outoflocks.c

unix环境高级编程的源代码

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

int
main(void)
{
    int        i, fd;

    if ( (fd = open("temp.lock", O_RDWR | O_CREAT | O_TRUNC,
                                                FILE_MODE)) < 0)
        err_sys("open error");

    for (i = 0; i < 1000000; i++) {    /* try to write 2 Mbytes */
                /* lock from current EOF to EOF */
        if (writew_lock(fd, 0, SEEK_END, 0) < 0)
            err_sys("writew_lock error");

        if (write(fd, &fd, 1) != 1)
            err_sys("write error");

        if (un_lock(fd, 0, SEEK_END, 0) < 0)
            err_sys("un_lock error");

        if (write(fd, &fd, 1) != 1)
            err_sys("write error");
    }
    exit(0);
}