bash command to extract sequences of texts based on a starting key - bash

Question

I have a log file as the following. Each line logs some string and the thread id. Each thread belongs to a process and a process can have N threads.
Based on the following sample, I want to extract (using bash tools, grep, sed and whatever) all the lines of all threads that belongs to a given process. Note that the process is mentioned only once, at the top of a thread sequence:
line1 thread= 150 process= 200
line2 thread= 152 whatever
line3 thread= 150 whatever
line4 thread= 150 whatever
line5 thread= 130 whatever
line6 thread= 130 process= 200
line7 thread= 150 process= 201
line8 thread= 130 whatever
line9 thread= 130 whatever
For this sample, give process 200 the output should be:
line1 thread= 150 process= 200
line3 thread= 150 whatever
line4 thread= 150 whatever
line6 thread= 130 process= 200
line8 thread= 130 whatever
line9 thread= 130 whatever

Answer 1

awk solution:
filter_threads.awk script:
#!/bin/awk -f
function get_thread(s){ # extracts thread number from the string
t = substr(s,index(s,"=")+1); # considering `=` as separator (e.g. `thread=150`)
return t;
}
BEGIN {
pat = "process="p # regex pattern to match the line with specified process
}
$3~pat { # on encountering "process" line
thread = get_thread($2); print; next # getting base thread number
}
{
t = get_thread($2);
if (t==thread) print # comparing current thread numbers with base thread number
}
Usage:
awk -f filter_threads.awk -v p=200 yourfile
- where p is process number
The output:
line1 thread=150 process=200
line3 thread=150 whatever
line4 thread=150 whatever
line6 thread=130 process=200
line8 thread=130 whatever
line9 thread=130 whatever
Update:
As you have changed you initial input the new solution would be as below:
awk -v p=200 '$4~/process=/ && $5==p{ thread=$3; print; next }$3==thread{ print }' yourfile