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Linux 目录操作和4中文件拷贝效率测试
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/*
1、用户输入任意目录名称，显示该目录下的文件列表信息，包括文件类型，文件权限，文件大小，文件名称
2、拷贝用户输入的文件到当前目录下
3、第二点功能，使用4种方式完成，并比较说明效率
*/
/*
struct stat {
dev_t st_dev; //文件的设备编号
ino_t st_ino; //节点
mode_t st_mode; //文件的类型和存取的权限
nlink_t st_nlink; //连到该文件的硬连接数目，刚建立的文件值为1
uid_t st_uid; //用户ID
gid_t st_gid; //组ID
dev_t st_rdev; //(设备类型)若此文件为设备文件，则为其设备编号
off_t st_size; //文件字节数(文件大小)
unsigned long st_blksize; //块大小(文件系统的I/O 缓冲区大小)
unsigned long st_blocks; //块数
time_t st_atime; //最后一次访问时间
time_t st_mtime; //最后一次修改时间
time_t st_ctime; //最后一次改变时间(指属性)
};
先前所描述的st_mode 则定义了下列数种情况：
S_IFMT 0170000 文件类型的位遮罩
S_IFSOCK 0140000 scoket
S_IFLNK 0120000 符号连接
S_IFREG 0100000 一般文件
S_IFBLK 0060000 区块装置
S_IFDIR 0040000 目录
S_IFCHR 0020000 字符装置
S_IFIFO 0010000 先进先出
S_ISUID 04000 文件的(set user-id on execution)位
S_ISGID 02000 文件的(set group-id on execution)位
S_ISVTX 01000 文件的sticky位
S_IRUSR(S_IREAD) 00400 文件所有者具可读取权限
S_IWUSR(S_IWRITE)00200 文件所有者具可写入权限
S_IXUSR(S_IEXEC) 00100 文件所有者具可执行权限
S_IRGRP 00040 用户组具可读取权限
S_IWGRP 00020 用户组具可写入权限
S_IXGRP 00010 用户组具可执行权限
S_IROTH 00004 其他用户具可读取权限
S_IWOTH 00002 其他用户具可写入权限
S_IXOTH 00001 其他用户具可执行权限
上述的文件类型在POSIX中定义了检查这些类型的宏定义：
S_ISLNK (st_mode) 判断是否为符号连接
S_ISREG (st_mode) 是否为一般文件
S_ISDIR (st_mode) 是否为目录
S_ISCHR (st_mode) 是否为字符装置文件
S_ISBLK (s3e) 是否为先进先出
S_ISSOCK (st_mode) 是否为socket
*/
#include<stdio.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/stat.h>
#include <string.h>
#include<sys/time.h>
#include<fcntl.h>
int mode_to_letters(int mode,char *str)
{
strcpy(str,"----------");
if(S_ISDIR(mode))str[0] = 'd';
if(S_ISCHR(mode))str[0] = 'c';
if(S_ISBLK(mode))str[0] = 'b';
if(mode&S_IRUSR)str[1] = 'r';
if(mode&S_IWUSR)str[2] = 'w';
if(mode&S_IXUSR)str[3] = 'x';
if(mode&S_IRGRP)str[4] = 'r';
if(mode&S_IWGRP)str[5] = 'w';
if(mode&S_IXGRP)str[6] = 'x';
if(mode&S_IROTH)str[7] = 'r';
if(mode&S_IWOTH)str[8] = 'w';
if(mode&S_IXOTH)str[9] = 'x';
return 0;
}
int dostat(const char *path)
{
struct stat info;
char modestr[16];
if(stat(path, &info)==-1)
{
printf("%s stat error\n",path);
return -1;
}
printf(" %s %ld ", path,info.st_size);
mode_to_letters(info.st_mode,modestr);
printf("%s\n",modestr);
return 0;
}
int cpchar(char *src, char *des)
{
FILE *fpsrc,*fpdes;
char ch;
fpsrc = fopen(src, "r");
if(fpsrc==NULL)
{
printf("open src fail\n");
return -1;
}
fpdes = fopen(des, "w");
if(fpdes==NULL)
{
printf("open des fail\n");
return -1;
}
while(1)
{
if((ch=fgetc(fpsrc))!=EOF)
{
fputc(ch,fpdes);
//printf("%c",ch);
}
else
{
break;
}
}
fclose(fpsrc);
fclose(fpdes);
return 0;
}
/*fgets fputs 一行*/
int cpline(char *src, char *des)
{
FILE *fpsrc,*fpdes;
char buf[1024];
fpsrc = fopen(src, "r");
if(fpsrc==NULL)
{
printf("open src fail\n");
return -1;
}
fpdes = fopen(des, "w");
if(fpdes==NULL)
{
printf("open des fail\n");
return -1;
}
while(1)
{
if(fgets(buf,1024,fpsrc)!=NULL)
{
fputs(buf,fpdes);
//printf("%s",buf);
}
else
{
break;
}
}
fclose(fpsrc);
fclose(fpdes);
return 0;
}
/*fread fwrite 一块*/
int cpblk(char *src, char *des)
{
FILE *fpsrc,*fpdes;
char buf[1024];
int num;
fpsrc = fopen(src, "r");
if(fpsrc==NULL)
{
printf("open src %s fail\n",src);
return -1;
}
fpdes = fopen(des, "w");
if(fpdes==NULL)
{
printf("open des %s fail\n",des);
return -1;
}
while(1)
{
if((num=fread(buf,sizeof(char),1024,fpsrc))>0)
{
fwrite(buf,sizeof(char),num,fpdes);
//printf("%d ",num);
}
else
{
break;
}
}
fclose(fpsrc);
fclose(fpdes);
return 0;
}
/*系统read write*/
int cp(char *src, char *des)
{
int fd1,fd2;
char buf[1024];
int nbyte;
if((fd1 = open(src, O_RDONLY)) < 0)
{
printf("open src fail!\n");
return -1;
}
if((fd2 = open(des, O_WRONLY)) < 0)
{
printf("open des fail!\n");
return -1;
}
while((nbyte = read(fd1, buf, sizeof(buf))) > 0)
{
write(fd2, buf, nbyte);
}
close(fd1);
close(fd2);
return 0;
}
int mydir(const char *dirname){
DIR *dp;
struct dirent *dir;
dp=opendir(dirname);
char path[256];
char inputfilename[256];
char pathbuf[256];
char path_getcwd[256];
int ret;
if(dp==NULL)
{
printf("open dir fail");
return -1;
}
strncpy(path,dirname,strlen(dirname)+1);
while(1)
{
dir=readdir(dp);
if(dir!=NULL)
{
//printf("%ld %s\n",dir->d_ino,dir->d_name);
strncpy(pathbuf,path,strlen(path)+1);
dostat(strcat(strcat(pathbuf,"/"),dir->d_name));
}
else
{
break;
}
}
//拷贝用户输入的文件到当前目录下
printf("please input copy file name to current dir\n");
scanf("%s",inputfilename);
strncpy(pathbuf,path,strlen(path)+1);
printf("%s\n",pathbuf);
getcwd(path_getcwd,256);
strcat(strcat(pathbuf,"/"),inputfilename);
strcat(strcat(path_getcwd,"/"),inputfilename);
struct timeval tv;
long start_time,stop_time,use_time;
gettimeofday(&tv,NULL);
//printf("tv_usec:%d\n",tv.tv_usec);
start_time=tv.tv_sec*1000+tv.tv_usec/1000;
ret=cp(pathbuf,path_getcwd);
gettimeofday(&tv,NULL);
//printf("tv_usec:%d\n",tv.tv_usec);
stop_time=tv.tv_sec*1000+tv.tv_usec/1000;
use_time=stop_time-start_time;
if(ret==0)
{
printf("cp test success! use time= %ld msec\n",use_time);
}
gettimeofday(&tv,NULL);
//printf("tv_usec:%d\n",tv.tv_usec);
start_time=tv.tv_sec*1000+tv.tv_usec/1000;
ret=cpchar(pathbuf,path_getcwd);
gettimeofday(&tv,NULL);
//printf("tv_usec:%d\n",tv.tv_usec);
stop_time=tv.tv_sec*1000+tv.tv_usec/1000;
use_time=stop_time-start_time;
if(ret==0)
{
printf("cpchar test success! use time= %ld msec\n",use_time);
}
gettimeofday(&tv,NULL);
//printf("tv_usec:%d\n",tv.tv_usec);
start_time=tv.tv_sec*1000+tv.tv_usec/1000;
ret=cpline(pathbuf,path_getcwd);
gettimeofday(&tv,NULL);
//printf("tv_usec:%d\n",tv.tv_usec);
stop_time=tv.tv_sec*1000+tv.tv_usec/1000;
use_time=stop_time-start_time;
if(ret==0)
{
printf("cpline test success! use time= %ld msec\n",use_time);
}
gettimeofday(&tv,NULL);
//printf("tv_usec:%d\n",tv.tv_usec);
start_time=tv.tv_sec*1000+tv.tv_usec/1000;
ret=cpblk(pathbuf,path_getcwd);
gettimeofday(&tv,NULL);
//printf("tv_usec:%d\n",tv.tv_usec);
stop_time=tv.tv_sec*1000+tv.tv_usec/1000;
use_time=stop_time-start_time;
if(ret==0)
{
printf("cpblk test success! use time= %ld msec\n",use_time);
}
closedir(dp);
return 0;
}
int main(int argc, char * argv[])
{
if(argc != 2)
{
printf("Input dir error\n");
return -1;
}
mydir(argv[1]);
return 0;
}
运行结果如下，read write 最快， fread fwrite次之， 之后是fputs 和fputc.
另外fputs和fputc用于非字符串文件时会有问题，深层原因还待分析。
