Bash script to create sequential, numbered directories

ericcarlson · 01-18-2008, 04:34 AM

Hi, I am working on a backup system which needs to create numbered sub dirs for each run. For example, when first run it creates one called "1", next time "2" etc. So it needs to detect how many of these numbered dirs are present, increment that count and call mkdir using it. Thanks.

homey · 01-18-2008, 05:08 AM

Something like this?

Code:

#!/bin/bash

cd /home/images
n=0
for i in $(ls) ; do
let n=$n+1
done
let n=$n+1
mkdir "dir$n"

colucix · 01-18-2008, 05:19 AM

I'd suggest to write numbered directories padded with zeros, e.g. 0001, 0002, 0003... instead of 1, 2, 3. In this way they will be sorted sequentially.

It also will be simplier to check the last one and create the new directory at each run. For example:

Code:

#!/bin/bash
# -------------------------------------------------------
#  find last created directory: format NNNN
# -------------------------------------------------------
lastdir=$(ls -d [0-9][0-9][0-9][0-9] | tail -1)

# -------------------------------------------------------
#  create new sequential directory
# -------------------------------------------------------
newdir=$((++lastdir))
mkdir $(printf "%04u" $newdir)

ericcarlson · 01-18-2008, 07:20 AM

Very helpful, cheers.!

Trap · 01-08-2010, 09:43 AM

I am perplexed. I have a situation where I have a folder named parts. In parts I have numerous subfolders labeled sprocket1, sprocket2, spoke1, spoke2, spoke3, rim1, rim2, etc.

I need to occasionally create new sequential subfolders via a bash script. I can't seem to adjust either of the scripts in this thread to do that.

Let's say I need to create a sequential spoke subfolder. As listed above, we know that would be spoke3. But let's say we don't know what the sequence number is for the last created spoke subfolder. How can I determine that via bash and create a new subfolder in sequence?