Ttyjfyk

What can I do if someone tampers with my SSH public key?

Too soon for a plot twist?

Converting from "matrix" data into "coordinate" data

Automaton recognizing ambiguously accepted words of another automaton

Smooth vector fields on a surface modulo diffeomorphisms

Is it possible to clone a polymorphic object without manually adding overridden clone method into each derived class in C++?

How do we create new idioms and use them in a novel?

Sampling from Gaussian mixture models, when are the sampled data independent?

Can the Witch Sight warlock invocation see through the Mirror Image spell?

Why does this boat have a landing pad? (SpaceX's GO Searcher) Any plans for propulsive capsule landings?

Do black holes violate the conservation of mass?

Cycles on the torus

How exactly does an Ethernet collision happen in the cable, since nodes use different circuits for Tx and Rx?

How to install round brake pads

Is there a logarithm base for which the logarithm becomes an identity function?

Locked Away- What am I?

Graphic representation of a triangle using ArrayPlot

Finding the minimum value of a function without using Calculus

Movie: boy escapes the real world and goes to a fantasy world with big furry trolls

What is this tube in a jet engine's air intake?

Are all players supposed to be able to see each others' character sheets?

What does the Digital Threat scope actually do?

Either of .... (Plural/Singular)

Writing text next to a table

Replace only on the first matching line with sed

How to delete empty comments with sed?sed replace only lines with matching groupsSed: replace particular one/two digit(s)how to modify matches to a regular expression with sed or another tool?BSD sed: Replace only the Nth occurrence of a patternRemove hyphenation with sedHow to delete everything (in every line) in a text file after a pattern of characters(including the pattern)?RegEx match + additional line removalUsing sed to replace all occurrences at the beginning with a matching number of replacement stringssed replace matching line which does not start with #

4

Using BSD sed (no GNU extensions), how can I perform an operation similar to the example provided below, but where instead of the line number, the replacement is performed on the first line in which a pattern occurs (rather than having to specify an actual number)?

Restricting to a line number

The simplest restriction is a line number.

If you wanted to delete the first number on line 3, just add a "3" before the command:

sed '3 s/[0-9][0-9]*//' <filename >newfilename

Source: http://www.grymoire.com/Unix/Sed.html#uh-26

text-processing sed osx regular-expression bsd

share|improve this question

edited Dec 24 '15 at 15:53

tjt263

asked Dec 20 '15 at 22:40

tjt263tjt263

5571520

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Please edit your question and give us an example input and the output you would like to see. It seems like you are just asking how you can replace only the first occurrence of a string in a file but it's hard to understand without an example.
  
  – terdon♦
  Dec 20 '15 at 22:59
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @terdon "It seems like you are just asking how you can replace only the first occurrence of a string in a file.." Yes, exactly. That's correct.
  
  – tjt263
  Dec 20 '15 at 23:05
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  OK. So, please edit your question and add an example input and the output you would like to see with it.
  
  – terdon♦
  Dec 20 '15 at 23:09
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  That's question 4.11 of the sed FAQ
  
  – Stéphane Chazelas
  Dec 20 '15 at 23:22
  

  
  
  
  

add a comment | 

4

Using BSD sed (no GNU extensions), how can I perform an operation similar to the example provided below, but where instead of the line number, the replacement is performed on the first line in which a pattern occurs (rather than having to specify an actual number)?

Restricting to a line number

The simplest restriction is a line number.

If you wanted to delete the first number on line 3, just add a "3" before the command:

sed '3 s/[0-9][0-9]*//' <filename >newfilename

Source: http://www.grymoire.com/Unix/Sed.html#uh-26

text-processing sed osx regular-expression bsd

share|improve this question

edited Dec 24 '15 at 15:53

tjt263

asked Dec 20 '15 at 22:40

tjt263tjt263

5571520

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  Please edit your question and give us an example input and the output you would like to see. It seems like you are just asking how you can replace only the first occurrence of a string in a file but it's hard to understand without an example.
  
  – terdon♦
  Dec 20 '15 at 22:59
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @terdon "It seems like you are just asking how you can replace only the first occurrence of a string in a file.." Yes, exactly. That's correct.
  
  – tjt263
  Dec 20 '15 at 23:05
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  OK. So, please edit your question and add an example input and the output you would like to see with it.
  
  – terdon♦
  Dec 20 '15 at 23:09
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  That's question 4.11 of the sed FAQ
  
  – Stéphane Chazelas
  Dec 20 '15 at 23:22
  

  
  
  
  

add a comment | 

Using BSD sed (no GNU extensions), how can I perform an operation similar to the example provided below, but where instead of the line number, the replacement is performed on the first line in which a pattern occurs (rather than having to specify an actual number)?

Restricting to a line number

The simplest restriction is a line number.

If you wanted to delete the first number on line 3, just add a "3" before the command:

sed '3 s/[0-9][0-9]*//' <filename >newfilename

Source: http://www.grymoire.com/Unix/Sed.html#uh-26

text-processing sed osx regular-expression bsd

share|improve this question

edited Dec 24 '15 at 15:53

tjt263

asked Dec 20 '15 at 22:40

tjt263tjt263

5571520

share|improve this question

edited Dec 24 '15 at 15:53

tjt263

asked Dec 20 '15 at 22:40

tjt263tjt263

5571520

share|improve this question

edited Dec 24 '15 at 15:53

tjt263

asked Dec 20 '15 at 22:40

tjt263tjt263

5571520

asked Dec 20 '15 at 22:40

tjt263tjt263

5571520

asked Dec 20 '15 at 22:40

tjt263tjt263

5571520

2 Answers
2

active

oldest

votes

0

 sed -Ee'/[0-9]+/s///;q;'; cat; <in >out

^should work w/ a BSD sed. but apparently it doesn't.

and so:

sed -e'/[0-9][0-9]*/s///;:b' -e'n;bb' -e <in >out

...should work with any of them.

share|improve this answer

edited Dec 20 '15 at 23:56

Stéphane Chazelas

309k57582942

answered Dec 20 '15 at 23:18

mikeservmikeserv

45.8k668160

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Doesn't work on FreeBSD 10 even on seekable input. On FreeBSD, you can run sed under stdbuf -i 1 to work around it (would read the input one byte at a time though)
  
  – Stéphane Chazelas
  Dec 20 '15 at 23:33
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @StéphaneChazelas - weird. should work on a Mac, though. I would think - it has the stamp.
  
  – mikeserv
  Dec 20 '15 at 23:40
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  To clarify, now that the answer was edited with a second, portable solution, it's the first one that doesn't work on FreeBSD 10 (though should on seekable files if FreeBSD were POSIX (q leaving the cursor in the right place)), the second one is even better than the solution given in the FAQ as the FAQ one uses N instead of n (which would slurp the rest of the file in the pattern space).
  
  – Stéphane Chazelas
  Dec 20 '15 at 23:55
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @StéphaneChazelas - I noticed that as well, which is why I didn't delete it - though I thought at first I would. thanks again, sc.
  
  – mikeserv
  Dec 21 '15 at 0:01
  

  
  
  
  

add a comment | 

0

This works perfectly:

sed '1,/abc/s/abc/xyz/' file.txt

Can be abbreviated to:

sed '1,/abc/s//xyz/' file.txt

Compatible with GNU & BSD:

sed '1,/[0-9][0-9]*/s///' <filename >newfilename

share|improve this answer

edited 7 mins ago

Spooky

20126

answered Dec 21 '15 at 10:37

tjt263tjt263

5571520

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  That doesn't work (could run that s command on more than one line) if the first match is on the first line (as noted in the FAQ)
  
  – Stéphane Chazelas
  Dec 21 '15 at 11:08
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  (Yeah, okay, we get it - You've read the FAQ.) If theres a match on the first line; the question is irrelevant, so thats fine.
  
  – tjt263
  Jan 4 '16 at 7:25
  

  
  
  
  

add a comment | 

Your Answer

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "106"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f250603%2freplace-only-on-the-first-matching-line-with-sed%23new-answer', 'question_page');

);

Post as a guest

Name

Email

Required, but never shown

0

 sed -Ee'/[0-9]+/s///;q;'; cat; <in >out

^should work w/ a BSD sed. but apparently it doesn't.

and so:

sed -e'/[0-9][0-9]*/s///;:b' -e'n;bb' -e <in >out

...should work with any of them.

share|improve this answer

edited Dec 20 '15 at 23:56

Stéphane Chazelas

309k57582942

answered Dec 20 '15 at 23:18

mikeservmikeserv

45.8k668160

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Doesn't work on FreeBSD 10 even on seekable input. On FreeBSD, you can run sed under stdbuf -i 1 to work around it (would read the input one byte at a time though)
  
  – Stéphane Chazelas
  Dec 20 '15 at 23:33
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @StéphaneChazelas - weird. should work on a Mac, though. I would think - it has the stamp.
  
  – mikeserv
  Dec 20 '15 at 23:40
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  To clarify, now that the answer was edited with a second, portable solution, it's the first one that doesn't work on FreeBSD 10 (though should on seekable files if FreeBSD were POSIX (q leaving the cursor in the right place)), the second one is even better than the solution given in the FAQ as the FAQ one uses N instead of n (which would slurp the rest of the file in the pattern space).
  
  – Stéphane Chazelas
  Dec 20 '15 at 23:55
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @StéphaneChazelas - I noticed that as well, which is why I didn't delete it - though I thought at first I would. thanks again, sc.
  
  – mikeserv
  Dec 21 '15 at 0:01
  

  
  
  
  

add a comment | 

0

 sed -Ee'/[0-9]+/s///;q;'; cat; <in >out

^should work w/ a BSD sed. but apparently it doesn't.

and so:

sed -e'/[0-9][0-9]*/s///;:b' -e'n;bb' -e <in >out

...should work with any of them.

share|improve this answer

edited Dec 20 '15 at 23:56

Stéphane Chazelas

309k57582942

answered Dec 20 '15 at 23:18

mikeservmikeserv

45.8k668160

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Doesn't work on FreeBSD 10 even on seekable input. On FreeBSD, you can run sed under stdbuf -i 1 to work around it (would read the input one byte at a time though)
  
  – Stéphane Chazelas
  Dec 20 '15 at 23:33
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @StéphaneChazelas - weird. should work on a Mac, though. I would think - it has the stamp.
  
  – mikeserv
  Dec 20 '15 at 23:40
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  To clarify, now that the answer was edited with a second, portable solution, it's the first one that doesn't work on FreeBSD 10 (though should on seekable files if FreeBSD were POSIX (q leaving the cursor in the right place)), the second one is even better than the solution given in the FAQ as the FAQ one uses N instead of n (which would slurp the rest of the file in the pattern space).
  
  – Stéphane Chazelas
  Dec 20 '15 at 23:55
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @StéphaneChazelas - I noticed that as well, which is why I didn't delete it - though I thought at first I would. thanks again, sc.
  
  – mikeserv
  Dec 21 '15 at 0:01
  

  
  
  
  

add a comment | 

 sed -Ee'/[0-9]+/s///;q;'; cat; <in >out

^should work w/ a BSD sed. but apparently it doesn't.

and so:

sed -e'/[0-9][0-9]*/s///;:b' -e'n;bb' -e <in >out

...should work with any of them.

share|improve this answer

edited Dec 20 '15 at 23:56

Stéphane Chazelas

309k57582942

answered Dec 20 '15 at 23:18

mikeservmikeserv

45.8k668160

 sed -Ee'/[0-9]+/s///;q;'; cat; <in >out

sed -e'/[0-9][0-9]*/s///;:b' -e'n;bb' -e <in >out

share|improve this answer

edited Dec 20 '15 at 23:56

Stéphane Chazelas

309k57582942

answered Dec 20 '15 at 23:18

mikeservmikeserv

45.8k668160

edited Dec 20 '15 at 23:56

Stéphane Chazelas

309k57582942

edited Dec 20 '15 at 23:56

Stéphane Chazelas

309k57582942

answered Dec 20 '15 at 23:18

mikeservmikeserv

45.8k668160

answered Dec 20 '15 at 23:18

mikeservmikeserv

45.8k668160

0

This works perfectly:

sed '1,/abc/s/abc/xyz/' file.txt

Can be abbreviated to:

sed '1,/abc/s//xyz/' file.txt

Compatible with GNU & BSD:

sed '1,/[0-9][0-9]*/s///' <filename >newfilename

share|improve this answer

edited 7 mins ago

Spooky

20126

answered Dec 21 '15 at 10:37

tjt263tjt263

5571520

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  That doesn't work (could run that s command on more than one line) if the first match is on the first line (as noted in the FAQ)
  
  – Stéphane Chazelas
  Dec 21 '15 at 11:08
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  (Yeah, okay, we get it - You've read the FAQ.) If theres a match on the first line; the question is irrelevant, so thats fine.
  
  – tjt263
  Jan 4 '16 at 7:25
  

  
  
  
  

add a comment | 

0

This works perfectly:

sed '1,/abc/s/abc/xyz/' file.txt

Can be abbreviated to:

sed '1,/abc/s//xyz/' file.txt

Compatible with GNU & BSD:

sed '1,/[0-9][0-9]*/s///' <filename >newfilename

share|improve this answer

edited 7 mins ago

Spooky

20126

answered Dec 21 '15 at 10:37

tjt263tjt263

5571520

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  That doesn't work (could run that s command on more than one line) if the first match is on the first line (as noted in the FAQ)
  
  – Stéphane Chazelas
  Dec 21 '15 at 11:08
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  (Yeah, okay, we get it - You've read the FAQ.) If theres a match on the first line; the question is irrelevant, so thats fine.
  
  – tjt263
  Jan 4 '16 at 7:25
  

  
  
  
  

add a comment | 

This works perfectly:

sed '1,/abc/s/abc/xyz/' file.txt

Can be abbreviated to:

sed '1,/abc/s//xyz/' file.txt

Compatible with GNU & BSD:

sed '1,/[0-9][0-9]*/s///' <filename >newfilename

share|improve this answer

edited 7 mins ago

Spooky

20126

answered Dec 21 '15 at 10:37

tjt263tjt263

5571520

sed '1,/abc/s/abc/xyz/' file.txt

sed '1,/abc/s//xyz/' file.txt

sed '1,/[0-9][0-9]*/s///' <filename >newfilename

share|improve this answer

edited 7 mins ago

Spooky

20126

answered Dec 21 '15 at 10:37

tjt263tjt263

5571520

edited 7 mins ago

Spooky

20126

edited 7 mins ago

Spooky

20126

answered Dec 21 '15 at 10:37

tjt263tjt263

5571520

answered Dec 21 '15 at 10:37

tjt263tjt263

5571520