- #include <stdio.h>
-
#include <sys/types.h>
-
#include <dirent.h>
-
#include <sys/stat.h>
-
#include <string.h>
-
#include <time.h>
-
#include <pwd.h>
-
#include <grp.h>
-
-
void do_ls(char[]);
-
void do_stat(char*);
-
void show_file_info(char*, struct stat*);
-
void mode_str(int, char[]);
-
char *uid_str(uid_t);
-
char *gid_str(gid_t);
-
-
int main(int argc, char *argv[])
-
{
-
if(argc == 1)
-
do_ls(".");
-
else
-
while(--argc){
-
printf("%s:\n", *++argv);
-
do_ls(*argv);
-
}
-
-
return 0;
-
}
-
void do_ls(char dirname[])
-
{
-
DIR *dir_ptr; /* the directory */
-
struct dirent *direntp; /* each entry */
-
char full_path[256];
-
-
if((dir_ptr = opendir(dirname)) == NULL){
-
fprintf(stderr, "ls2: cannot open %s\n", dirname);
-
}else{
-
while((direntp = readdir(dir_ptr)) != NULL){
-
strcpy(full_path, dirname);
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int dir_len = strlen(dirname);
-
if(dirname[dir_len - 1] != '/'){ /* 處理目錄字符串最后沒有‘/’的情況 */
-
full_path[dir_len] = '/';
-
strcpy(full_path + dir_len + 1, direntp->d_name);
-
}else
-
strcpy(full_path + dir_len, direntp->d_name);
-
-
do_stat(full_path);
-
}
-
closedir(dir_ptr);
-
}
- }
-
void do_stat(char *filename) /* 獲得目錄中文件的相關(guān)信息 */
-
{
-
struct stat info;
-
- /* 如果filename最后沒有‘/’的話，stat調(diào)用失敗 */
-
if(stat(filename, &info) == -1){ /* cannot stat */
-
perror("stat"); /* say why */
-
printf("filename:%s\n", filename);
-
}else{
-
char *pname = strrchr(filename, '/');
-
show_file_info(pname + 1, &info);
-
}
-
}
-
-
void show_file_info(char *filename, struct stat *info_p) /* 打印文件的相關(guān)信息 */
-
{
-
char modestr[11];
-
-
mode_str(info_p->st_mode, modestr);
-
-
printf("%s", modestr);
-
printf("%3d ", (int)info_p->st_nlink);
-
printf("%-8s", uid_str(info_p->st_uid));
-
printf("%-8s", gid_str(info_p->st_gid));
-
printf("%4ld ", (long)info_p->st_size);
-
printf("%.12s ", 4 + ctime(&info_p->st_mtime));
-
printf("%s\n", filename);
-
}
-
-
void mode_str(int mode, char str[]) /* 將文件的相關(guān)信息轉(zhuǎn)化成 “crw-rw---"的形式 */
-
{
-
strcpy(str, "----------"); /* default = no perms */
-
if(S_ISDIR(mode)) str[0] = 'd'; /* directory */
-
if(S_ISCHR(mode)) str[0] = 'c'; /* char device */
-
if(S_ISBLK(mode)) str[0] = 'b'; /* block device */
-
if(S_ISLNK(mode)) str[0] = 'l';
-
-
if(mode & S_IRUSR) str[1] = 'r'; /* 3 bits for user */
-
if(mode & S_IWUSR) str[2] = 'w';
-
if(mode & S_IXUSR) str[3] = 'x';
-
-
if(mode & S_IRGRP) str[4] = 'r'; /* 3 bits for group */
-
if(mode & S_IWGRP) str[5] = 'w';
-
if(mode & S_IXGRP) str[6] = 'x';
-
-
if(mode & S_IROTH) str[7] = 'r'; /* 3 bits for other */
-
if(mode & S_IWOTH) str[8] = 'w';
-
if(mode & S_IXOTH) str[9] = 'x';
-
}
-
-
char *uid_str(uid_t uid) /* 將uid轉(zhuǎn)化成username */
-
{
-
static char numstr[10];
-
struct passwd *pw_ptr;
-
-
if((pw_ptr = getpwuid(uid)) == NULL){
-
sprintf(numstr, "%d", uid);
-
return numstr;
-
}else
-
return pw_ptr->pw_name;
-
}
-
char *gid_str(gid_t gid) /* 將gid轉(zhuǎn)化成groupname */
-
{
-
static char numstr[10];
-
struct group *grp_ptr;
-
-
if((grp_ptr = getgrgid(gid)) == NULL){
-
sprintf(numstr, "% d", gid);
-
return numstr;
-
}else
-
return grp_ptr->gr_name;
-
}
編譯和運(yùn)行結(jié)果： digdeep@ubuntu:~/uulp$ gcc -Wall -o ls1 ls1.c digdeep@ubuntu:~/uulp$ ./ls1 /etc/network/ /etc/network/: drwxr-x--- 2 root root 4096 Apr 26 07:03 if-down.d drwxr-x--- 2 root root 4096 Jul 14 10:47 if-up.d drwxr-x--- 2 root root 4096 Apr 26 07:05 if-pre-up.d drwxr-x--- 6 root root 4096 Jun 14 05:34 . drwxr-x--- 2 root root 4096 Apr 26 07:05 if-post-down.d -rwrr----- 1 root root 196 Jun 14 05:33 interfaces drwxr-x---147 root root 12288 Sep 19 20:33 .. |
