Linux 下三种文件锁 —— fcntllockf、flock

因为文件锁的事踩了点坑（还是在生产环境），花时间了解整理了一下。以下结论基本经过 demo 验证，先简略写写结论，总结总结历史，有空再补其他的。

http://man7.org/linux/man-pages/man2/fcntl.2.html

http://man7.org/linux/man-pages/man2/flock.2.html

http://blog.csdn.net/jnu_simba/article/details/8806654

你写错了

#include <stdio.h>

#include <stdlib.h>

#include<unistd.h>

#include<sys/types.h>

#include <fcntl.h>

int main(void)

{

int fd1=0,fd2=0

int output

output=open("/root/647.txt", O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR)

if( (fd1=fork() )==0)

{

lockf(output, 1, 0)

write(output,"fd1\n",4)

sleep(2)

write(output,"fd1\n",4)

lockf(output, 0, 0)

}

else if( (fd2=fork() )==0)

{

lockf(output, 1, 0)

write(output,"fd2\n",4)

sleep(2)

write(output,"fd2\n",4)

lockf(output, 0, 0)

}

else

{

lockf(output, 1, 0)

write(output,"fd\n",3)

sleep(2)

write(output,"fd\n",3)

lockf(output, 0, 0)

}

return 0

}

结果为

fd

fd

fd2

fd2

fd1

fd1

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