prog.c: In function ‘main’:
prog.c:26:5: warning: implicit declaration of function ‘getch’ [-Wimplicit-function-declaration]
getch();
^~~~~
/home/IM2cFY/ccvZELjz.o: In function `main':
prog.c:(.text.startup+0xa5): undefined reference to `getch'
collect2: error: ld returned 1 exit status