msdos/directory.c

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