How to compare variable dynamically inside awk in bash?

Question

I want to dynamically compare the value of two variable and write the answer to a file:

#!bin/bash
Timestamp2="19:16:35"

cat find_thread |awk -F'.' '{print $1}'|awk '{for (i=1; i<=NF;i++) {if ( $i == $(Timestamp2)  ) {print (i-1)}}}'>ThreadID

where find_thread file has the following content:

8361 19:16:35.493540
8361 19:16:35.493594
8360 19:16:41.242314
8360 19:16:41.242343
8278 19:16:39.179931
8278 19:16:39.179973

Answer 1

If I understood correctly, here you go:

awk -v ts="$Timestamp2" '$2 ~ "^" ts {print $1}' find_thread > ThreadID

Explanation:

• Put $Timestamp2 in the variable ts using the -v flag.
• Filter by the pattern: $2 ~ "^" ts = the 2nd column (for example 19:16:35.493540) should start with ts
• Print the 1st column of matched lines

Here's another variation of the same thing:

awk -F'[ .]' -v ts="$Timestamp2" '$2 == ts {print $1}' find_thread > ThreadID