What to put into ~/.gitconfig to imply --show-signature for every git subcommand that supports it?

I just searched through the git-config(1), git-log(1) and git-show(1) man pages of git 2.6.2, but haven't found any hint that the --show-signature option (to e.g. git show or git log) can be configured globally in my ~/.gitconfig for all git subcommands that support it.

One option would be aliases, but since I don't know which subcommands all support it, that's just a workaround, not a solution.

I guessed it may be core.show-signature = yes or core.showSignature = yes but that didn't change anything.

I confirm that this --show-signature option (initially introduced in commit 0c37f1f, Oct 2011, Git v1.7.9-rc0) has no config setting or environment variable.

As illustrated by commit f2fef7b, that option is part of the "pretty options" Documentation/pretty-options.txt, which are supported by:

• git show
• git diff-tree
• git rev-list
• git log

---

Update July 2016 (8 months later), with Git 2.10 (Q3 2016): "git log" learns log.showSignature configuration variable, and a command line option "--no-show-signature" to countermand it.

See commit fce04c3, commit aa37999 (22 Jun 2016), commit aa37999 (22 Jun 2016), and commit aefc81a (24 Jun 2016) by Mehul Jain (mehul2029).
^{(Merged by Junio C Hamano -- gitster -- in commit 369dc40, 11 Jul 2016)}

log: add log.showSignature configuration variable

Users may want to always use "--show-signature" while using git-log and related commands.

When log.showSignature is set to true, git-log and related commands will behave as if "--show-signature" was given to them.

Note that this config variable is meant to affect git-log, git-show, git-whatchanged and git-reflog.
Other commands like git-format-patch, git-rev-list are not to be affected by this config variable.

---

Update May 2017 (11 more months later)

The git config man page is now clearer:

log.showSignature

If true, makes git-log, git-show, and git-whatchanged assume --show-signature.