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test the string is char or integer

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# 8  
Old 10-09-2008
I thought of case 1st too, but I was not able to put the expressions together so it would work correctly. Since I was nosy I tried your case script, and it does not work for me either like my former tries with case (just changed $string to $1):

Code:
root@isau02:/data/tmp/testfeld> ./era.ksh ab1cde
Pure alpha

# 9  
Old 10-09-2008
You are correct of course; the matching is greedy, and tries its darndest to find a match, so using a negation between wildcards will find a match if there is a way to match it, regardless of the other characters. So the label "pure alpha" is wrong; it should be "alpha + possibly numbers", or the logic should be changed to do additional cases within that case statement.

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

# 10  
Old 10-09-2008
How greedy! Smilie Smilie
I guess we found, thanks to the OP, that we are lacking a fine small binary standard tool to check stuff like this! Smilie (though I never needed that yet). But aren't there tools about for everything?! Smilie
# 11  
Old 10-10-2008
It is probably time we started using POSIX character classes in our examples more often!
Code:
#!/bin/bash

shopt -s extglob

INPUT="123"

case $INPUT in
   ( +([[:digit:]])  ) echo "$INPUT is all numbers" ;;
   ( +([[:alpha:]])  ) echo "$INPUT is all characters" ;;
   ( +([[:alnum:]])  ) echo "$INPUT is alphanumeric" ;;
   (                *) echo "$INPUT is empty or something unknown" ;;
esac

exit 0
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