Some basic concepts and basic concepts of Innovation

Some basic concepts and basic concepts of Innovation

1. With or without caching

System calls do not contain cache. If you use it to write programs, you need to set the cache for the programmer. database functions do not need to be cached.

2. Three-byte streams

The program automatically opens three byte streams during execution, including standard input, standard input, and standard error.

3. standard output redirection

Ls> a.txt echo LWJin> a.txt

4. Standard input redirection

Cat <a.txt> B .txt

5. Standard Error redirection

Cd void 2> a.txt

6. MPS queue

You can direct the output of the byte stream of one command to the input of another command to continuously process the byte stream.

Cat <a.txt | wc