associative array in bash

divyashree · 09-21-2014, 09:23 AM

I have a file with lines which I am taking input by $1:

PHP Code:



   X B C D E
    X G H I J
    X L M N 
    Y G  
    Z B
    Y L

In each line starts with X, the key is the 2nd element and the values are the rest elements.

I am reading the file line by lines creating associate array for each.

Code:

 while read LINE
    do
     INPUT=$(echo $LINE |awk '{print $1}')
     if [[ "$INPUT" = X ]]
     then
         key_name=$(echo $LINE | awk '{print $2}')
         declare -A dependencies 
         value_names=($(echo $LINE|awk '{$1=$2=""; print $0}'))
         dependencies[key_name]=value_names
         echo -e "\nvalues of $key_name are ${key_name[*]}\n"
         sleep 1
     fi
    done < $1

So I am losing the value for each line reading.

But I need to store all the lines with X in the associate arays,
because I need to search for the key later for the later lines, lets say: a line start with Y, and it has `G`, so here I need to find the valuess from the associated arrays
with key G.

Can anyone suggest some idea how to store all lines start with X in a single associative array by reading line line the file? Or any better approach?

Here from the sample input given, the output will be in 3 lines:

PHP Code:



H I J
    C D E
    M N

Here X,Y,Z cant be keys/values as they are recognizing the lines what to do with the next characters. If X store the rest in KEY-PAIR or if Y or Z extract the values from associative arrays.

Ser Olmy · 09-21-2014, 09:49 AM

I'm not sure I understand exactly what you're trying to do, and the script seems to contain a number of errors/mistakes.

You're declaring the variable dependencies as an associate array, but then you put the actual contents in a variable called key_value. Also, you store the data from LINE in value_names, but store something called pkd_depends in key_value (incorrectly referenced as an associative array with a static, probably incorrect index).

If you declare a variable as an associative array with declare -A, you can use any text as an array index. The question is, what do you wish to use as an indiex? One of the (other) fields from the line of the input file?

divyashree · 09-21-2014, 10:40 AM

Quote:

Originally Posted by Ser Olmy

I'm not sure I understand exactly what you're trying to do, and the script seems to contain a number of errors/mistakes.

You're declaring the variable dependencies as an associate array, but then you put the actual contents in a variable called key_value. Also, you store the data from LINE in value_names, but store something called pkd_depends in key_value (incorrectly referenced as an associative array with a static, probably incorrect index).

If you declare a variable as an associative array with declare -A, you can use any text as an array index. The question is, what do you wish to use as an indiex? One of the (other) fields from the line of the input file?

Thank you Ser, for responding. I have updated some sample output and removed the typos.

grail · 09-21-2014, 11:19 AM

If you are going to use bash, then use it, no need to go off to other commands like awk.

Are you looking for something like:

Code:

#!/usr/bin/env bash

declare -A deps

while read -r id index rest
do
	[[ "$id" == X ]] && deps[$index]="$rest"
done<"$1"

for i in "${!deps[@]}"
do
	echo "deps index $i has values: ${deps[$i]}"
done

DarrenDrapkin · 09-22-2014, 12:13 PM

To me finding the symbol Y after a symbol X is quite easy in awk

/X/{Y = $2 ;print Y;}

now using the value of y to tag the rest of the line is a bit harder
Z=($3 to $nf)
unfortunatelly this second expression does not work; or if it does, awk has a new feature