How to read multiple files at the same time under shell
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1. Reading of a single file
Under the shell script, you can read files by line in a variety of ways, as follows:
For line in `cat ${input_filename} `do echo $linedonewhile read linedo echo $linedone
< ${input_filename} 其中第二种方式是将文件重定向到标准输入中 2. 多个文件读取方法 那如何实现同时多个文件的读呢？ 我们可以继续利用bash中的文件重定向功能，将文件重定向到特定的文件描述符中，语法如下： nfilen>> filenfile
The n here represents the file descriptor of the open file file, similar to fd in other programming languages. If n is not specified, the default behavior is as follows:
Filefile # same as 0file
We can use the exec command to open the file we want to redirect:
Exec 7
