Shell Programming and Scripting

Code:

echo -n "read this also:"
read NewAuthor


if [ -z $( echo "$NewAuthor" | tr -d '[[:digit:]]' ) ] ; then
echo "its a digit"
else
echo "something else"
fi

Hey guys , i am trying to do a search to check if the input is using alphabets and nothing else. I tried using [[:digit:]] and [[:alpha:]] but none seems to work


When i use digit, it read 22.k as alphabet and not as a wrong syntax.
For alpha , it does not allow me to input data which has spaces such as " hello world". how can i solve this issue.

Code:

#!/bin/ksh
input="1234abc"
digits=$(echo "$input" | tr -dc '[:digit:]')
alpha=$(echo "$input" | tr -dc '[:alpha:]')
[[ ${#alpha} -eq ${#input} ]] && echo 'all alphabetic characters'
[[ ${#digits} -eq ${#input} ]] && echo 'all numeric characters'
[[ ${#alpha} -ne ${#digits} ]] && echo 'not all alpha and not all digits '

thanks jim. But i would only like the search to allow those using alphabets only to be true.
If there is any "." or numbers or any other characters, it should return a false.

The above example shows you how to detect a string that's all alphabetic characters. What else do you want?

Sorry, what i meant is . when i entered "." or "" , it seems to give me an error saying ./test: line 8: [[: A time: syntax error in expression (error token is "time").

my test data was

#!/bin/ksh
input="abc time"
digits=$(echo "$input" | tr -dc '[:digit:]')
alpha=$(echo "$input" | tr -dc '[:alpha:]')
[[ ${#alpha} -eq ${#input} ]] && echo 'all alphabetic characters'
[[ ${#digits} -eq ${#input} ]] && echo 'all numeric characters'
[[ ${#alpha} -ne ${#digits} ]] && echo 'not all alpha and not all digits

why does it not read space ?

It works fine for me in sh when you add the missing ' to the end of the last line. You are using ksh, which is radically different. Try replacing the [[ ]] with [ ] . Try making all the variables enclosed in ""'s. And reject empty input explicitly.

And lastly, code tags for code. You've done it before, you know how.