Sort and copy files from one directory to another via bash

Question

I have about 4 million extension less files in one directory.

I need a bash script to copy them into another directory such that those files will be sorted into 1000 files per directory.

Eg. source directory is /temp/hugenooffiles/

The file names are like m_100, m_1005, m_10005 , etc.

destination directory is /temp/sortedfiles/

In the destination directory, a directory named 1 should be created containing files from m_1 through m_999 .

directory 2 should be created containing files m_1000 through m_1999 and so on.

The destination files should be renamed to 1_m, 1000_m , etc.

Also, if files in destination folder already exist then they should be overwritten.

Kindly help.

Answer 1

#!/bin/bash

SOURCE='/temp/hugenooffiles'
DEST='/temp/sortedfiles'

I=0
for FILE in "$SOURCE"/m_*; do
    (( D = 1 + ++I / 1000 ))
    [[ -d $DEST/$D ]] || mkdir -p "$DEST/$D"  ## You can just skip dir checking but that would be slow.
    cp -v "$FILE" "$DEST/$D/m_$I"
done

Note: By default pathname expansions in Bash ( "$SOURCE"/m_* ) are sorted.

Answer 2

I modified konsolebox's script and it did the job. Thank you.

> #!/bin/bash
> 
> SOURCE='/temp/hugenooffiles' 
> DEST='/temp/sortedfiles'
> 
> I=0 
> for FILE in "$SOURCE"/m_*;
> do
>     (( D = (( ${FILE#*_} / 1000 )) + 1 ))
>     [[ -d $DEST/$D ]] || mkdir -p "$DEST/$D"
>     mv -v "$FILE" "$DEST/$D/${FILE#*_}_m"
>     (( ++I )) 
> done