为Mac OS X创建bash的替代品

Question

Shell是普通的CLI应用程序，还是不同于接受来自标准输入的输入并将结果输出到标准输出的应用程序？

Answer 1

A shell reads standard input, writes to standard output/error as appropriate, and executes other programs. If you are interested in what it takes to write one, I would recommend reading "UNIX Systems Programming" by Kay Robbins and Steve Robbins . I haven't read this version, the original copy was named "Practical UNIX Programming" . It does contain sections devoted to process management that include writing a very basic shell. If you haven't read "Advanced Programming in the UNIX Environment" by Stevens , then I would suggest reading it as well.

Answer 2

No, a shell just reads from stdin and outputs to stdout. Obviously it does do more than that, but that's the basics.