What does ,^@ means in a sed expression

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I came across this code sed ',^@, s/ABC/XYZ/' filename
What does ,^@, means here. I thought comma , operator defines the line range on which substitute expression will operate.




sed




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  • , means , is regex delimiter instead of usual /... ^@ to match @ at beginning of line... , to end the match... s/ABC/XYZ/ to perform substitutions only on lines matching @ at beginning of line...
    – Sundeep
    Apr 11 at 13:26










  • see also: stackoverflow.com/questions/5864146/use-slashes-in-sed-replace
    – Sundeep
    Apr 11 at 13:27










  • Thanks Sundeep, sorry but I am still not clear. I understood ^@ denotes lines starting with @. Are you saying , means alternate regex delimeter , then shouldn't it be just ,@, or ,@,. Thanks
    – CppLearner
    Apr 11 at 13:46










  • see Find the line [...] using custom regex delimiter
    – don_crissti
    Apr 11 at 14:29











  • @CppLearner for substitute commands, s,foo,baz, will work.. but for address matching, you need extra at start...
    – Sundeep
    Apr 11 at 14:30















up vote
3
down vote

favorite












I came across this code sed ',^@, s/ABC/XYZ/' filename
What does ,^@, means here. I thought comma , operator defines the line range on which substitute expression will operate.




sed




share|improve this question






















  • , means , is regex delimiter instead of usual /... ^@ to match @ at beginning of line... , to end the match... s/ABC/XYZ/ to perform substitutions only on lines matching @ at beginning of line...
    – Sundeep
    Apr 11 at 13:26










  • see also: stackoverflow.com/questions/5864146/use-slashes-in-sed-replace
    – Sundeep
    Apr 11 at 13:27










  • Thanks Sundeep, sorry but I am still not clear. I understood ^@ denotes lines starting with @. Are you saying , means alternate regex delimeter , then shouldn't it be just ,@, or ,@,. Thanks
    – CppLearner
    Apr 11 at 13:46










  • see Find the line [...] using custom regex delimiter
    – don_crissti
    Apr 11 at 14:29











  • @CppLearner for substitute commands, s,foo,baz, will work.. but for address matching, you need extra at start...
    – Sundeep
    Apr 11 at 14:30













up vote
3
down vote

favorite









up vote
3
down vote

favorite











I came across this code sed ',^@, s/ABC/XYZ/' filename
What does ,^@, means here. I thought comma , operator defines the line range on which substitute expression will operate.




sed




share|improve this question














I came across this code sed ',^@, s/ABC/XYZ/' filename
What does ,^@, means here. I thought comma , operator defines the line range on which substitute expression will operate.





sed





share|improve this question













share|improve this question




share|improve this question








edited Apr 11 at 14:30









don_crissti

46.4k15123152




46.4k15123152










asked Apr 11 at 13:21









CppLearner

3481212




3481212











  • , means , is regex delimiter instead of usual /... ^@ to match @ at beginning of line... , to end the match... s/ABC/XYZ/ to perform substitutions only on lines matching @ at beginning of line...
    – Sundeep
    Apr 11 at 13:26










  • see also: stackoverflow.com/questions/5864146/use-slashes-in-sed-replace
    – Sundeep
    Apr 11 at 13:27










  • Thanks Sundeep, sorry but I am still not clear. I understood ^@ denotes lines starting with @. Are you saying , means alternate regex delimeter , then shouldn't it be just ,@, or ,@,. Thanks
    – CppLearner
    Apr 11 at 13:46










  • see Find the line [...] using custom regex delimiter
    – don_crissti
    Apr 11 at 14:29











  • @CppLearner for substitute commands, s,foo,baz, will work.. but for address matching, you need extra at start...
    – Sundeep
    Apr 11 at 14:30

















  • , means , is regex delimiter instead of usual /... ^@ to match @ at beginning of line... , to end the match... s/ABC/XYZ/ to perform substitutions only on lines matching @ at beginning of line...
    – Sundeep
    Apr 11 at 13:26










  • see also: stackoverflow.com/questions/5864146/use-slashes-in-sed-replace
    – Sundeep
    Apr 11 at 13:27










  • Thanks Sundeep, sorry but I am still not clear. I understood ^@ denotes lines starting with @. Are you saying , means alternate regex delimeter , then shouldn't it be just ,@, or ,@,. Thanks
    – CppLearner
    Apr 11 at 13:46










  • see Find the line [...] using custom regex delimiter
    – don_crissti
    Apr 11 at 14:29











  • @CppLearner for substitute commands, s,foo,baz, will work.. but for address matching, you need extra at start...
    – Sundeep
    Apr 11 at 14:30
















, means , is regex delimiter instead of usual /... ^@ to match @ at beginning of line... , to end the match... s/ABC/XYZ/ to perform substitutions only on lines matching @ at beginning of line...
– Sundeep
Apr 11 at 13:26




, means , is regex delimiter instead of usual /... ^@ to match @ at beginning of line... , to end the match... s/ABC/XYZ/ to perform substitutions only on lines matching @ at beginning of line...
– Sundeep
Apr 11 at 13:26












see also: stackoverflow.com/questions/5864146/use-slashes-in-sed-replace
– Sundeep
Apr 11 at 13:27




see also: stackoverflow.com/questions/5864146/use-slashes-in-sed-replace
– Sundeep
Apr 11 at 13:27












Thanks Sundeep, sorry but I am still not clear. I understood ^@ denotes lines starting with @. Are you saying , means alternate regex delimeter , then shouldn't it be just ,@, or ,@,. Thanks
– CppLearner
Apr 11 at 13:46




Thanks Sundeep, sorry but I am still not clear. I understood ^@ denotes lines starting with @. Are you saying , means alternate regex delimeter , then shouldn't it be just ,@, or ,@,. Thanks
– CppLearner
Apr 11 at 13:46












see Find the line [...] using custom regex delimiter
– don_crissti
Apr 11 at 14:29





see Find the line [...] using custom regex delimiter
– don_crissti
Apr 11 at 14:29













@CppLearner for substitute commands, s,foo,baz, will work.. but for address matching, you need extra at start...
– Sundeep
Apr 11 at 14:30





@CppLearner for substitute commands, s,foo,baz, will work.. but for address matching, you need extra at start...
– Sundeep
Apr 11 at 14:30











1 Answer
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4
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According to the man page, In a context address, the construction "cBREc", where c is any character other than backslash or newline, shall be identical to "/BRE/". So your script is identical to



sed '/^@/ s/ABC/XYZ/' filename


which means the replacement is only to be done in lines starting with @






share|improve this answer






















  • Perfect Philippos. This is what I was looking for thanks a lot for your help and explanation. Upvoting and accepting this as answer. Thank you.
    – CppLearner
    Apr 11 at 15:25










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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes








up vote
4
down vote



accepted










According to the man page, In a context address, the construction "cBREc", where c is any character other than backslash or newline, shall be identical to "/BRE/". So your script is identical to



sed '/^@/ s/ABC/XYZ/' filename


which means the replacement is only to be done in lines starting with @






share|improve this answer






















  • Perfect Philippos. This is what I was looking for thanks a lot for your help and explanation. Upvoting and accepting this as answer. Thank you.
    – CppLearner
    Apr 11 at 15:25














up vote
4
down vote



accepted










According to the man page, In a context address, the construction "cBREc", where c is any character other than backslash or newline, shall be identical to "/BRE/". So your script is identical to



sed '/^@/ s/ABC/XYZ/' filename


which means the replacement is only to be done in lines starting with @






share|improve this answer






















  • Perfect Philippos. This is what I was looking for thanks a lot for your help and explanation. Upvoting and accepting this as answer. Thank you.
    – CppLearner
    Apr 11 at 15:25












up vote
4
down vote



accepted







up vote
4
down vote



accepted






According to the man page, In a context address, the construction "cBREc", where c is any character other than backslash or newline, shall be identical to "/BRE/". So your script is identical to



sed '/^@/ s/ABC/XYZ/' filename


which means the replacement is only to be done in lines starting with @






share|improve this answer














According to the man page, In a context address, the construction "cBREc", where c is any character other than backslash or newline, shall be identical to "/BRE/". So your script is identical to



sed '/^@/ s/ABC/XYZ/' filename


which means the replacement is only to be done in lines starting with @







share|improve this answer














share|improve this answer



share|improve this answer








edited Apr 11 at 14:23









Kusalananda

102k13199316




102k13199316










answered Apr 11 at 14:20









Philippos

5,90211545




5,90211545











  • Perfect Philippos. This is what I was looking for thanks a lot for your help and explanation. Upvoting and accepting this as answer. Thank you.
    – CppLearner
    Apr 11 at 15:25
















  • Perfect Philippos. This is what I was looking for thanks a lot for your help and explanation. Upvoting and accepting this as answer. Thank you.
    – CppLearner
    Apr 11 at 15:25















Perfect Philippos. This is what I was looking for thanks a lot for your help and explanation. Upvoting and accepting this as answer. Thank you.
– CppLearner
Apr 11 at 15:25




Perfect Philippos. This is what I was looking for thanks a lot for your help and explanation. Upvoting and accepting this as answer. Thank you.
– CppLearner
Apr 11 at 15:25












 

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