linux ls 源码 (自写)

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <pwd.h>
#include <grp.h>
#include <glob.h>
#define BUFSIZE 1024
static int is_dot_dir(const char *path)
{
    char *p = NULL;

    p = strrchr(path, '.');
    if (p != NULL) {
        if (!strcmp(p, ".") || !strcmp(p, "..") || !strcmp(p,"./"))
            return 1;
    }

    return 0;
}

static int myino(const char *path)
{
    DIR *dp = NULL;
    struct dirent *entry = NULL;
    char buf[BUFSIZE]={};
    dp = opendir(path);
    int i;
    if (dp == NULL)
    {
        perror("opendir()");
        return 1;
    }
    while (1)
    {
        entry = readdir(dp);
        if (entry == NULL)
        {
            if (errno)
            {
                perror("readdir()");
                goto ERROR;
            }
            break;
        }

        if(!is_dot_dir(entry->d_name))
        {
            strcpy(buf,entry->d_name);
            printf("     %ld %s",entry->d_ino,buf);
        }

    }
        printf("\n");


ERROR:
    closedir(dp);
    return 1;

}


static int mypath(const char *path)
{
    struct stat mystat;
    if (lstat(path, &mystat) == -1)
    {
        perror("stat()");
        return 1;
    }

    
    switch(mystat.st_mode & S_IFMT)// 类型
    {
        case S_IFREG:
            printf("-");
            break;
        case S_IFDIR:
            putchar('d');
            break;
        default:
            break;
    }
    
    
    if (mystat.st_mode & S_IRUSR)// 权限
        putchar('r');
    else
        putchar('-');
    if (mystat.st_mode & S_IWUSR)
        putchar('w');
    else 
        putchar('-');
    if (mystat.st_mode & S_IXUSR)
    {
        if (mystat.st_mode & S_ISUID) 
        {
            putchar('s');
        } else 
            putchar('x');
    } else
        putchar('-');

    
    printf(" %ld ", mystat.st_nlink);// 硬链接

    // 文件拥有者名
    struct passwd *pwd = NULL; 
    pwd = getpwuid(mystat.st_uid);
    printf("%s ", pwd->pw_name);

    // 文件所属组
    struct group *grp = NULL;
    grp = getgrgid(mystat.st_gid);
    printf("%s ", grp->gr_name);

    // 总字节个数 磁盘空间大小st_blocks/2 k
    printf("%ld ", mystat.st_size);

    // 获取文件时间 atime mtime ctime
    struct tm *tmp = NULL;
    tmp = localtime(&mystat.st_mtim.tv_sec);//将时间错转换成已分解的结构体
    // if error
    char buf[BUFSIZE] = {};
    strftime(buf, BUFSIZE, "%m月  %d %H:%M", tmp);
    printf("%s ", buf);

    // 文件名
    printf("%s ", path);

    putchar('\n');
    return 0;
}

static int mydir(const char *path)
{

    DIR *dp = NULL;
    struct dirent *entry = NULL;
    char buf[BUFSIZE]={};
    dp = opendir(path);
    if (dp == NULL)
    {
        perror("opendir()");
        return 1;
    }
    while (1)
    {
        entry = readdir(dp);
        if (entry == NULL)
        {
            if (errno)
            {
                perror("readdir()");
                goto ERROR;
            }
            break;
        }


            printf("%s ", entry->d_name);

    }
            printf("\n");

    closedir(dp);
    return 0;

ERROR:
    closedir(dp);
    return 1;
            
}



static int myndir(const char *path)
{

    DIR *dp = NULL;
    struct dirent *entry = NULL;
    char buf[BUFSIZE]={};
    dp = opendir(path);
    if (dp == NULL)
    {
        perror("opendir()");
        return 1;
    }
    while (1)
    {
        entry = readdir(dp);
        if (entry == NULL)
        {
            if (errno)
            {
                perror("readdir()");
                goto ERROR;
            }
            break;
        }
        if(!is_dot_dir(entry->d_name))
        {
            strcpy(buf,entry->d_name);
            printf("%s ",buf);
        }

            

    }
            printf("\n");

    closedir(dp);
    return 0;

ERROR:
    closedir(dp);
    return 1;
            
}
            

int main(int argc, char **argv)
{
    if(argc < 2)
        return 1;
    char *optstring = "-l:a:i:h:";
    int c;

    while (1) {
        c = getopt(argc, argv, optstring);    
        if (c == -1)
            break;
        switch (c) {
            case 'l':
                mypath(argv[2]);//显示文件的详细信息
        
                break;
            case 'a':
                mydir(argv[2]);//显示目录文件名(带隐藏文件)
                
                break;
            case 'i':
                myino(argv[2]);//显示文件的inod号
                break;
            case 'h':
                myndir(argv[2]);//显示目录名(不带隐藏文件)
                    break;
            case '?':
                printf("不认识此选项%s\n", argv[optind-1]);
                break;
            case 1:
                printf("非选项参数%s\n", argv[optind-1]);
                break;
            default:
                break;
        }
    }

    return 0;

}