UNIX help to print 50 lines after every 3rd occurrence pattern till end of file

Shell Programming and Scripting
1

I need help with extract/print lines till stop pattern. This needs to happen after every 3rd occurrence of start pattern and continue till end of file. Consider below is an example of the log file. my start pattern will be every 3rd occurrence of ERROR_FILE_NOT_FOUND and stop pattern will be Stop_pattern

ERROR_FILE_NOT_FOUND
some textlsjljsl
ERROR_FILE_NOT_FOUND
some textjljss0
ERROR_FILE_NOT_FOUND
some textwwkw
Extract line 1
Extract line 2
Extract line 3
Stop_pattern
some text99mlll
ERROR_FILE_NOT_FOUND
some textjsjsj1
ERROR_FILE_NOT_FOUND
some text9kk
ERROR_FILE_NOT_FOUND
some textllsljlj
Extract line 5
Extract line 6
Extract line 7
Stop_pattern
some textljljljsl
ERROR_FILE_NOT_FOUND
some textppi
ERROR_FILE_NOT_FOUND
some textnnn
ERROR_FILE_NOT_FOUND
some texthkhk
Extract line 9
Extract line 10
Extract line 11
Stop_pattern

desired output:

Extract line 1
Extract line 2
Extract line 3
//separator if possible
Extract line 5
Extract line 6
Extract line 7
//separator if possible
Extract line 9
Extract line 10
Extract line 11
//separator if possible

---------- Post updated at 02:21 PM ---------- Previous update was at 02:11 PM ----------

ignore the input/output provided in last thread here's correct one however problem statement remains same

ERROR_FILE_NOT_FOUND
some text
ERROR_FILE_NOT_FOUND
some text
ERROR_FILE_NOT_FOUND
Extract line 1
Extract line 2
Extract line 3
Stop_pattern
some text
ERROR_FILE_NOT_FOUND
some text
ERROR_FILE_NOT_FOUND
some text
ERROR_FILE_NOT_FOUND
Extract line 5
Extract line 6
Extract line 7
Stop_pattern
some text
ERROR_FILE_NOT_FOUND
some text
ERROR_FILE_NOT_FOUND
some text
ERROR_FILE_NOT_FOUND
Extract line 9
Extract line 10
Extract line 11
Stop_pattern

desired output:

Extract line 1
Extract line 2
Extract line 3
Extract line 5
Extract line 6
Extract line 7
Extract line 9
Extract line 10
Extract line 11
2

Try

awk '/Stop_pattern/ {P=0} P==3; /ERROR_FILE_NOT_FOUND/ {P++}' file
Extract line 1
Extract line 2
Extract line 3
Extract line 5
Extract line 6
Extract line 7
Extract line 9
Extract line 10
Extract line 11
3

Can you explain command pls, just wanted to make sure my problem statement was understood.

---------- Post updated at 02:39 PM ---------- Previous update was at 02:33 PM ----------

I got this error while running

awk: record ` "Cookie" Str...' too long
record number 16374

4 
awk     '/Stop_pattern/         {P=0}   # stop pattern will reset the print counter
         P==3                           # if true (i.e. pattern found thrice), do default action = print
         /ERROR_FILE_NOT_FOUND/ {P++}   # count start patterns
        ' file

---------- Post updated at 21:44 ---------- Previous update was at 21:42 ----------

There's no " "Cookie" Str..." " involved.

5

Thanks for reply.

'/Stop_pattern/ {P=0} # stop pattern will reset the print counter

why are we resetting print counter ?

6

So P==3 is not true any more, printing stops, and a new cycle with three start patterns can start.