p4.8.c

来自「《linux编程技术详解》 linux编程入门的好书」· C语言 代码 · 共 47 行

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(void){
        int fd1,fd2;
        
        fd1=open("test",O_CREAT | O_RDWR,0777);	
 	
	if(fd1<0){
		perror("Cannot create the test file");
		return 1;
	}
	
 	close(fd1);

        struct stat file_stat;
	
	if(stat("test",&file_stat)==-1){
		perror("Cannot get the information of the file!\n");
		return 1;
	}

	printf("Premission is : %o\n",file_stat.st_mode & 0x1ff);

	umask(S_IWGRP | S_IRGRP | S_IXGRP | S_IROTH | S_IWOTH | S_IXOTH);
	
 	fd2=open("test1",O_CREAT | O_RDWR,0777);

	if(fd2<0){
		 perror("Cannot create the test file");
	 	 return 1;
	}
	
	close(fd1);

	 if(stat("test1",&file_stat)==-1){
		 perror("Cannot get the information of the file!\n");
		 return 1;
	 }       

 	printf("After Modify umask value, Premission is : %o\n",file_stat.st_mode & 0x1ff);

	return 0;
}