github.com/afumu/libc@v0.0.6/musl/src/unistd/isatty.c (about)

     1  #include <unistd.h>
     2  #include <errno.h>
     3  #include <sys/ioctl.h>
     4  #include "syscall.h"
     5  
     6  int isatty(int fd)
     7  {
     8  	struct winsize wsz;
     9  	unsigned long r = syscall(SYS_ioctl, fd, TIOCGWINSZ, &wsz);
    10  	if (r == 0) return 1;
    11  	if (errno != EBADF) errno = ENOTTY;
    12  	return 0;
    13  }