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Sed substitute pattern with command

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

2

A propo of this question.

Let's say I want to substitute <number with commas> for <number> in string something, "10,000", something.

Number could be 1,000, 10,000... so on.

I was experimenting if it's possible to use a command for the substitution:

echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1 | sed 's/,//')/"

Which doesn't work, nothing happens.

What triggers my question is that if I only use echo

echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1)/"

the parameter \1 is read OK, but it looks like it can't be piped to sed (or grep).

Is this possible in some way?

sed

share|improve this question

edited 25 mins ago

mosvy

15.6k22 gold badges1818 silver badges5151 bronze badges

asked 7 hours ago

guillermo chamorroguillermo chamorro

3841212 bronze badges

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  
  The command substitution in the replacement part of your sed command is executed before the sed command runs.
  
  – Kusalananda♦
  7 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  .. which means it will sed the string '1' and not the actual captured string.
  
  – Jonas Berlin
  7 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @JonasBerlin That was my conclusion, what loses me is that echo \1 outputs the captured pattern, not the string "1"
  
  – guillermo chamorro
  7 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  yeah the 1 gets used in the main sed command replacement part as-is and thus the replacement becomes the captured group's contents.
  
  – Jonas Berlin
  7 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  I'd suggest that you try running your pipelines with set -x activated.
  
  – Kusalananda♦
  6 hours ago
  

  
  
  
  

 | 
show 1 more comment

2

A propo of this question.

Let's say I want to substitute <number with commas> for <number> in string something, "10,000", something.

Number could be 1,000, 10,000... so on.

I was experimenting if it's possible to use a command for the substitution:

echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1 | sed 's/,//')/"

Which doesn't work, nothing happens.

What triggers my question is that if I only use echo

echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1)/"

the parameter \1 is read OK, but it looks like it can't be piped to sed (or grep).

Is this possible in some way?

sed

share|improve this question

edited 25 mins ago

mosvy

15.6k22 gold badges1818 silver badges5151 bronze badges

asked 7 hours ago

guillermo chamorroguillermo chamorro

3841212 bronze badges

• 
  
  
  

  
  3
  

  
  
  
  
  
  

  
  
  The command substitution in the replacement part of your sed command is executed before the sed command runs.
  
  – Kusalananda♦
  7 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  .. which means it will sed the string '1' and not the actual captured string.
  
  – Jonas Berlin
  7 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @JonasBerlin That was my conclusion, what loses me is that echo \1 outputs the captured pattern, not the string "1"
  
  – guillermo chamorro
  7 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  yeah the 1 gets used in the main sed command replacement part as-is and thus the replacement becomes the captured group's contents.
  
  – Jonas Berlin
  7 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  I'd suggest that you try running your pipelines with set -x activated.
  
  – Kusalananda♦
  6 hours ago
  

  
  
  
  

 | 
show 1 more comment

A propo of this question.

Let's say I want to substitute <number with commas> for <number> in string something, "10,000", something.

Number could be 1,000, 10,000... so on.

I was experimenting if it's possible to use a command for the substitution:

echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1 | sed 's/,//')/"

Which doesn't work, nothing happens.

What triggers my question is that if I only use echo

echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1)/"

the parameter \1 is read OK, but it looks like it can't be piped to sed (or grep).

Is this possible in some way?

sed

share|improve this question

edited 25 mins ago

mosvy

15.6k22 gold badges1818 silver badges5151 bronze badges

asked 7 hours ago

guillermo chamorroguillermo chamorro

3841212 bronze badges

echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1 | sed 's/,//')/"

echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1)/"

share|improve this question

edited 25 mins ago

mosvy

15.6k22 gold badges1818 silver badges5151 bronze badges

asked 7 hours ago

guillermo chamorroguillermo chamorro

3841212 bronze badges

share|improve this question

edited 25 mins ago

mosvy

15.6k22 gold badges1818 silver badges5151 bronze badges

asked 7 hours ago

guillermo chamorroguillermo chamorro

3841212 bronze badges

edited 25 mins ago

mosvy

15.6k22 gold badges1818 silver badges5151 bronze badges

edited 25 mins ago

mosvy

15.6k22 gold badges1818 silver badges5151 bronze badges

asked 7 hours ago

guillermo chamorroguillermo chamorro

3841212 bronze badges

asked 7 hours ago

guillermo chamorroguillermo chamorro

3841212 bronze badges

2 Answers
2

active

oldest

votes

1

The expansion of the command substitution that is part of your sed expression happens before the sed command is executed.

This means that the shell, to execute the command

sed "s/(".*")/$(echo \1 | sed 's/,//')/"

first runs

echo \1 | sed 's/,//'

This outputs 1 since there are no commas in the string outputted by echo.

The shell then inserts this string where the command substitution was, yielding

sed "s/(".*")/1/"

This is also clear if we run the pipeline with tracing enabled in the shell:

$ set -x

$ echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1 | sed 's/,//')/"

+ echo 'something, "10,000", something'

+ echo '1'

+ sed s/,//

+ sed 's/(".*")/1/'

something, "10,000", something

In your second pipeline, the same thing happens (minus the execution of sed 's/,//'):

$ set -x

$ echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1)/"

+ echo 'something, "10,000", something'

+ echo '1'

+ sed 's/(".*")/1/'

something, "10,000", something

In conclusion: It is not possible to call another shell command from within sed using command substitutions to process a substring matched by a regular expression, as the command substitutions are processed before sed is called (in order to resolve what the sed editing script is before calling sed).

sed moreover does not provide any mechanism in its language to call out to another command, like some other editing/processing languages do (e.g. the rudimentary r and w commands in the ed editor allows this, as does awk).

share|improve this answer

edited 3 hours ago

answered 3 hours ago

Kusalananda♦Kusalananda

158k1818 gold badges313313 silver badges499499 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  With GNU sed one could do e.g. echo 'something, "10,000", something' | sed 's/.*"([[:digit:]]+),?.*/seq 1/e'. The e can be used as a flag for the s function or as a standalone function
  
  – LL3
  2 hours ago
  

  
  
  
  

add a comment | 

0

sed 's/([0-9]),([0-9])/12/g'

This works only if there are at least two numbers between two commas, so

123,456,789 -> 123456789

12,34,56,78 -> 12345678

but

1,2,3,4,5,6 -> 12,34,56

share|improve this answer

answered 7 hours ago

Jonas BerlinJonas Berlin

60866 silver badges1010 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  sed -e :top -e 's/([[:digit:]]),([[:digit:]])/12/g; ttop'
  
  – Kusalananda♦
  3 hours ago
  

  
  
  
  

add a comment | 

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1

The expansion of the command substitution that is part of your sed expression happens before the sed command is executed.

This means that the shell, to execute the command

sed "s/(".*")/$(echo \1 | sed 's/,//')/"

first runs

echo \1 | sed 's/,//'

This outputs 1 since there are no commas in the string outputted by echo.

The shell then inserts this string where the command substitution was, yielding

sed "s/(".*")/1/"

This is also clear if we run the pipeline with tracing enabled in the shell:

$ set -x

$ echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1 | sed 's/,//')/"

+ echo 'something, "10,000", something'

+ echo '1'

+ sed s/,//

+ sed 's/(".*")/1/'

something, "10,000", something

In your second pipeline, the same thing happens (minus the execution of sed 's/,//'):

$ set -x

$ echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1)/"

+ echo 'something, "10,000", something'

+ echo '1'

+ sed 's/(".*")/1/'

something, "10,000", something

In conclusion: It is not possible to call another shell command from within sed using command substitutions to process a substring matched by a regular expression, as the command substitutions are processed before sed is called (in order to resolve what the sed editing script is before calling sed).

sed moreover does not provide any mechanism in its language to call out to another command, like some other editing/processing languages do (e.g. the rudimentary r and w commands in the ed editor allows this, as does awk).

share|improve this answer

edited 3 hours ago

answered 3 hours ago

Kusalananda♦Kusalananda

158k1818 gold badges313313 silver badges499499 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  With GNU sed one could do e.g. echo 'something, "10,000", something' | sed 's/.*"([[:digit:]]+),?.*/seq 1/e'. The e can be used as a flag for the s function or as a standalone function
  
  – LL3
  2 hours ago
  

  
  
  
  

add a comment | 

1

The expansion of the command substitution that is part of your sed expression happens before the sed command is executed.

This means that the shell, to execute the command

sed "s/(".*")/$(echo \1 | sed 's/,//')/"

first runs

echo \1 | sed 's/,//'

This outputs 1 since there are no commas in the string outputted by echo.

The shell then inserts this string where the command substitution was, yielding

sed "s/(".*")/1/"

This is also clear if we run the pipeline with tracing enabled in the shell:

$ set -x

$ echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1 | sed 's/,//')/"

+ echo 'something, "10,000", something'

+ echo '1'

+ sed s/,//

+ sed 's/(".*")/1/'

something, "10,000", something

In your second pipeline, the same thing happens (minus the execution of sed 's/,//'):

$ set -x

$ echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1)/"

+ echo 'something, "10,000", something'

+ echo '1'

+ sed 's/(".*")/1/'

something, "10,000", something

In conclusion: It is not possible to call another shell command from within sed using command substitutions to process a substring matched by a regular expression, as the command substitutions are processed before sed is called (in order to resolve what the sed editing script is before calling sed).

sed moreover does not provide any mechanism in its language to call out to another command, like some other editing/processing languages do (e.g. the rudimentary r and w commands in the ed editor allows this, as does awk).

share|improve this answer

edited 3 hours ago

answered 3 hours ago

Kusalananda♦Kusalananda

158k1818 gold badges313313 silver badges499499 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  With GNU sed one could do e.g. echo 'something, "10,000", something' | sed 's/.*"([[:digit:]]+),?.*/seq 1/e'. The e can be used as a flag for the s function or as a standalone function
  
  – LL3
  2 hours ago
  

  
  
  
  

add a comment | 

The expansion of the command substitution that is part of your sed expression happens before the sed command is executed.

This means that the shell, to execute the command

sed "s/(".*")/$(echo \1 | sed 's/,//')/"

first runs

echo \1 | sed 's/,//'

This outputs 1 since there are no commas in the string outputted by echo.

The shell then inserts this string where the command substitution was, yielding

sed "s/(".*")/1/"

This is also clear if we run the pipeline with tracing enabled in the shell:

$ set -x

$ echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1 | sed 's/,//')/"

+ echo 'something, "10,000", something'

+ echo '1'

+ sed s/,//

+ sed 's/(".*")/1/'

something, "10,000", something

In your second pipeline, the same thing happens (minus the execution of sed 's/,//'):

$ set -x

$ echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1)/"

+ echo 'something, "10,000", something'

+ echo '1'

+ sed 's/(".*")/1/'

something, "10,000", something

In conclusion: It is not possible to call another shell command from within sed using command substitutions to process a substring matched by a regular expression, as the command substitutions are processed before sed is called (in order to resolve what the sed editing script is before calling sed).

sed moreover does not provide any mechanism in its language to call out to another command, like some other editing/processing languages do (e.g. the rudimentary r and w commands in the ed editor allows this, as does awk).

share|improve this answer

edited 3 hours ago

answered 3 hours ago

Kusalananda♦Kusalananda

158k1818 gold badges313313 silver badges499499 bronze badges

sed "s/(".*")/$(echo \1 | sed 's/,//')/"

echo \1 | sed 's/,//'

sed "s/(".*")/1/"

$ set -x

$ echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1 | sed 's/,//')/"

+ echo 'something, "10,000", something'

+ echo '1'

+ sed s/,//

+ sed 's/(".*")/1/'

something, "10,000", something

$ set -x

$ echo 'something, "10,000", something' | sed "s/(".*")/$(echo \1)/"

+ echo 'something, "10,000", something'

+ echo '1'

+ sed 's/(".*")/1/'

something, "10,000", something

share|improve this answer

edited 3 hours ago

answered 3 hours ago

Kusalananda♦Kusalananda

158k1818 gold badges313313 silver badges499499 bronze badges

answered 3 hours ago

Kusalananda♦Kusalananda

158k1818 gold badges313313 silver badges499499 bronze badges

answered 3 hours ago

Kusalananda♦Kusalananda

158k1818 gold badges313313 silver badges499499 bronze badges

0

sed 's/([0-9]),([0-9])/12/g'

This works only if there are at least two numbers between two commas, so

123,456,789 -> 123456789

12,34,56,78 -> 12345678

but

1,2,3,4,5,6 -> 12,34,56

share|improve this answer

answered 7 hours ago

Jonas BerlinJonas Berlin

60866 silver badges1010 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  sed -e :top -e 's/([[:digit:]]),([[:digit:]])/12/g; ttop'
  
  – Kusalananda♦
  3 hours ago
  

  
  
  
  

add a comment | 

0

sed 's/([0-9]),([0-9])/12/g'

This works only if there are at least two numbers between two commas, so

123,456,789 -> 123456789

12,34,56,78 -> 12345678

but

1,2,3,4,5,6 -> 12,34,56

share|improve this answer

answered 7 hours ago

Jonas BerlinJonas Berlin

60866 silver badges1010 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  sed -e :top -e 's/([[:digit:]]),([[:digit:]])/12/g; ttop'
  
  – Kusalananda♦
  3 hours ago
  

  
  
  
  

add a comment | 

sed 's/([0-9]),([0-9])/12/g'

This works only if there are at least two numbers between two commas, so

123,456,789 -> 123456789

12,34,56,78 -> 12345678

but

1,2,3,4,5,6 -> 12,34,56

share|improve this answer

answered 7 hours ago

Jonas BerlinJonas Berlin

60866 silver badges1010 bronze badges

sed 's/([0-9]),([0-9])/12/g'

123,456,789 -> 123456789

12,34,56,78 -> 12345678

but

1,2,3,4,5,6 -> 12,34,56

share|improve this answer

answered 7 hours ago

Jonas BerlinJonas Berlin

60866 silver badges1010 bronze badges

answered 7 hours ago

Jonas BerlinJonas Berlin

60866 silver badges1010 bronze badges

answered 7 hours ago

Jonas BerlinJonas Berlin

60866 silver badges1010 bronze badges