Renamed modules

modules/create_archive

@@ -0,0 +1,111 @@
+#!/bin/bash
+# This script packs a file or directory into a 7z archive with the given password.
+# It can (optionally) split the archives into volumes of a fixed size in megabytes.
+
+source functions.sh
+
+set -euo pipefail
+
+cleanup() {
+	local archive_name="$1"
+	rm -f "${archive_name}"*
+	log "INFO" "Cleaning up ${archive_name##*/} remains before exit"
+}
+
+check_input() {
+	local input_file="$1"
+	local password="$2"
+	local size="$3"
+
+	[[ -e "$input_file" ]] || { log "ERROR" "Input file '${input_file}' does not exist"; exit 2; }
+	[[ -n "${password}" ]] || { log "ERROR" "No password given"; exit 2; }
+	[[ "$size" =~ ^([1-9][0-9]*)?$ ]] || { log "ERROR" "Invalid size '$size', must be empty or a positive number"; exit 2; }
+}
+
+calc_smart_volumes() {
+	# Calculates a "smart" volume size so that each volume (including the final part)
+	# will be approximately the same size
+	local input_file="$1"
+	local size="$2"
+	local total_size num_volumes smart_size
+
+	total_size=$(du -s -BM "${input_file}" | grep -oP '^\d+') || return 1
+
+	# If total file size is smaller than volume size, don't pack it into volumes
+	(( total_size < size )) && return 1
+
+	num_volumes=$(( (total_size + size - 1) / size ))
+	smart_size=$(( (total_size + num_volumes - 1) / num_volumes ))
+
+	log "INFO" "Calculated smart volume size '$smart_size'"
+
+	echo "$smart_size"
+}
+
+get_volumes() {
+	local input_file="$1"
+	local size="${2:-}"
+	local volumes=""
+	local smart_size
+
+	if [[ -n "$size" ]]; then
+		log "INFO" "Volumes size is set to ${size}MB"
+		smart_size="$(calc_smart_volumes "$input_file" "$size" || echo -n)"
+		volumes="-v${smart_size}m"
+	fi
+
+	[[ -n "$volumes" ]] && log "INFO" "Volumes set to '$volumes'" || log "INFO" "Volumes argument unset"
+
+	echo "$volumes"
+}
+
+generate_name() {
+	# Generates a random archive name of 20 alphanumeric characters
+	local archive_name
+	archive_name="$archive_dir/$(tr -dc '[:alnum:]' < /dev/urandom | head -c 20).7z"
+
+	log "INFO" "Generated archive name '$archive_name'"
+	
+	echo "$archive_name"
+}
+
+create_archive() {
+	local input_file="$1"
+	local password="$2"
+	local volumes="$3"
+	local size="$4"
+	local archive_name="$5"
+
+	7z a -mhe=on "-p${password}" "$volumes" "$archive_name" "${input_file}"
+}
+
+main() {
+	local input_file="${1:-}"
+	local password="${2:-}"
+	local size="${3:-}"
+	local volumes archive_name archive_dir
+	archive_dir="$(dirname "$0")/../archives"
+
+	check_dependencies "7z"
+	check_input "$input_file" "$password" "$size"
+
+	mkdir -p "$archive_dir" || { log "ERROR" "Unable to create archive directory"; exit 1; }
+
+	volumes="$(get_volumes "$input_file" "$size")"
+	archive_name="$(generate_name)"
+
+	trap 'cleanup "$archive_name"' ERR INT
+
+	log "INFO" "Packing '${input_file}' into archive '$archive_name' with password '${password}'"
+
+	create_archive \
+		"$input_file" \
+		"$password" \
+		"$volumes" \
+		"$size" \
+		"$archive_name"
+
+	log "NOTICE" "Archive created"
+}
+
+main "$@"