test the string is char or integer


 
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# 1  
Old 10-08-2008
test the string is char or integer

How will test the string contains numeric character or alphabet, is there any script to test ?
# 2  
Old 10-08-2008
If the string is somewhat fix, you can test it with case/esac, or should it be generic?
# 3  
Old 10-08-2008
it is generic.
# 4  
Old 10-08-2008
I had the problem not this way yet nor could I find a nice tool to test it. So I come up with this ugly but working solution:

Code:
echo "$1" |\
sed 's/./&\n/g' |\
awk '
        /[a-zA-Z]/ {a+=1}
        /[0-9]/    {n+=1}
        END{
                sum=a+n
                print sum,a,n
                if ( a == 0 && sum == NR-1 ) { print "numeric" }
                if ( n == 0 && sum == NR-1 ) { print "alpha" }
                else { print "something else" }
        }'

# 5  
Old 10-08-2008
If you are using phksh, ksh88 or ksh93, here is an example of testing an input to determine if it is all numeric, letters or a mix of numbers and letters:
Code:
#!/bin/ksh

INPUT="ABC"

case $INPUT in
   ( +([0-9])       ) echo "$INPUT is all numbers" ;;
   ( +([a-zA-Z])    ) echo "$INPUT is all characters" ;;
   ( +([0-9a-zA-Z]) ) echo "$INPUT is alphanumeric" ;; 
   (               *) echo "$INPUT is something unknown" ;;
esac

exit 0

# 6  
Old 10-08-2008
Hammer & Screwdriver what about this approach?

Code:
> cat test_alpha 
sample1="abcdef"
echo $sample1 - checking alpha
if [ $sample1 = `echo $sample1 | tr -d [0-9]` ]; then  echo "same"; fi

sample2="abc123def"
echo $sample2 - checking alpha
if [ $sample2 = `echo $sample2 | tr -d [0-9]` ]; then  echo "same"; fi

sample3="123456"
echo $sample3 - checking numeric
if [ $sample3 = `echo $sample3 | tr -d [:alpha:]` ]; then  echo "same"; fi

sample4="123abc456"
echo $sample4 - checking numeric
if [ $sample4 = `echo $sample4 | tr -d [:alpha:]` ]; then  echo "same"; fi

and its execution; showing the first is alpha (same) and the third is all numeric (same)
Code:
> test_alpha 
abcdef - checking alpha
same
abc123def - checking alpha
123456 - checking numeric
same
123abc456 - checking numeric

# 7  
Old 10-09-2008
Why not use plain old case?

Code:
case $string in
  *[!0-9A-Za-z]*) echo "Not pure alpha + numbers" ;;
  *[!0-9]*) echo "Pure alpha";;
  '') echo "Empty string (duh)" ;;
  *) echo "Pure numbers" ;;
esac

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