How to replace the value after = using sed command to null-CodePudding

I have scenario where i want to replace the digit or string after equal to = to null [ blank ] Without creating new file need to replace in the same file

Data in file :

name=vilas
age=21
code=1345

Need to replace the digit after code=1345 to code=

I have tried this but stuck

sed -i 's/^code=$/code=/1g' file.txt

Note : The value after code= is going to be dynamic need to use regex pattern match which i am not good with

CodePudding user response：

var1=456
$ sed -Ei "s/(code=).*/\1$var1/" file
name=vilas
age=21
code=456

CodePudding user response：

Based on your question:

On MacOS and FreeBSD

sed -i '' -E 's/^code=[[:digit:]] $/code=/g' test1.txt

On CentOS and Debian

sed -i -E 's/^code=[[:digit:]] $/code=/g' test1.txt

You can update the character class to fit your needs.

where

-i  Edit files in-place
-E  Interpret regular expressions as extended (modern) regular expressions rather than basic regular expressions (BRE's).
s   The substitute command
g   Apply the replacement to all matches to the regexp, not just the first.

GNU docs: https://www.gnu.org/software/sed/manual/html_node/Character-Classes-and-Bracket-Expressions.html SED docs: https://www.gnu.org/software/sed/manual/sed.html