I'm new to linux about ten days, and my English is not good. I'm learning the I/O redirection part.
I know when a command is successful, the screen do not display error message, and the command failed have one.
For example when I input cat file1
.
Before the command issued. What is the state of stdin, stdout and stderr?
After I issued the command. What is the state of the standard stream?
When the file1 exist. In my opinion the final input is file1 and final output is the terminal.(not sure;-0-) And I don't have a error message. So does it mean that I don't have stderr here? Or where is it?
When there is no file exist. I have just a error message. So does it mean that I don't have stdin and redirect the stderr to stdout?
Thank you who can explain this to me or give me some clue like using man-page or anything else.