Writing an application with command line interface and I would like to know at any time if F1 or ESC or an arrow key is pressed. What is the simplest way of doing this? I would like to avoid using a readline type library.
This is a Linux specific question; the program is not multithreaded.
An implementation of kbhit() for Linux is presented in Beginning Linux Programming page 167. You can read it on-line at the link provided.
EDIT: I mention kbhit() because it was posted as a solution before it was made clear that the question related to Linux. Unfortunately the solution has been deleted, which is unfortunate. The principle is that when kbhit() returns non-zero, a subsequent blocking character-oriented read call will not block. This is only true for character oriented input; getchar() and other standard functions that read stdio are typically line-oriented, so block until newline.
There is no way to do this in the C standard, but C implementations on various operating systems usually have some extension to do this.
On Windows, you can use getch(). On Linux and Unix, look at this question:
Also, this is the very first question in the "System Dependencies" section in the C FAQ list:
Multiple threads?
来源：https://stackoverflow.com/questions/1513344/how-to-get-the-last-key-pressed-without-stopping-the-c-program