[SOLVED] Help with IF statements and SPACES

birdman16 · 07-09-2012, 06:25 PM

Hey guys, I'm working on a script here and I need a bit of help, the area where I bolded, I want to know how to make the script read spaces as errors.

What I mean is. The user has to enter both their first name and last name, I try testing it out but it doesn't seem to work in my favour, the script is ignoring the fact that im using spaces or not

#!/bin/bash
entername=1
name=""
while [ $entername -le 1 ]
do
echo -n "Enter your first name and last name: "
read name

if [ name = "*_*" ]; then
echo "Hello" $name
entername=2
else
echo "Please ENTER both first and last name"
entername=0

fi
done

~

pixellany · 07-09-2012, 06:50 PM

I'm having trouble following---please put the code into [code] tags.

2 things jump out at me:

You say you want to test for a space, but the code shows an underscore

I don't know what this does (try it by itself in a terminal):

Code:

echo "Hello" $nameentername=2

birdman16 · 07-09-2012, 06:58 PM

sorry, I figured it out, but thank you!

grail · 07-09-2012, 08:31 PM

Please mark as SOLVED once you have a solution. Also, nice to advise if you are using the suggested solution or an alternate one and if so to demonstrate
for others to also learn by

birdman16 · 07-10-2012, 01:06 AM

How do I mark as solved?

Never mind, ill also edit the script to.

My mistake was

if [ name = "*_*" ]; then
echo "Hello"
$nameentername=2

I didn't put the $ beside name.

David the H. · 07-10-2012, 02:36 AM

It's generally cleaner and more efficient to use a case statement instead in this kind of situation. Also, you might consider using a character class to eliminate all non-alphanumeric characters (or else build your own list of illegal characters inside the bracket expression). Wrapping the prompt in a while+true loop ensures that it will keep asking until you get a legal name.

Code:

while true; do

	read -r -p "Please enter your first name: " firstname

	case $firstname in

		*[^[:alnum:]]*) echo "Name contains illegal characters."
				echo "Please try again."
				continue
		;;

			     *) echo "First name accepted: $firstname"
		   		break
		;;

	esac

done

# do the same for the last name...

Also, when using bash or ksh, it's recommended to use [[..]] for string/file tests, and ((..)) for numerical tests. Avoid using the old [..] test unless you specifically need POSIX-style portability.

http://mywiki.wooledge.org/ArithmeticExpression
http://mywiki.wooledge.org/BashFAQ/031
http://wiki.bash-hackers.org/commands/classictest
http://wiki.bash-hackers.org/syntax/...nal_expression

(I'm specifically referring to your "while [ $entername -le 1 ]" line here.)

Speaking of which, the bash/ksh "[[" extended test can also do complex globbing and regex matches, but note that any special patterns on the right-hand-side need to remain unquoted.

Finally, please note that you were asked to use ***[code][/code] tags*** around your code and data, which preserves formatting and improves readability. Please do not use quote tags, colors, bolding, or other fancy formatting.

grail · 07-10-2012, 03:32 AM

Quote:

How do I mark as solved?

Under Thread Tools at the top of the question.

Also, the following (as written) will not work in bash:

Code:

$nameentername=2

Try it on the command line to see the reply from the shell.