[SOLVED] need help with my first script

ianconner · 12-18-2015, 10:16 AM

PHP Code:



Hey there, I'm fairly new to Linux (actually sitting in a Linux + class right now) and very new to scripting in Linux.

I keep getting a syntax error saying "Near Unexpected toke n `do'" On Line 15

Here is a copy of my script

#!/bin/bash
MAX_NO=0
echo -n "Enter Number between (5 to 9) : "
read MAX_NO
if ! [ $MAX_NO -ge 5 -a $MAX_NO -le 9 ] ; then
   echo "WTF... I ask to enter number between 5 and 9, Try Again"
   exit 1
fi
clear
for (( i=1; i<=MAX_NO; i++ )) do     for (( s=MAX_NO; s>=i; s-- ))
    do
       echo -n " "
    done
    for (( j=1; j<=i;  j++ ))     do      echo -n " ."      done     echo "" done ###### Second stage ###################### for (( i=MAX_NO; i>=1; i-- ))
do
    for (( s=i; s<=MAX_NO; s++ ))
    do
       echo -n " "
    done
    for (( j=1; j<=i;  j++ ))
    do
     echo -n " ."
    done
    echo ""
done



Any help would be appreciated!!

Mr. Alex · 12-18-2015, 10:34 AM

Quote:

###### Second stage ######################

After "#" symbol everything is considered a comment and is not executed. You have to remove comments from your script or move them somewhere where there is no executable code.

Keith Hedger · 12-18-2015, 10:38 AM

To start please don't wrap your entire post in code tags just around the code bit.
You have a peculier coding style which is causing the problems, with bash if you put more than one statement on a line you must use the ; as a seperator, or better yet stick to one patricular style if you want your do/done loops on seperate line do it thoughout the script, other wise it is awkward to follow and you get syntax errors, your code when smartened up works fine like so

Code:

#!/bin/bash -e

#©keithhedger Fri 18 Dec 16:30:09 GMT 2015 kdhedger68713@gmail.com
#!/bin/bash
MAX_NO=0
echo -n "Enter Number between (5 to 9) : "
read MAX_NO
if ! [ $MAX_NO -ge 5 -a $MAX_NO -le 9 ] ; then
   echo "WTF... I ask to enter number between 5 and 9, Try Again"
   exit 1
fi
clear
for (( i=1; i<=MAX_NO; i++ ))
	do
		for (( s=MAX_NO; s>=i; s-- ))
    do
       echo -n " "
    done
    for (( j=1; j<=i;  j++ ))
    do
    	echo -n " ."
    done
    	echo ""
    done
###### Second stage ######################
    for (( i=MAX_NO; i>=1; i-- ))
	do
    	for (( s=i; s<=MAX_NO; s++ ))
    do
       echo -n " "
    done
    for (( j=1; j<=i;  j++ ))
    do
     echo -n " ."
    done
    echo ""
done

I haven't actual changed any code just seperated the commands onto their own lines.

Keith Hedger · 12-18-2015, 10:39 AM

Quote:

Originally Posted by Mr. Alex

After "#" symbol everything is considered a comment and is not executed. You have to remove comments from your script or move them somewhere where there is no executable code.

Yeah that as well!

grail · 12-18-2015, 11:03 AM

Others have answered the issue, here are some other points:

1. Be consistent with testing, ie. if you are going to use (()) for testing numbers, like in your for loops, do not start your script by using []. Especially as (()) is designed specifically for dealing with numbers

Code:

if ! [ $MAX_NO -ge 5 -a $MAX_NO -le 9 ] ; then

if ! (( MAX_NO >= 5 && MAX_NO <= 9 )) ; then

2. As above with placing 'do' on same line or on next line, if you are going to place on the next line then place 'then' for your 'if' on the next line too

Code:

if ! (( MAX_NO >= 5 && MAX_NO <= 9 )) ; then

if ! (( MAX_NO >= 5 && MAX_NO <= 9 ))
then

3. Your 'if' advises the user to try again, but to do this they currently need to re-run the script. Maybe try putting the test in a loop. Remember though, if you do this, you might also need to offer
them a way out

4. I would also suggest having a look at how you might reduce your code from needing 6 for loops (hint: if you search this site for something like 'pyramid', I think you might find some alternatives)

My last thought is a question ... your current solution repeats the longest line, ie. if you user enters 5 then they get a diamond shape with 2 rows of 5 dots in the center. Unless this was the question
asked, I would think the diamond should be uniform and only have a single row of maximum dots (even if not, it would make a good challenge for you to work out how to solve

)

ianconner · 12-18-2015, 11:17 AM

Thank you for the help and guidance. This is my first time scripting in any language or OS. That cleared up the issue and ill work on condensing and modifying. I just wanted to get it to work as a baseline and then go in a tweak things to see how changing things will create different results.

grail · 12-18-2015, 11:49 AM

All good

Just to let you know I had a quick play and managed to use a single for loop.

Some hints to look into:

1. Arrays

2. printf

3. IFS variable

4. ternary operator (?:)