如何在Bash脚本中显示两个文件的差异？

Question

我正在尝试比较bash脚本中两个文件的内容.

local_file=$(cat my_local_file.txt)
remote_file=$(curl -s "http://example.com/remote-file.txt")

if [ local_file == remote_file ]; then
  echo "Files are the same"
else
  echo "Files are different. Here is the diff:"
  diff <(echo "$local_file") <(echo "$remote_file")
fi

当我运行脚本时,我发现我有一个语法错误:

./bin/check_files.sh: line 8: syntax error near unexpected token `('
./bin/check_files.sh: line 8: `  diff <(echo "$local_file") <(echo "$remote_file")'

我究竟做错了什么？如何从bash脚本中显示这两个字符串的差异？

Answer 1

进程替换是一种bash功能,通常不/bin/sh支持与POSIX兼容.

如果要将脚本作为可执行文件运行,请确保使用以下shebang行:

#!/bin/bash

代替

#!/bin/sh

或使用

bash script.sh

代替

sh script.sh

如果你这样运行它

为了使脚本适用于POSIX符合shell,我只需下载该文件并将其与本地文件进行比较.差异后删除下载的文件.