perl - i命令在原地对file . txt进行修改，而perl -i.b ak则为原始文件建立一个副本，并在其名称后面添加.bak，以区别于新的、经过修改的版本。
In-place; perl -i.bak makes a copy of the original file and appends.bak to distinguish it from its new, modified version. Therefore, a command such as.
以结构拟动力试验为例，详细说明了基于计算命令控制试验系统的建立方法及试验流程。
The calculation command control method and testing flow for structural pseudo-dynamic testing were described in detail.
以结构拟动力试验为例，详细说明了基于计算命令控制试验系统的建立方法及试验流程。
The calculation command control method and testing flow for structural pseudo-dynamic testing were described in detail.
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