msdos/directory.c

   1 /* $Header: directory.c,v 3.0.1.1 90/03/27 16:07:37 lwall Locked $
   2  *
   3  *    (C) Copyright 1987, 1988, 1990 Diomidis Spinellis.
   4  *
   5  *    You may distribute under the terms of the GNU General Public License
   6  *    as specified in the README file that comes with the perl 3.0 kit.
   7  *
   8  * $Log:        directory.c,v $
   9  * Revision 3.0.1.1  90/03/27  16:07:37  lwall
  10  * patch16: MSDOS support
  11  *
  12  * Revision 1.3  90/03/16  22:39:40  dds
  13  * Fixed malloc problem.
  14  *
  15  * Revision 1.2  88/07/23  00:08:39  dds
  16  * Added inode non-zero filling.
  17  *
  18  * Revision 1.1  88/07/23  00:03:50  dds
  19  * Initial revision
  20  *
  21  */
  22
  23 /*
  24  * UNIX compatible directory access functions
  25  */
  26
  27 #include <sys/types.h>
  28 #include <sys/dir.h>
  29 #include <stddef.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <dos.h>
  33 #include <ctype.h>
  34
  35 /*
  36  * File names are converted to lowercase if the
  37  * CONVERT_TO_LOWER_CASE variable is defined.
  38  */
  39 #define CONVERT_TO_LOWER_CASE
  40
  41 #define PATHLEN 65
  42
  43 #ifndef lint
  44 static char     rcsid[] = "$Header: director.c;v 1.3 90/03/16 22:39:40 dds Exp
  45  $";
  46 #endif
  47
  48 DIR *
  49 opendir(char *filename)
  50 {
  51         DIR            *p;
  52         char           *oldresult, *result;
  53         union REGS      srv;
  54         struct SREGS    segregs;
  55         register        reslen = 0;
  56         char            scannamespc[PATHLEN];
  57         char            *scanname = scannamespc;        /* To take address we need a pointer */
  58
  59         /*
  60          * Structure used by the MS-DOS directory system calls.
  61          */
  62         struct dir_buff {
  63                 char            reserved[21];   /* Reserved for MS-DOS */
  64                 unsigned char   attribute;      /* Attribute */
  65                 unsigned int    time;           /* Time */
  66                 unsigned int    date;           /* Date */
  67                 long            size;           /* Size of file */
  68                 char            fn[13];         /* Filename */
  69         } buffspc, *buff = &buffspc;
  70
  71
  72         if (!(p = (DIR *) malloc(sizeof(DIR))))
  73                 return NULL;
  74
  75         /* Initialize result to use realloc on it */
  76         if (!(result = malloc(1))) {
  77                 free(p);
  78                 return NULL;
  79         }
  80
  81         /* Create the search pattern */
  82         strcpy(scanname, filename);
  83         if (strchr("/\\", *(scanname + strlen(scanname) - 1)) == NULL)
  84                 strcat(scanname, "/*.*");
  85         else
  86                 strcat(scanname, "*.*");
  87
  88         segread(&segregs);
  89 #if ( defined(M_I86LM) || defined(M_I86CM) || defined(M_I86HM) )
  90         segregs.ds = FP_SEG(buff);
  91         srv.x.dx = FP_OFF(buff);
  92 #else
  93         srv.x.dx = (unsigned int) buff;
  94 #endif
  95         srv.h.ah = 0x1a;        /* Set DTA to DS:DX */
  96         intdosx(&srv, &srv, &segregs);
  97
  98 #if ( defined(M_I86LM) || defined(M_I86CM) || defined(M_I86HM) )
  99         segregs.ds = FP_SEG(scanname);
 100         srv.x.dx = FP_OFF(scanname);
 101 #else
 102         srv.x.dx = (unsigned int) scanname;
 103 #endif
 104         srv.x.cx = 0xff;        /* Search mode */
 105
 106         for (srv.h.ah = 0x4e; !intdosx(&srv, &srv, &segregs); srv.h.ah = 0x4f) {
 107                 if ((result = (char *) realloc(result, reslen + strlen(buff->fn) + 1)) ==
 108  NULL) {
 109                         free(p);
 110                         free(oldresult);
 111                         return NULL;
 112                 }
 113                 oldresult = result;
 114 #ifdef CONVERT_TO_LOWER_CASE
 115                 strcpy(result + reslen, strlwr(buff->fn));
 116 #else
 117                 strcpy(result + reslen, buff->fn);
 118 #endif
 119                 reslen += strlen(buff->fn) + 1;
 120         }
 121
 122         if (!(result = realloc(result, reslen + 1))) {
 123                 free(p);
 124                 free(oldresult);
 125                 return NULL;
 126         } else {
 127                 p->start = result;
 128                 p->curr = result;
 129                 *(result + reslen) = '\0';
 130                 return p;
 131         }
 132 }
 133
 134
 135 struct direct  *
 136 readdir(DIR *dirp)
 137 {
 138         char           *p;
 139         register        len;
 140         static          dummy;
 141
 142         p = dirp->curr;
 143         len = strlen(p);
 144         if (*p) {
 145                 dirp->curr += len + 1;
 146                 strcpy(dirp->dirstr.d_name, p);
 147                 dirp->dirstr.d_namlen = len;
 148                 /* To fool programs */
 149                 dirp->dirstr.d_ino = ++dummy;
 150                 return &(dirp->dirstr);
 151         } else
 152                 return NULL;
 153 }
 154
 155 long
 156 telldir(DIR *dirp)
 157 {
 158         return (long) dirp->curr;       /* ouch! pointer to long cast */
 159 }
 160
 161 void
 162 seekdir(DIR *dirp, long loc)
 163 {
 164         dirp->curr = (char *) loc;      /* ouch! long to pointer cast */
 165 }
 166
 167 void
 168 rewinddir(DIR *dirp)
 169 {
 170         dirp->curr = dirp->start;
 171 }
 172
 173 void
 174 closedir(DIR *dirp)
 175 {
 176         free(dirp->start);
 177         free(dirp);
 178 }