Sometimes you need to know when name of a variable or any of its default value was changed in your commit history. The following command will come in really handy.
git log -G<regex>
For example to search for the text — ‘welcome’, you would use
git log -Gwelcome
This will search the content of the files where the word ‘welcome’ was present and if any changes were made to that line aka — even the word itself was not changed but its number of occurences on that line changed, you would get a result.
If you are only interested in knowing when the word itself changed, use the –S option
git log -S<string>
git log -Swelcome
Note that –G accepts a regex whereas –S accepts a string.