How to remove regex from a line in SED?

How to remove regex from a line in SED?

So every lines containing regex will be uncomented (if line begin with a #) where regex could be [0-9] as: will remove # at begin of lines containing a number as last character. Then will remove # at begin of lines ended by 12. Or will remove # at begin of lines containing word two or three. should do it.

How to replace all matches in SED Stack Overflow?

Add the ‘g’ option to the end to replace all matches (which I’m guessing is what you want to do in this case). BTW, there is no need to escape $ in the right side of the “s” operator. The \\ (…\\) remembers…and is referenced as \\1 in the expansion. Use single quotes to save your sanity.

What does it mean to delete Rev in SED?

The commands you passed to sed mean: if a line matches the regex, delete it. That’s not what you want. This means: on each line, remove rev followed by any number of zeroes. Also, you don’t need sed for such a simple thing.

Can a range of characters be expressed by a start-end?

You have already used the fact that ranges of characters can be expressed by [ start – end], as in [a-z] being shorthand for [abcdefghijkl…xyz] (although see the caveat below).

How to use sed for extended regular expressions?

\\1, \\2, etc. in the second part are references to the i-th group captured in the first part (the numbering starts with 1) -E enables extended regular expressions (needed for + and grouping). The /username/ before the s tells sed to only work on lines containing the string ‘username’.

How to use sed to replace two matches?

You can use groups to avoid repeating some parts in the replacement text, and accommodate variation on these parts. You can simply use addresses as in the number preceding “s” which indicates the line number. Also the number in the end tells sed to replace the second match instead of replacing the first match.

How to keep part of matched while using regex?

Using the basic pattern, well described in the accepted answer here is an example to add the class=”odd” and class=”even” to every element in Notepad++ or any other regex compatible editor: Thanks for contributing an answer to Stack Overflow!

How to find and replace all occurrences of a string recursively?

grep -rl ‘SearchString’./ | xargs sed -i ‘s/REPLACESTRING/WITHTHIS/g’ grep -rl will recursively search for the SEARCHSTRING in the directories./ and will replace the strings using sed.

When to use LC _ ALL = C in SED?

That LC_ALL=C option is to avoid getting sed: RE error: illegal byte sequence if sed finds a byte sequence that is not a valid UTF-8 character. That’s another difference between BSD and GNU.

How to replace a whole line with SED?

How can I replace all this lines aaa= [something] with aaa=xxx using sed? This will go through and find any lines that pass the aaa= test, which means that the line contains the letters aaa=. Then it replaces the entire line with aaa=xxx.

How can SED be used to search and replace files?

sed is a s tream ed itor. It can perform basic text manipulation on files and input streams such as pipelines. With sed, you can search, find and replace, insert, and delete words and lines.

Why does SED not work with POSIX regex?

It didn’t work with sed because it will by default use POSIX’s basic regular expressions, where the characters for grouping are \\ ( and \\), while ( and ) will match literal characters. There were no such brackets in your input text, so it didn’t match.

How to remove a regex pattern in Bash?

There were no such brackets in your input text, so it didn’t match. Your regular expression would have worked if you had used GNU’s sed -r or BSD’s sed -E, the flag switching to POSIX’s extended regular expressions where ( and ) are used to group and \\ ( \\) match the literal brackets. Remove the brackets. Both will work.

How to pass variable containing backslashes to SED?

Another way of doing it, although uglier than anubhava’s answer, is by escaping all the backslashes in var using another sed command: Using / in sed as a delimiter will conflict with the slashes in the variable when substituted and as a result you will get an error.