Copy from SD cards to another USB disk. https://wp.secretnest.info/archives/12140

sdcopy.sh

#!/bin/sh

# test and mount
function Test_n_Mount() {
	sudo mkdir $MountPointTest
	for SDDEV in /dev/sd?
	do
		for PARTITION in $SDDEV*
		do
			if [ "$PARTITION" != "$SDDEV" ]
			then
				if [ "$TargetFound" = false ] || [ "$SourceFound" = false ]
				then
					sudo mount $PARTITION $MountPointTest > /dev/null 2>&1
					if [ "$TargetFound" = false ] && test -d "$MountPointTest$TargetFolder" > /dev/null 2>&1
					then
						sudo mount $PARTITION $MountPointTarget
						TargetFound=true
						echo "Target Device: $PARTITION"
					elif [ "$SourceFound" = false ] && test -d "$MountPointTest$SourceTestFolder" > /dev/null 2>&1
					then
						sudo mount $PARTITION $MountPointSource
						SourceFound=true
						echo "Source Device: $PARTITION"
					fi
					sudo umount $MountPointTest > /dev/null 2>&1
				fi
			fi
		done
	done
	sudo rm -fr $MountPointTest
}

# sub folder
function CreateSubFolder() {
	if [ -z "$SubFolder" ]
	then
		# interactive
		while [ "$SubFolderCreated" = false ]
		do
			echo -n "Please input a folder name and press [ENTER]: "
			read TextInput
			if [ -z "$TextInput" ]
			then
				break
			fi
			SubFolder="$MountPointTarget$TargetFolder/$TextInput"
			if test -d $SubFolder > /dev/null 2>&1
			then
				AskYN "Folder exists. Resync?"
				if [ "$AskYNResult" = true ]
				then
					SubFolderCreated=true
				fi
			else
				AskYN "Folder doesn't exist. Create?"
				if [ "$AskYNResult" = true ]
				then
					sudo mkdir $SubFolder
					if test -d $SubFolder
					then
						SubFolderCreated=true
					else
						echo "Cannot create folder $SubFolder."
					fi
				fi
			fi
		done
	else
	# from argument
		SubFolder="$MountPointTarget$TargetFolder/$SubFolder"
		if test -d $SubFolder > /dev/null 2>&1
		then
			SubFolderCreated=true
		elif test -e $SubFolder > /dev/null 2>&1
		then
			echo "Cannot create folder $SubFolder. A file with the same name exists."
		else
			sudo mkdir $SubFolder
			if test -d $SubFolder
			then
				SubFolderCreated=true
			else
				echo "Cannot create folder $SubFolder."
			fi
		fi
	fi
}

# copy
function CopyData() {
	echo "Copy data to $SubFolder"
	sudo rsync -ah --progress $MountPointSource $SubFolder
	echo "done."
}

# AskYN
function AskYN() {
	echo -n "$1 (Press Y to continue, or any other key to quit): "
	read -n1 AskYNReply
	echo ""
	if [ "$AskYNReply" = "y" ] || [ "$AskYNReply" = "Y" ]
	then
		AskYNResult=true
	else
		AskYNResult=false
	fi
}

# define

MountPointTarget="/tmp/MyTargetDisk"
MountPointSource="/tmp/MySourceDisk"
MountPointTest="/tmp/MyTestDisk"
TargetFolder="/Target"
SourceTestFolder="/DCIM"

# main

TargetFound=false
SourceFound=false
SubFolderCreated=false
SubFolder=$1
sudo mkdir $MountPointTarget
sudo mkdir $MountPointSource

Test_n_Mount

if [ "$TargetFound" = true ] && [ "$SourceFound" = true ]
then
	CreateSubFolder
	if [ "$SubFolderCreated" = true ]
	then
		CopyData
	fi
else
	echo "Error: Some device is not located."
fi

# final

sudo umount $MountPointTarget
sudo umount $MountPointSource
sudo rm -fr $MountPointTarget
sudo rm -fr $MountPointSource