Initial Commit

This commit is contained in:
Drew Bonasera 2016-04-11 23:05:00 -04:00
commit ca4de5aa4e
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The MIT License (MIT)
Copyright (c) 2016 Drew Bonasera
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

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# PiShrink #
PiShrink is a bash script that automatically shrink a pi image that will then resize to the max size of the SD card on boot.
`Usage: ./pishrink imagefile.img`
## Example ##
```bash
[user@localhost PiShrink]$ sudo ./shrink.sh pi.img
e2fsck 1.42.9 (28-Dec-2013)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/loop1: 88262/1929536 files (0.2% non-contiguous), 842728/7717632 blocks
resize2fs 1.42.9 (28-Dec-2013)
resize2fs 1.42.9 (28-Dec-2013)
Resizing the filesystem on /dev/loop1 to 773603 (4k) blocks.
Begin pass 2 (max = 100387)
Relocating blocks XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Begin pass 3 (max = 236)
Scanning inode table XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Begin pass 4 (max = 7348)
Updating inode references XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
The filesystem on /dev/loop1 is now 773603 blocks long.
Shrunk pi.img from 30G to 3.1G
```
## Credits ##
Thanks to SirLagz for the code to shrink http://sirlagz.net/2013/03/10/script-automatic-rpi-image-downsizer/

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#!/bin/bash
#Args
img=$1
#Usage checks
if [[ -z $img ]]; then
echo "Usage: $0 imagefile.img"
exit -1
fi
if [[ ! -e $img ]]; then
echo "ERROR: $img is not a file..."
exit -2
fi
if (( EUID != 0 )); then
echo "ERROR: You need to be running as root."
exit -3
fi
#Gather info
beforesize=`ls -lah $img | cut -d ' ' -f 5`
partinfo=`parted -m $img unit B print`
partnumber=`echo "$partinfo" | grep ext4 | awk -F: ' { print $img } '`
partstart=`echo "$partinfo" | grep ext4 | awk -F: ' { print substr($2,0,length($2)-1) } '`
loopback=`losetup -f --show -o $partstart $img`
#Make pi expand rootfs on next boot
mountdir=`mktemp -d`
mount $loopback $mountdir
mv $mountdir/etc/rc.local $mountdir/etc/rc.expand.tmp
cat <<\EOF > $mountdir/etc/rc.local
#!/bin/sh
/usr/bin/raspi-config --expand-rootfs; mv -f /etc/rc.expand.tmp /etc/rc.local; reboot
exit 0
EOF
chmod +x $mountdir/etc/rc.local
umount $loopback
#Shrink filesystem
e2fsck -f $loopback
minsize=`resize2fs -P $loopback | awk -F': ' ' { print $2 } '`
minsize=`echo $minsize+20000 | bc`
resize2fs -p $loopback $minsize
sleep 1
#Shrink partition
losetup -d $loopback
partnewsize=`echo "$minsize * 4096" | bc`
newpartend=`echo "$partstart + $partnewsize" | bc`
part1=`parted $img rm 2`
part2=`parted $img unit B mkpart primary $partstart $newpartend`
#Truncate the file
endresult=`parted -m $img unit B print free | tail -1 | awk -F: ' { print substr($2,0,length($2)-1) } '`
truncate -s $endresult $img
aftersize=`ls -lah $img | cut -d ' ' -f 5`
echo "Shrunk $img from $beforesize to $aftersize"