transferring files from remote servers to local

Question

I am working on a project for which I'm using 30 Raspberry Pi (B) camera modules in the same network. I can take pictures from all of these simultaneously and now I want to copy these pictures from all Pi's to my local machine for further processing. I have used pscp and pslurp commands for this purpose but it returns me with error: Exited with error code 1. I used the commands like as follow;

$ pscp -h hosts.txt ~/camera/*.jpg ~/camera/*.jpg

$ pslurp -h hosts.txt -v -L ~/camera/1.jpg 2.jpg

Where hosts.txt is a file in which I have saved IP addresses of all remote machines and one camera directory is in the remote machine contains 1.jpg and later directory is in local machine. I have made public key and already saved in all remote machines so I don't need to give password flag in command. I use -v flag for verbose but it doesn't display me any information regarding error.

Any help will be much appreciated. Thanks in advance.

Answer 1

Just built this script - you can use use it with list of raspberry pi.

Prerequisite -

• You will need sshpass, you can install using $sudo apt-get install sshpass

• You will need to create a file with following entry for each raspberry pi

  ip_address password

File should look like this hostname.txt

192.168.1.1 raspberry
192.168.1.2 raspberry

Once you create this file just save the following snippet with whatever name you like e.g. raspberry_sync.sh

#!/bin/bash

filename="$1"

download_and_delete(){
  ip_address=$1
  password=$2
  sshpass -p "$password" scp "pi@$ip_address:~/camera/*" .
  sshpass -p "$password" ssh "pi@$ip_address" "rm ~/camera/*"
}

while read -r line
do
  (download_and_delete $line)&
done < "$filename"

Once you save the script raspberry_sync.sh you can run it with parameter hostname.txt

• Give execute access to file $chmod +x raspberry_sync.sh
• Runt the script with hostname.txt as param ./raspberry_sync.sh hostname.txt

Happy Coding!! Cheers!!

Answer 2

I suggest you use SCP instead. Here are a few examples:

scp picture1.jpeg [email protected]:/home/remoteuser/place

Specifying a port with SCP

scp -P 1337 picture1.jpeg [email protected]:/home/remoteuser/place

Send files FROM remote host to local:

scp [email protected]:/home/remoteuser/place/picture2.jpg /home/localuser

You could always check

man scp

for mor information

Answer 3

I have a sample shell script below . You may tweak this as per your need. Since you mentioned you already have a host file and you have keys to access the pi's without password

I expected that your hosts.txt will be as below

10.17.36.133
10.17.36.134

Script

dt=`date +%d%m%Y`
for ipaddr in `cat hosts.txt`
do
    dirname=echo "$ipaddr-$dt"|sed 's/\./_/g'
    [ -d foo ] || mkdir $dirname
    echo "starting transfer:" $ipaddr
    scp <userid>@$ipaddr:<source path> <destpath>/$dirname
    echo "completed"
done

Let me know if you have questions