Incrementing variable in Bash -sed command

Question

I have a bash script that I'm trying to put together that finds all of the images in a folder and then puts the names of those files into a pre-formatted CSV. I actually have the more complicated parts of it figured out and working well... I'm stuck on a really basic part. I have a variable that I need to increment for each file found, simple enough right? I've tried a bunch of different things and cannot for the life of me get it to increment. Here's the script I'm working with:

EDITED to show less context

i=0
find "$(pwd)" -maxdepth 1 -type f -exec file {} \; | awk -F: '{if ($2 ~/image/) print $1}' | grep -o -E '[^/]*$' | sed -e "s/^/$((++i))/" > "$(pwd)/inventory-$(date +%Y%m%d)-$(date +%I%M).csv"

I've tried incrementing it with i++ , i=+1 , i=i+1 as well as putting the dollar sign before the different iterations of the i variable... nothing seems to actually increment the variable. My best guess is that this isn't a true loop so it doesn't save the changes to the variable? Any guidance would be greatly appreciated!

Answer 1

The $((++i)) is performed by your shell. But the shell executes this line only once. This line cannot do what you need.

I would increment in inside awk , print it alongside the file name, and then combine output in the further commands.