Run command on all files in directory in parallel - bash

Question

I have a directory containing multiple files. These files are coming via a network location; the source is sending these file via scp command. I have a batch command that will run for each of these incoming files; this command runs for around 5-6 hours.
I am trying to run below command in by linux box
find Documents/wget/ -maxdepth 1 -type f -exec btaudip '{}' \;
My goal is to start the batch program for all files in the directory simultaneously. but, the above command only run for one file at a time. So, for this I changed this command as below. but it failed.
find Documents/wget/ -maxdepth 1 -type f -exec btaudip '{}' & \;
How should I change the my command for this?

Answer 1

The fact is that find gathers all arguments after the -exec option up to the first semicolon and then runs (exec) the resulting command, without passing them to a shell.
With your modifications, the final command generated by find is something like:
btaudip FNAME '&'
Therefore at each run btaudip is passed two parameters: the current file name (as found by find) and an ampersand.
To achieve what you want, you need to invoke a shell to process the '&' correctly, for example by using the following command:
find Documents/wget/ -maxdepth 1 -type f -exec bash -c "btaudip '{}' &" \;

Answer 2

I don't think find has this kind of job control; it is not a shell, and while it is able to spawn shells, the shells would run in sequence. Commands run asynchronously in those shells would run in sequence as a result.
Instead, you can rewrite this as a shell loop:
for f in *; do [ -f "$f" ] || continue; btaudip "$f" & done

Answer 3

Using above suggestions and improvisong I made a script file to convert all the PDF files in a folder and move to respective folders
ConvertPDFtoJPG.sh
#!/bin/bash
sudo apt-get install poppler-utils
mkdir ConvertedJPG
for f in *
do
echo "converting" $f
pdftoppm -jpeg -rx 300 -ry 300 "$f" JPG
echo "moving converted JPG to " $f "\n"
mkdir "./ConvertedJPG/$f"
mv *.jpg "./ConvertedJPG/$f/"
done
you can create this file by opening terminal in the folder and using these commands
touch ConvertPDFtoJPG.sh
chmod ./ConvertPDFtoJPG.sh +x
gedit ./ConvertPDFtoJPG.sh
paste the code in the text editor
#!/bin/bash
sudo apt-get install poppler-utils
mkdir ConvertedJPG
for f in *
do
echo "converting" $f
pdftoppm -jpeg -rx 300 -ry 300 "$f" JPG
echo "moving converted JPG to " $f "\n"
mkdir "./ConvertedJPG/$f"
mv *.jpg "./ConvertedJPG/$f/"
done
close editor
run in terminal
./ConvertPDFtoJPG.sh