github.com/afumu/libc@v0.0.6/musl/src/legacy/isastream.c (about)

     1  #include <stropts.h>
     2  #include <fcntl.h>
     3  
     4  int isastream(int fd)
     5  {
     6  	return fcntl(fd, F_GETFD) < 0 ? -1 : 0;
     7  }