highlight a word without affecting the structure of text [duplicate]

3

This question already has an answer here:

• 
  Convince grep to output all lines, not just those with matches
  
  11 answers
  
  

$cat contents.txt



cat-1.15



cat-1.15



cat-1.15

cat-1.18

The above output has blank lines

$cat contents.txt | grep cat
results in the word cat being highlighted, but the resultant text is also merged, eliminating blank lines

cat-1.15

cat-1.15

cat-1.15

cat-1.18

How can I grep to highlight without grep affecting the text structure, so that the only difference is the grep term being highlighted ?

awk sed grep

share|improve this question

edited Jan 25 at 17:09

user607694

asked Jan 25 at 17:07

user607694user607694

504

marked as duplicate by steeldriver, Isaac, don_crissti, Gilles, Jeff Schaller Jan 25 at 23:22

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

add a comment | 

3

This question already has an answer here:

• 
  Convince grep to output all lines, not just those with matches
  
  11 answers
  
  

$cat contents.txt



cat-1.15



cat-1.15



cat-1.15

cat-1.18

The above output has blank lines

$cat contents.txt | grep cat
results in the word cat being highlighted, but the resultant text is also merged, eliminating blank lines

cat-1.15

cat-1.15

cat-1.15

cat-1.18

How can I grep to highlight without grep affecting the text structure, so that the only difference is the grep term being highlighted ?

awk sed grep

share|improve this question

edited Jan 25 at 17:09

user607694

asked Jan 25 at 17:07

user607694user607694

504

marked as duplicate by steeldriver, Isaac, don_crissti, Gilles, Jeff Schaller Jan 25 at 23:22

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

add a comment | 

3

3

3

This question already has an answer here:

• 
  Convince grep to output all lines, not just those with matches
  
  11 answers
  
  

$cat contents.txt



cat-1.15



cat-1.15



cat-1.15

cat-1.18

The above output has blank lines

$cat contents.txt | grep cat
results in the word cat being highlighted, but the resultant text is also merged, eliminating blank lines

cat-1.15

cat-1.15

cat-1.15

cat-1.18

How can I grep to highlight without grep affecting the text structure, so that the only difference is the grep term being highlighted ?

awk sed grep

share|improve this question

edited Jan 25 at 17:09

user607694

asked Jan 25 at 17:07

user607694user607694

504

This question already has an answer here:

• 
  Convince grep to output all lines, not just those with matches
  
  11 answers
  
  

$cat contents.txt



cat-1.15



cat-1.15



cat-1.15

cat-1.18

The above output has blank lines

$cat contents.txt | grep cat
results in the word cat being highlighted, but the resultant text is also merged, eliminating blank lines

cat-1.15

cat-1.15

cat-1.15

cat-1.18

How can I grep to highlight without grep affecting the text structure, so that the only difference is the grep term being highlighted ?

This question already has an answer here:

• 
  Convince grep to output all lines, not just those with matches
  
  11 answers
  
  

awk sed grep

awk sed grep

share|improve this question

edited Jan 25 at 17:09

user607694

asked Jan 25 at 17:07

user607694user607694

504

share|improve this question

edited Jan 25 at 17:09

user607694

asked Jan 25 at 17:07

user607694user607694

504

share|improve this question

share|improve this question

edited Jan 25 at 17:09

user607694

edited Jan 25 at 17:09

user607694

edited Jan 25 at 17:09

user607694

asked Jan 25 at 17:07

user607694user607694

504

asked Jan 25 at 17:07

user607694user607694

504

asked Jan 25 at 17:07

user607694user607694

504

504

marked as duplicate by steeldriver, Isaac, don_crissti, Gilles, Jeff Schaller Jan 25 at 23:22

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

marked as duplicate by steeldriver, Isaac, don_crissti, Gilles, Jeff Schaller Jan 25 at 23:22

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

add a comment | 

add a comment | 

4 Answers
4

active

oldest

votes

5

With GNU grep this can be accomplished with the -z option.

-z, --null-data

Treat input and output data as sequences of lines, each terminated by a zero byte (the ASCII NUL character) instead of a newline. Like the -Z or --null
option, this option can be used with commands like sort -z to process arbitrary file names.

Also this is a UUOC. You can specify an input file with grep.

$ grep --color cat contents.txt

cat-1.15

cat-1.15

cat-1.15

cat-1.18

$ grep --color -z cat contents.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

share|improve this answer

answered Jan 25 at 17:14

Jesse_bJesse_b

13.7k23471

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Note that this will try to read the whole file into memory. If it is big, a big chunk of memory will be used.
  
  – Isaac
  Jan 25 at 19:51
  

  
  
  
  

add a comment | 

4

Another possible solution is to provide two patterns to grep: one will be the actual pattern or term to be searched for, and the second one will be an empty string.

$ grep --color -e 'cat' -e '' testfile.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

The -e option is used for specify multiple patterns. From the manual:

-e PATTERN, --regexp=PATTERN

Use PATTERN as the pattern. This can be used to specify multiple search patterns, or to protect a pattern beginning with a hyphen (-). (-e is specified by POSIX.)

You can also combine those patterns as a single extended regular expression, if required:

$ grep --color -E 'cat|' testfile.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

Also, you can simply add another pattern to the list if you need to highlight more than one keyword.

share|improve this answer

edited Jan 26 at 6:03

answered Jan 25 at 17:35

HaxielHaxiel

3,35511021

add a comment | 

1

A couple more possibilities with grep:

grep for 0 or more instances of cat:

grep --color '(cat)*' contents.txt

grep for cat or the empty string:

grep -E --color 'cat|' contents.txt

(The -E specifies extended regex syntax. egrep may be used instead of grep -E here.)

---

Alternatively you can use sed to do the colourization manually using ANSI escape codes:

red='c[[1;31m'

default='c[[0m'

sed "s/cat/${red}cat${default}/g" contents.txt

Here the red and default shell variables are conveniences only - their values could just as well be placed inline in the sed expression.

share|improve this answer

edited Jan 25 at 22:02

answered Jan 25 at 21:49

Digital TraumaDigital Trauma

5,98211730

add a comment | 

0

I tried with below command

sed -r "/cat/{N;s/^$/&=/}" filename





awk '{if(((length($1)>3)&& ($1 ~ /cat/))||($0~/^$/)){print $0}}' filename

share|improve this answer

answered Jan 25 at 19:07

Praveen Kumar BSPraveen Kumar BS

1,6351311

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  How do these highlight the output?
  
  – wjandrea
  Jan 25 at 20:50
  

  
  
  
  

add a comment | 

4 Answers
4

active

oldest

votes

4 Answers
4

active

oldest

votes

active

oldest

votes

active

oldest

votes

5

With GNU grep this can be accomplished with the -z option.

-z, --null-data

Treat input and output data as sequences of lines, each terminated by a zero byte (the ASCII NUL character) instead of a newline. Like the -Z or --null
option, this option can be used with commands like sort -z to process arbitrary file names.

Also this is a UUOC. You can specify an input file with grep.

$ grep --color cat contents.txt

cat-1.15

cat-1.15

cat-1.15

cat-1.18

$ grep --color -z cat contents.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

share|improve this answer

answered Jan 25 at 17:14

Jesse_bJesse_b

13.7k23471

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Note that this will try to read the whole file into memory. If it is big, a big chunk of memory will be used.
  
  – Isaac
  Jan 25 at 19:51
  

  
  
  
  

add a comment | 

5

With GNU grep this can be accomplished with the -z option.

-z, --null-data

Treat input and output data as sequences of lines, each terminated by a zero byte (the ASCII NUL character) instead of a newline. Like the -Z or --null
option, this option can be used with commands like sort -z to process arbitrary file names.

Also this is a UUOC. You can specify an input file with grep.

$ grep --color cat contents.txt

cat-1.15

cat-1.15

cat-1.15

cat-1.18

$ grep --color -z cat contents.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

share|improve this answer

answered Jan 25 at 17:14

Jesse_bJesse_b

13.7k23471

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Note that this will try to read the whole file into memory. If it is big, a big chunk of memory will be used.
  
  – Isaac
  Jan 25 at 19:51
  

  
  
  
  

add a comment | 

5

5

5

With GNU grep this can be accomplished with the -z option.

-z, --null-data

Treat input and output data as sequences of lines, each terminated by a zero byte (the ASCII NUL character) instead of a newline. Like the -Z or --null
option, this option can be used with commands like sort -z to process arbitrary file names.

Also this is a UUOC. You can specify an input file with grep.

$ grep --color cat contents.txt

cat-1.15

cat-1.15

cat-1.15

cat-1.18

$ grep --color -z cat contents.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

share|improve this answer

answered Jan 25 at 17:14

Jesse_bJesse_b

13.7k23471

With GNU grep this can be accomplished with the -z option.

-z, --null-data

Treat input and output data as sequences of lines, each terminated by a zero byte (the ASCII NUL character) instead of a newline. Like the -Z or --null
option, this option can be used with commands like sort -z to process arbitrary file names.

Also this is a UUOC. You can specify an input file with grep.

$ grep --color cat contents.txt

cat-1.15

cat-1.15

cat-1.15

cat-1.18

$ grep --color -z cat contents.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

share|improve this answer

answered Jan 25 at 17:14

Jesse_bJesse_b

13.7k23471

share|improve this answer

share|improve this answer

answered Jan 25 at 17:14

Jesse_bJesse_b

13.7k23471

answered Jan 25 at 17:14

Jesse_bJesse_b

13.7k23471

answered Jan 25 at 17:14

Jesse_bJesse_b

13.7k23471

13.7k23471

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Note that this will try to read the whole file into memory. If it is big, a big chunk of memory will be used.
  
  – Isaac
  Jan 25 at 19:51
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Note that this will try to read the whole file into memory. If it is big, a big chunk of memory will be used.
  
  – Isaac
  Jan 25 at 19:51
  

  
  
  
  

2

2

Note that this will try to read the whole file into memory. If it is big, a big chunk of memory will be used.

– Isaac
Jan 25 at 19:51

Note that this will try to read the whole file into memory. If it is big, a big chunk of memory will be used.

– Isaac
Jan 25 at 19:51

add a comment | 

4

Another possible solution is to provide two patterns to grep: one will be the actual pattern or term to be searched for, and the second one will be an empty string.

$ grep --color -e 'cat' -e '' testfile.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

The -e option is used for specify multiple patterns. From the manual:

-e PATTERN, --regexp=PATTERN

Use PATTERN as the pattern. This can be used to specify multiple search patterns, or to protect a pattern beginning with a hyphen (-). (-e is specified by POSIX.)

You can also combine those patterns as a single extended regular expression, if required:

$ grep --color -E 'cat|' testfile.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

Also, you can simply add another pattern to the list if you need to highlight more than one keyword.

share|improve this answer

edited Jan 26 at 6:03

answered Jan 25 at 17:35

HaxielHaxiel

3,35511021

add a comment | 

4

Another possible solution is to provide two patterns to grep: one will be the actual pattern or term to be searched for, and the second one will be an empty string.

$ grep --color -e 'cat' -e '' testfile.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

The -e option is used for specify multiple patterns. From the manual:

-e PATTERN, --regexp=PATTERN

Use PATTERN as the pattern. This can be used to specify multiple search patterns, or to protect a pattern beginning with a hyphen (-). (-e is specified by POSIX.)

You can also combine those patterns as a single extended regular expression, if required:

$ grep --color -E 'cat|' testfile.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

Also, you can simply add another pattern to the list if you need to highlight more than one keyword.

share|improve this answer

edited Jan 26 at 6:03

answered Jan 25 at 17:35

HaxielHaxiel

3,35511021

add a comment | 

4

4

4

Another possible solution is to provide two patterns to grep: one will be the actual pattern or term to be searched for, and the second one will be an empty string.

$ grep --color -e 'cat' -e '' testfile.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

The -e option is used for specify multiple patterns. From the manual:

-e PATTERN, --regexp=PATTERN

Use PATTERN as the pattern. This can be used to specify multiple search patterns, or to protect a pattern beginning with a hyphen (-). (-e is specified by POSIX.)

You can also combine those patterns as a single extended regular expression, if required:

$ grep --color -E 'cat|' testfile.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

Also, you can simply add another pattern to the list if you need to highlight more than one keyword.

share|improve this answer

edited Jan 26 at 6:03

answered Jan 25 at 17:35

HaxielHaxiel

3,35511021

Another possible solution is to provide two patterns to grep: one will be the actual pattern or term to be searched for, and the second one will be an empty string.

$ grep --color -e 'cat' -e '' testfile.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

The -e option is used for specify multiple patterns. From the manual:

-e PATTERN, --regexp=PATTERN

Use PATTERN as the pattern. This can be used to specify multiple search patterns, or to protect a pattern beginning with a hyphen (-). (-e is specified by POSIX.)

You can also combine those patterns as a single extended regular expression, if required:

$ grep --color -E 'cat|' testfile.txt

cat-1.15



cat-1.15



cat-1.15

cat-1.18

Also, you can simply add another pattern to the list if you need to highlight more than one keyword.

share|improve this answer

edited Jan 26 at 6:03

answered Jan 25 at 17:35

HaxielHaxiel

3,35511021

share|improve this answer

share|improve this answer

edited Jan 26 at 6:03

edited Jan 26 at 6:03

edited Jan 26 at 6:03

answered Jan 25 at 17:35

HaxielHaxiel

3,35511021

answered Jan 25 at 17:35

HaxielHaxiel

3,35511021

answered Jan 25 at 17:35

HaxielHaxiel

3,35511021

3,35511021

add a comment | 

add a comment | 

1

A couple more possibilities with grep:

grep for 0 or more instances of cat:

grep --color '(cat)*' contents.txt

grep for cat or the empty string:

grep -E --color 'cat|' contents.txt

(The -E specifies extended regex syntax. egrep may be used instead of grep -E here.)

---

Alternatively you can use sed to do the colourization manually using ANSI escape codes:

red='c[[1;31m'

default='c[[0m'

sed "s/cat/${red}cat${default}/g" contents.txt

Here the red and default shell variables are conveniences only - their values could just as well be placed inline in the sed expression.

share|improve this answer

edited Jan 25 at 22:02

answered Jan 25 at 21:49

Digital TraumaDigital Trauma

5,98211730

add a comment | 

1

A couple more possibilities with grep:

grep for 0 or more instances of cat:

grep --color '(cat)*' contents.txt

grep for cat or the empty string:

grep -E --color 'cat|' contents.txt

(The -E specifies extended regex syntax. egrep may be used instead of grep -E here.)

---

Alternatively you can use sed to do the colourization manually using ANSI escape codes:

red='c[[1;31m'

default='c[[0m'

sed "s/cat/${red}cat${default}/g" contents.txt

Here the red and default shell variables are conveniences only - their values could just as well be placed inline in the sed expression.

share|improve this answer

edited Jan 25 at 22:02

answered Jan 25 at 21:49

Digital TraumaDigital Trauma

5,98211730

add a comment | 

1

1

1

A couple more possibilities with grep:

grep for 0 or more instances of cat:

grep --color '(cat)*' contents.txt

grep for cat or the empty string:

grep -E --color 'cat|' contents.txt

(The -E specifies extended regex syntax. egrep may be used instead of grep -E here.)

---

Alternatively you can use sed to do the colourization manually using ANSI escape codes:

red='c[[1;31m'

default='c[[0m'

sed "s/cat/${red}cat${default}/g" contents.txt

Here the red and default shell variables are conveniences only - their values could just as well be placed inline in the sed expression.

share|improve this answer

edited Jan 25 at 22:02

answered Jan 25 at 21:49

Digital TraumaDigital Trauma

5,98211730

A couple more possibilities with grep:

grep for 0 or more instances of cat:

grep --color '(cat)*' contents.txt

grep for cat or the empty string:

grep -E --color 'cat|' contents.txt

(The -E specifies extended regex syntax. egrep may be used instead of grep -E here.)

---

Alternatively you can use sed to do the colourization manually using ANSI escape codes:

red='c[[1;31m'

default='c[[0m'

sed "s/cat/${red}cat${default}/g" contents.txt

Here the red and default shell variables are conveniences only - their values could just as well be placed inline in the sed expression.

share|improve this answer

edited Jan 25 at 22:02

answered Jan 25 at 21:49

Digital TraumaDigital Trauma

5,98211730

share|improve this answer

share|improve this answer

edited Jan 25 at 22:02

edited Jan 25 at 22:02

edited Jan 25 at 22:02

answered Jan 25 at 21:49

Digital TraumaDigital Trauma

5,98211730

answered Jan 25 at 21:49

Digital TraumaDigital Trauma

5,98211730

answered Jan 25 at 21:49

Digital TraumaDigital Trauma

5,98211730

5,98211730

add a comment | 

add a comment | 

0

I tried with below command

sed -r "/cat/{N;s/^$/&=/}" filename





awk '{if(((length($1)>3)&& ($1 ~ /cat/))||($0~/^$/)){print $0}}' filename

share|improve this answer

answered Jan 25 at 19:07

Praveen Kumar BSPraveen Kumar BS

1,6351311

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  How do these highlight the output?
  
  – wjandrea
  Jan 25 at 20:50
  

  
  
  
  

add a comment | 

0

I tried with below command

sed -r "/cat/{N;s/^$/&=/}" filename





awk '{if(((length($1)>3)&& ($1 ~ /cat/))||($0~/^$/)){print $0}}' filename

share|improve this answer

answered Jan 25 at 19:07

Praveen Kumar BSPraveen Kumar BS

1,6351311

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  How do these highlight the output?
  
  – wjandrea
  Jan 25 at 20:50
  

  
  
  
  

add a comment | 

0

0

0

I tried with below command

sed -r "/cat/{N;s/^$/&=/}" filename





awk '{if(((length($1)>3)&& ($1 ~ /cat/))||($0~/^$/)){print $0}}' filename

share|improve this answer

answered Jan 25 at 19:07

Praveen Kumar BSPraveen Kumar BS

1,6351311

I tried with below command

sed -r "/cat/{N;s/^$/&=/}" filename





awk '{if(((length($1)>3)&& ($1 ~ /cat/))||($0~/^$/)){print $0}}' filename

share|improve this answer

answered Jan 25 at 19:07

Praveen Kumar BSPraveen Kumar BS

1,6351311

share|improve this answer

share|improve this answer

answered Jan 25 at 19:07

Praveen Kumar BSPraveen Kumar BS

1,6351311

answered Jan 25 at 19:07

Praveen Kumar BSPraveen Kumar BS

1,6351311

answered Jan 25 at 19:07

Praveen Kumar BSPraveen Kumar BS

1,6351311

1,6351311

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  How do these highlight the output?
  
  – wjandrea
  Jan 25 at 20:50
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  How do these highlight the output?
  
  – wjandrea
  Jan 25 at 20:50
  

  
  
  
  

How do these highlight the output?

– wjandrea
Jan 25 at 20:50

How do these highlight the output?

– wjandrea
Jan 25 at 20:50

add a comment | 

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