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Pass awk array variable to shell

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# 1  
Old 04-19-2013
Pass awk array variable to shell
Hi, all

suppose I have following myfile (delimited by tab)

Code:
aa bb
cc dd
ee ff

and I have following awk command:

Code:
awk 'BEGIN{FS="\t"}{AwkArrayVar_1[x++]=$1;AwkArrayVar_2[y++]=$2};END{for(i=0; i<NR; i++) print i, AwkArrayVar_1[i], AwkArrayVar_2[i],}' myfile

My question is: how can I assign the awk array variable to shell array variable, such as ShellArrayVar_1 = AwkArrayVar_1, and ShellArrayVar_2 = AwkArrayVar_2?
# 2  
Old 04-19-2013
If you want a shell array, I would use shell programming directly. I am not aware of a way to assign an awk array to a shell array.
Code:
n=0
while read fld_1 fld_2; do
  array_var_1[n]=$fld_1
  array_var_2[n]=$fld_2
  n=`expr $n + 1`
done < myfile

# 3  
Old 04-20-2013
Thank you very much.

What if my file is delimited by "|" or";"? can shell read fields of such files into array variables?
# 4  
Old 04-20-2013
Yes, to do that, set the IFS (input field separator) variable as follows:
Code:
aa|bb
cc|dd
ee|ff

Code:
IFS='|'
n=0
while read fld_1 fld_2; do
  array_var_1[n]=$fld_1
  array_var_2[n]=$fld_2
  n=`expr $n + 1`
done < myfile

# 5  
Old 04-20-2013
Thank you so much for helping me.

I am sorry to ask you so many questions; but I am just wondering what if I only want to read the 2nd filed? maybe with combined use of "cut" command? such as

Code:
while read fld2; do
array_var_2[n]=$fld_2
n=`expr $n + 1`
done < (cut -f2 myFile)

Last edited by littlewenwen; 04-20-2013 at 01:00 AM..
# 6  
Old 04-20-2013
Yes, you can use the second field alone, using cut. Here is how I would do it, which seems simple and clear.
Code:
n=0
cut -f 2 myfile > fld2.txt
while read fld_2; do
  array_var[n]=$fld_2
  n=`expr $n + 1`
done < fld2.txt

Of course, you could also:
Code:
n=0
while read fld_1 fld_2; do
  array_var[n]=$fld_2
  n=`expr $n + 1`
done < myfile

This User Gave Thanks to hanson44 For This Post:
littlewenwen
# 7  
Old 04-20-2013
Thank you very much for help, really appreciate it.
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