msdos/directory.c

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