Match patternA and print it only when patternB is matched including the following line

up vote
4
down vote

favorite

I am looking to get all the lines which have the word 'search_string' + the line after it + the line matching 'mod' before it.

I tried:

grep -n 'mod|search_string' ip | grep --before 1 search_string> inter 
grep -n --after 1 search_string ip >> inter 
sort -t':' -k1,1n -u inter -o op

Is there a better way?

File:

mod start1 
some lines 
mod start2 
other lines 
mod start3 
 many other lines 
 search_string yada yada 
 hello 
 many other lines 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too 
mod start5

Expected output :

mod start3 
 search_string yada yada 
 hello 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too

edited Aug 26 at 7:52

ÃŽÂ±Ã’Â“sÃÂ½ÃŽÂ¹ÃŽÂ·

15.5k92563

asked Aug 25 at 18:46

romi

235

In your example you have search_string and search string. Are they both valid?
â€“Â Kamil Maciorowski
Aug 25 at 19:28

The output of the commands you show do not match the expected output you present. Which is correct ?
â€“Â Isaac
Aug 25 at 19:34

It was a typo. Corrected it to show search_string. The final results should match the expected results. I was only trying to show the convoluted steps I was thinking of and not getting proper results.
â€“Â romi
Aug 25 at 20:27

add a commentÂ |Â

up vote
4
down vote

favorite

I am looking to get all the lines which have the word 'search_string' + the line after it + the line matching 'mod' before it.

I tried:

grep -n 'mod|search_string' ip | grep --before 1 search_string> inter 
grep -n --after 1 search_string ip >> inter 
sort -t':' -k1,1n -u inter -o op

Is there a better way?

File:

mod start1 
some lines 
mod start2 
other lines 
mod start3 
 many other lines 
 search_string yada yada 
 hello 
 many other lines 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too 
mod start5

Expected output :

mod start3 
 search_string yada yada 
 hello 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too

edited Aug 26 at 7:52

ÃŽÂ±Ã’Â“sÃÂ½ÃŽÂ¹ÃŽÂ·

15.5k92563

asked Aug 25 at 18:46

romi

235

In your example you have search_string and search string. Are they both valid?
â€“Â Kamil Maciorowski
Aug 25 at 19:28

The output of the commands you show do not match the expected output you present. Which is correct ?
â€“Â Isaac
Aug 25 at 19:34

It was a typo. Corrected it to show search_string. The final results should match the expected results. I was only trying to show the convoluted steps I was thinking of and not getting proper results.
â€“Â romi
Aug 25 at 20:27

add a commentÂ |Â

up vote
4
down vote

favorite

I am looking to get all the lines which have the word 'search_string' + the line after it + the line matching 'mod' before it.

I tried:

grep -n 'mod|search_string' ip | grep --before 1 search_string> inter 
grep -n --after 1 search_string ip >> inter 
sort -t':' -k1,1n -u inter -o op

Is there a better way?

File:

mod start1 
some lines 
mod start2 
other lines 
mod start3 
 many other lines 
 search_string yada yada 
 hello 
 many other lines 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too 
mod start5

Expected output :

mod start3 
 search_string yada yada 
 hello 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too

edited Aug 26 at 7:52

ÃŽÂ±Ã’Â“sÃÂ½ÃŽÂ¹ÃŽÂ·

15.5k92563

asked Aug 25 at 18:46

romi

235

I am looking to get all the lines which have the word 'search_string' + the line after it + the line matching 'mod' before it.

I tried:

grep -n 'mod|search_string' ip | grep --before 1 search_string> inter 
grep -n --after 1 search_string ip >> inter 
sort -t':' -k1,1n -u inter -o op

Is there a better way?

File:

mod start1 
some lines 
mod start2 
other lines 
mod start3 
 many other lines 
 search_string yada yada 
 hello 
 many other lines 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too 
mod start5

Expected output :

mod start3 
 search_string yada yada 
 hello 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too

edited Aug 26 at 7:52

ÃŽÂ±Ã’Â“sÃÂ½ÃŽÂ¹ÃŽÂ·

15.5k92563

asked Aug 25 at 18:46

romi

235

edited Aug 26 at 7:52

ÃŽÂ±Ã’Â“sÃÂ½ÃŽÂ¹ÃŽÂ·

15.5k92563

edited Aug 26 at 7:52

ÃŽÂ±Ã’Â“sÃÂ½ÃŽÂ¹ÃŽÂ·

15.5k92563

edited Aug 26 at 7:52

ÃŽÂ±Ã’Â“sÃÂ½ÃŽÂ¹ÃŽÂ·

15.5k92563

asked Aug 25 at 18:46

romi

235

asked Aug 25 at 18:46

romi

235

asked Aug 25 at 18:46

romi

235

In your example you have search_string and search string. Are they both valid?
â€“Â Kamil Maciorowski
Aug 25 at 19:28

The output of the commands you show do not match the expected output you present. Which is correct ?
â€“Â Isaac
Aug 25 at 19:34

It was a typo. Corrected it to show search_string. The final results should match the expected results. I was only trying to show the convoluted steps I was thinking of and not getting proper results.
â€“Â romi
Aug 25 at 20:27

add a commentÂ |Â

In your example you have search_string and search string. Are they both valid?
â€“Â Kamil Maciorowski
Aug 25 at 19:28

The output of the commands you show do not match the expected output you present. Which is correct ?
â€“Â Isaac
Aug 25 at 19:34

It was a typo. Corrected it to show search_string. The final results should match the expected results. I was only trying to show the convoluted steps I was thinking of and not getting proper results.
â€“Â romi
Aug 25 at 20:27

In your example you have search_string and search string. Are they both valid?
â€“Â Kamil Maciorowski
Aug 25 at 19:28

The output of the commands you show do not match the expected output you present. Which is correct ?
â€“Â Isaac
Aug 25 at 19:34

It was a typo. Corrected it to show search_string. The final results should match the expected results. I was only trying to show the convoluted steps I was thinking of and not getting proper results.
â€“Â romi
Aug 25 at 20:27

add a commentÂ |Â

3 Answers
3

active

oldest

votes

up vote
4
down vote

accepted

awk '
 $0 ~ /mod/ md=$0 
 $0 ~ /search_string/ if(md!="") print md ; md="" ; print; getline; print 
 '

Explanation:

A line containing mod is saved as md.

A line containing search_string triggers printing the previously saved md, the line itself and the next line.

if(md!="") and md="" are there to make sure you don't get duplicated mod lines when there are many search_string-s under a single mod (mod start3 in your example).

Note:

A line containing both mod and search_string will break this logic.

edited Aug 26 at 13:34

answered Aug 25 at 19:27

Kamil Maciorowski

1,0791523

Kamil, Thankyou! This works for me!
â€“Â romi
Aug 26 at 7:31

add a commentÂ |Â

up vote
2
down vote

Your file contains "carriage return" characters. It is better to remove them in Unix. To print what the sequence of commands you posted print (with carriage returns removed), try:

awk 'gsub(/r/,"")
 /mod/ a = $0 
 /search_string/ if(a!="")print(a);a=""
 print;getline;print
 
 ' infile

Or as a one-liner:

$ awk 'gsub(/r/,"")/mod/a=$0/search_string/if(a!="")print(a);a=""print;getline;print' infile

mod start3 
 search_string yada yada 
 hello 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too

As it is possible to use a multi character record separator in (GNU) awk we can set the record separator to mod and print only records that contain search_string. The printf is required to reconstruct the original record.

To print what you posted as "Expected output" try:

awk '/search_string/printf("mod%s", $0)' RS=mod infile

edited Aug 25 at 20:33

answered Aug 25 at 19:25

Isaac

6,8001834

add a commentÂ |Â

up vote
0
down vote

If you want this in a Python script:

# Read file into memory.
with open('myfile.txt') as f:
 lines = [line.rstrip() for line in f]

# Loops through lines backwards, looking for string and optionally mod.
output_lines = list()
find_mod = False
for i, line in enumerate(lines[::-1]):
 if 'search_string' in line:
 output_lines.append(lines[::-1][i-1])
 output_lines.append(lines[::-1][i])
 find_mod = True
 elif find_mod and 'mod' in line:
 output_lines.append(lines[::-1][i])
 find_mod=False

print("n".join(output_lines[::-1]))

answered Aug 26 at 2:36

user1717828

1,59611125

add a commentÂ |Â

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3 Answers
3

active

oldest

votes

3 Answers
3

active

oldest

votes

up vote
4
down vote

accepted

awk '
 $0 ~ /mod/ md=$0 
 $0 ~ /search_string/ if(md!="") print md ; md="" ; print; getline; print 
 '

Explanation:

A line containing mod is saved as md.

A line containing search_string triggers printing the previously saved md, the line itself and the next line.

if(md!="") and md="" are there to make sure you don't get duplicated mod lines when there are many search_string-s under a single mod (mod start3 in your example).

Note:

A line containing both mod and search_string will break this logic.

edited Aug 26 at 13:34

answered Aug 25 at 19:27

Kamil Maciorowski

1,0791523

Kamil, Thankyou! This works for me!
â€“Â romi
Aug 26 at 7:31

add a commentÂ |Â

up vote
4
down vote

accepted

awk '
 $0 ~ /mod/ md=$0 
 $0 ~ /search_string/ if(md!="") print md ; md="" ; print; getline; print 
 '

Explanation:

A line containing mod is saved as md.

A line containing search_string triggers printing the previously saved md, the line itself and the next line.

if(md!="") and md="" are there to make sure you don't get duplicated mod lines when there are many search_string-s under a single mod (mod start3 in your example).

Note:

A line containing both mod and search_string will break this logic.

edited Aug 26 at 13:34

answered Aug 25 at 19:27

Kamil Maciorowski

1,0791523

Kamil, Thankyou! This works for me!
â€“Â romi
Aug 26 at 7:31

add a commentÂ |Â

up vote
4
down vote

accepted

awk '
 $0 ~ /mod/ md=$0 
 $0 ~ /search_string/ if(md!="") print md ; md="" ; print; getline; print 
 '

Explanation:

A line containing mod is saved as md.

A line containing search_string triggers printing the previously saved md, the line itself and the next line.

if(md!="") and md="" are there to make sure you don't get duplicated mod lines when there are many search_string-s under a single mod (mod start3 in your example).

Note:

A line containing both mod and search_string will break this logic.

edited Aug 26 at 13:34

answered Aug 25 at 19:27

Kamil Maciorowski

1,0791523

awk '
 $0 ~ /mod/ md=$0 
 $0 ~ /search_string/ if(md!="") print md ; md="" ; print; getline; print 
 '

Explanation:

A line containing mod is saved as md.

A line containing search_string triggers printing the previously saved md, the line itself and the next line.

if(md!="") and md="" are there to make sure you don't get duplicated mod lines when there are many search_string-s under a single mod (mod start3 in your example).

Note:

A line containing both mod and search_string will break this logic.

edited Aug 26 at 13:34

answered Aug 25 at 19:27

Kamil Maciorowski

1,0791523

edited Aug 26 at 13:34

answered Aug 25 at 19:27

Kamil Maciorowski

1,0791523

answered Aug 25 at 19:27

Kamil Maciorowski

1,0791523

answered Aug 25 at 19:27

Kamil Maciorowski

1,0791523

Kamil, Thankyou! This works for me!
â€“Â romi
Aug 26 at 7:31

add a commentÂ |Â

Kamil, Thankyou! This works for me!
â€“Â romi
Aug 26 at 7:31

Kamil, Thankyou! This works for me!
â€“Â romi
Aug 26 at 7:31

add a commentÂ |Â

up vote
2
down vote

Your file contains "carriage return" characters. It is better to remove them in Unix. To print what the sequence of commands you posted print (with carriage returns removed), try:

awk 'gsub(/r/,"")
 /mod/ a = $0 
 /search_string/ if(a!="")print(a);a=""
 print;getline;print
 
 ' infile

Or as a one-liner:

$ awk 'gsub(/r/,"")/mod/a=$0/search_string/if(a!="")print(a);a=""print;getline;print' infile

mod start3 
 search_string yada yada 
 hello 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too

To print what you posted as "Expected output" try:

awk '/search_string/printf("mod%s", $0)' RS=mod infile

edited Aug 25 at 20:33

answered Aug 25 at 19:25

Isaac

6,8001834

add a commentÂ |Â

up vote
2
down vote

Your file contains "carriage return" characters. It is better to remove them in Unix. To print what the sequence of commands you posted print (with carriage returns removed), try:

awk 'gsub(/r/,"")
 /mod/ a = $0 
 /search_string/ if(a!="")print(a);a=""
 print;getline;print
 
 ' infile

Or as a one-liner:

$ awk 'gsub(/r/,"")/mod/a=$0/search_string/if(a!="")print(a);a=""print;getline;print' infile

mod start3 
 search_string yada yada 
 hello 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too

To print what you posted as "Expected output" try:

awk '/search_string/printf("mod%s", $0)' RS=mod infile

edited Aug 25 at 20:33

answered Aug 25 at 19:25

Isaac

6,8001834

add a commentÂ |Â

up vote
2
down vote

Your file contains "carriage return" characters. It is better to remove them in Unix. To print what the sequence of commands you posted print (with carriage returns removed), try:

awk 'gsub(/r/,"")
 /mod/ a = $0 
 /search_string/ if(a!="")print(a);a=""
 print;getline;print
 
 ' infile

Or as a one-liner:

$ awk 'gsub(/r/,"")/mod/a=$0/search_string/if(a!="")print(a);a=""print;getline;print' infile

mod start3 
 search_string yada yada 
 hello 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too

To print what you posted as "Expected output" try:

awk '/search_string/printf("mod%s", $0)' RS=mod infile

edited Aug 25 at 20:33

answered Aug 25 at 19:25

Isaac

6,8001834

Your file contains "carriage return" characters. It is better to remove them in Unix. To print what the sequence of commands you posted print (with carriage returns removed), try:

awk 'gsub(/r/,"")
 /mod/ a = $0 
 /search_string/ if(a!="")print(a);a=""
 print;getline;print
 
 ' infile

Or as a one-liner:

$ awk 'gsub(/r/,"")/mod/a=$0/search_string/if(a!="")print(a);a=""print;getline;print' infile

mod start3 
 search_string yada yada 
 hello 
 search_string yada yada 
 bye 
mod start4 
 search_string baba baba 
 this too

To print what you posted as "Expected output" try:

awk '/search_string/printf("mod%s", $0)' RS=mod infile

edited Aug 25 at 20:33

answered Aug 25 at 19:25

Isaac

6,8001834

edited Aug 25 at 20:33

answered Aug 25 at 19:25

Isaac

6,8001834

answered Aug 25 at 19:25

Isaac

6,8001834

answered Aug 25 at 19:25

Isaac

6,8001834

add a commentÂ |Â

up vote
0
down vote

If you want this in a Python script:

# Read file into memory.
with open('myfile.txt') as f:
 lines = [line.rstrip() for line in f]

# Loops through lines backwards, looking for string and optionally mod.
output_lines = list()
find_mod = False
for i, line in enumerate(lines[::-1]):
 if 'search_string' in line:
 output_lines.append(lines[::-1][i-1])
 output_lines.append(lines[::-1][i])
 find_mod = True
 elif find_mod and 'mod' in line:
 output_lines.append(lines[::-1][i])
 find_mod=False

print("n".join(output_lines[::-1]))

answered Aug 26 at 2:36

user1717828

1,59611125

add a commentÂ |Â

up vote
0
down vote

If you want this in a Python script:

# Read file into memory.
with open('myfile.txt') as f:
 lines = [line.rstrip() for line in f]

# Loops through lines backwards, looking for string and optionally mod.
output_lines = list()
find_mod = False
for i, line in enumerate(lines[::-1]):
 if 'search_string' in line:
 output_lines.append(lines[::-1][i-1])
 output_lines.append(lines[::-1][i])
 find_mod = True
 elif find_mod and 'mod' in line:
 output_lines.append(lines[::-1][i])
 find_mod=False

print("n".join(output_lines[::-1]))

answered Aug 26 at 2:36

user1717828

1,59611125

add a commentÂ |Â

up vote
0
down vote

If you want this in a Python script:

# Read file into memory.
with open('myfile.txt') as f:
 lines = [line.rstrip() for line in f]

# Loops through lines backwards, looking for string and optionally mod.
output_lines = list()
find_mod = False
for i, line in enumerate(lines[::-1]):
 if 'search_string' in line:
 output_lines.append(lines[::-1][i-1])
 output_lines.append(lines[::-1][i])
 find_mod = True
 elif find_mod and 'mod' in line:
 output_lines.append(lines[::-1][i])
 find_mod=False

print("n".join(output_lines[::-1]))

answered Aug 26 at 2:36

user1717828

1,59611125

If you want this in a Python script:

# Read file into memory.
with open('myfile.txt') as f:
 lines = [line.rstrip() for line in f]

# Loops through lines backwards, looking for string and optionally mod.
output_lines = list()
find_mod = False
for i, line in enumerate(lines[::-1]):
 if 'search_string' in line:
 output_lines.append(lines[::-1][i-1])
 output_lines.append(lines[::-1][i])
 find_mod = True
 elif find_mod and 'mod' in line:
 output_lines.append(lines[::-1][i])
 find_mod=False

print("n".join(output_lines[::-1]))

answered Aug 26 at 2:36

user1717828

1,59611125

answered Aug 26 at 2:36

user1717828

1,59611125

answered Aug 26 at 2:36

user1717828

1,59611125

answered Aug 26 at 2:36

user1717828

1,59611125

add a commentÂ |Â

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