Because you typed ‘a‘ and ‘\n‘… The ‘\n‘ is a result of pressing the [ENTER] key after typing into your terminal/console’s input line. The getchar() function will return each character, one at a time, until the input buffer is clear. So your loop will continue to cycle until getchar() has eaten any remaining characters from … Read more
The input is only sent to the program after you typed a newline, but scanf(“%s”, command ); leaves the newline in the input buffer, since the %s(1) format stops when the first whitespace character is encountered after some non-whitespace, getchar() then returns that newline immediately and doesn’t need to wait for further input. Your workaround … Read more
How to clear stdin before getting new input? .. so I need something with the same functionality. With portable C this is not possible. Instead suggest a different (and more usual C) paradigm: Insure previous input functions consumes all the previous input. fgets() (or *nix getline()) is the typical approach and solves most situations. Or … Read more
This code can be written more clearly as: main() { int c; while (1) { c = getchar(); // Get one character from the input if (c == EOF) { break; } // Exit the loop if we receive EOF (“end of file”) putchar(c); // Put the character to the output } } The EOF … Read more
On Unix-like systems (at least by default), an end-of-file condition is triggered by typing Ctrl-D at the beginning of a line or by typing Ctrl-D twice if you’re not at the beginning of a line. In the latter case, the last line you read will not have a ‘\n’ at the end of it; you … Read more
You need to hit Enter and then use ctrl+Z and then Enter again. or, you may also use F6
Unlike some other languages you may have used, chars in C are integers. char is just another integer type, usually 8 bits and smaller than int, but still an integer type. So, you don’t need ord() and chr() functions that exist in other languages you may have used. In C you can convert between char … Read more
To enter an EOF, use: ^Z (CtrlZ) in Windows ^D on Unix-like systems
Yes, you have to consume newlines after each input: char1 = getchar(); getchar(); // To consume `\n` char2 = getchar(); getchar(); // To consume `\n` This is not compiler-dependent. This is true for all platforms as there’ll be carriage return at the end of each input line (Although the actual line feed may vary across … Read more
The terminal driver doesn’t return anything until you hit return, even if the read() operation would accept what’s already there. To get character-by-character input from a terminal, you have to get it out of canonical mode into raw or cbreak mode, and that requires different operations altogether. Take a look at the POSIX manual on … Read more