Shell Programming and Scripting

Hi,

I need help with AWK. Here is the issue that i'm facing.

I have a variable in KSH script set as below.
user_text="first second third fourth"

My Requirement is to print 'first', 'second', 'third' or 'fourth' based on setting a variable

Example 1
user_text="first second third fourth"
var=1
echo $user_text | awk '{print $var}'

Ouput expected:
first

Example 2
user_text="first second third fourth"
var=3
echo $user_text | awk '{print $var}'

Ouput expected:
third

I'm new to AWK. I would be grateful if you could reply with correct AWK syntax. Your help is highly appreciated.

Thanks for your time.

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you need array not awk, please refer to your shell array assignment

Code:

-bash-3.2$ x=(first second third fourth)
-bash-3.2$ echo ${x[0]}
first
-bash-3.2$ echo ${x[1]}
second
-bash-3.2$ echo ${x[2]}
third
-bash-3.2$ echo ${x[3]}
fourth
-bash-3.2$

Code:

 
set first second third fourth
echo $1 $4
Output==> first fourth

wow i didnt know that.. what happens if i use this to a script?
what happens to $1 if i have argumented script?

Coming back to original question, how to achieve this by passing variable to awk.

Code:

user_text="first second third fourth"
var=1
echo $user_text | awk -v awk_var="$var" '{print $awk_var}'

---------- Post updated at 09:40 AM ---------- Previous update was at 09:39 AM ----------

$1 will be overwritten...
to avoid that, first store the passed argument and then use set.

Hello Everyone,

Thanks for your replies. I tried set and array solutions but it didn't work.

I'm using ksh in AIX 5.3

Here is my input string
-parm a=b -parm c=d -parm e=f -parm g=h \

Note: At the end of each line in my input file there is a Back slash charater.

My input string can be of variable length. For example it can be
-parm a=b -parm c=d \
or
-parm a=b -parm c=d -parm e=f \

My requirement is to check for values for each -parm and do a particular action.

For example if my input string is
-parm a=b -parm c=d -parm e=f -parm g=h \

If the last -parm value is g=h then I need to set a variable X to 1.
If the 2nd -parm value is a=b then I need to set a variable Y to 1.
That is I need to read the value one at a time from my input string and perform a particular action.

I thought it would be possible in awk and hence my original question.

Your different approachs to this problem or solutions to this problem is highly appreciated.

Thanks for your time.