Weird Behaviour with New Lines Using grunt-exec

Question

I am using ImageMagick and grunt-exec to generate a favicon for a website I am working on using the command found in the ImageMagick documentation.

convert image.png  -bordercolor white -border 0 \
      \( -clone 0 -resize 16x16 \) \
      \( -clone 0 -resize 32x32 \) \
      \( -clone 0 -resize 48x48 \) \
      \( -clone 0 -resize 64x64 \) \
      -delete 0 -alpha off -colors 256 favicon.ico

However I am getting some issues with line breaks which I think is partially because I do not fully understand what I should do with the line breaks.

In my Gruntfile.js I am currently using no line breaks and it works as expected. Notice that I had to remove all the line breaks and double escape the parentheses because apparently grunt-exec parses the string before it executes it.

exec: {
    favicon: 'convert _favicon.svg -bordercolor white -border 0 \\( -clone 0 -resize 16x16 \\) \\( -clone 0 -resize 32x32 \\) \\( -clone 0 -resize 48x48 \\) \\( -clone 0 -resize 64x64 \\) -delete 0 -alpha off -colors 256 favicon.ico'
}

Like I said, I have it working right now but I would like to be able to use line breaks for readability and also because I would like to fully understand what is going on here. So far I have tried adding an extra \ and leaving everything the same, replacing the new lines with \n or \\n and putting everything on the same line but no luck.

Answer 1

The solution I was looking for turned out to be to use \n\ for new lines, like this:

convert image.png  -bordercolor white -border 0 \n\
    \( -clone 0 -resize 16x16 \) \n\
    \( -clone 0 -resize 32x32 \) \n\
    \( -clone 0 -resize 48x48 \) \n\
    \( -clone 0 -resize 64x64 \) \n\
    -delete 0 -alpha off -colors 256 favicon.ico

Answer 2

Try using this:

exec: {
    favicon: 'convert _favicon.svg -bordercolor white -border 0 "( -clone 0 -resize 16x16 )" "( -clone 0 -resize 32x32 )" "( -clone 0 -resize 48x48 )" "( -clone 0 -resize 64x64 )" -delete 0 -alpha off -colors 256 favicon.ico'
}