android-copy-backups/home/.termux/tasker/android-copy-backups.sh

#!/bin/bash

declare thisScriptCallCommand thisScriptAbsPath thisScriptFileName thisScriptBaseName
thisScriptCallCommand="${BASH_SOURCE[0]}"
thisScriptAbsPath="$(realpath -s "${thisScriptCallCommand}" 2>/dev/null || { pushd "$(dirname "${0}")" &>/dev/null || exit 1; echo -n "$(cd "$(dirname "${0}")"
&>/dev/null || true; pwd -P)/$(basename "${BASH_SOURCE[0]}")"; })"
thisScriptFileName=$(basename "${thisScriptAbsPath}")
thisScriptBaseName="${thisScriptFileName%\.*}"

declare lockFileDescriptor lockFileDir lockFileNameAbsPath
lockFileDescriptor='200'
lockFileDir='/data/data/com.termux/files/usr/run/lock/quico-ops/scripts'
lockFileDir="${lockFileDir%/}"'/'"${thisScriptBaseName}"
mkdir -p "${lockFileDir}"
lockFileNameAbsPath="${lockFileDir}/${thisScriptBaseName}.lock"

# Locking mechanism is pretty much
# http://www.kfirlavi.com/blog/2012/11/06/elegant-locking-of-bash-program/

# shellcheck disable=SC2120
function lock () {
    local fd="${1:-$lockFileDescriptor}"

    # Create lock file
    eval "exec ${fd}> ${lockFileNameAbsPath}"

    # Acquire lock
    flock -n "${fd}" && return 0 || return 1
}

function eexit () {
    local errorStr="${*}"
    echo "${errorStr}"
    exit 1
}

lock || eexit "Only one instance of ${thisScriptAbsPath} can run at a time."

function cleanup () {
    rm -f "${lockFileNameAbsPath}" &> /dev/null
}
trap cleanup EXIT

declare target sourceDirBasePath sshFilesBaseDir sshPrivateKeyFileName sshKnownHostsFileName
declare -a sourceDirChildPathComponents

[[ ! "${1}" ]] && {
    printf -- '%s\n' 'Argument 1 is empty. Must be rsync [USER@]HOST:DEST string. Exiting 1 ...'
    exit 1
}
target="${1}"

sourceDirBasePath='/storage/3430-3833'
sourceDirBasePath="${sourceDirBasePath%/}"
sshFilesBaseDir='/data/data/com.termux/files/home/.ssh'
sshFilesBaseDir="${sshFilesBaseDir%/}"
sshPrivateKeyFileName='android-copy-backups.sh.ssh-private-key'
sshKnownHostsFileName='android-copy-backups.sh.known_hosts'

sourceDirChildPathComponents[0]='DCIM'
sourceDirChildPathComponents[1]='Signal'
sourceDirChildPathComponents[2]='User'
sourceDirChildPathComponents[3]='SwiftBackup'

for sourceDir in "${sourceDirChildPathComponents[@]}"; do
    rsync -a --delete -e 'ssh -o IdentitiesOnly=yes -o StrictHostKeyChecking=yes -o PasswordAuthentication=no -o ChallengeResponseAuthentication=no -o PubkeyAuthentication=yes -o IdentityFile='"${sshFilesBaseDir}"'/'"${sshPrivateKeyFileName}"' -o UserKnownHostsFile='"${sshFilesBaseDir}"'/'"${sshKnownHostsFileName}" "${sourceDirBasePath}"'/'"${sourceDir%/}" "${target}"'/'
    if [[ "${?}" -eq '0' ]]; then
        printf -- '%s\n' 'Successfully copied '"'${sourceDir}'"' data'
    fi
done