Using awk to process ls output with spaces in filenames/paths

Question

All,
I have a script in which I use find command to filter out all png files in a given folder and list them along with their size. I want the output in the following format:

 someFile.png => 1.2K 

I'm using awk to to fetch $5(file size in human friendly format) and $9(path). Here is what I'm currently using:

 find "$somePath"  -iname "*.png" -print0 | xargs -0 ls -lh  | awk '{print $9,"=>",$5}'

Sometimes the file names or the paths have spaces and this trips the script. Here is an example output:
/Users/test/Desktop/Test/image1 => 1.2K
/Users/test/Desktop/Test/image1.png => 1.4K

The first entry in output is a file called "image1 test.png". I read somewhere that one should not parse the ls output. What's is the best way to tackle this?

Answer 1

Usually, find can be made to do what you want by using exec instead of piping the output to other programs.

find "$somePath" -iname "*.png" -printf '%p => %s\n'

If you really need human-friendly sizes, then it's slightly more complicated:

find "$somePath" -iname "*.png" -exec printf '{} => ' \; -exec sh -c 'ls -sh "{}" | cut -f1 -d\  ' \;

Note, the last one is parsing ls, but as far as I know, it's impossible for a space to show up in the first column; since we're only taking the first column here, and because we're operating on a single entry at a time (not a list), it's fine. Otherwise, you can use some other program to show the size. On BSD and Linux, you can use stat; on Solaris, you might have to write your own program to output only the size of a file.

The important part is that you can always use find to exec anything you want, passing it complete filenames - this way you're not trying to pull filenames out of a list that doesn't have good delimiters.

Answer 2

The most convenient way is to use printf from find, but it hasn't exactly the option you're looking for. %k prints the size in K, but the size, allocated on the disk, so depending on your settings, this might be always a multiple of 4k (like on my system) or something similar:

find  -name "C*.png" -printf "%f => %k \n"

CalculatorVergleich.png => 28 
ClassifierImage.png => 8 
ClassifierImage.png => 8 

There is an option with size in bytes:

find  -name "C*.png" -printf "%f => %s \n"
CalculatorVergleich.png => 26256 
ClassifierImage.png => 6313 
ClassifierImage.png => 6473 

And there is the %b for occupied 512b Blocks:

find  -name "C*.png" -printf "%f => %b  \n" 
CalculatorVergleich.png => 56  
ClassifierImage.png => 16  
ClassifierImage.png => 16  

Maybe it is useful for you? It shouldn't have problems with blanks in filenames.