msdos/directory.c

   1 /* $RCSfile: directory.c,v $$Revision: 4.1 $$Date: 92/08/07 18:24:42 $
   2  *
   3  *    (C) Copyright 1987, 1988, 1990 Diomidis Spinellis.
   4  *
   5  *    You may distribute under the terms of either the GNU General Public
   6  *    License or the Artistic License, as specified in the README file.
   7  *
   8  * $Log:        directory.c,v $
   9  * Revision 4.1  92/08/07  18:24:42  lwall
  10  *
  11  * Revision 4.0.1.1  91/06/07  11:22:24  lwall
  12  * patch4: new copyright notice
  13  *
  14  * Revision 4.0  91/03/20  01:34:24  lwall
  15  * 4.0 baseline.
  16  *
  17  * Revision 3.0.1.1  90/03/27  16:07:37  lwall
  18  * patch16: MSDOS support
  19  *
  20  * Revision 1.3  90/03/16  22:39:40  dds
  21  * Fixed malloc problem.
  22  *
  23  * Revision 1.2  88/07/23  00:08:39  dds
  24  * Added inode non-zero filling.
  25  *
  26  * Revision 1.1  88/07/23  00:03:50  dds
  27  * Initial revision
  28  *
  29  */
  30
  31 /*
  32  * UNIX compatible directory access functions
  33  */
  34
  35 #include <sys/types.h>
  36 #include <sys/dir.h>
  37 #include <stddef.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <dos.h>
  41 #include <ctype.h>
  42
  43 /*
  44  * File names are converted to lowercase if the
  45  * CONVERT_TO_LOWER_CASE variable is defined.
  46  */
  47 #define CONVERT_TO_LOWER_CASE
  48
  49 #define PATHLEN 65
  50
  51 #ifndef lint
  52 static char rcsid[] = "$RCSfile: directory.c,v $$Revision: 4.1 $$Date: 92/08/07 18:24:42 $";
  53 #endif
  54
  55 DIR *
  56 opendir(char *filename)
  57 {
  58         DIR            *p;
  59         char           *oldresult, *result;
  60         union REGS      srv;
  61         struct SREGS    segregs;
  62         register        reslen = 0;
  63         char            scannamespc[PATHLEN];
  64         char            *scanname = scannamespc;        /* To take address we need a pointer */
  65
  66         /*
  67          * Structure used by the MS-DOS directory system calls.
  68          */
  69         struct dir_buff {
  70                 char            reserved[21];   /* Reserved for MS-DOS */
  71                 unsigned char   attribute;      /* Attribute */
  72                 unsigned int    time;           /* Time */
  73                 unsigned int    date;           /* Date */
  74                 long            size;           /* Size of file */
  75                 char            fn[13];         /* Filename */
  76         } buffspc, *buff = &buffspc;
  77
  78
  79         if (!(p = (DIR *) malloc(sizeof(DIR))))
  80                 return NULL;
  81
  82         /* Initialize result to use realloc on it */
  83         if (!(result = malloc(1))) {
  84                 free(p);
  85                 return NULL;
  86         }
  87
  88         /* Create the search pattern */
  89         strcpy(scanname, filename);
  90         if (strchr("/\\", *(scanname + strlen(scanname) - 1)) == NULL)
  91                 strcat(scanname, "/*.*");
  92         else
  93                 strcat(scanname, "*.*");
  94
  95         segread(&segregs);
  96 #if ( defined(M_I86LM) || defined(M_I86CM) || defined(M_I86HM) )
  97         segregs.ds = FP_SEG(buff);
  98         srv.x.dx = FP_OFF(buff);
  99 #else
 100         srv.x.dx = (unsigned int) buff;
 101 #endif
 102         srv.h.ah = 0x1a;        /* Set DTA to DS:DX */
 103         intdosx(&srv, &srv, &segregs);
 104
 105 #if ( defined(M_I86LM) || defined(M_I86CM) || defined(M_I86HM) )
 106         segregs.ds = FP_SEG(scanname);
 107         srv.x.dx = FP_OFF(scanname);
 108 #else
 109         srv.x.dx = (unsigned int) scanname;
 110 #endif
 111         srv.x.cx = 0xff;        /* Search mode */
 112
 113         for (srv.h.ah = 0x4e; !intdosx(&srv, &srv, &segregs); srv.h.ah = 0x4f) {
 114                 if ((result = (char *) realloc(result, reslen + strlen(buff->fn) + 1)) ==
 115  NULL) {
 116                         free(p);
 117                         free(oldresult);
 118                         return NULL;
 119                 }
 120                 oldresult = result;
 121 #ifdef CONVERT_TO_LOWER_CASE
 122                 strcpy(result + reslen, strlwr(buff->fn));
 123 #else
 124                 strcpy(result + reslen, buff->fn);
 125 #endif
 126                 reslen += strlen(buff->fn) + 1;
 127         }
 128
 129         if (!(result = realloc(result, reslen + 1))) {
 130                 free(p);
 131                 free(oldresult);
 132                 return NULL;
 133         } else {
 134                 p->start = result;
 135                 p->curr = result;
 136                 *(result + reslen) = '\0';
 137                 return p;
 138         }
 139 }
 140
 141
 142 struct direct  *
 143 readdir(DIR *dirp)
 144 {
 145         char           *p;
 146         register        len;
 147         static          dummy;
 148
 149         p = dirp->curr;
 150         len = strlen(p);
 151         if (*p) {
 152                 dirp->curr += len + 1;
 153                 strcpy(dirp->dirstr.d_name, p);
 154                 dirp->dirstr.d_namlen = len;
 155                 /* To fool programs */
 156                 dirp->dirstr.d_ino = ++dummy;
 157                 return &(dirp->dirstr);
 158         } else
 159                 return NULL;
 160 }
 161
 162 long
 163 telldir(DIR *dirp)
 164 {
 165         return (long) dirp->curr;       /* ouch! pointer to long cast */
 166 }
 167
 168 void
 169 seekdir(DIR *dirp, long loc)
 170 {
 171         dirp->curr = (char *) loc;      /* ouch! long to pointer cast */
 172 }
 173
 174 void
 175 rewinddir(DIR *dirp)
 176 {
 177         dirp->curr = dirp->start;
 178 }
 179
 180 void
 181 closedir(DIR *dirp)
 182 {
 183         free(dirp->start);
 184         free(dirp);
 185 }