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Grep contents before a colon

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Grep contents before a colon

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.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;

2

1

I have a text file on Linux where the contents are like below:

help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com

I want to grep the contents before the colon like below:

help.helloworld.com
dev.helloworld.com

How can I do that within the terminal?

text-processing grep

share|improve this question

edited 8 hours ago

terdon♦

141k3434 gold badges290290 silver badges469469 bronze badges

asked 9 hours ago

Gabrial JohnasGabrial Johnas

11733 bronze badges

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Gabrial Johnas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  The grep utility is used for looking for lines matching regular expressions. You could possibly use it here, but it would be more appropriate to use a tool that extracts data from fields given some delimiter, such as the cut utility.
  
  – Kusalananda♦
  8 hours ago
  
  

  
  
  
  

add a comment | 

2

1

I have a text file on Linux where the contents are like below:

help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com

I want to grep the contents before the colon like below:

help.helloworld.com
dev.helloworld.com

How can I do that within the terminal?

text-processing grep

share|improve this question

edited 8 hours ago

terdon♦

141k3434 gold badges290290 silver badges469469 bronze badges

asked 9 hours ago

Gabrial JohnasGabrial Johnas

11733 bronze badges

New contributor

Gabrial Johnas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  The grep utility is used for looking for lines matching regular expressions. You could possibly use it here, but it would be more appropriate to use a tool that extracts data from fields given some delimiter, such as the cut utility.
  
  – Kusalananda♦
  8 hours ago
  
  

  
  
  
  

add a comment | 

I have a text file on Linux where the contents are like below:

help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com

I want to grep the contents before the colon like below:

help.helloworld.com
dev.helloworld.com

How can I do that within the terminal?

text-processing grep

share|improve this question

edited 8 hours ago

terdon♦

141k3434 gold badges290290 silver badges469469 bronze badges

asked 9 hours ago

Gabrial JohnasGabrial Johnas

11733 bronze badges

New contributor

Gabrial Johnas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com

help.helloworld.com
dev.helloworld.com

share|improve this question

edited 8 hours ago

terdon♦

141k3434 gold badges290290 silver badges469469 bronze badges

asked 9 hours ago

Gabrial JohnasGabrial Johnas

11733 bronze badges

New contributor

Gabrial Johnas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

edited 8 hours ago

terdon♦

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asked 9 hours ago

Gabrial JohnasGabrial Johnas

11733 bronze badges

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Gabrial Johnas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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edited 8 hours ago

terdon♦

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edited 8 hours ago

terdon♦

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asked 9 hours ago

Gabrial JohnasGabrial Johnas

11733 bronze badges

New contributor

Gabrial Johnas is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 9 hours ago

Gabrial JohnasGabrial Johnas

11733 bronze badges

5 Answers
5

active

oldest

votes

1

Requires GNU grep. It would not work with the default grep on
e.g. macOS or any of the other BSDs.

Do you mean like this:

grep -oP '.*(?=:)' file

Output:

help.helloworld.com
dev.helloworld.com

share|improve this answer

edited 8 hours ago

answered 9 hours ago

guillermo chamorroguillermo chamorro

62311 silver badge1212 bronze badges

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  If there are two or more colons on the line, this will print everything until the last one, so not what the OP needs. Try echo foo:bar:baz | grep -oP '.*(?=:)'. This will work for the OP's example, but not for the general case as described in the question.
  
  – terdon♦
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  there is only one colon and its working fine , but thanks for the update
  
  – Gabrial Johnas
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Also requires GNU grep. It would not work with the default grep on e.g. macOS or any of the other BSDs.
  
  – Kusalananda♦
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Kusalananda I edited the question adding your observation.
  
  – guillermo chamorro
  8 hours ago
  

  
  
  
  

add a comment | 

6

Or an alternative:

$ grep -o '^[^:]*' file
help.helloworld.com
dev.helloworld.com

This returns any characters beginning at the start of each line (^) which are no colons ([^:]*).

share|improve this answer

answered 8 hours ago

FreddyFreddy

6,94811 gold badge66 silver badges2424 bronze badges

add a comment | 

6

Would definitely recommend awk:

awk -F ':' 'print $1' file

Uses : as a field separator and prints the first field.

share|improve this answer

answered 8 hours ago

CentimaneCentimane

3,30311 gold badge1313 silver badges3636 bronze badges

add a comment | 

5

This is what cut is for:

$ cat file
help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com
foo:baz:bar
foo

$ cut -d: -f1 file
help.helloworld.com
dev.helloworld.com
foo
foo

You just set the delimiter to : with -d: and tell it to only print the 1st field (-f1).

share|improve this answer

answered 8 hours ago

terdon♦terdon

141k3434 gold badges290290 silver badges469469 bronze badges

add a comment | 

0

All the other answers are probably better, but you could even use sed:

sed -nEe 's/([^:]):.+/1/p' file.txt

where file.txt contains the following:

$ cat file.txt
help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com

I tested this with Android BusyBox sed on my way to work.

A short explanation:

• 
  -n: don't print by default


• 
  -E: use extended regex (less backslash escaping)


• 
  -e (probably unnecessary) marks the following expression as a command, not something else, like a file

share|improve this answer

edited 12 mins ago

answered 22 mins ago

Randy JosleynRandy Josleyn

2044 bronze badges

add a comment | 

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1

Requires GNU grep. It would not work with the default grep on
e.g. macOS or any of the other BSDs.

Do you mean like this:

grep -oP '.*(?=:)' file

Output:

help.helloworld.com
dev.helloworld.com

share|improve this answer

edited 8 hours ago

answered 9 hours ago

guillermo chamorroguillermo chamorro

62311 silver badge1212 bronze badges

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  If there are two or more colons on the line, this will print everything until the last one, so not what the OP needs. Try echo foo:bar:baz | grep -oP '.*(?=:)'. This will work for the OP's example, but not for the general case as described in the question.
  
  – terdon♦
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  there is only one colon and its working fine , but thanks for the update
  
  – Gabrial Johnas
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Also requires GNU grep. It would not work with the default grep on e.g. macOS or any of the other BSDs.
  
  – Kusalananda♦
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Kusalananda I edited the question adding your observation.
  
  – guillermo chamorro
  8 hours ago
  

  
  
  
  

add a comment | 

1

Requires GNU grep. It would not work with the default grep on
e.g. macOS or any of the other BSDs.

Do you mean like this:

grep -oP '.*(?=:)' file

Output:

help.helloworld.com
dev.helloworld.com

share|improve this answer

edited 8 hours ago

answered 9 hours ago

guillermo chamorroguillermo chamorro

62311 silver badge1212 bronze badges

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  If there are two or more colons on the line, this will print everything until the last one, so not what the OP needs. Try echo foo:bar:baz | grep -oP '.*(?=:)'. This will work for the OP's example, but not for the general case as described in the question.
  
  – terdon♦
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  there is only one colon and its working fine , but thanks for the update
  
  – Gabrial Johnas
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  Also requires GNU grep. It would not work with the default grep on e.g. macOS or any of the other BSDs.
  
  – Kusalananda♦
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Kusalananda I edited the question adding your observation.
  
  – guillermo chamorro
  8 hours ago
  

  
  
  
  

add a comment | 

Requires GNU grep. It would not work with the default grep on
e.g. macOS or any of the other BSDs.

Do you mean like this:

grep -oP '.*(?=:)' file

Output:

help.helloworld.com
dev.helloworld.com

share|improve this answer

edited 8 hours ago

answered 9 hours ago

guillermo chamorroguillermo chamorro

62311 silver badge1212 bronze badges

grep -oP '.*(?=:)' file

help.helloworld.com
dev.helloworld.com

share|improve this answer

edited 8 hours ago

answered 9 hours ago

guillermo chamorroguillermo chamorro

62311 silver badge1212 bronze badges

answered 9 hours ago

guillermo chamorroguillermo chamorro

62311 silver badge1212 bronze badges

answered 9 hours ago

guillermo chamorroguillermo chamorro

62311 silver badge1212 bronze badges

6

Or an alternative:

$ grep -o '^[^:]*' file
help.helloworld.com
dev.helloworld.com

This returns any characters beginning at the start of each line (^) which are no colons ([^:]*).

share|improve this answer

answered 8 hours ago

FreddyFreddy

6,94811 gold badge66 silver badges2424 bronze badges

add a comment | 

6

Or an alternative:

$ grep -o '^[^:]*' file
help.helloworld.com
dev.helloworld.com

This returns any characters beginning at the start of each line (^) which are no colons ([^:]*).

share|improve this answer

answered 8 hours ago

FreddyFreddy

6,94811 gold badge66 silver badges2424 bronze badges

add a comment | 

Or an alternative:

$ grep -o '^[^:]*' file
help.helloworld.com
dev.helloworld.com

This returns any characters beginning at the start of each line (^) which are no colons ([^:]*).

share|improve this answer

answered 8 hours ago

FreddyFreddy

6,94811 gold badge66 silver badges2424 bronze badges

$ grep -o '^[^:]*' file
help.helloworld.com
dev.helloworld.com

share|improve this answer

answered 8 hours ago

FreddyFreddy

6,94811 gold badge66 silver badges2424 bronze badges

answered 8 hours ago

FreddyFreddy

6,94811 gold badge66 silver badges2424 bronze badges

answered 8 hours ago

FreddyFreddy

6,94811 gold badge66 silver badges2424 bronze badges

6

Would definitely recommend awk:

awk -F ':' 'print $1' file

Uses : as a field separator and prints the first field.

share|improve this answer

answered 8 hours ago

CentimaneCentimane

3,30311 gold badge1313 silver badges3636 bronze badges

add a comment | 

6

Would definitely recommend awk:

awk -F ':' 'print $1' file

Uses : as a field separator and prints the first field.

share|improve this answer

answered 8 hours ago

CentimaneCentimane

3,30311 gold badge1313 silver badges3636 bronze badges

add a comment | 

Would definitely recommend awk:

awk -F ':' 'print $1' file

Uses : as a field separator and prints the first field.

share|improve this answer

answered 8 hours ago

CentimaneCentimane

3,30311 gold badge1313 silver badges3636 bronze badges

awk -F ':' 'print $1' file

share|improve this answer

answered 8 hours ago

CentimaneCentimane

3,30311 gold badge1313 silver badges3636 bronze badges

answered 8 hours ago

CentimaneCentimane

3,30311 gold badge1313 silver badges3636 bronze badges

answered 8 hours ago

CentimaneCentimane

3,30311 gold badge1313 silver badges3636 bronze badges

5

This is what cut is for:

$ cat file
help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com
foo:baz:bar
foo

$ cut -d: -f1 file
help.helloworld.com
dev.helloworld.com
foo
foo

You just set the delimiter to : with -d: and tell it to only print the 1st field (-f1).

share|improve this answer

answered 8 hours ago

terdon♦terdon

141k3434 gold badges290290 silver badges469469 bronze badges

add a comment | 

5

This is what cut is for:

$ cat file
help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com
foo:baz:bar
foo

$ cut -d: -f1 file
help.helloworld.com
dev.helloworld.com
foo
foo

You just set the delimiter to : with -d: and tell it to only print the 1st field (-f1).

share|improve this answer

answered 8 hours ago

terdon♦terdon

141k3434 gold badges290290 silver badges469469 bronze badges

add a comment | 

This is what cut is for:

$ cat file
help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com
foo:baz:bar
foo

$ cut -d: -f1 file
help.helloworld.com
dev.helloworld.com
foo
foo

You just set the delimiter to : with -d: and tell it to only print the 1st field (-f1).

share|improve this answer

answered 8 hours ago

terdon♦terdon

141k3434 gold badges290290 silver badges469469 bronze badges

$ cat file
help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com
foo:baz:bar
foo

$ cut -d: -f1 file
help.helloworld.com
dev.helloworld.com
foo
foo

share|improve this answer

answered 8 hours ago

terdon♦terdon

141k3434 gold badges290290 silver badges469469 bronze badges

answered 8 hours ago

terdon♦terdon

141k3434 gold badges290290 silver badges469469 bronze badges

answered 8 hours ago

terdon♦terdon

141k3434 gold badges290290 silver badges469469 bronze badges

0

All the other answers are probably better, but you could even use sed:

sed -nEe 's/([^:]):.+/1/p' file.txt

where file.txt contains the following:

$ cat file.txt
help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com

I tested this with Android BusyBox sed on my way to work.

A short explanation:

• 
  -n: don't print by default


• 
  -E: use extended regex (less backslash escaping)


• 
  -e (probably unnecessary) marks the following expression as a command, not something else, like a file

share|improve this answer

edited 12 mins ago

answered 22 mins ago

Randy JosleynRandy Josleyn

2044 bronze badges

add a comment | 

0

All the other answers are probably better, but you could even use sed:

sed -nEe 's/([^:]):.+/1/p' file.txt

where file.txt contains the following:

$ cat file.txt
help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com

I tested this with Android BusyBox sed on my way to work.

A short explanation:

• 
  -n: don't print by default


• 
  -E: use extended regex (less backslash escaping)


• 
  -e (probably unnecessary) marks the following expression as a command, not something else, like a file

share|improve this answer

edited 12 mins ago

answered 22 mins ago

Randy JosleynRandy Josleyn

2044 bronze badges

add a comment | 

All the other answers are probably better, but you could even use sed:

sed -nEe 's/([^:]):.+/1/p' file.txt

where file.txt contains the following:

$ cat file.txt
help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com

I tested this with Android BusyBox sed on my way to work.

A short explanation:

• 
  -n: don't print by default


• 
  -E: use extended regex (less backslash escaping)


• 
  -e (probably unnecessary) marks the following expression as a command, not something else, like a file

share|improve this answer

edited 12 mins ago

answered 22 mins ago

Randy JosleynRandy Josleyn

2044 bronze badges

sed -nEe 's/([^:]):.+/1/p' file.txt

$ cat file.txt
help.helloworld.com:latest.world.com
dev.helloworld.com:latest.world.com

share|improve this answer

edited 12 mins ago

answered 22 mins ago

Randy JosleynRandy Josleyn

2044 bronze badges

answered 22 mins ago

Randy JosleynRandy Josleyn

2044 bronze badges

answered 22 mins ago

Randy JosleynRandy Josleyn

2044 bronze badges