Merge branch 'sg/help-group'

Group list of commands shown by "git help" along the workflow
elements to help early learners.

* sg/help-group:
  help: respect new common command grouping
  command-list.txt: drop the "common" tag
  generate-cmdlist: parse common group commands
  command-list.txt: add the common groups block
  command-list: prepare machinery for upcoming "common groups" section

7 files changed, 117 insertions, 51 deletions

diff --git a/Documentation/cmd-list.perl b/Documentation/cmd-list.perl
index 04f99778d8..5aa73cfe45 100755
--- a/Documentation/cmd-list.perl
+++ b/Documentation/cmd-list.perl
@@ -38,6 +38,10 @@ sub format_one {
 	}
 }
 
+while (<>) {
+	last if /^### command list/;
+}
+
 my %cmds = ();
 for (sort <>) {
 	next if /^#/;
diff --git a/Documentation/howto/new-command.txt b/Documentation/howto/new-command.txt
index d7de5a3e9e..6d772bd927 100644
--- a/Documentation/howto/new-command.txt
+++ b/Documentation/howto/new-command.txt
@@ -95,7 +95,9 @@ your language, document it in the INSTALL file.
 that categorizes commands by type, so they can be listed in appropriate
 subsections in the documentation's summary command list.  Add an entry
 for yours.  To understand the categories, look at git-commands.txt
-in the main directory.
+in the main directory.  If the new command is part of the typical Git
+workflow and you believe it common enough to be mentioned in 'git help',
+map this command to a common group in the column [common].
 
 7. Give the maintainer one paragraph to include in the RelNotes file
 to describe the new feature; a good place to do so is in the cover
diff --git a/Makefile b/Makefile
index 323c401e96..54ec511dff 100644
--- a/Makefile
+++ b/Makefile
@@ -1694,10 +1694,10 @@ $(BUILT_INS): git$X
 	ln -s $< $@ 2>/dev/null || \
 	cp $< $@
 
-common-cmds.h: ./generate-cmdlist.sh command-list.txt
+common-cmds.h: generate-cmdlist.perl command-list.txt
 
 common-cmds.h: $(wildcard Documentation/git-*.txt)
-	$(QUIET_GEN)./generate-cmdlist.sh > $@+ && mv $@+ $@
+	$(QUIET_GEN)$(PERL_PATH) generate-cmdlist.perl command-list.txt > $@+ && mv $@+ $@
 
 SCRIPT_DEFINES = $(SHELL_PATH_SQ):$(DIFF_SQ):$(GIT_VERSION):\
 	$(localedir_SQ):$(NO_CURL):$(USE_GETTEXT_SCHEME):$(SANE_TOOL_PATH_SQ):\
@@ -2455,7 +2455,7 @@ check-docs::
 		esac ; \
 		test -f "Documentation/$$v.txt" || \
 		echo "no doc: $$v"; \
-		sed -e '/^#/d' command-list.txt | \
+		sed -e '1,/^### command list/d' -e '/^#/d' command-list.txt | \
 		grep -q "^$$v[ 	]" || \
 		case "$$v" in \
 		git) ;; \
@@ -2463,7 +2463,8 @@ check-docs::
 		esac ; \
 	done; \
 	( \
-		sed -e '/^#/d' \
+		sed -e '1,/^### command list/d' \
+		    -e '/^#/d' \
 		    -e 's/[ 	].*//' \
 		    -e 's/^/listed /' command-list.txt; \
 		$(MAKE) -C Documentation print-man1 | \
diff --git a/command-list.txt b/command-list.txt
index 54d8d21ad2..b17c011bfd 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -1,29 +1,39 @@
-# List of known git commands.
+# common commands are grouped by themes
+# these groups are output by 'git help' in the order declared here.
+# map each common command in the command list to one of these groups.
+### common groups (do not change this line)
+init         start a working area (see also: git help tutorial)
+worktree     work on the current change (see also: git help everyday)
+info         examine the history and state (see also: git help revisions)
+history      grow, mark and tweak your common history
+remote       collaborate (see also: git help workflows)
+
+### command list (do not change this line)
 # command name                          category [deprecated] [common]
-git-add                                 mainporcelain common
+git-add                                 mainporcelain           worktree
 git-am                                  mainporcelain
 git-annotate                            ancillaryinterrogators
 git-apply                               plumbingmanipulators
 git-archimport                          foreignscminterface
 git-archive                             mainporcelain
-git-bisect                              mainporcelain common
+git-bisect                              mainporcelain           info
 git-blame                               ancillaryinterrogators
-git-branch                              mainporcelain common
+git-branch                              mainporcelain           history
 git-bundle                              mainporcelain
 git-cat-file                            plumbinginterrogators
 git-check-attr                          purehelpers
 git-check-ignore                        purehelpers
 git-check-mailmap                       purehelpers
-git-checkout                            mainporcelain common
+git-checkout                            mainporcelain           history
 git-checkout-index                      plumbingmanipulators
 git-check-ref-format                    purehelpers
 git-cherry                              ancillaryinterrogators
 git-cherry-pick                         mainporcelain
 git-citool                              mainporcelain
 git-clean                               mainporcelain
-git-clone                               mainporcelain common
+git-clone                               mainporcelain           init
 git-column                              purehelpers
-git-commit                              mainporcelain common
+git-commit                              mainporcelain           history
 git-commit-tree                         plumbingmanipulators
 git-config                              ancillarymanipulators
 git-count-objects                       ancillaryinterrogators
@@ -35,14 +45,14 @@ git-cvsimport                           foreignscminterface
 git-cvsserver                           foreignscminterface
 git-daemon                              synchingrepositories
 git-describe                            mainporcelain
-git-diff                                mainporcelain common
+git-diff                                mainporcelain           history
 git-diff-files                          plumbinginterrogators
 git-diff-index                          plumbinginterrogators
 git-diff-tree                           plumbinginterrogators
 git-difftool                            ancillaryinterrogators
 git-fast-export                         ancillarymanipulators
 git-fast-import                         ancillarymanipulators
-git-fetch                               mainporcelain common
+git-fetch                               mainporcelain           remote
 git-fetch-pack                          synchingrepositories
 git-filter-branch                       ancillarymanipulators
 git-fmt-merge-msg                       purehelpers
@@ -51,7 +61,7 @@ git-format-patch                        mainporcelain
 git-fsck                                ancillaryinterrogators
 git-gc                                  mainporcelain
 git-get-tar-commit-id                   ancillaryinterrogators
-git-grep                                mainporcelain common
+git-grep                                mainporcelain           info
 git-gui                                 mainporcelain
 git-hash-object                         plumbingmanipulators
 git-help                                ancillaryinterrogators
@@ -60,17 +70,17 @@ git-http-fetch                          synchelpers
 git-http-push                           synchelpers
 git-imap-send                           foreignscminterface
 git-index-pack                          plumbingmanipulators
-git-init                                mainporcelain common
+git-init                                mainporcelain           init
 git-instaweb                            ancillaryinterrogators
 git-interpret-trailers                  purehelpers
 gitk                                    mainporcelain
-git-log                                 mainporcelain common
+git-log                                 mainporcelain           info
 git-ls-files                            plumbinginterrogators
 git-ls-remote                           plumbinginterrogators
 git-ls-tree                             plumbinginterrogators
 git-mailinfo                            purehelpers
 git-mailsplit                           purehelpers
-git-merge                               mainporcelain common
+git-merge                               mainporcelain           history
 git-merge-base                          plumbinginterrogators
 git-merge-file                          plumbingmanipulators
 git-merge-index                         plumbingmanipulators
@@ -79,7 +89,7 @@ git-mergetool                           ancillarymanipulators
 git-merge-tree                          ancillaryinterrogators
 git-mktag                               plumbingmanipulators
 git-mktree                              plumbingmanipulators
-git-mv                                  mainporcelain common
+git-mv                                  mainporcelain           worktree
 git-name-rev                            plumbinginterrogators
 git-notes                               mainporcelain
 git-p4                                  foreignscminterface
@@ -90,11 +100,11 @@ git-parse-remote                        synchelpers
 git-patch-id                            purehelpers
 git-prune                               ancillarymanipulators
 git-prune-packed                        plumbingmanipulators
-git-pull                                mainporcelain common
-git-push                                mainporcelain common
+git-pull                                mainporcelain           remote
+git-push                                mainporcelain           remote
 git-quiltimport                         foreignscminterface
 git-read-tree                           plumbingmanipulators
-git-rebase                              mainporcelain common
+git-rebase                              mainporcelain           history
 git-receive-pack                        synchelpers
 git-reflog                              ancillarymanipulators
 git-relink                              ancillarymanipulators
@@ -103,28 +113,28 @@ git-repack                              ancillarymanipulators
 git-replace                             ancillarymanipulators
 git-request-pull                        foreignscminterface
 git-rerere                              ancillaryinterrogators
-git-reset                               mainporcelain common
+git-reset                               mainporcelain           worktree
 git-revert                              mainporcelain
 git-rev-list                            plumbinginterrogators
 git-rev-parse                           ancillaryinterrogators
-git-rm                                  mainporcelain common
+git-rm                                  mainporcelain           worktree
 git-send-email                          foreignscminterface
 git-send-pack                           synchingrepositories
 git-shell                               synchelpers
 git-shortlog                            mainporcelain
-git-show                                mainporcelain common
+git-show                                mainporcelain           info
 git-show-branch                         ancillaryinterrogators
 git-show-index                          plumbinginterrogators
 git-show-ref                            plumbinginterrogators
 git-sh-i18n                             purehelpers
 git-sh-setup                            purehelpers
 git-stash                               mainporcelain
-git-status                              mainporcelain common
+git-status                              mainporcelain           info
 git-stripspace                          purehelpers
 git-submodule                           mainporcelain
 git-svn                                 foreignscminterface
 git-symbolic-ref                        plumbingmanipulators
-git-tag                                 mainporcelain common
+git-tag                                 mainporcelain           history
 git-unpack-file                         plumbinginterrogators
 git-unpack-objects                      plumbingmanipulators
 git-update-index                        plumbingmanipulators
diff --git a/generate-cmdlist.perl b/generate-cmdlist.perl
new file mode 100755
index 0000000000..31516e36ac
--- /dev/null
+++ b/generate-cmdlist.perl
@@ -0,0 +1,50 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+print <<"EOT";
+/* Automatically generated by $0 */
+
+struct cmdname_help {
+	char name[16];
+	char help[80];
+	unsigned char group;
+};
+
+static char *common_cmd_groups[] = {
+EOT
+
+my $n = 0;
+my %grp;
+while (<>) {
+	last if /^### command list/;
+	next if (1../^### common groups/) || /^#/ || /^\s*$/;
+	chop;
+	my ($k, $v) = split ' ', $_, 2;
+	$grp{$k} = $n++;
+	print "\tN_(\"$v\"),\n";
+}
+
+print "};\n\nstatic struct cmdname_help common_cmds[] = {\n";
+
+while (<>) {
+	next if /^#/ || /^\s*$/;
+	my @tags = split;
+	my $cmd = shift @tags;
+	for my $t (@tags) {
+		if (exists $grp{$t}) {
+			my $s;
+			open my $f, '<', "Documentation/$cmd.txt" or die;
+			while (<$f>) {
+				($s) = /^$cmd - (.+)$/;
+				last if $s;
+			}
+			close $f;
+			$cmd =~ s/^git-//;
+			print "\t{\"$cmd\", N_(\"$s\"), $grp{$t}},\n";
+			last;
+		}
+	}
+}
+
+print "};\n";
diff --git a/generate-cmdlist.sh b/generate-cmdlist.sh
deleted file mode 100755
index 9a4c9b94e6..0000000000
--- a/generate-cmdlist.sh
+++ /dev/null
@@ -1,23 +0,0 @@
-#!/bin/sh
-
-echo "/* Automatically generated by $0 */
-struct cmdname_help {
-    char name[16];
-    char help[80];
-};
-
-static struct cmdname_help common_cmds[] = {"
-
-sed -n -e 's/^git-\([^ 	]*\)[ 	].* common.*/\1/p' command-list.txt |
-sort |
-while read cmd
-do
-     sed -n '
-     /^NAME/,/git-'"$cmd"'/H
-     ${
-	    x
-	    s/.*git-'"$cmd"' - \(.*\)/  {"'"$cmd"'", N_("\1")},/
-	    p
-     }' "Documentation/git-$cmd.txt"
-done
-echo "};"
diff --git a/help.c b/help.c
index 2072a873e2..8f72051ae0 100644
--- a/help.c
+++ b/help.c
@@ -218,17 +218,39 @@ void list_commands(unsigned int colopts,
 	}
 }
 
+static int cmd_group_cmp(const void *elem1, const void *elem2)
+{
+	const struct cmdname_help *e1 = elem1;
+	const struct cmdname_help *e2 = elem2;
+
+	if (e1->group < e2->group)
+		return -1;
+	if (e1->group > e2->group)
+		return 1;
+	return strcmp(e1->name, e2->name);
+}
+
 void list_common_cmds_help(void)
 {
 	int i, longest = 0;
+	int current_grp = -1;
 
 	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
 		if (longest < strlen(common_cmds[i].name))
 			longest = strlen(common_cmds[i].name);
 	}
 
-	puts(_("The most commonly used git commands are:"));
+	qsort(common_cmds, ARRAY_SIZE(common_cmds),
+		sizeof(common_cmds[0]), cmd_group_cmp);
+
+	puts(_("These are common Git commands used in various situations:"));
+
 	for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
+		if (common_cmds[i].group != current_grp) {
+			printf("\n%s\n", _(common_cmd_groups[common_cmds[i].group]));
+			current_grp = common_cmds[i].group;
+		}
+
 		printf("   %s   ", common_cmds[i].name);
 		mput_char(' ', longest - strlen(common_cmds[i].name));
 		puts(_(common_cmds[i].help));