test the string is char or integer

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Top Forums UNIX for Advanced & Expert Users test the string is char or integer
# 1  
test the string is char or integer

How will test the string contains numeric character or alphabet, is there any script to test ?
# 2  
If the string is somewhat fix, you can test it with case/esac, or should it be generic?
# 3  
it is generic.
# 4  
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:

echo "$1" |\
sed 's/./&\n/g' |\
awk '
        /[a-zA-Z]/ {a+=1}
        /[0-9]/    {n+=1}
                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  
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:


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" ;;

exit 0

# 6  
Hammer & Screwdriver what about this approach?

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

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

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

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)
> test_alpha 
abcdef - checking alpha
abc123def - checking alpha
123456 - checking numeric
123abc456 - checking numeric

# 7  
Why not use plain old case?

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

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