[SOLVED] Script Code Error

zetrotrack000 · 01-11-2020, 08:50 AM

Hi
I am learning Linux Shell Scripting from a book (titled: Mastering Shell Scripting, by: Andrew Mallett). On page 40, the author presented following example script (to evaluate students' grades):

Code:

#!/bin/bash
# Script to evaluate grades
# Usage: grade.sh student grade
# Author: @theurbanpenguin
# Date: 1/1/1971
if [ ! $# -eq2 ] ; then
echo "You must provide <student><grade>
exit 2
fi
case $2 in
[A-C]|[a-c]) echo "$1 is a star pupil"
;;
[Dd]) echo "$1 needs to try a little harder!"
;;
[E-F]|[e-f]) echo "$1 could do a lot better next year"
;;
*) echo "Grade could not be evaluated for $1"
esac

However, upon running the script by following command:

Code:

./grade.sh bob b

gives following error:

Code:

grade.sh: line 17: unexpected EOF while looking for matching `"'
grade.sh: line 19: syntax error: unexpected end of file

Can you guide me that whats wrong here with the code?
Thanks

TB0ne · 01-11-2020, 08:56 AM

Quote:

Originally Posted by zetrotrack000

Hi
I am learning Linux Shell Scripting from a book (titled: Mastering Shell Scripting, by: Andrew Mallett). On page 40, the author presented following example script (to evaluate students' grades):

Code:

#!/bin/bash
# Script to evaluate grades
# Usage: grade.sh student grade
# Author: @theurbanpenguin
# Date: 1/1/1971
if [ ! $# -eq2 ] ; then
echo "You must provide <student><grade>
exit 2
fi
case $2 in
[A-C]|[a-c]) echo "$1 is a star pupil"
;;
[Dd]) echo "$1 needs to try a little harder!"
;;
[E-F]|[e-f]) echo "$1 could do a lot better next year"
;;
*) echo "Grade could not be evaluated for $1"
esac

However, upon running the script by following command:

Code:

./grade.sh bob b

gives following error:

Code:

grade.sh: line 17: unexpected EOF while looking for matching `"'
grade.sh: line 19: syntax error: unexpected end of file

Can you guide me that whats wrong here with the code? Thanks

Sorry, but I find this fairly ironic that you're reading a book on how to write shell scripts that has explanations, examples, etc....and ask us to figure it out what's wrong.

That said, I'd suggest you look at the error message, think about what it means, and then look *CAREFULLY* at what you keyed in. The error tells you what you're missing; this is part of the learning process for programming, and it is very, VERY frustrating. It is also valuable later on, since it'll make things like this much easier to fix in the future.

pan64 · 01-11-2020, 08:59 AM

at first I would suggest you to use www.shellcheck.net.
that will immediately tell you:

Code:

Line 6:
if [ ! $# -eq2 ] ; then
             ^-- SC1035: You are missing a required space here.

but this is only just the first error.
Here you need to write

Code:

if [ ! $# -eq 2 ] ; then

zetrotrack000 · 01-11-2020, 09:07 AM

Quote:

Originally Posted by TB0ne

Sorry, but I find this fairly ironic that you're reading a book on how to write shell scripts that has explanations, examples, etc....and ask us to figure it out what's wrong.

That said, I'd suggest you look at the error message, think about what it means, and then look *CAREFULLY* at what you keyed in. The error tells you what you're missing; this is part of the learning process for programming, and it is very, VERY frustrating. It is also valuable later on, since it'll make things like this much easier to fix in the future.

The error is fixed, thanks to pan64.
The script contains 18 lines but the error is saying "Line 19". Isn't that strange?

pan64 · 01-11-2020, 09:12 AM

just try to understand the error messages you got:

Code:

grade.sh: line 17: unexpected EOF while looking for matching `"'  -> there is an unpaired "
grade.sh: line 19: syntax error: unexpected end of file           -> end of file and still not found the pair

by the way, if you want to say thanks jus click on yes

dugan · 01-11-2020, 09:45 AM

In addition to what was already been said, the following would also have helped:

Code:

bash -x grade.sh bob b

NevemTeve · 01-11-2020, 01:30 PM

@OP: You have an unfinished "string literal" in your program -- If you use a syntax-highlighting text-editor (such as mcedit), you can find it easily.

rnturn · 01-11-2020, 02:30 PM

Quote:

Originally Posted by zetrotrack000

...

gives following error:

Code:

grade.sh: line 17: unexpected EOF while looking for matching `"'
grade.sh: line 19: syntax error: unexpected end of file

Can you guide me that whats wrong here with the code?
Thanks

Yes. When the shell gripes about not finding a quote, you should begin by looking at all the lines before the line number included in the error messge. What's happening is that the quote in "line 17" is being interpreted as the closing quote for a quote in a previous line. You've forgotten a quote somewhere above. Read your code carefully... I think it'll jump out at you.

I'd also look into using an editor that "understands" shell scripts and automagically indents your code (usually by pressing "Tab"). Vim might do this. Emacs (or one of its close relatives) certainly does this. Either will highlight variables and keywords in your script to help you distinguish between the two. You'll usually need to ensure that the editor knows what language it's dealing with. I do this by doing something like:

Code:

$ echo "#!/bin/bash" > my_new_script
$ emacs my_new_script

Once the editor sees the "shebang" line it knows to employ shell rules for highlighting and indentation. The same goes for other languages you might be using. Believe me, once you start using an editor like that... you'll never go back.

HTH...

TB0ne · 01-11-2020, 03:26 PM

Quote:

Originally Posted by zetrotrack000

The error is fixed, thanks to pan64.

You mean the website that checked your code FOR YOU, rather than you learning/thinking about what was going on?

Quote:

The script contains 18 lines but the error is saying "Line 19". Isn't that strange?

No...it isn't, probably because you had a blank-line at the end of your script, or an unmatched pair somewhere. Again, referencing the book would teach you why this happens.

If you looked carefully at the error that clearly said you were missing one of (`"') those characters, and then looked carefully at line 7, you would have seen where you were missing one. Again...you would have learned to spot an error on your own, without a website telling you.