nonblockw.c

unix环境高级编程的源代码

#include    <sys/types.h>
#include    <errno.h>
#include    <fcntl.h>
#include    "ourhdr.h"

char    buf[100000];

int
main(void)
{
    int        ntowrite, nwrite;
    char    *ptr;

    ntowrite = read(STDIN_FILENO, buf, sizeof(buf));
    fprintf(stderr, "read %d bytes\n", ntowrite);

    set_fl(STDOUT_FILENO, O_NONBLOCK);    /* set nonblocking */

    for (ptr = buf; ntowrite > 0; ) {
        errno = 0;
        nwrite = write(STDOUT_FILENO, ptr, ntowrite);
        fprintf(stderr, "nwrite = %d, errno = %d\n", nwrite, errno);
        if (nwrite > 0) {
            ptr += nwrite;
            ntowrite -= nwrite;
        }
    }

    clr_fl(STDOUT_FILENO, O_NONBLOCK);    /* clear nonblocking */
    exit(0);
}