Move files with a certain pattern to a certain folder in bash

March 28, 2022

I have thousands of files that look like this:

6_2_S28_R1_001.fastq.gz
19_1_S160_R1_001.fastq.gz
25_3_S114_R1_001.fastq.gz

in the same directory I have the folders

rep1
rep2
rep3

I am trying to move each file to a different folder based on the prefix, second number:
6_2_S28_R1_001.fastq.gz, this file needs to be moved to rep2
19_1_S160_R1_001.fastq.gz, this file needs to be moved to rep1
25_3_S114_R1_001.fastq.gz, thus file needs to go to rep3 folder

I have tried an unsuccessful for loop.
Any help or guidance are appreciated

>Solution :

#! /bin/bash
for f in *_*_*_*_*.gz; do
    i="${f#*_}"; i="${i%%_*}"
    d="rep$i"
    echo "Move '$f' to '$d'"
    mkdir -p "$d" \
    && mv "$f" "$d"
done