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Why is my regex not working with SED?
In the simplest calling of sed, it has one line of text in the pattern space, ie. 1 line of n delimited text from the input. The single line in the pattern space has no n… That’s why your regex is not finding anything.
How can I use sed to replace a multi line string?
The hold space however is preserved. Finally, on the very last line, g restores the accumulation of every line from the hold space so that sed is able to run its regex on the whole input (rather than in a line-at-a-time fashion), and hence is able to match on s.
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.
Why do you never get a newline in SED?
This is because since sed is 100% line-based, a newline is the one-and-only character you are guaranteed to never receive when a new line is fetched (forget about GNU multi-line extensions for this discussion).
Is it possible to delete multiple characters using SED?
I tried using sed ‘s/<>,//g’ but it didn’t work (it didn’t change anything). Do I need to escape these special characters. Is it possible to delete multiple characters using a single sed command?
How to replace a string with a SED?
Almost any character should work, but be careful with the characters that need escaping in your environment, sed, etc. depending on how you intend to use the results. If replacing the string by Variable, the solution doesn’t work. The sed command need to be in double quotes instead on single quote.
How to replace multiple patterns at once with SED?
Since there was a answer saying that sed is a stream editor and its replaces are greedily I think that I will need to use some script language for that. Replace ~ with a character that you know won’t be in the string. some text AB some more text “BC” and more text. some text BC some more text “CD” and more text.
How to change the delimiter in a SED?
You’ll have to quote that character instead, but usually the point of changing the delimiter is to pick one that doesn’t occur in either the text to replace or the replacement text. sed -e ‘s~ ~
Which is the command to run regex on s?
Finally, on the very last line, g restores the accumulation of every line from the hold space so that sed is able to run its regex on the whole input (rather than in a line-at-a-time fashion), and hence is able to match on s. sed has three commands to manage multi-line operations: N, D and P (compare them to normal n, d and p ).