在macOS shell脚本上转义空格

Question

在使用macOS内置rsync版本(rsync版本2.6.9协议版本29)在macOS上运行以下脚本时，我运行了一个问题。

该脚本将一些文件和文件夹备份到my dropbox中的特定文件夹，并由plist macOS启动守护程序在特定时间运行。

#!/bin/bash

# Halt the script on any errors.
set -e

target_path="/Users/alex/Dropbox/backup"

# Create the target path if it doesn't exist.
mkdir -p "${target_path}"

# A list of absolute paths to backup.
things3="${HOME}/Library/Containers/com.culturedcode.ThingsMac/Data/Library/Application Support/Cultured Code/Things/Things.sqlite3"

include_paths=(
  "${HOME}/.ssh"
  "$things3"
  # [...]
)

# A list of folder names and files to exclude.
exclude_paths=(
  # [...]
)

# rsync allows you to exclude certain paths.
for item in "${exclude_paths[@]}"
do
  exclude_flags="${exclude_flags} --exclude='"${item}"'"
done

# rsync allows you to pass in a list of paths to copy.
for item in "${include_paths[@]}"
do
  include_args="${include_args} --include='"${item}"'"
done


# Finally, we just run rsync
rsync -avR --dry-run ${exclude_flags} ${include_args} ${target_path}

我正面临以下错误，你知道为什么会发生这个问题吗？

building file list ... rsync: link_stat "/Users/alex/Dropbox/bin/" failed: No such file or directory (2) rsync: 
link_stat "/Users/alex/bin/ --include='/Users/alex/.ssh' --include='/Users/alex/Library/Containers/com.culturedcode.ThingsMac/Data/Library/Application Support/Cultured Code/Things/Things.sqlite3'" failed: No such file or directory (2) done

sent 29 bytes  received 20 bytes  98.00 bytes/sec total size is 0  speedup is 0.00 rsync error: some files could not be transferred (code 23) at /BuildRoot/Library/Caches/com.apple.xbs/Sources/rsync/rsync-52.200.1/rsync/main.c(996) [sender=2.6.9]

谢谢。

Answer 1

也可以对*_flags值使用数组。添加到字符串中的引号不会转义空格；这些引号是数据的文字部分，而不是shell语法，在无引号的参数展开之后。

for item in "${exclude_paths[@]}"; do
  exclude_flags+=(--exclude "$item")
done

for item in "${include_paths[@]}"; do
  include_flags+=(--include "$item")
done

rsync -avR --dry-run "${exclude_flags[@]}" "${include_args[@]}" "${target_path}"