Menu
Both stdin and stdout file descriptors point to it. How does it work? Can some one point to a good resource for understanding UNIX terminals and system calls that interact with it.
633
In Linux, there are two special files /dev/null and /dev/tty. / dev/null will drop all the data written to it, i.e, when program writes data to this file, it means the program has completed the data write operation.
/dev/tty0 is a alias of current(foreground) virtual console, so it could be tty1, tty2, and so on. Notice that ttyS0 is not a alias; It's the first serial port. /dev/console is the system console, it points to /dev/tty0 as a default.
/dev/console is known as the system console. Historically this was the terminal attached directly to the Linux computer. Now it provides an option to connect a serial terminal to a Linux computer.
The difference between TTY and PTS is the type of connection to the computer. TTY ports are direct connections to the computer such as a keyboard/mouse or a serial connection to the device. PTS connections are SSH connections or telnet connections.
dev/tty is a file system object that represents the current console. Copying files into this "directory" from the command line prints out the content of these files to your console:
cp myfile.txt /dev/tty is equivalent to
cat myfile.txt These objects are there to let you use the familiar file APIs to interact with console. It is a clever way to unify console API with file API. You can use fopen, fprintf, etc. to interact with the console in the same way that you interact with regular files.
This example writes "Hello, world\n" to the terminal:
#include <stdio.h> int main (int argc, const char * argv[]) { FILE *f = fopen("/dev/tty", "w"); fprintf(f, "Hello, world!\n"); return 0; } If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
