基本实现了Linux下的ls -l命令,对于不同的文件显示不同的颜色和显示符号链接暂时没有实现:
1 /************************************************************************* 2 > File Name: dirwalk.c 3 > Author: 4 > Mail: 5 > Created Time: Tue 31 Mar 2015 11:56:38 AM CST 6 ************************************************************************/ 7 8 #include9 #include 10 #include 11 #include 12 #include 13 #include 14 #include 15 #include 16 #include 17 18 #define MAX_PATH 1024 19 #define MODE_LEN 10 20 #define TIME_LEN 20 21 #define NAME_LEN 30 22 23 unsigned long ugo_mode[9] = {S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IWGRP, S_IXGRP, S_IROTH, S_IWOTH, S_IXOTH}; 24 char* rwx[3] = { "r", "w", "x"}; 25 char* userpath = "/etc/passwd"; 26 char* grouppath = "/etc/group"; 27 28 /*dirwalk: apply fcn to all files in dir */ 29 void dirwalk(char* dir, void(*fcn)(char*)) 30 { 31 struct dirent *dp; 32 DIR* dfd; 33 34 char name[MAX_PATH]; 35 if((dfd = opendir(dir)) == NULL) 36 { 37 fprintf(stderr, "dirwalk: can't open %s\n", dir); 38 return; 39 } 40 41 while((dp = readdir(dfd)) != NULL) 42 { 43 if(strcmp(dp->d_name, ".") == 0 || strcmp(dp->d_name, "..") == 0) 44 { 45 continue; 46 } 47 48 if(strlen(dir) + strlen(dp->d_name) + 2 > sizeof(name)) 49 { 50 fprintf(stderr, "%s/%s too long\n", dir, dp->d_name); 51 }else 52 { 53 sprintf(name, "%s/%s", dir, dp->d_name); 54 (*fcn)(name); 55 } 56 } 57 closedir(dfd); 58 } 59 60 /*getname: get the name of the user and the name of the group name */ 61 void getname(char* path, int id, char* name) 62 { 63 64 int fd, save_fd; 65 if((fd = open(path, O_RDONLY)) < 0) 66 { 67 perror("open \n"); 68 exit(1); 69 } 70 71 save_fd = dup(STDIN_FILENO); 72 dup2(fd, STDIN_FILENO); 73 close(fd); 74 char p[MAX_PATH]; 75 char usrid[20]; 76 sprintf(usrid, "%d", id); 77 char* puid; 78 while((scanf("%s", p)) != EOF) 79 { 80 if((puid = strstr(p, usrid)) != NULL) 81 { 82 char* pFlag; 83 char* pResult; 84 if((pFlag = strstr(p, ":")) != NULL) 85 { 86 pResult = pFlag; 87 pFlag = strstr(pFlag + 1, ":"); 88 } 89 if(pFlag != NULL) 90 { 91 if((memcmp(pFlag + 1, puid, strlen(usrid))) == 0) 92 { 93 *pResult = '\0'; 94 strcpy(name, p); 95 } 96 } 97 //printf("%s\n", puid); 98 } 99 }100 101 dup2(save_fd, STDIN_FILENO);102 close(save_fd);103 }104 105 /*getmode: get the mode of a file in string format by st_mode */106 void getmode(unsigned long st_mode, char* mode)107 {108 switch(st_mode & S_IFMT)109 {110 case S_IFDIR:111 mode[0] = 'd';112 break;113 case S_IFIFO:114 mode[0] = 'p';115 break;116 case S_IFBLK:117 mode[0] = 'b';118 break;119 case S_IFCHR:120 mode[0] = 'c';121 break;122 case S_IFREG:123 mode[0] = '-';124 break;125 case S_IFLNK:126 mode[0] = 'l';127 break;128 case S_IFSOCK:129 mode[0] = 's';130 break;131 default:132 mode[0] = 'u';133 break;134 }135 136 int i;137 for(i = 0; i < 9; ++i)138 {139 if(st_mode & ugo_mode[i])140 {141 strcat(mode, rwx[i % 3]);142 }else143 {144 strcat(mode, "-");145 }146 }147 }148 149 150 /*gettime: get the time in string format */151 void gettime(const time_t ct, char* time)152 {153 char* tmp = ctime(&ct);154 time[0] = tmp[4];155 time[1] = tmp[5];156 time[2] = tmp[6];157 time[3] = ' ';158 159 struct tm* tm_buf = gmtime(&ct);160 char last[20];161 sprintf(last, "%02d %02d:%02d", tm_buf->tm_mday, tm_buf->tm_hour, tm_buf->tm_min);162 strcat(time, last);163 }164 165 /* print the file name and the size of the "name" */166 void fsize(char* name)167 {168 struct stat st_buf;169 if(stat(name, &st_buf) < 0)170 {171 fprintf(stderr, "fsize: can't access %s\n", name);172 return;173 }174 175 176 177 if((st_buf.st_mode & S_IFMT) == S_IFDIR)178 {179 dirwalk(name, fsize);180 }181 char* time = (char*)malloc(sizeof(char) * TIME_LEN);182 memset(time, 0, TIME_LEN);183 gettime(st_buf.st_atime, time);184 185 char* mode = (char*)malloc(sizeof(char) * MODE_LEN);186 memset(mode, 0, MODE_LEN);187 getmode(st_buf.st_mode, mode);188 189 190 char* username = (char*)malloc(sizeof(char) * NAME_LEN);191 memset(username, 0, NAME_LEN);192 getname(userpath, st_buf.st_uid, username);193 194 char* groupname = (char*)malloc(sizeof(char) * NAME_LEN);195 memset(groupname, 0, NAME_LEN);196 getname(grouppath, st_buf.st_gid, groupname);197 198 printf("%s %d %s %s %4ld %s %s\n", mode, (int)st_buf.st_nlink, username, groupname, st_buf.st_size, time, name);199 free(groupname);200 free(username);201 free(mode);202 free(time);203 }204 205 int main(int argc, char* argv[])206 {207 if(argc == 1)208 fsize(".");209 while(--argc)210 fsize(*++argv);211 return 0;