In the Windows file refers to ordinary visible files, and Linux everything is a file https://blog.csdn.net/nan_nan_nan_nan_nan/article/details/81233599
1. Standard stream and stream read and write functions can read and write to any file
stdin 0 Standard Input
standard output stdout 1
stderr 2 standard error (error)
You can use write instead of printf, printf is also more complicated to realize the limitations of small
write (object / 0, buff, length) of the object or the target file is written using the above std printing and output to the console, buff the data is to be written, length is the size of the write
2.