diff options
Diffstat (limited to 'Documentation/diff-options.txt')
| -rw-r--r-- | Documentation/diff-options.txt | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt index b8a9b86375..a85288f23e 100644 --- a/Documentation/diff-options.txt +++ b/Documentation/diff-options.txt @@ -383,14 +383,36 @@ ifndef::git-format-patch[] that matches other criteria, nothing is selected. -S<string>:: - Look for differences that introduce or remove an instance of - <string>. Note that this is different than the string simply - appearing in diff output; see the 'pickaxe' entry in - linkgit:gitdiffcore[7] for more details. + Look for differences that change the number of occurrences of + the specified string (i.e. addition/deletion) in a file. + Intended for the scripter's use. ++ +It is useful when you're looking for an exact block of code (like a +struct), and want to know the history of that block since it first +came into being: use the feature iteratively to feed the interesting +block in the preimage back into `-S`, and keep going until you get the +very first version of the block. -G<regex>:: - Look for differences whose added or removed line matches - the given <regex>. + Look for differences whose patch text contains added/removed + lines that match <regex>. ++ +To illustrate the difference between `-S<regex> --pickaxe-regex` and +`-G<regex>`, consider a commit with the following diff in the same +file: ++ +---- ++ return !regexec(regexp, two->ptr, 1, ®match, 0); +... +- hit = !regexec(regexp, mf2.ptr, 1, ®match, 0); +---- ++ +While `git log -G"regexec\(regexp"` will show this commit, `git log +-S"regexec\(regexp" --pickaxe-regex` will not (because the number of +occurrences of that string did not change). ++ +See the 'pickaxe' entry in linkgit:gitdiffcore[7] for more +information. --pickaxe-all:: When `-S` or `-G` finds a change, show all the changes in that @@ -398,8 +420,8 @@ ifndef::git-format-patch[] in <string>. --pickaxe-regex:: - Make the <string> not a plain string but an extended POSIX - regex to match. + Treat the <string> given to `-S` as an extended POSIX regular + expression to match. endif::git-format-patch[] -O<orderfile>:: |