add usage-strings ci check and amend remaining usage strings

Usage strings for git (sub)command flags has a style guide that
suggests - first letter should not capitalized (unless requied)
and it should skip full-stop at the end of line. But there are
some files where usage-strings do not follow the above mentioned
guide. Moreover, there are no checks to verify if all usage strings
are following the guide/convention or not.

Amend the usage strings that don't follow the convention/guide and
add a `CI` check for checking the usage strings (whether the first
letter is capital or it ends with full-stop). If the `check` find
such strings then print those strings and return a non-zero status.

Also provide a script that takes an optional argument (a valid <tree>
string), to check the usage strings in the given <tree> (`HEAD` is
the default argument).

Signed-off-by: Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com>

Makefile

@@ -3416,6 +3416,11 @@ check-docs::
 check-builtins::
 	./check-builtins.sh
 
+### Make sure all the usage strings follow usage string style guide
+#
+check-usage-strings::
+	./check-usage-strings.sh
+
 ### Test suite coverage testing
 #
 .PHONY: coverage coverage-clean coverage-compile coverage-test coverage-report

builtin/bisect--helper.c

@@ -1209,7 +1209,7 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		OPT_CMDMODE(0, "bisect-visualize", &cmdmode,
 			 N_("visualize the bisection"), BISECT_VISUALIZE),
 		OPT_CMDMODE(0, "bisect-run", &cmdmode,
-			 N_("use <cmd>... to automatically bisect."), BISECT_RUN),
+			 N_("use <cmd>... to automatically bisect"), BISECT_RUN),
 		OPT_BOOL(0, "no-log", &nolog,
 			 N_("no log for BISECT_WRITE")),
 		OPT_END()

builtin/submodule--helper.c

@@ -1874,7 +1874,7 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 		OPT_STRING(0, "depth", &clone_data.depth,
 			   N_("string"),
 			   N_("depth for shallow clones")),
-		OPT__QUIET(&quiet, "Suppress output for cloning a submodule"),
+		OPT__QUIET(&quiet, "suppress output for cloning a submodule"),
 		OPT_BOOL(0, "progress", &progress,
 			   N_("force cloning progress")),
 		OPT_BOOL(0, "require-init", &require_init,

check-usage-strings.sh

@@ -0,0 +1,33 @@
+{
+  if test -d ".git"
+  then
+    rev=${1:-"HEAD"}
+    for entry in $(git grep -l 'struct option .* = {$' "$rev" -- \*.c);
+    do
+      git show "$entry" |
+      sed -n '/struct option .* = {/,/OPT_END/{=;p;}' |
+      sed "N;s/^\\([0-9]*\\)\\n/$(echo "$entry" | sed 's/\//\\&/g'):\\1/";
+    done
+  else
+    for entry in $(grep -rl --include="*.c" 'struct option .* = {$' . );
+    do
+      cat "$entry" |
+      sed -n '/struct option .* = {/,/OPT_END/{=;p;}' |
+      sed "N;s/^\\([0-9]*\\)\\n/$(echo "$entry" | sed -e 's/\//\\&/g' -e 's/^\.\\\///'):\\1/";
+    done
+  fi
+} |
+grep -Pe '((?<!OPT_GROUP\(N_\(|OPT_GROUP\()"(?!GPG|DEPRECATED|SHA1|HEAD)[A-Z]|(?<!"|\.\.)\.")' |
+{
+  status=0
+  while read content;
+  do
+    if test -n "$content"
+    then
+      echo "$content";
+      status=1;
+    fi
+  done
+
+  exit $status
+}

ci/test-documentation.sh

@@ -15,6 +15,7 @@ filter_log () {
 }
 
 make check-builtins
+make check-usage-strings
 make check-docs
 
 # Build docs with AsciiDoc

diff.c

@@ -5596,7 +5596,7 @@ static void prep_parse_options(struct diff_options *options)
 			       N_("select files by diff type"),
 			       PARSE_OPT_NONEG, diff_opt_diff_filter),
 		{ OPTION_CALLBACK, 0, "output", options, N_("<file>"),
-		  N_("Output to a specific file"),
+		  N_("output to a specific file"),
 		  PARSE_OPT_NONEG, NULL, 0, diff_opt_output },
 
 		OPT_END()

t/helper/test-run-command.c

@@ -221,9 +221,9 @@ static int quote_stress_test(int argc, const char **argv)
 	struct strbuf out = STRBUF_INIT;
 	struct strvec args = STRVEC_INIT;
 	struct option options[] = {
-		OPT_INTEGER('n', "trials", &trials, "Number of trials"),
-		OPT_INTEGER('s', "skip", &skip, "Skip <n> trials"),
-		OPT_BOOL('m', "msys2", &msys2, "Test quoting for MSYS2's sh"),
+		OPT_INTEGER('n', "trials", &trials, "number of trials"),
+		OPT_INTEGER('s', "skip", &skip, "skip <n> trials"),
+		OPT_BOOL('m', "msys2", &msys2, "test quoting for MSYS2's sh"),
 		OPT_END()
 	};
 	const char * const usage[] = {