AvaSattva

See https://github.com/qualiu/msr/

Match/Search/Replace: msr.exe/msr-Win32.exe/msr.cygwin/msr.gcc**/msr-i386.gcc**
Match/Search/Replace/Execute/* Files/Pipe Lines/Blocks.
Filter/Load/Extract/Transform/Stats/* Files/Pipe Lines/Blocks.

Not-IN-latter: nin.exe/nin-Win32.exe/nin.cygwin/nin.gcc**/nin-i386.gcc**
Get Exclusive/Mutual Line-Set or Key-Set;
Remove Line-Set or Key-Set matched in latter file/pipe;
Get Unique/Mutual/Distribution/Stats/* Files/Pipe Line-Set or Key-Set.
Match/Search/Replace files/pipe text with plain/Regex syntax.

And for ETL alike work like Load and filter files -> Extract -> Transform output.

For replacing files, you can preview and backup, in multiple directories and files or pipe, with plain text matching or using general Regex as C++, C#, Java, Scala; So msr is a good tool to learn and test Regex since it has different colors for matched groups captured by the Regex pattern.