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[PATCH v2 1/3] help: redirect to aliased commands for "git cmd --help"

From
Rasmus Villemoes <rv@rasmusvillemoes.dk>
Date
Oct 1, 2018, 11:21 UTC
Message-ID
<20181001112107.28956-1-rv@rasmusvillemoes.dk>
In-Reply-To
<20180926102636.30691-1-rv@rasmusvillemoes.dk>

As discussed in the thread for v1 of this patch [1] [2], this changes the rules for "git foo --help" when foo is an alias.

(0) When invoked as "git help foo", we continue to print the "foo is aliased to bar" message and nothing else.

(1) If foo is an alias for a shell command, print "foo is aliased to !bar" as usual.

(2) Otherwise, break the alias string into words, and pretend that "git word0 --help" was called.

At least for me, getting the man page for git-cherry-pick directly with "git cp --help" is more useful (and how I expect an alias to behave) than the short "is aliased to" notice. It is also consistent with "--help" generally providing more comprehensive help than "-h".

I believe that printing the "is aliased to" message also in case (2) has value: Depending on pager setup, or if the user has help.format=web, the message is still present immediately above the prompt when the user quits the pager/returns to the terminal. That serves as an explanation for why one was redirected to "man git-cherry-pick" from "git cp --help", and if cp is actually 'cherry-pick -n', it reminds the user that using cp has some flag implicitly set before firing off the next command.

It also provides some useful info in case we end up erroring out, either in the "bad alias string" check, or in the "No manual entry for gitbar" case.

[1] https://public-inbox.org/git/20180926102636.30691-1-rv@rasmusvillemoes.dk/ [2] https://public-inbox.org/git/20180926184914.GC30680@sigill.intra.peff.net/

Signed-off-by: Rasmus Villemoes <rv@rasmusvillemoes.dk>
---
 builtin/help.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)
diff --git a/builtin/help.c b/builtin/help.c
index 8d4f6dd301..4802a06f37 100644
--- a/builtin/help.c
+++ b/builtin/help.c
@@ -415,9 +415,29 @@ static const char *check_git_cmd(const char* cmd)
 
 	alias = alias_lookup(cmd);
 	if (alias) {
-		printf_ln(_("'%s' is aliased to '%s'"), cmd, alias);
-		free(alias);
-		exit(0);
+		const char **argv;
+		int count;
+
+		/*
+		 * If we were invoked as "git help cmd", or cmd is an
+		 * alias for a shell command, we inform the user what
+		 * cmd is an alias for and do nothing else.
+		 */
+		if (!exclude_guides || alias[0] == '!') {
+			printf_ln(_("'%s' is aliased to '%s'"), cmd, alias);
+			free(alias);
+			exit(0);
+		}
+		/*
+		 * Otherwise, we pretend that the command was "git
+		 * word0 --help.
+		 */
+		fprintf_ln(stderr, _("'%s' is aliased to '%s'"), cmd, alias);
+		count = split_cmdline(alias, &argv);
+		if (count < 0)
+			die(_("bad alias.%s string: %s"), cmd,
+			    split_cmdline_strerror(count));
+		return alias;
 	}
 
 	if (exclude_guides)
-- 
2.19.0
Previous: Duy NguyenNext: Rasmus Villemoes
Message 22 of 43 in “help: allow redirecting to help for aliased command”
  1. help: allow redirecting to help for aliased commandRasmus Villemoes, Sep 26, 2018
  2. Taylor BlauSep 26, 2018
  3. Duy NguyenSep 26, 2018
  4. Rasmus VillemoesSep 28, 2018
  5. Junio C HamanoSep 26, 2018
  6. Taylor BlauSep 26, 2018
  7. Junio C HamanoSep 26, 2018
  8. Junio C HamanoSep 26, 2018
  9. Taylor BlauSep 26, 2018
  10. Rasmus VillemoesSep 28, 2018
  11. Jeff KingSep 26, 2018
  12. Junio C HamanoSep 26, 2018
  13. Rasmus VillemoesSep 28, 2018
  14. Jeff KingSep 29, 2018
  15. Junio C HamanoSep 29, 2018
  16. Jeff KingSep 30, 2018
  17. Junio C HamanoSep 30, 2018
  18. Jeff KingSep 30, 2018
  19. Rasmus VillemoesSep 28, 2018
  20. Junio C HamanoSep 28, 2018
  21. Duy NguyenSep 26, 2018
  22. 1/3 help: redirect to aliased commands for "git cmd --help"Rasmus Villemoes, Oct 1, 2018
  23. 2/3 git.c: handle_alias: prepend alias info when first argument is -hRasmus Villemoes, Oct 1, 2018
  24. Jeff KingOct 3, 2018
  25. 3/3 git-help.txt: document "git help cmd" vs "git cmd --help" for aliasesRasmus Villemoes, Oct 1, 2018
  26. Jeff KingOct 3, 2018
  27. Rasmus VillemoesOct 3, 2018
  28. Jeff KingOct 3, 2018
  29. Rasmus VillemoesOct 3, 2018
  30. Jeff KingOct 3, 2018
  31. 0/3 alias help tweaksRasmus Villemoes, Oct 3, 2018
  32. 1/3 help: redirect to aliased commands for "git cmd --help"Rasmus Villemoes, Oct 3, 2018
  33. Junio C HamanoOct 5, 2018
  34. Rasmus VillemoesOct 5, 2018
  35. Junio C HamanoOct 5, 2018
  36. 2/3 git.c: handle_alias: prepend alias info when first argument is -hRasmus Villemoes, Oct 3, 2018
  37. 3/3 git-help.txt: document "git help cmd" vs "git cmd --help" for aliasesRasmus Villemoes, Oct 3, 2018
  38. Jeff KingOct 4, 2018
  39. 0/3 alias help tweaksRasmus Villemoes, Oct 9, 2018
  40. 1/3 help: redirect to aliased commands for "git cmd --help"Rasmus Villemoes, Oct 9, 2018
  41. 2/3 git.c: handle_alias: prepend alias info when first argument is -hRasmus Villemoes, Oct 9, 2018
  42. 3/3 git-help.txt: document "git help cmd" vs "git cmd --help" for aliasesRasmus Villemoes, Oct 9, 2018
  43. Junio C HamanoOct 12, 2018

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