Shell Programming and Scripting

Era, yes, I noticed your "read -r" all the while but I keep forgetting to tell you "-r" is not a valid option in my environment.

egrep will not help as well because during the read statement, the variable storing the value will not contain "\" in the first place. You can see what I mean below. I'm pretty sure you're aware since you recommended "read -r". Unfortunately, I cannot use "-r". I have a feeling that there is no solution.

I wrote a simple code as follows:

echo "Enter directory: \c"
read b
echo "b is $b"

What I notice is:

A) If user keys in "1\2\3", the variable storing the input will automatically convert to "123".

B) Only when user keys in "1\\2\\3", you will see "1\2\3". The first "\" is always treated as a command.

C) If user keys in "1\", it will skip to the next line waiting for the user to enter the next input. After user keys in "2", it will store "12" in the input variable.



See the sample output below (this is not my actual script). "b" is the variable name:

Enter directory: 1\2\3
b is 123

Enter directory: 1\\2\\3b is 1\2\3

Enter directory: 1\
2
b is 12

read suggests there might be an old line utility you could use instead of read, do you have that?

... At the end of the day, would it be acceptable to use a small Perl or awk script for the input processing?

Code:

echo "Enter directory: \c"
b=`awk '/[^-_A-Za-z0-9\/]/ { print "@@@invalid@@@"; exit 2; } { print; exit 0; }'`
case $b in @@@invalid@@@) die horribly or whatever;; esac

Hi Era,

Thank you very much. Your solution works perfectly the way I want it to be.

I just have to do a minor change as highlighted in red to make it work:

echo "Enter directory: \c"
b=`awk '/[^-_A-Za-z0-9//]/ { print "@@@invalid@@@"; exit 2; } { print; exit 0; }'`
case $b in @@@invalid@@@) echo "die horribly or whatever";; esac