博客

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <dirent.h>
#include <sys/stat.h>
#include <pwd.h>
#include <grp.h>
#define NAME_SIZE 128

struct filename
{               //定义一个结构体，用于存储文件名称
    char name[NAME_SIZE];
};

void output_info(struct filename *head);           //输出所有信息
void output_mode(mode_t mode);           //输出文件权限信息
void output_user_group(uid_t uid,gid_t gid);          //输出文件所属用户名和组名
void output_mytime(time_t mytime );                 //输出文件最后一次被修改的时间

int main(int argc,char *argv[])
{
    if(argc < 2)       //判断参数个数，少于两个参数报错
    {
        fprintf(stderr,"usage:%s <pathname>",argv[0]);
        exit(EXIT_FAILURE);
    }
    int i;
    for(i = 1;i < argc;i ++)          //分别对每一个参数的文件属性进行判断
    {
        struct stat stat_info;                     //文件属性
        if(stat(argv[i],&stat_info) == -1)
        {
            printf("%s is wrong\n",argv[i] );         //参数有错误，报错，判断下一个参数属性
            continue;
        }

        if(S_ISREG(stat_info.st_mode))       //文件属性是文件类型
        {
            struct filename *temp = malloc(sizeof(struct filename));      //申明一个指针，给他分配一个struct filename大小的空间

            if(temp == NULL)
            {
                perror("malloc in regular file");
                exit(EXIT_FAILURE);
            }

            memset(temp->name,'\0',NAME_SIZE);        //初始化
            memcpy(temp->name,argv[i],strlen(argv[i]));    //将参数名称拷贝到name中
            output_info(temp);      //输出文件信息
            free(temp);    
        }

        else if(S_ISDIR(stat_info.st_mode))           //文件属性是文件夹
        {
            DIR *dirp = NULL;
            if((dirp = opendir(argv[i])) == NULL)        //打开文件夹
            {
                perror("opendir");
                exit(EXIT_FAILURE);
            }

            struct dirent *entp;          
            while((entp = readdir(dirp)) != NULL)        //依次读取文件夹内部的文件
            {
                if(strcmp(entp->d_name,".") == 0 || strcmp(entp->d_name,"..") == 0)   //如果是“.”和“..”文件，跳过
                    continue;
                struct filename *temp = malloc(sizeof(struct filename));
                if(temp == NULL)
                {
                    perror("malloc in directory");
                    exit(EXIT_FAILURE);
                }

                char *name_dir = malloc(strlen(argv[i]) + 1 + strlen(entp->d_name) + 1);   
                sprintf(name_dir,"%s/%s\0",argv[i],entp->d_name);     //将文件夹内文件的路径保存在name_dir中
                memset(temp->name,'\0',NAME_SIZE);
                memcpy(temp->name,name_dir,strlen(argv[i]) + 1 + strlen(entp->d_name) + 1);
                output_info(temp);
                free(temp);
                free(name_dir);
            }
        }
    }
    return 0;
}

void output_info(struct filename *temp)
{
    struct stat mystat;
    if(stat(temp->name,&mystat) == -1)
    {
        perror("mystat temp->name");
        exit(EXIT_FAILURE);
    }
    output_mode(mystat.st_mode);
    printf(" %ld",mystat.st_nlink);
    output_user_group(mystat.st_uid,mystat.st_gid);
    printf(" %ld",mystat.st_size );
    output_mytime(mystat.st_mtime);
    printf(" %s\n",temp->name );
}

void output_mode(mode_t mode)       
{
    char type[7] = {'p','c','d','b','-','l','s'};
    int index = (mode >>12 & 0xF) / 2;
    printf("%c",type[index] );

    char *perm[8] = {"---","--x","-w-","-wx","r--","r-x","rw-","rwx"}; //按照000，001，010，011...111排列
    printf("%s",perm[mode >> 6 & 07] );     //root用户权限
    printf("%s",perm[mode >> 3 & 07] );   //组用户权限
    printf("%s",perm[mode >> 0 & 07] );   //其他用户权限
}

void output_user_group(uid_t uid,gid_t gid)
{
    struct passwd *user;
    user = getpwuid(uid);     //通过用户ID查看用户信息
    printf(" %s",user->pw_name );        //打印用户名信息
    struct group *group;
    group = getgrgid(gid);    //通过组ID查看用户信息
    printf(" %s",group->gr_name );            //打印组名信息
}

void output_mytime(time_t mytime )
{
    char buf[128];
    memset(buf,'\0',sizeof(buf));
    memcpy(buf,ctime(&mytime),strlen(ctime(&mytime)) -1);   //打印文件最后一次被修改的时间，保存在buf中，ctime将时间转换为字符串形式
    printf(" %s",buf );
}