Add update checking!

README.md

@@ -8,10 +8,11 @@ using multiple cores is supported.
 ## Usage ##
 
 ```text
-Usage: $0 [-adhrsvzZ] imagefile.img [newimagefile.img]
+Usage: pishrink.sh [-adhnrsvzZ] imagefile.img [newimagefile.img]
 
   -s         Don't expand filesystem when image is booted the first time
   -v         Be verbose
+  -n         Disable automatic update checking
   -r         Use advanced filesystem repair option if the normal one fails
   -z         Compress image after shrinking with gzip
   -Z         Compress image after shrinking with xz
@@ -23,6 +24,7 @@ If you specify the `newimagefile.img` parameter, the script will make a copy of
 
 * `-s` prevents automatic filesystem expansion on the images next boot
 * `-v` enables more verbose output
+* `-n` disables the script from checking Github for a new PiShrink release
 * `-r` will attempt to repair the filesystem using additional options if the normal repair fails
 * `-z` will compress the image after shrinking using gzip. `.gz` extension will be added to the filename.
 * `-Z` will compress the image after shrinking using xz. `.xz` extension will be added to the filename.

pishrink.sh

@@ -169,10 +169,11 @@ EOFRC
 help() {
 	local help
 	read -r -d '' help << EOM
-Usage: $0 [-adhrsvzZ] imagefile.img [newimagefile.img]
+Usage: $0 [-adhnrsvzZ] imagefile.img [newimagefile.img]
 
   -s         Don't expand filesystem when image is booted the first time
   -v         Be verbose
+  -n         Disable automatic update checking
   -r         Use advanced filesystem repair option if the normal one fails
   -z         Compress image after shrinking with gzip
   -Z         Compress image after shrinking with xz
@@ -185,15 +186,17 @@ EOM
 
 should_skip_autoexpand=false
 debug=false
+update_check=true
 repair=false
 parallel=false
 verbose=false
 ziptool=""
 
-while getopts ":adhrsvzZ" opt; do
+while getopts ":adnhrsvzZ" opt; do
   case "${opt}" in
     a) parallel=true;;
     d) debug=true;;
+    n) update_check=false;;
     h) help;;
     r) repair=true;;
     s) should_skip_autoexpand=true ;;
@@ -214,6 +217,15 @@ fi
 
 echo -e "PiShrink $version - https://github.com/Drewsif/PiShrink\n"
 
+# Try and check for updates
+if $update_check; then
+  latest_release=$(curl -m 5 https://api.github.com/repos/Drewsif/PiShrink/releases/latest 2>/dev/null | grep -i "tag_name" 2>/dev/null | awk -F '"' '{print $4}' 2>/dev/null)
+  if [[ $? ]] && [ "$latest_release" \> "$version" ]; then
+    echo "WARNING: You do not appear to be running the latest version of PiShrink. Head on over to https://github.com/Drewsif/PiShrink to grab $latest_release"
+    echo ""
+  fi
+fi
+
 #Args
 src="$1"
 img="$1"
@@ -239,7 +251,6 @@ export LANGUAGE=POSIX
 export LC_ALL=POSIX
 export LANG=POSIX
 
-
 # check selected compression tool is supported and installed
 if [[ -n $ziptool ]]; then
 	if [[ ! " ${ZIPTOOLS[@]} " =~ $ziptool ]]; then