my_ls

#include<stdio.h>
#include<dirent.h>
#include<string.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<unistd.h>
#include<pwd.h>
#include<grp.h>
#include<time.h>

/*
 * $ls -la ~
 * total 460
 * drwxr-xr-x 31 linux linux  4096 10月 27 17:27 .
 * drwxr-xr-x  3 root  root   4096  9月 22  2012 ..
 * -rw-------  1 linux linux  3126 10月  5 12:56 altvimrc
 * -rw-rw-r--  1 linux linux   102 10月 27 11:31 .apport-ignore.xml
 * -rw-------  1 linux linux 20110 10月 27 15:47 .bash_history
 * -rw-r--r--  1 linux linux   220  9月 22  2012 .bash_logout
 */
int main(int argc, const char *argv[])
{
    //打开目录流
    //循环读取其中的文件名，
    //将文件名使用stat()读取属性,并做相应解析
    //写入到文件
    DIR* dp=opendir(".");
    struct dirent* Dir;
    struct stat File;
    while(Dir=readdir(dp)){
        stat(Dir->d_name,&File);
        char prot[11]={0};
        //获取文件类型并解析
        switch (File.st_mode&S_IFMT){
        case S_IFSOCK:
            strcpy(prot,"s");
            break;
        case S_IFLNK:
            strcpy(prot,"l");
            break;
        case S_IFREG:
            strcpy(prot,"-");
            break;
        case S_IFBLK:
            strcpy(prot,"b");
            break;
        case S_IFDIR:
            strcpy(prot,"d");
            break;
        case S_IFCHR:
            strcpy(prot,"c");
            break;
        case S_IFIFO:
            strcpy(prot,"p");
            break;

        }
        //获取文件权限并解析
        //处理属主权限
        if(S_IRUSR==((File.st_mode&S_IRWXU)&S_IRUSR))
            strcat(prot,"r");
        else
            strcat(prot,"-");
        if(S_IWUSR==((File.st_mode&S_IRWXU)&S_IWUSR))
            strcat(prot,"w");
        else
            strcat(prot,"-");
        if(S_IXUSR==((File.st_mode&S_IRWXU)&S_IXUSR))
            strcat(prot,"x");
        else
            strcat(prot,"-");

        //处理属组权限
        if(S_IRGRP==((File.st_mode&S_IRWXG)&S_IRGRP))
            strcat(prot,"r");
        else
            strcat(prot,"-");
        if(S_IWGRP==((File.st_mode&S_IRWXG)&S_IWGRP))
            strcat(prot,"w");
        else
            strcat(prot,"-");
        if(S_IXGRP==((File.st_mode&S_IRWXG)&S_IXGRP))
            strcat(prot,"x");
        else
            strcat(prot,"-");

        //处理其他权限
        if(S_IROTH==((File.st_mode&S_IRWXO)&S_IROTH))
            strcat(prot,"r");
        else
            strcat(prot,"-");
        if(S_IWOTH==((File.st_mode&S_IRWXO)&S_IWOTH))
            strcat(prot,"w");
        else
            strcat(prot,"-");
        if(S_IXOTH==((File.st_mode&S_IRWXO)&S_IXOTH))
            strcat(prot,"x");
        else
            strcat(prot,"-");
        //获取文件硬链接数
        //获取文件属主的名
        struct passwd* pwd=getpwuid(File.st_uid);
        //获取文件属主的组名
        struct group* grp=getgrgid(File.st_gid);
        //获取文件的大小
        //获取文件的mtime
        struct tm* myTime;
        myTime=localtime(&File.st_mtime);
        printf("%s %d %s %s %5ld %d月 %d %02d:%02d %s\n",
                prot,
                File.st_nlink,
                pwd->pw_name,
                grp->gr_name,
                File.st_size,
                myTime->tm_mon+1,
                myTime->tm_mday,
                myTime->tm_hour,
                myTime->tm_min,
                Dir->d_name
                );
    }
    return 0;
}