实验

来源：互联网发布：napa软件建模案例编辑：程序博客网时间：2024/04/29 03:14

#include<sys/types.h>

#include<sys/stat.h>

#include<errno.h>

#include<fcntl.h>

#include<stdio.h>

#include<stdlib.h>

#include<limits.h>

#define MYFIFO "/tmp/myfifo" /* 有名管道文件名*/

#defineMAX_BUFFER_SIZE PIPE_BUF /*定义在于limits.h中*/

int main(intargc, char * argv[]) /*参数为即将写入的字符串*/

{

int fd;

char buff[MAX_BUFFER_SIZE];

int nwrite;

if(argc <= 1)

{

printf("Usage: ./fifo_writestring\n");

exit(1);

}

sscanf(argv[1], "%s", buff);

/* 以只写阻塞方式打开FIFO管道 */

fd = open(MYFIFO, O_WRONLY);

if (fd == -1)

{

printf("Open fifo fileerror\n");

exit(1);

}

/*向管道中写入字符串*/

if ((nwrite = write(fd, buff,MAX_BUFFER_SIZE)) > 0)

{

printf("Write '%s' toFIFO\n", buff);

}

close(fd);

exit(0);

}

(2)读管道的程序

#include<sys/types.h>

#include<sys/stat.h>

#include<errno.h>

#include<fcntl.h>

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

#include<limits.h>

#define MYFIFO "/tmp/myfifo"

#defineMAX_BUFFER_SIZE PIPE_BUF /*定义在于limits.h中*/

int main()

{

char buff[MAX_BUFFER_SIZE];

int fd;

int nread;

/* 判断有名管道是否已存在，若尚未创建，则以相应的权限创建*/

if (access(MYFIFO, F_OK) == -1)

{

if ((mkfifo(MYFIFO, 0666) < 0)&& (errno != EEXIST))

{

printf("Cannot createfifo file\n");

exit(1);

}

/* 以只读阻塞方式打开有名管道 */

fd = open(MYFIFO, O_RDONLY);

if (fd == -1)

{

printf("Open fifo fileerror\n");

exit(1);

}

while (1)

{

memset(buff, 0, sizeof(buff));

if ((nread = read(fd, buff,MAX_BUFFER_SIZE)) > 0)

{

printf("Read '%s' fromFIFO\n", buff);

}

close(fd);

exit(0);

}

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