Monday, June 6, 2022

[SOLVED] Computing the size of array in text file in bash

Issue

I have a text file that sometimes-not always- will have an array with a unique name like this

unique_array=(1,2,3,4,5,6)

I would like to find the size of the array-6 in the above example- when it exists and skip it or return -1 if it doesnt exist.

grepping the file will tell me if the array exists but not how to find its size.

The array can fill multiple lines like

unique_array=(1,2,3,
   4,5,6,
7,8,9,10)

Some of the elements in the array can be negative as in

unique_array=(1,2,-3,
   4,5,6,
7,8,-9,10)

Solution

awk -v RS=\) -F, '/unique_array=\(/ {print /[0-9]/?NF:0}' file.txt
  • -v RS=\) - delimit records by ) instead of newlines
  • -F, - delimit fields by , instead of whitespace
  • /unique_array=(/ - look for a record containing the unique identifier
  • /[0-9]?NF:0 - if record contains digit, number of fields (ie. commas+1), otherwise 0


Answered By - jhnc
Answer Checked By - Cary Denson (WPSolving Admin)
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