answering command automatically - performing cp operation between answers [closed]

Question

The idea is that I want to execute a command, then it asks for a file name to process, and after it is done with processing, it outputs an image with the name prediction.png, it asks for the next filename and so on. I have thousands of files, so I cannot enter them manually one by one. However, I have a .txt file containing all the filenames.

So I wanted to write a bash script which:

1- execute the command

2- when it asks about a filename, it reads the first line from the txt file

3- the program will process the file, outputs an image, then cp this image to another directory (to avoid overwriting for the next file)

4- then asks for the next, do the same and so on

until the program asks for a file, and already the .txt file is done, then it terminates automatically

What I can do up till now is reading files one by one and passing them as answers for my program when it asks using

cat filenames.txt | ./program.sh

The problem, is that I want to cp the output before processing the new file

Answer 1

I don't think you can do this while running program.sh just once, as it will continue creating the files, and you can never be sure when a file is complete.

Instead run the program once for each line filenames.txt:

while IFS= read -r FILE; do # loop through files in filenames.txt
  echo "$FILE" | ./program.sh # run program once and end it with newline
  mv created_filename /some/other/location/${FILE}.ext; # move file
done < filenames.txt

• Use mv instead of cp, it will be faster if you're moving to the same file system.
• Change .ext to the output format (e.g. .png).

Answer 2

You can do it like this:

(
while IFS= read -r FILE; do
    echo "$FILE"
    sleep 1 # or somehow make a trigger to see when the file is ready ...
    mv output_file /somewhere/else
done < filenames.txt;
) | ./program.sh

(via)

---

same using xargs:

(
xargs -a filenames.txt -I{} sh -c 'echo {}; sleep 1; mv file /somewhere/else'
) | ./program.sh