41>>ls
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<pwd.h>
#include<grp.h>
#include<time.h>
#include<dirent.h>
#include<linux/kdev_t.h>
#define A ~(0<<1)<<0
#define B ~(0<<1)<<1
#define C ~(0<<1)<<2
#define D ~(0<<1)<<3
#define E ~(0<<1)<<4
#define F ~(0<<1)<<5
#define G ~(0<<1)<<6
#define H ~(0<<1)<<7
#define I ~(0<<1)<<8
#define J ~(0<<1)<<9
#define K ~(0<<1)<<10
#define L ~(0<<1)<<11
#define M ~(0<<1)<<12
#define N ~(0<<1)<<13
#define O ~(0<<1)<<14
#define P ~(0<<1)<<15
#define Q ~(0<<1)<<16
#define R ~(0<<1)<<17
#define S ~(0<<1)<<18
#define T ~(0<<1)<<19
#define U ~(0<<1)<<20
#define V ~(0<<1)<<21
#define W ~(0<<1)<<22
#define X ~(0<<1)<<23
#define Y ~(0<<1)<<24
#define Z ~(0<<1)<<25
#define IS_A(mode) ((mode)&(~(~0<<1)<<0))
#define IS_B(mode) ((mode)&(~(~0<<1)<<1))
#define IS_C(mode) ((mode)&(~(~0<<1)<<2))
#define IS_D(mode) ((mode)&(~(~0<<1)<<3))
#define IS_E(mode) ((mode)&(~(~0<<1)<<4))
#define IS_F(mode) ((mode)&(~(~0<<1)<<5))
#define IS_G(mode) ((mode)&(~(~0<<1)<<6))
#define IS_H(mode) ((mode)&(~(~0<<1)<<7))
#define IS_I(mode) ((mode)&(~(~0<<1)<<8))
#define IS_J(mode) ((mode)&(~(~0<<1)<<9))
#define IS_K(mode) ((mode)&(~(~0<<1)<<10))
#define IS_L(mode) ((mode)&(~(~0<<1)<<11))
#define IS_M(mode) ((mode)&(~(~0<<1)<<12))
#define IS_N(mode) ((mode)&(~(~0<<1)<<13))
#define IS_O(mode) ((mode)&(~(~0<<1)<<14))
#define IS_P(mode) ((mode)&(~(~0<<1)<<15))
#define IS_Q(mode) ((mode)&(~(~0<<1)<<16))
#define IS_R(mode) ((mode)&(~(~0<<1)<<17))
#define IS_S(mode) ((mode)&(~(~0<<1)<<18))
#define IS_T(mode) ((mode)&(~(~0<<1)<<19))
#define IS_U(mode) ((mode)&(~(~0<<1)<<20))
#define IS_V(mode) ((mode)&(~(~0<<1)<<21))
#define IS_W(moed) ((mode)&(~(~0<<1)<<22))
#define IS_X(mode) ((mode)&(~(~0<<1)<<23))
#define IS_Y(mode) ((mode)&(~(~0<<1)<<24))
#define IS_Z(mode) ((mode)&(~(~0<<1)<<25))
/* defined this struct FILEPATH mainly to deal with
* the display of file which in the sub directory
*/
typedef struct FILEPATH
{
char *full_path;
char *name;
}Fpath;
int my_get_opt(const int argc,const char **argv);
int get_file_list(const int argc,const char **argv,Fpath **file_list);
int show_dir(Fpath *file_list,const long int mode);
int show_file(Fpath *file_list,struct stat *buf,const long int mode);
int show_link_content(Fpath *file_list,struct stat *buf);
int main(int argc,char **argv)
{
int i=0;
Fpath *file_list=NULL; //get the file list from the command line and store them in a struct Fpath
int file_num=0; //the file num that get from the command line
struct stat buf;
long int mode=9; //option status
mode=my_get_opt(argc,(const char **)argv); //get the option and store the in a long int variable define in "myopt.h" file
file_num=get_file_list(argc,(const char **)argv,&file_list);
/*-------------------------------------------------------------------------------*/
/*display every file that store in the file_list*/
for(i=0;i<file_num;i++)
{
if ( lstat(file_list[i].full_path,&buf)==-1)
{
perror(file_list[i].full_path);
continue;
}
/* if file is a symbol file, read the name of its refer and
* store it in the buf point by real_path*/
if(S_ISLNK(buf.st_mode))
{
show_file((file_list+i),&buf,mode);
if( IS_L(mode) )
{
show_link_content((file_list+i),&buf);
printf("\n");
}
}
/* if file is a directory, make decision from the options
* whether display the directory itself or the files
* it contains. this is judge by a macro IS_D(mode)*/
else if( S_ISDIR(buf.st_mode))
{
if(IS_D(mode))
{
show_file((file_list+i),&buf,mode);
if(IS_L(mode))
printf("\n");
continue;
}
else
{
show_dir((file_list + i),mode);
if( IS_L(mode))
{
printf("\n");
}
}
}
else
{
show_file((file_list + i ),&buf,mode);
if( IS_L(mode))
printf("\n");
}
}
free(file_list);
if(!(IS_L(mode)))
{
printf("\n");
}
return 0;
}
int show_link_content(Fpath *file_list,struct stat *buf)
{
char real_path_buf[512]={'\0'};
char *real_path=real_path_buf;
int real_path_len=0;
if((real_path_len=readlink(file_list->full_path,real_path_buf,512))==-1)
{
perror(file_list->full_path);
return -1;
}
*(real_path + real_path_len)='\0';
printf("->%s",real_path);
return 0;
}
int show_file(Fpath *file_list,struct stat *buf,const long int mode)
{
if(IS_I(mode))
{
printf("%lu",(unsigned long)(buf->st_ino));
}
if(IS_L(mode))
{
mode_t file_mode = (*buf).st_mode;
char file_type = '\0';
/* file type */
if(S_ISREG(file_mode))
file_type='-';
else if(S_ISDIR(file_mode))
file_type='d';
else if(S_ISCHR(file_mode))
file_type='c';
else if(S_ISBLK(file_mode))
file_type='b';
else if(S_ISFIFO(file_mode))
file_type='p';
else if(S_ISSOCK(file_mode))
file_type='s';
else if(S_ISLNK(file_mode))
file_type='l';
printf("%c",file_type);
char perm_buf[10]={'-','-','-','-','-','-','-','-','-','\0'};
/*file permission */
if(file_mode & S_IRUSR)
perm_buf[0]='r';
if(file_mode & S_IWUSR)
perm_buf[1]='w';
if(file_mode & S_IXUSR)
{
if(file_mode & S_ISUID)
perm_buf[2]='s';
else
perm_buf[2]='x';
}
else
{
if(file_mode & S_ISUID)
perm_buf[2]='S';
}
if(file_mode & S_IRGRP)
perm_buf[3]='r';
if(file_mode & S_IWGRP)
perm_buf[4]='w';
if(file_mode & S_IXGRP)
{
if(file_mode & S_ISGID)
perm_buf[5]='s';
else
perm_buf[5]='x';
}
else
{
if(file_mode & S_ISGID)
perm_buf[5]='S';
}
if(file_mode & S_IROTH)
perm_buf[6]='r';
if(file_mode & S_IWOTH)
perm_buf[7]='w';
if(file_mode & S_IXOTH)
{
if(file_mode & S_ISVTX)
perm_buf[8]='t';
else
perm_buf[8]='x';
}
else
{
if(file_mode & S_ISVTX)
perm_buf[8]='T';
}
printf("%s ",perm_buf);
printf("%d ",(*buf).st_nlink);
struct passwd *passwd_file;
struct group *group_file;
/*file owner and group*/
if((passwd_file=getpwuid((*buf).st_uid))!=NULL)
printf("%s ",(passwd_file->pw_name));
else
printf("%d ",(*buf).st_uid);
if((group_file=getgrgid((*buf).st_gid))!=NULL)
{
printf("%s ",*group_file -> gr_name);
}
else
printf("%d ",(*buf).st_gid);
/*file size or device number */
switch(file_type)
{
case '-':
case 'd':
case 'l':
case 's':
case 'p':
printf("%8ld ",(*buf).st_size);
break;
case 'c':
case 'b':
printf("%lu %lu ",(unsigned long)MAJOR(buf->st_rdev),(unsigned long)MINOR(buf->st_rdev));
break;
default:
break;
}
/*file tiome*/
time_t *get_time=&((*buf).st_mtime);
char time_buf[100] = {'\0'},*my_time = time_buf;
int time_len=0;
strcpy(time_buf, ctime(get_time));
time_len = strlen(my_time);
*(my_time + time_len -1) = '\0';
printf("%s ", my_time);
printf("%s", file_list->name);
}
else
{
printf("%s\t", file_list->name);
}
return 0;
}
int show_dir(Fpath *file_list, const long int mode)
{
DIR *dir;
struct dirent *dir_str;
struct stat sub_buf;
char path_buf[512] = { '\0'}, *ppath_buf = path_buf;
char path[512] = {'\0'}, *ppath = path;
ppath_buf = strcpy( ppath_buf, file_list->full_path);
if ((dir = opendir( file_list->full_path))==NULL)
{
perror( file_list->full_path );
return -1;
}
if( IS_R( mode ))
printf( "%s:\n", file_list->full_path);
while(( dir_str = readdir( dir ))!= NULL)
{
ppath = strcpy( ppath, ppath_buf);
if( !IS_A(mode) && *(dir_str->d_name) == '.')
continue;
if( ppath[strlen(ppath) - 1] != '/')
ppath = strcat( ppath, "/");
ppath = strcat( ppath, dir_str->d_name);
file_list->full_path = ppath;
file_list->name = dir_str->d_name;
if( lstat( file_list->full_path, &sub_buf) == -1)
{
perror( file_list->full_path);
continue;
}
show_file( file_list, &sub_buf, mode);
if( S_ISLNK( sub_buf.st_mode) && ( IS_L(mode)))
show_link_content(file_list, &sub_buf);
if( IS_L(mode) )
printf( "\n");
}
/* traverse directory again, recursively show all sub directories */
if( IS_R(mode) )
{
rewinddir( dir );
while(( dir_str = readdir( dir ))!=NULL)
{
ppath = strcpy( ppath, ppath_buf );
if( IS_A(mode) && *(dir_str->d_name) == '.' )
continue;
if( ppath[strlen( ppath ) - 1] != '/' )
ppath = strcat( ppath, "/" );
ppath = strcat(ppath, dir_str->d_name );
file_list->full_path=ppath;
file_list->name = dir_str->d_name;
if( lstat( file_list->full_path, &sub_buf ) == -1)
{
perror( file_list->full_path );
continue;
}
if( S_ISDIR( sub_buf.st_mode ) && strcmp( dir_str->d_name, ".") !=0 && strcmp( dir_str->d_name, ".." ) != 0 )
{
printf("\n");
show_dir( file_list, mode);
}
}
}
closedir(dir);
return 0;
}
/* scan the arg list to get the cmd line args start with the '-' */
/*long int my_get_opt(const int argc, cont char * argv[]) */
int my_get_opt( const int argc, const char **argv)
{
int i=0;
int opt_sub_num = 0;
long int mode = 0;
char ch = '\0';
for( i = 1; i < argc; i++)
{
ch = **(argv + i);
if(( ch == '-' ) && ((opt_sub_num = strlen( *(argv + i))) > 1 ))
{
int j = 0;
while( --opt_sub_num )
{
switch( *(*(argv + i) + (++j)))
{
case 'l':
mode |= L; /* L is defined in the header "myopt.h"*/
break;
case 'd':
mode |= D;
break;
case 'r':
mode |= R;
break;
case 'i':
mode |= I;
break;
case 'a':
mode |= A;
break;
default:
break;
}
}
}
}
return mode;
}
/* get the file list which would list by the command */
int get_file_list( const int argc, const char **argv, Fpath **file_list)
{
int file_num = 0, i = 0, file_index = 0;
char ch = '\0';
for( i=1; i < argc ; i++)
{
ch = **(argv + i);
if( ch == '-' )
{
continue;
}
file_num++;
}
// printf( "file_num = %d\n",file_num );
if( file_num ==0 )
{
file_num = 1;
*file_list = (Fpath *)malloc(sizeof(Fpath));
(*file_list + file_index)->full_path = ".";
(*file_list + file_index++)->name = ".";
}
else
{
*file_list = (Fpath *)malloc(file_num * sizeof (Fpath));
for( i=1; i< argc; i++)
{
ch = **(argv+ i);
if( ch== '-')
continue;
(*file_list + file_index)->full_path = (char *)*(argv+ i);
(*file_list + file_index++)->name = (char *)*(argv + i);
}
}
/*
* for( i = 0; i < file_index; i++ )
* printf( "file %d :%s\n", i, file_list[i].full_path );
*/
return file_num;
}
