From 2ee402b3d082da097a6b78e68b4e1a2011e7e837 Mon Sep 17 00:00:00 2001
From: martin <martin@NetBSD.org>
Date: Sun, 24 Mar 2019 13:45:35 +0000
Subject: [PATCH] Make the "show" subcommand accept -b startsec to identify a
 partition (very usefull for scripts and other robotic callers).

---
 sbin/gpt/gpt.8  |  8 +++++---
 sbin/gpt/show.c | 22 ++++++++++++++++++++--
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/sbin/gpt/gpt.8 b/sbin/gpt/gpt.8
index 31fb743d73be..e5d59a608a24 100644
--- a/sbin/gpt/gpt.8
+++ b/sbin/gpt/gpt.8
@@ -1,4 +1,4 @@
-.\" $NetBSD: gpt.8,v 1.64 2019/03/24 13:31:00 martin Exp $
+.\" $NetBSD: gpt.8,v 1.65 2019/03/24 13:45:35 martin Exp $
 .\"
 .\" Copyright (c) 2002 Marcel Moolenaar
 .\" All rights reserved.
@@ -466,7 +466,7 @@ See above for a description of these options.
 Partitions are removed by clearing the partition type.
 No other information is changed.
 .\" ==== resize ====
-.It Nm Ic resize [ Fl i Ar index | Fl b Ar startsec ] Oo Fl a Ar alignment Oc \
+.It Nm Ic resize Oo Fl i Ar index Oc Oo Fl b Ar startsec Oc Oo Fl a Ar alignment Oc \
 Oo Fl s Ar size Oc
 The
 .Ic resize
@@ -592,7 +592,7 @@ They may be used by
 .Nx
 in the future.
 .\" ==== show ====
-.It Nm Ic show Oo Fl aglu Oc Oo Fl i Ar index Oc
+.It Nm Ic show Oo Fl aglu Oc Oo Fl i Ar index Oc Oo Fl b Ar startsec Oc
 The
 .Ic show
 command displays the current partitioning on the listed devices and gives
@@ -611,6 +611,8 @@ option the GPT partition type is displayed as an UUID instead of in a
 user friendly form.
 With the
 .Fl i
+or the
+.Fl b
 option, all the details of a particular GPT partition will be displayed.
 The format of this display is subject to change.
 With the
diff --git a/sbin/gpt/show.c b/sbin/gpt/show.c
index 28e99936fcce..d52d83d0fcae 100644
--- a/sbin/gpt/show.c
+++ b/sbin/gpt/show.c
@@ -33,7 +33,7 @@
 __FBSDID("$FreeBSD: src/sbin/gpt/show.c,v 1.14 2006/06/22 22:22:32 marcel Exp $");
 #endif
 #ifdef __RCSID
-__RCSID("$NetBSD: show.c,v 1.42 2019/03/03 03:20:42 jnemeth Exp $");
+__RCSID("$NetBSD: show.c,v 1.43 2019/03/24 13:45:35 martin Exp $");
 #endif
 
 #include <sys/bootblock.h>
@@ -317,8 +317,10 @@ cmd_show(gpt_t gpt, int argc, char *argv[])
 	int ch;
 	int xshow = 0;
 	unsigned int entry = 0;
+	off_t start = 0;
+	map_t m;
 
-	while ((ch = getopt(argc, argv, "gi:lua")) != -1) {
+	while ((ch = getopt(argc, argv, "gi:b:lua")) != -1) {
 		switch(ch) {
 		case 'a':
 			xshow |= SHOW_ALL;
@@ -330,6 +332,10 @@ cmd_show(gpt_t gpt, int argc, char *argv[])
 			if (gpt_uint_get(gpt, &entry) == -1)
 				return usage();
 			break;
+		case 'b':
+			if (gpt_human_get(gpt, &start) == -1)
+				return usage();
+			break;
 		case 'l':
 			xshow |= SHOW_LABEL;
 			break;
@@ -350,5 +356,17 @@ cmd_show(gpt_t gpt, int argc, char *argv[])
 	if (xshow & SHOW_ALL)
 		return show_all(gpt);
 
+	if (start > 0) {
+		for (m = map_first(gpt); m != NULL; m = m->map_next) {
+			if (m->map_type != MAP_TYPE_GPT_PART ||
+			    m->map_index < 1)
+				continue;
+			if (start != m->map_start)
+				continue;
+			entry = m->map_index;
+			break;
+		}
+	}
+
 	return entry > 0 ? show_one(gpt, entry) : show(gpt, xshow);
 }