UNIX for Dummies Questions & Answers

Hello to everyone!

I'm really new in shell scripting and I'm experiencing a very odd problem. This is my first post in this forum, hope you can help!

I know that declaring arrays in Bourne Shell is impossible. But this is where I start having problems - system administrator did not install ksh. So after searching some in google, I found an alternative way to declare an array, however I do not know if this is gonna work.

Code:

for i in $*
do
for word in $i
do
echo "$word"
done
done

It reads values from command line and prints them out. I need characters entered in command line to be printed out in one line without spaces and I've done it by myself too:

Code:

echo "Formatted text:"
for var in $*
do
printf "%s$var"
done > "text"
cat text

But what about arrays? Would this work for me? (Found it by googling):

Code:

echo "Enter the line: \c"
read temp
n=0
for word in $temp
do
n=`expr $n + 1`
   eval part$n="$word"
done

All I could achieve was printing out the number of $n which was storing information. Creating another loop below this code trying to take values from part$n or $part$n did not give any results:

Code:

for var in $part$n
do
printf "%s$var"
done

Also, what exactly 'expr' and 'eval' stands for?

Any help would be appreciated,

onstock

On what platform are you running?

Code:

echo $* | tr -d ' '

js.

---------- Post updated at 10:23 AM ---------- Previous update was at 10:20 AM ----------

Here's another in bash (not bourne):

Code:

var="$*"
echo ${var// /}

js.

It's FreeBSD 6.2-RELEASE-p3 (GENERIC) #0

@jsmoriss

Thank you, I will try it out as soon as I get back home!

Code:

echo $* | tr -d ' '

Works great and efficient. Thank you! But I'm wondering if there is something that could be done in sort-of array (code written in my first post - code #3)? If it is possible to use it, I could use it for my further studying of scripting.

Thanks again for your help

You want to create "array like variables" in bourne shell? Hm. How about this?

Code:

n=0
for val in a b c
do 
    eval var$n="$val"
    n="`expr $n + 1`"
done

That would give you 3 variables, in this example, $var0, $var1, and $var2.

js.

jsmoriss,

Thank you for your fast reply!

Your example works, but as I mentioned in my first post, I have troubles with printing out values:

Code:

for val in $*
do
        eval var$n="$val"
        n="`expr $n + 1`"
        echo $val$n
done

And the result is:

Code:

hallerx@ktl ~ $ sh dir1 10 5 9
1
2
3

I am sure I'm calling the output in a wrong way (echo line). How could I print out the values stored in this array?

Thanks for your help

Try something like this:

Code:

echo "Enter the line: "
read temp
n=0
for word in $temp
do
  n=`expr $n + 1`
  eval part$n="$word"
done

i=1
while [ $i -le $n ]
do
  eval echo "\$part$i"
  i=`expr $i + 1`
done

Code:

eval string ...
            Concatenate all the arguments with spaces.  Then re-parse and execute the command.

Eval first evaluates the variables and the executes the result, a kind of execute in two stages.

Probably you are running posix, not bourne shell which would allow you to lose the expr statements:

instead of

Code:

n=`expr $n + 1`

you could use

Code:

n=$((n + 1))