find and grep / zgrep / lzgrep progress bar - bash

Question

I would like to add a progress bar to this command line:
find . \( -iname "*.bz" -o -iname "*.zip" -o -iname "*.gz" -o -iname "*.rar" \) -print0 | while read -d '' file; do echo "$file"; lzgrep -a stringtosearch\.anything "$file"; done
The progress file should be calculated on the total of compressed size files (not on the single file).
Of course, it can be a script too.
I would also like to add other progress bars, if possible:
The total number of files processed (example 3 out of 21)
The percentage of progress of the single file
Can anybody help me please?
Here some example of it should look alike (example from here):
tar cf - /folder-with-big-files -P | pv -s $(du -sb /folder-with-big-files | awk '{print $1}') | gzip > big-files.tar.gz
Multiple progress bars (example from here):
pv -cN orig < foo.tar.bz2 | bzcat | pv -cN bzcat | gzip -9 | pv -cN gzip > foo.tar.gz
Thanks,

Answer 1

This is the first time I've ever heard of pv and it's not on any machine I have access to but assuming it needs to know a total at startup and then a number on each iteration of a command, you could do something like this to get a progress bar per file processed:
IFS= readarray -d '' files < <(find . -whatever -print0)
printf '%s\n' "${files[#]}" | pv -s "${#files[#]}" | command
The first line gives you an array of files so you can then use "${#files[#]}" to provide pv it's initial total value (looks like you use -s value for that?) and then do whatever you normally do to get progress as each file is processed.
I don't see any way to tell pv that the pipe it's reading from is NUL-terminated rather than newline-terminated so if your files can have newlines in their names then you'd have to figure out how to solve that problem.
To additionally get progress on a single file you might need something like:
IFS= readarray -d '' files < <(find . -whatever -print0)
printf '%s\n' "${files[#]}" |
pv -s "${#files[#]}" |
xargs -n 1 -I {} sh -c 'pv {} | command'
I don't have pv so all of the above is untested so check the syntax, especially since I've never heard of pv :-).

Answer 2

Thanks to Max C., I found a solution for the main question:
find ./ -type f -iname *\.gz -o -iname *\.bz | (tot=0;while read fname; do s=$(stat -c%s "$fname"); if [ ! -z "$s" ] ; then echo "$fname"; tot=$(($tot+$s)); fi; done; echo $tot) | tac | (read size; xargs -i{} cat "{}" | pv -s $size | lzgrep -a something -)
But this work only for gz and bz files, now I have to develop to use different tool according to extension.
I'm gonna to try the Ed solution too.

Answer 3

Thanks to ED and Max C., here the verision 0.2
This version work with zgrep, but not with lzgrep. :-\
#!/bin/bash
echo -n "collecting dump... "
IFS= readarray -d '' files < <(find . \( -iname "*.bz" -o -iname "*.gz" \) -print0)
echo done
echo "Calculating archives size..."
tot=0
for line in "${files[#]}"; do
s=$(stat -c\%s "$line")
if [ ! -z "$s" ]
then
tot=$(($tot+$s))
fi
done
(for line in "${files[#]}"; do
s=$(stat -c\%s "$line")
if [ ! -z "$s" ]
then
echo "$line"
fi
done
) | xargs -i{} sh -c 'echo Processing file: "{}" 1>&2 ; cat "{}"' | pv -s $tot | zgrep -a anything -