p2-10.c

SUN Solaris8平台下进程间通信

#include <stdio.h>
#include <stdlib.h>
#include "err_exit.h"
char buf[132];
int get_line(char *,int size, FILE *);     /* 程序2－8 */
int main(void)
{
    FILE *fd;
    /* 创建一个文件并写入二行数据 */
    if ((fd = fopen("test_file","w+")) == NULL)
        err_exit("fopen faild");
    fprintf(fd,"this is first line.\n");
    fprintf(fd,"this is second line.\n");
    fclose(fd);
    /* 再次打开该文件读写数据*/
    if ((fd = fopen("test_file","r+")) == NULL)
        err_exit("fopen faild");
    /* 读一行数据 */
    get_line(buf, sizeof(buf), fd);
    /* 由读变为写 */
    /* fflush(fd); */ 
    fprintf(fd,"I hope this line become the new second line.\n");
    /* 由写变为读 */
    /* fflush(fd); */  
    get_line(buf, sizeof(buf), fd);
    fclose(fd);
}