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How to use sed to replace a pattern only?
Also being able to constrain sed in general to just a line that matches a pattern would by a nice tool to add to me sed arsenal. Any help that leads to solution here will be very appreciated.
How to use sed to replace only the first occurrence in a file?
The net effect is the same as with GNU sed ‘s 0,/re/: only the first occurrence is replaced, whether it occurs on the 1st line or any other. potong’s answer demonstrates loop techniques that bypass the need for a range; since he uses GNU sed syntax, here are the POSIX-compliant equivalents:
How to replace every nth occurrence of pattern in Bash?
I mean you can do a simple substitution for occurrence number 5 for example like: sed ‘s/pattern/replace/5’ to replace only the 5th instance. Why can’t sed do ‘s/pattern/replace/ ‘ for one line? Isn’t that a basic function..
How to SED only lines that contains given string?
In searching Google, the only semi relevant link I found about this was: How to sed only that lines that contains given string?. But it didn’t sufficiently answer my question. Also being able to constrain sed in general to just a line that matches a pattern would by a nice tool to add to me sed arsenal.
How to replace single quotes with double quotes in SED?
To replace single quotes (‘) it’s easiest to put the sed command within double quotes and escape the double quote in the replacement: $ cat quotes.txt I’m Alice $ sed -e “s/’/”/g” quotes.txt I”m Alice Note that the single quote is not special within double quotes, so it must not be escaped.
Why do I need to use a sed command?
Because all of the URLs will have different domains I cannot use a sed command like: Because the files contain other lines which may contain com, I cannot use something like: I need to do this search and replace only on a specific line containing a pattern, such as from my example below in regex: ^ENVIRONMENT.*
How to replace multiple lines in SED Stack Overflow?
Just in the next line you will have why huh in the pattern space to be replaced. The solution is to concatenate the next line only when your current line is why, using the address /^why$/: The reason why it didn’t replace both pairs of lines is explained beautifully in brandizzi ‘s answer.
Which is the command for multi-line operations in SED?
sed has three commands to manage multi-line operations: N, D and P (compare them to normal n, d and p ). In this case, you can match the first line of your pattern, use N to append the second line to pattern space and then use s to do your substitution.
How do you use unique markers in SED?
An unique marker (in this case ) is prepended to the start of the line and used as a method to bump-along the search throughout the length of the line. Once the marker reaches the end of the line the process is finished and is printed out the lookup table and markers being discarded.
How to replace whole line with sed command?
To do this without relying on any GNUisms such as -i without a parameter or c without a linebreak: text can consist of one or multiple lines, and linebreaks that should become part of the replacement have to be escaped: where s/x/y/ is a new sed command after the pattern space has been replaced by the two lines
How to replace a pattern in a file only?
I want to replace ENVIRONMENT=”someurl.com” with ENVIRONMENT=”someurl.com.orign.net” The following command line shows two possible solutions: You can restrict the replacement to certain lines with /regex/. And you can use the matched text in replacements with \\0, \\1, etc.