1 #include <stdio.h>
  2 #include <sys/types.h>
  3 #include <sys/stat.h>
  4 #include <dirent.h>
  5 #include <pwd.h>
  6 #include <grp.h>
  7 #include <string.h>
  8 #include <time.h>
  9
 10 void do_ls(char[]);
 11 void show_file_info(char * filename , struct stat * statbufp );
 12 void mode2letter(int mode , char str[]);
 13 void print_uid2name(uid_t uid );
 14 void print_gid2name(gid_t gid );
 15
 16 int main(int ac , char * av[])
 17 {
 18     if(ac == 1 )
 19     {
 20         do_ls(".");
 21     }
 22     else
 23     {
 24         while( -- ac )
 25         {
 26             printf("%s:\n", * (++ av) );
 27             do_ls(*av);
 28         }
 29     }
 30     return 0 ;
 31 }
 32
 33 void do_ls(char dirname[])
 34 {
 35     DIR * dir_ptr ;
 36     struct dirent * direntp ;
 37     struct stat statbuf ;
 38
 39     if( ( dir_ptr = opendir(dirname) )== NULL )
 40     {
 41         fprintf(stderr, "ls1 can not open %s\n", dirname );
 42     }
 43     else
 44     {
 45         while( ( direntp = readdir(dir_ptr ) ) != NULL )
 46         {
 47             if( stat(direntp -> d_name , &statbuf) == -1 )
 48             {
 49                 perror(direntp -> d_name );
 50             }
 51             else
 52             {
 53                 show_file_info( direntp -> d_name , &statbuf);
 54             }
 55         }
 56     }
 57
 58     closedir(dir_ptr);
 59 }
 60
 61 void show_file_info( char * filename, struct stat * statbufp )
 62 {
 63     char modestr[11]; // include '\0' so 10 + 1 = 11
 64
 65     mode2letter(statbufp -> st_mode , modestr) ;
 66     printf("%s",  modestr );
 67
 68     printf("%4d", (int)statbufp -> st_nlink ) ;
 69     print_uid2name( statbufp -> st_uid ) ;
 70     print_gid2name( statbufp -> st_gid ) ;
 71     printf("%8ld", (long) (statbufp -> st_size) );
 72     printf(" %12.12s", (char*)(4 + ctime(&(statbufp -> st_mtime)) ));
 73     printf(" %s\n",filename );
 74 }
 75
 76 void mode2letter(int mode , char str[])
 77 {
 78     strcpy(str , "----------");
 79
 80     if( S_ISDIR( mode ))
 81         str[0] = 'd' ;
 82     else if( S_ISCHR( mode ))
 83         str[0] = 'c' ;    // else for efficience
 84     else if( S_ISBLK( mode ))
 85         str[0] = 'b' ;
 86
 87     if( mode & S_IRUSR )
 88         str[1] = 'r' ;
 89     if( mode & S_IWUSR )
 90         str[2] = 'w' ;
 91     if(mode & S_IXUSR )
 92         str[3] = 'x' ;
 93
 94     if( mode & S_IRGRP )
 95         str[4] = 'r' ;
 96     if( mode & S_IWGRP )
 97         str[5] = 'w' ;
 98     if( mode & S_IXGRP )
 99         str[6] = 'x' ;
100
101     if( mode & S_IROTH )
102         str[7] = 'r' ;
103     if( mode & S_IWOTH )
104         str[8] = 'w' ;
105     if( mode & S_IXOTH )
106         str[9] = 'x' ;
107 }
108
109 void print_uid2name( uid_t uid )
110 {
111     struct passwd * passwdbufp ;
112
113     if(( passwdbufp = getpwuid(uid)) != (struct passwd *)NULL ) // Except for error
114     {
115         printf( "%-8s" , passwdbufp -> pw_name ) ;
116     }
117     else
118     {
119         printf( "%8d" , uid) ;
120     }
121
122 }
123
124 void print_gid2name(gid_t gid)
125 {
126     struct group * grp_ptr ;
127     if(( grp_ptr = getgrgid(gid)) != (struct group * )NULL )
128     {
129         printf("%-8s" , grp_ptr -> gr_name ) ;
130     }
131     else
132     {
133         printf("%8d" , gid ) ;
134     }
135 }