#include <stdio.h> #include <sys/types.h> #include <dirent.h> #include <sys/stat.h> #include <pwd.h> #include <grp.h> #include <unistd.h> #include <string.h> #define LS_NONE 0 #define LS_L 101 #define LS_R 102 #define LS_D 103 #define LS_I 104 #define LS_A 200 #define LS_AL (LS_A+LS_L) #define LS_AI (LS_A+LS_I) // 展示单个文件的详细信息 void show_file_info(char* filename, struct stat* info_p) { char* uid_to_name(), *ctime(), *gid_to_name(), *filemode(); void mode_to_letters(); char modestr[11]; mode_to_letters(info_p->st_mode, modestr); printf("%s", modestr); printf(" %4d", (int) info_p->st_nlink); printf(" %-8s", uid_to_name(info_p->st_uid)); printf(" %-8s", gid_to_name(info_p->st_gid)); printf(" %8ld", (long) info_p->st_size); printf(" %.12s", 4 + ctime(&info_p->st_mtime)); printf(" %s ", filename); } void 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'; } } char* uid_to_name(uid_t uid) { struct passwd* getpwuid(),* pw_ptr; static char numstr[10]; if((pw_ptr = getpwuid(uid)) == NULL) { sprintf(numstr,"%d",uid); return numstr; } else { return pw_ptr->pw_name; } } char* gid_to_name(gid_t gid) { struct group* getgrgid(),* grp_ptr; static char numstr[10]; if(( grp_ptr = getgrgid(gid)) == NULL) { sprintf(numstr,"%d",gid); return numstr; } else { return grp_ptr->gr_name; } } void do_ls(char dirname[],int mode) { DIR* dir_ptr; struct dirent* direntp; if ((dir_ptr = opendir(dirname)) == NULL) { fprintf(stderr, "ls2: cannot open %s ", dirname); } else { if(mode==LS_D) { printf("%s ", dirname); } else { char dirs[20][100]; int dir_count = 0; while ((direntp = readdir(dir_ptr)) != NULL) { if(mode < 200 && direntp->d_name[0]=='.') { continue; } char complete_d_name[200]; // 文件的完整路径 strcpy (complete_d_name,dirname); strcat (complete_d_name,"/"); strcat (complete_d_name,direntp->d_name); struct stat info; if (stat(complete_d_name, &info) == -1) { perror(complete_d_name); } else { if(mode == LS_L||mode == LS_AL) { show_file_info(direntp->d_name, &info); } else if(mode == LS_A||mode == LS_NONE||mode == LS_I||mode == LS_AI) { if(mode == LS_I||mode == LS_AI) { printf("%llu ", direntp->d_ino); } printf("%s ", direntp->d_name); } else if(mode == LS_R) { if(S_ISDIR(info.st_mode)) { printf("%s ", direntp->d_name); strcpy (dirs[dir_count],complete_d_name); dir_count++; } else { printf("%s ", direntp->d_name); } } } } if(mode == LS_R) { int i=0; printf(" "); for(;i<dir_count;i++){ printf("%s: ", dirs[i]); do_ls(dirs[i],LS_R); printf(" "); } } } closedir(dir_ptr); } } // 解析一个单词参数,如-l,-i int analyzeParam(char* input){ if(strlen(input)==2) { if(input[1]=='l') return LS_L; if(input[1]=='a') return LS_A; if(input[1]=='d') return LS_D; if(input[1]=='R') return LS_R; if(input[1]=='i') return LS_I; } else if(strlen(input)==3) { if(input[1]=='a'&& input[2]=='l') return LS_AL; if(input[1]=='a'&& input[2]=='i') return LS_AI; } return -1; } int main(int ac,char* av[]) { if(ac == 1) { do_ls(".",LS_NONE); } else { int mode = LS_NONE; // 默认为无参数ls int have_file_param = 0; // 是否有输入文件参数 while(ac>1) { ac--; av++; int calMode = analyzeParam(*av); if(calMode!=-1) { mode+=calMode; } else { have_file_param = 1; do { printf("%s: ", *av); do_ls(*av,mode); printf(" "); ac--; av++; }while(ac>=1); } } if (!have_file_param) { do_ls(".",mode); } } }