问题
I'm currently setting up a node.js server and I'm using the debug module here https://github.com/visionmedia/debug.
I'm trying to enable it so I can get the colored debugging information in my output, however my terminal looks like the last terminal screen at the bottom after it says:
When stdout is not a TTY, Date#toUTCString() is used, making it more useful for logging the debug information as shown below:
Can anyone shed some light on this? Thanks.
回答1:
tty is one of those funky Unix commands that prints (or, displays) to standard output the name of the terminal connected to standard input.
These are commonly used as a way to get access to the computer to fix things, without actually logging into a possibly b0rked desktop.
Related: What is tty7 in the commandline?
By default Ubuntu has 7 tty's.
1-6 are command line only, 7 runs your X session (your normal desktop).
To access them, use this keyboard shortcut:
Ctrl + Alt + F1
(changing F1 to F1-F6 to access the terminal that you need)
To get back to your X session (the normal desktop),
Ctrl + Alt + F7
回答2:
The TTY is the terminal or command prompt itself.
The screenshots are demonstrating the different results when stdout is directed to the terminal/TTY (with colors and time diffs) vs. when it's redirected elsewhere, such as to a file (via > out and with timestamps).
It determines which format to use with tty.isatty.
Note that not all terminals support the ANSI escape codes it's using to display colors.
来源：https://stackoverflow.com/questions/13388704/what-is-a-tty-and-how-can-i-enable-it-on-ubuntu