curl 命令中文件名前的@ (at) 符号是什么意思？

Question

我正在查看一个curl命令示例，该命令在文件名前使用 @ 符号将数据发布到服务器。

curl http://localhost/ --data-binary @file.txt

这是什么意思？它是否将文件的内容插入到命令中？是特定的curl吗？

Answer 1

它特定于 curl。来自man curl：

--data-binary <data>
  (HTTP) This posts data exactly as specified with no extra processing whatsoever.
  If you start the data with the letter @, the rest should be a filename.  Data is
  posted in a similar manner as --data-ascii does, except that newlines are preserved
  and conversions are never done.

  If this option is used several times, the ones following the first will append data
  as described in -d, --data.