/*********************************************************************************
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* Copyright: (C) 2025 LingYun IoT System Studio
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* All rights reserved.
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*
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* Filename: myls.c
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* Description: This file is a simple ls command implement.
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*
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* Version: 1.0.0(10/15/2025)
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* Author: Guo Wenxue <guowenxue@gmail.com>
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* ChangeLog: 1, Release initial version on "10/15/2025 11:08:39 AM"
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*
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********************************************************************************/
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <dirent.h>
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#include <string.h>
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#include <time.h>
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#include <pwd.h>
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#include <grp.h>
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#include <sys/sysmacros.h>
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// 格式化输出文件权限
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void print_permissions(mode_t mode)
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{
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printf("%c", S_ISDIR(mode) ? 'd' : S_ISLNK(mode) ? 'l' : S_ISCHR(mode) ? 'c' :
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S_ISBLK(mode) ? 'b' : S_ISFIFO(mode) ? 'p' : S_ISSOCK(mode) ? 's' : '-');
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printf("%c", mode & S_IRUSR ? 'r' : '-');
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printf("%c", mode & S_IWUSR ? 'w' : '-');
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printf("%c", mode & S_IXUSR ? 'x' : '-');
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printf("%c", mode & S_IRGRP ? 'r' : '-');
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printf("%c", mode & S_IWGRP ? 'w' : '-');
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printf("%c", mode & S_IXGRP ? 'x' : '-');
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printf("%c", mode & S_IROTH ? 'r' : '-');
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printf("%c", mode & S_IWOTH ? 'w' : '-');
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printf("%c", mode & S_IXOTH ? 'x' : '-');
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}
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// 格式化输出时间（省略年份）
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void print_time(time_t t)
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{
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char time_str[20];
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strftime(time_str, sizeof(time_str), "%b %d %H:%M", localtime(&t));
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printf("%s", time_str);
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}
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// 输出单个文件的详细信息
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void print_file_info(const char *path)
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{
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struct stat sb;
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if (lstat(path, &sb) == -1)
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{
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perror("lstat");
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return;
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}
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// 文件权限
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print_permissions(sb.st_mode);
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printf(" ");
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// 硬链接数
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printf("%ld ", (long)sb.st_nlink);
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// 所有者用户名
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struct passwd *pw = getpwuid(sb.st_uid);
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printf("%s ", pw ? pw->pw_name : "?");
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// 组名
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struct group *gr = getgrgid(sb.st_gid);
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printf("%s ", gr ? gr->gr_name : "?");
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// 文件大小
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if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode))
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{
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printf("%4d,%4d ", major(sb.st_rdev), minor(sb.st_rdev)); // 设备文件
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}
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else
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{
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printf("%8ld ", (long)sb.st_size); // 普通文件
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}
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// 修改时间
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print_time(sb.st_mtime);
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printf(" ");
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// 文件名
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printf("%s", path);
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// 如果是符号链接，打印链接目标
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if (S_ISLNK(sb.st_mode))
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{
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char target[1024];
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ssize_t len = readlink(path, target, sizeof(target) - 1);
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if (len != -1)
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{
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target[len] = '\0';
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printf(" -> %s", target);
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}
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}
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printf("\n");
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}
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// 处理目录或文件
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void process_path(const char *path)
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{
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struct stat sb;
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if (stat(path, &sb) == -1)
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{
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perror("stat");
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return;
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}
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if (S_ISDIR(sb.st_mode))
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{
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// 如果是目录，遍历其内容
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DIR *dir = opendir(path);
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if (!dir)
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{
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perror("opendir");
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return;
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}
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struct dirent *entry;
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while ((entry = readdir(dir)) != NULL)
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{
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if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
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{
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continue; // 跳过 . 和 ..
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}
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char full_path[1024];
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snprintf(full_path, sizeof(full_path), "%s/%s", path, entry->d_name);
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print_file_info(full_path);
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}
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closedir(dir);
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}
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else
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{
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// 如果是文件，直接输出信息
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print_file_info(path);
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}
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}
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int main(int argc, char *argv[])
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{
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if (argc < 2)
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{
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process_path("."); // 默认输出当前目录
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}
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else
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{
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for (int i = 1; i < argc; i++) // 处理每个参数
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{
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process_path(argv[i]);
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}
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}
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return 0;
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}
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