QWER,GHJK,123,FGHY,9876
GHTY,NVHR,WOPI,623,HFBS,5386

perl '-MScalar::Util qw/looks_like_number/' '-F, -ane
    print if looks_like_number $F[3] 
      and looks_like_number $F[5]
    ' infile

perl '-MScalar::Util qw/looks_like_number/' '-F, -lane
    print $_, " -> ", (looks_like_number $F[3] 
	  and looks_like_number $F[5])? "valid" : "invalid"
	' infile

#!/bin/ksh or bash or dash or ...
cat <<EOF > $0.txt
ASDF,QWER,GHJK,123,FGHY,9876
GHTY,NVHR,WOPI,623,HFBS,5386
GHTY,NVHR,WOPI,A623,HFBS,5386
EOF

num()
{
   val="$1"
   # replace numbers with nothing, rest chars are something else
   otherchars="${val//[0-9]/}"
   [ "$otherchars" != "" ] && return 1 # not num
   return 0 # it's num
}
############################

oifs="$IFS"
cat $0.txt | while read line
do
        IFS=","
        flds=($line)
        IFS="$oifs"
        f4=${flds[3]}
        f6=${flds[5]}
        num "$f4" || echo "not num $f4"
        num "$f6" || echo "not num $f6"
done

awk -F, 'match($4,"[a-zA-Z]")||match($6,"[a-zA-Z]"){print $0 " -> invalid";next}1' file

awk -F, 'int($4)==$4 && int($6)==$6' file

$
$ cat f0
ASDF,QWER,GHJK,123,FGHY,9876
GHTY,NVHR,WOPI,623,HFBS,5386
ABCD,EFGH,IJKL,23A,MNOP,9999
PQRS,TUVW,XYZA,999,BCDE,489X
$
$ perl -F, -lane 'print if $F[3]=~/^\d+$/ && $F[5]=~/^\d+$/' f0
ASDF,QWER,GHJK,123,FGHY,9876
GHTY,NVHR,WOPI,623,HFBS,5386
$
$