命名管道

#include<sys/types.h>

#include<sys/stat.h>

#include<unistd.h>

#include<fcntl.h>

int main(void)

{

char buf[80];

int fd;

unlink( "zieckey_fifo" );

mkfifo( "zieckey_fifo", 0777 );

if ( fork() > 0 )

{

char s[] = "Hello!\n";

fd = open( "zieckey_fifo", O_WRONLY );

write( fd, s, sizeof(s) );

//close( fd );

}

else

{

fd = open( "zieckey_fifo", O_RDONLY );

read( fd, buf, sizeof(buf) );

printf("The message from the pipe is:%s\n", buf );

//close( fd );

}

return 0;

}

1. 创建命名管道

#include<sys/types.h>

#include<sys/stat.h>

#include<unistd.h>

#include<fcntl.h>

int main(void)

{

char buf[80];

int fd;

unlink( "zieckey_fifo" );

mkfifo( "zieckey_fifo", 0777 );

}

2. 写命名管道代码

#include<sys/types.h>

#include<sys/stat.h>

#include<unistd.h>

#include<fcntl.h>

int main(void){

int fd;

char s[] = "Hello!\n";

fd = open( "zieckey_fifo", O_WRONLY );

while(1) {

write( fd, s, sizeof(s) );

sleep(1);

}

return 0;

}

3. 读命名管道代码

#include<sys/types.h>

#include<sys/stat.h>

#include<unistd.h>

#include<fcntl.h>

int main(void){

int fd;

char buf[80];

fd = open( "zieckey_fifo", O_RDONLY );

while(1) {

read( fd, buf, sizeof(buf) );

printf("%s\n", buf);

sleep(1);

}

return 0;

}

下面通过例子来说明该命令的用法：
创建一fifo
[root@localhost ~]# mkfifo -m 777  myfifo
将cat命令的输出作为此myfifo的输入，并放在后台运行
[root@localhost ~]# cat /etc/passwd > myfifo &
[10] 6285
再用cut命令从该myfifo中读出数据进行处理
[root@localhost ~]# cut -d: -f1-3 < myfifo