Bash Script to replicate files

Question

I have 25 files in a directory. I need to amass 25000 files for testing purposes. I thought I could just replicate these files over and over until I get 25000 files. I could manually copy paste 1000 times but that seemed tedious. So I thought I could write a script to do it for me. I tried

cp * .

As a trial but I got an error that said the source and destination file are the same. If I were to automate it how would i do it so that each of the 1000 times the new files are made with unique names?

Answer 1

If you want to keep the extension of the files, you can use this. Assuming, you want to copy all txt -files:

#!/bin/bash

for f in *.txt
do
  for i in {1..10000}
  do
    cp "$f" "${f%.*}_${i}.${f##*.}"
  done
done

Answer 2

As discussed in the comments, you can do something like this:

for file in *
do
   filename="${file%.*}"    # get everything up to last dot
   extension="${file##*.}"  # get extension (text after last dot)
   for i in {00001..10000}
   do
       cp $file ${filename}${i}${extension}
   done
done

The trick for i in {00001..10000} is used to loop from 1 to 10000 having the number with leading zeros.

The ${filename}${i}${extension} is the same as $filename$i$extension but makes more clarity over what is a variable name and what is text. This way, you can also do ${filename}_${i}${extension} to get files like a_23.txt , etc.

In case your current files match a specific pattern, you can always do for file in a* (if they all are on the a + something format).

Answer 3

You could try this:

for file in *; do for i in {1..1000}; do cp $file $file-$i; done; done;

It will append a number to any existing files.

Answer 4

The next script

for file in *.*
do
    eval $(sed 's/\(.*\)\.\([^\.]*\)$/base="\1";ext="\2";/' <<< "$file")
    for n in {1..1000}
    do
        echo cp "$file" "$base-$n.$ext"
    done
done

will:

• take all files with extensions *.*
• creates the basename and extension ( sed )
• in a cycle 1000 times copyes the original file to file-number.extension
• it is for DRY-RUN, remove the echo if satisfied