Show only certain tags when using gitk?

Question

Every commit in our repository has a tag associated with it. There are a lot of tags on a branch that have "B7" in the name. Can I run gitk and exclude all of these "B7" tags? Conversely, how can I run gitk and show only the commits that do have "B7" in them?

I'm tired of doing gitk --all and getting a bunch of extra fluff.

Answer 1

It occurred to me halfway through writing this that maybe you want the commits displayed, but just want some of those commits not to show tags that point to them. This answers instead the question "how do I see all commits reachable from some or all branches, but not commits reachable from certain tags that are not also reachable from those branches?".

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gitk takes the same options as git-rev-list, for selecting commits to display. Hence, instead of --all you can provide --branches and/or --tags, both of which accept "pattern" arguments.

Unfortunately, the pattern arguments are shell glob style patterns, where it's very easy to include those containing B7 (*B7* will do the trick) but difficult to exclude those that contain something that has B7 embedded at an arbitrary position within it. If the B7 is at the beginning or end of the name it's less difficult, though still a bit messy: --tags="[AC-Za-z]*" --tags="B[A-Za-z0-689]*", for instance, is probably good enough to match two-or-more character tags that do not begin with B7 (add --tags="?" to include one-character tags as well).

(The double quotes here are to prevent the shell from attempting to expand the shell-style globs, although in most shell variants, as long as there are no files [in the current directory] whose names start with --tags=, you can get away without them.)

For full flexibility, you can use git for-each-ref or git show-ref to enumerate references, piping the ref names through something like grep -v to include or exclude arbitrary regular expressions, and delivering the result as arguments to gitk. For instance, to see all commits on all branches, plus commits on

gitk --branches $(git for-each-ref --format='%(refname:short)' refs/tags/ |
    grep -v B7)

(not actually tested, but simple and should work, assuming sh or bash shells).

(For csh or tcsh, put everything on one line, or use backslash before newlines; and replace cmd ... $(subcmd ...) with cmd ... `subcmd ...`. The backquote version is generally inferior syntactically as it cannot be nested, but it will do in this case. Even though I use tcsh as an interactive shell, I switch to sh for scripting.)