Re: [PATCH] Get correct column with for options in command usage

From: Duy Nguyen <pclouds@gmail.com>
Date: Feb 5, 2013, 12:15 UTC
Message-ID: <20130205121552.GA16601@lanh>
In-Reply-To: <0b035132df6de2cac56ac59d66b04f30e90ad760.1360049671.git.worldhello.net@gmail.com>

On Tue, Feb 05, 2013 at 03:40:32PM +0800, Jiang Xin wrote:

> Command usage would not align well if command options are translated,
> especially to CJK. Call utf8_strwidth in function usage_argh, so that
> the caller will get correct column width.

Yeah, I just noticed a misalignment in Vietnamese translation (just two spaces to the left, hard to notice unless paying attention).

Show 16 quoted lines

>  static int usage_argh(const struct option *opts, FILE *outfile)
>  {
> -	const char *s;
> +	const char *s, *p;
>  	int literal = (opts->flags & PARSE_OPT_LITERAL_ARGHELP) || !opts->argh;
>  	if (opts->flags & PARSE_OPT_OPTARG)
>  		if (opts->long_name)
> @@ -482,7 +482,9 @@ static int usage_argh(const struct option *opts, FILE *outfile)
>  			s = literal ? "[%s]" : "[<%s>]";
>  	else
>  		s = literal ? " %s" : " <%s>";
> -	return fprintf(outfile, s, opts->argh ? _(opts->argh) : _("..."));
> +	p = opts->argh ? _(opts->argh) : _("...");
> +	fprintf(outfile, s, p);
> +	return utf8_strwidth(p) + strlen(s) - 2;
>  }

First of all, #include "utf8.h" is required for utf8_strwidth().

The "strlen(s) - 2" is quite sensitive to how "s" is written. How about this? A bit longer but clearer. Your version is OK too with a comment explaining "strlen(s) - 2".

-- 8< --

diff --git a/parse-options.c b/parse-options.c
index 67e98a6..0f803bd 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -474,6 +474,8 @@ int parse_options(int argc, const char **argv, const char *prefix,
 static int usage_argh(const struct option *opts, FILE *outfile)
 {
 	const char *s;
+	struct strbuf sb = STRBUF_INIT;
+	int columns;
 	int literal = (opts->flags & PARSE_OPT_LITERAL_ARGHELP) || !opts->argh;
 	if (opts->flags & PARSE_OPT_OPTARG)
 		if (opts->long_name)
@@ -482,7 +484,11 @@ static int usage_argh(const struct option *opts, FILE *outfile)
 			s = literal ? "[%s]" : "[<%s>]";
 	else
 		s = literal ? " %s" : " <%s>";
-	return fprintf(outfile, s, opts->argh ? _(opts->argh) : _("..."));
+	strbuf_addf(&sb, s, opts->argh ? _(opts->argh) : _("..."));
+	fprintf(outfile, sb.buf);
+	columns = utf8_strwidth(sb.buf);
+	strbuf_release(&sb);
+	return columns;
 }
 
 #define USAGE_OPTS_WIDTH 24
-- 8< --

While looking at parse-options.c, I notice "-NUM" is not marked for
translation. I think you might want to mark it so that you can
translate "NUM" to a similar abbreviation in a local language. A
similar patch like this is required so we get columns for "-NUM"
translation instead of the number of bytes.
--
Duy