Batch script for creating iOS icon sizes

generate_icons.sh

#!/bin/bash
 
#Usage:   
#generate_icons.sh /path/to/mastericon.png
 
#Assumes your master icon image is larger than 180px by 180px at least 
 
i=0
 
sizes=(76 72 50 40 29 57 60 167)
 
iconset=generated-icons
 
echo working into on $iconset
 
if [ -d $iconset ]; then
  rm -rf $iconset
fi
 
mkdir -p $iconset
 
base=iconbase.png
 
cp $1 $iconset/$base
 
echo working on $1
 
while [ $i -lt ${#sizes[@]} ]; do
 
nextsize=${sizes[$i]}
nextsize2x=$((2*nextsize))
nextsize3x=$((3*nextsize))
 
nextname=icon-$nextsize.png
nextname2x=icon-$nextsize@2x.png
nextname3x=icon-$nextsize@3x.png
 
echo generating files $nextname and $nextname2x and $nextname3x
 
cp $iconset/$base $iconset/$nextname
`sips -Z $nextsize $iconset/$nextname &>/dev/null` 
 
cp $iconset/$base $iconset/$nextname2x
`sips -Z $nextsize2x $iconset/$nextname2x &>/dev/null`

cp $iconset/$base $iconset/$nextname3x
`sips -Z $nextsize3x $iconset/$nextname3x &>/dev/null`
 
 
: $[ i++ ]
 
done

echo use 167@1x for 83.5@2x iPad Pro
rm $iconset/$base