From 26cd138b9b530151ae57ec7d50cc3e82ccb8ce02 Mon Sep 17 00:00:00 2001
From: Drew Bonasera <Drewsif@users.noreply.github.com>
Date: Mon, 27 Apr 2020 06:17:07 -0400
Subject: [PATCH] More verbose and earlier errors on incompatible images

---
 pishrink.sh | 161 +++++++++++++++++++++++++++++-----------------------
 1 file changed, 90 insertions(+), 71 deletions(-)

diff --git a/pishrink.sh b/pishrink.sh
index 7e308aa..5e63751 100755
--- a/pishrink.sh
+++ b/pishrink.sh
@@ -66,6 +66,88 @@ fi
 
 }
 
+function set_autoexpand() {
+    #Make pi expand rootfs on next boot
+    mountdir=$(mktemp -d)
+    mount "$loopback" "$mountdir"
+
+    if [ ! -d "$mountdir/etc" ]; then
+        info "/etc not found, autoexpand will not be enabled"
+        umount "$mountdir"
+        return
+    fi
+
+    if [ "$(md5sum "$mountdir/etc/rc.local" 2>/dev/null | cut -d ' ' -f 1)" != "0542054e9ff2d2e0507ea1ffe7d4fc87" ]; then
+    echo "Creating new /etc/rc.local"
+    if [ -f "$mountdir/etc/rc.local" ]; then
+        mv "$mountdir/etc/rc.local" "$mountdir/etc/rc.local.bak"
+    fi
+
+    #####Do not touch the following lines#####
+cat <<\EOF1 > "$mountdir/etc/rc.local"
+#!/bin/bash
+do_expand_rootfs() {
+  ROOT_PART=$(mount | sed -n 's|^/dev/\(.*\) on / .*|\1|p')
+
+  PART_NUM=${ROOT_PART#mmcblk0p}
+  if [ "$PART_NUM" = "$ROOT_PART" ]; then
+    echo "$ROOT_PART is not an SD card. Don't know how to expand"
+    return 0
+  fi
+
+  # Get the starting offset of the root partition
+  PART_START=$(parted /dev/mmcblk0 -ms unit s p | grep "^${PART_NUM}" | cut -f 2 -d: | sed 's/[^0-9]//g')
+  [ "$PART_START" ] || return 1
+  # Return value will likely be error for fdisk as it fails to reload the
+  # partition table because the root fs is mounted
+  fdisk /dev/mmcblk0 <<EOF
+p
+d
+$PART_NUM
+n
+p
+$PART_NUM
+$PART_START
+
+p
+w
+EOF
+
+cat <<EOF > /etc/rc.local &&
+#!/bin/sh
+echo "Expanding /dev/$ROOT_PART"
+resize2fs /dev/$ROOT_PART
+rm -f /etc/rc.local; cp -f /etc/rc.local.bak /etc/rc.local; /etc/rc.local
+
+EOF
+reboot
+exit
+}
+raspi_config_expand() {
+/usr/bin/env raspi-config --expand-rootfs
+if [[ $? != 0 ]]; then
+  return -1
+else
+  rm -f /etc/rc.local; cp -f /etc/rc.local.bak /etc/rc.local; /etc/rc.local
+  reboot
+  exit
+fi
+}
+raspi_config_expand
+echo "WARNING: Using backup expand..."
+sleep 5
+do_expand_rootfs
+echo "ERROR: Expanding failed..."
+sleep 5
+rm -f /etc/rc.local; cp -f /etc/rc.local.bak /etc/rc.local; /etc/rc.local
+exit 0
+EOF1
+    #####End no touch zone#####
+    chmod +x "$mountdir/etc/rc.local"
+    fi
+    umount "$mountdir"
+}
+
 help() {
 	local help
 	read -r -d '' help << EOM
@@ -189,6 +271,13 @@ partnum="$(echo "$parted_output" | tail -n 1 | cut -d ':' -f 1)"
 partstart="$(echo "$parted_output" | tail -n 1 | cut -d ':' -f 2 | tr -d 'B')"
 loopback="$(losetup -f --show -o "$partstart" "$img")"
 tune2fs_output="$(tune2fs -l "$loopback")"
+rc=$?
+if (( $rc )); then
+    echo "$tune2fs_output"
+    error $LINENO "tune2fs failed. Unable to shrink this type of image"
+    exit 7
+fi
+
 currentsize="$(echo "$tune2fs_output" | grep '^Block count:' | tr -d ' ' | cut -d ':' -f 2)"
 blocksize="$(echo "$tune2fs_output" | grep '^Block size:' | tr -d ' ' | cut -d ':' -f 2)"
 
@@ -196,77 +285,7 @@ logVariables $LINENO beforesize parted_output partnum partstart tune2fs_output c
 
 #Check if we should make pi expand rootfs on next boot
 if [ "$should_skip_autoexpand" = false ]; then
-  #Make pi expand rootfs on next boot
-  mountdir=$(mktemp -d)
-  mount "$loopback" "$mountdir"
-
-  if [ "$(md5sum "$mountdir/etc/rc.local" | cut -d ' ' -f 1)" != "0542054e9ff2d2e0507ea1ffe7d4fc87" ]; then
-    echo "Creating new /etc/rc.local"
-    mv "$mountdir/etc/rc.local" "$mountdir/etc/rc.local.bak"
-    #####Do not touch the following lines#####
-
-cat <<\EOF1 > "$mountdir/etc/rc.local"
-#!/bin/bash
-do_expand_rootfs() {
-  ROOT_PART=$(mount | sed -n 's|^/dev/\(.*\) on / .*|\1|p')
-
-  PART_NUM=${ROOT_PART#mmcblk0p}
-  if [ "$PART_NUM" = "$ROOT_PART" ]; then
-    echo "$ROOT_PART is not an SD card. Don't know how to expand"
-    return 0
-  fi
-
-  # Get the starting offset of the root partition
-  PART_START=$(parted /dev/mmcblk0 -ms unit s p | grep "^${PART_NUM}" | cut -f 2 -d: | sed 's/[^0-9]//g')
-  [ "$PART_START" ] || return 1
-  # Return value will likely be error for fdisk as it fails to reload the
-  # partition table because the root fs is mounted
-  fdisk /dev/mmcblk0 <<EOF
-p
-d
-$PART_NUM
-n
-p
-$PART_NUM
-$PART_START
-
-p
-w
-EOF
-
-cat <<EOF > /etc/rc.local &&
-#!/bin/sh
-echo "Expanding /dev/$ROOT_PART"
-resize2fs /dev/$ROOT_PART
-rm -f /etc/rc.local; cp -f /etc/rc.local.bak /etc/rc.local; /etc/rc.local
-
-EOF
-reboot
-exit
-}
-raspi_config_expand() {
-/usr/bin/env raspi-config --expand-rootfs
-if [[ $? != 0 ]]; then
-  return -1
-else
-  rm -f /etc/rc.local; cp -f /etc/rc.local.bak /etc/rc.local; /etc/rc.local
-  reboot
-  exit
-fi
-}
-raspi_config_expand
-echo "WARNING: Using backup expand..."
-sleep 5
-do_expand_rootfs
-echo "ERROR: Expanding failed..."
-sleep 5
-rm -f /etc/rc.local; cp -f /etc/rc.local.bak /etc/rc.local; /etc/rc.local
-exit 0
-EOF1
-    #####End no touch zone#####
-    chmod +x "$mountdir/etc/rc.local"
-  fi
-  umount "$mountdir"
+    set_autoexpand
 else
   echo "Skipping autoexpanding process..."
 fi