Subversion Repositories SvarDOS

/****************************************************************************

  Win32 File compatibility for DOS.

  [This version does support LFNs, if available.]

  Written by: Kenneth J. Davis

  Date:       August, 2000

  Contact:    jeremyd@computer.org

Copyright (c): Public Domain [United States Definition]

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so, subject to the following conditions:

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

NONINFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR AUTHORS BE

LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER

IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT

OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

DEALINGS IN THE SOFTWARE.

****************************************************************************/

/*** Expects Pointers to be near (Tiny, Small, and Medium models ONLY) ***/

#include <dos.h>

#include <stdio.h>   /* PATH_MAX */

#include <stdlib.h>

#include <string.h>

#include "dosdisk.h"

#define searchAttr ( FILE_A_DIR | FILE_A_HIDDEN | FILE_A_SYSTEM | FILE_A_READONLY | FILE_A_ARCH )

struct FFDTA *FindFirstFile(const char *pathname, struct FFDTA *hnd) {

  char path[PATH_MAX];

  short cflag = 0;  /* used to indicate if findfirst is succesful or not */

  /* initialize structure (clear) */

  /* hnd->handle = 0;  hnd->ffdtaptr = NULL; */

  memset(hnd, 0, sizeof(*hnd));

  /* if pathname ends in \* convert to \*.* */

  strcpy(path, pathname);

  {

  int eos = strlen(path) - 1;

  if ((path[eos] == '*') && (path[eos - 1] == '\\')) strcat(path, ".*");

  }

  {

    unsigned short ffdta_seg, ffdta_off;

    unsigned short path_seg, path_off;

    unsigned short sattr = searchAttr;

    ffdta_seg = FP_SEG(hnd);

    ffdta_off = FP_OFF(hnd);

    path_seg = FP_SEG(path);

    path_off = FP_OFF(path);

  _asm {

    push ax

    push bx

    push cx

    push dx

    push es

    mov ah, 0x2F                   //; Get Current DTA

    int 0x21                       //; Execute interrupt, returned in ES:BX

    push bx                        //; Store its Offset, then Segment

    push es

    mov ah, 0x1A                   //; Set Current DTA to our buffer, DS:DX

    mov dx, ffdta_off

    push ds

    mov ds, ffdta_seg

    int 0x21                       //; Execute interrupt

    pop ds

    mov ax, 0x4E00                 //; Actual findfirst call

    mov cx, sattr

    mov dx, path_off               //; Load DS:DX with pointer to path for Findfirt

    push ds

    mov ds, path_seg

    int 0x21                       //; Execute interrupt

    pop ds

    jnc success                    //; If carry is not set then succesful

    mov [cflag], ax                //; Set flag with error.

success:

    mov ah, 0x1A              //; Set Current DTA back to original, DS:DX

    mov dx, ds                //; Store DS, must be preserved

    pop ds                    //; Popping ES into DS since thats where we need it.

    pop bx                    //; Now DS:BX points to original DTA

    int 0x21                  //; Execute interrupt to restore.

    mov ds, dx                //; Restore DS

    pop es

    pop dx

    pop cx

    pop bx

    pop ax

  }

  }

  if (cflag) return(NULL);

  return hnd;

}

int FindNextFile(struct FFDTA *hnd) {

  short cflag = 0;  /* used to indicate if dos findnext succesful or not */

  /* if bad handle given return */

  if (hnd == NULL) return 0;

  { /* Use DOS (0x4F) findnext, returning if error */

    unsigned short dta_seg = FP_SEG(hnd);

    unsigned short dta_off = FP_OFF(hnd);

    _asm {

      push ax

      push bx

      push cx

      push dx

      push es

      mov ah, 0x2F                  //; Get Current DTA

      int 0x21                      //; Execute interrupt, returned in ES:BX

      push bx                       //; Store its Offset, then Segment

      push es

      mov ax, 0x1A00                //; Set Current DTA to our buffer, DS:DX

      mov dx, dta_off

      push ds

      mov ds, dta_seg

      int 0x21                      //; Execute interrupt

      pop ds

      mov ax, 0x4F00                //; Actual findnext call

      int 0x21                      //; Execute interrupt

      JNC success                   //; If carry is not set then succesful

      mov [cflag], ax               //; Set flag with error.

success:

      mov ah, 0x1A                  //; Set Current DTA back to original, DS:DX

      MOV dx, ds                    //; Store DS, must be preserved

      pop ds                        //; Popping ES into DS since thats where we need it.

      pop bx                        //; Now DS:BX points to original DTA

      int 0x21                      //; Execute interrupt to restore.

      mov ds, dx                    //; Restore DS

      pop es

      pop dx

      pop cx

      pop bx

      pop ax

    }

  }

  if (cflag) return 0;

  return 1;

}

/* free resources to prevent memory leaks */

void FindClose(struct FFDTA *hnd) {

  /* 1st check if valid handle given */

  if (hnd == NULL) return;

}

/**

 Try LFN getVolumeInformation 1st

 if successful, assume valid drive/share (ie will return 1 unless error getting label)

 if failed (any error other than unsupported) return 0

 if a drive (ie a hard drive, ram drive, network mapped to letter) [has : as second letter]

 {

   try findfirst for volume label. (The LFN api does not seem to support LABEL attribute searches.)

     If getVolInfo unsupported but get findfirst succeed, assume valid (ie return 1)

   Try Get Serial#

 }

 else a network give \\server\share and LFN getVol unsupported, assume failed 0, as the

   original findfirst/next I haven't seen support UNC naming, clear serial and volume.

*** Currently trying to find a way to get a \\server\share 's serial & volume if LFN available ***

*/

/* returns zero on failure, if lpRootPathName is NULL or "" we use current

 * default drive. */

int GetVolumeInformation(const char *lpRootPathName, char *lpVolumeNameBuffer,

  size_t nVolumeNameSize, unsigned long *lpVolumeSerialNumber) {

  /* Using DOS interrupt to get serial number */

  struct media_info {

    short dummy;

    unsigned long serial;

    char volume[11];

    short ftype[8];

  } media;

  /* Stores the root path we use. */

  char pathname[260];

  unsigned short cflag;

  /* validate root path to obtain info on, NULL or "" means use current */

  if ((lpRootPathName == NULL) || (*lpRootPathName == '\0')) {

    /* Assume if NULL user wants current drive, eg C:\ */

    _asm {

      push ax

      push bx

      mov ah, 0x19            //; Get Current Default Drive

      int 0x21                //; returned in AL, 0=A, 1=B,...

      lea bx, pathname        //; load pointer to our buffer

      add al, 'A'             //; Convert #returned to a letter

      mov [bx], al            //; Store drive letter

      inc bx                  //; point to next character

      mov byte ptr [bx], ':'  //; Store the colon

      inc bx

      mov byte ptr [bx], '\'  //; this gets converted correctly as a single bkslsh

      inc bx

      mov byte ptr [bx], 0    //; Most importantly the '\0' terminator

      pop bx

      pop ax

    }

  } else {

    strcpy(pathname, lpRootPathName);

  }

  /* if a drive, test if valid, get volume, and possibly serial # */

  /* assume these calls will succeed, change on an error */

  cflag = 0;

  /* get path ending in \*.*, */

  if (pathname[strlen(pathname)-1] != '\\') {

    strcat(pathname, "\\*.*");

  } else {

    strcat(pathname, "*.*");

  }

  /* Search for volume using old findfirst, as LFN version (NT5 DOS box) does

   * not recognize FILE_A_VOL = 0x0008 as label attribute.

   */

  {

    struct FFDTA finfo;

    unsigned short attr_seg = FP_SEG(finfo.ff_attr);

    unsigned short attr_off = FP_OFF(finfo.ff_attr);

    unsigned short finfo_seg = FP_SEG(&finfo);

    unsigned short finfo_off = FP_OFF(&finfo);

    unsigned short pathname_seg = FP_SEG(pathname);

    unsigned short pathname_off = FP_OFF(pathname);

    _asm {

      push ax

      push bx

      push cx

      push dx

      push es

      mov ah, 0x2F              //; Get Current DTA

      int 0x21                  //; Execute interrupt, returned in ES:BX

      push bx                   //; Store its Offset, then Segment

      push es

      mov ah, 0x1A              //; Set Current DTA to our buffer, DS:DX

      mov dx, finfo_off         //; Load our buffer for new DTA.

      push ds

      mov ds, finfo_seg

      int 0x21                  //; Execute interrupt

      pop ds

      mov ax, 0x4E00            //; Actual findfirst call

      mov cx, FILE_A_VOL

      mov dx, pathname_off      //; Load DS:DX with pointer to modified RootPath for Findfirt

      push ds

      mov ds, pathname_seg

      int 0x21                  //; Execute interrupt, Carry set on error, unset on success

      pop ds

      jnc success               //; If carry is not set then succesful

      mov [cflag], ax           //; Set flag with error.

      jmp cleanup               //; Restore DTA

    success:                    //; True volume entry only has volume attribute set [MS' LFNspec]

      mov bx, attr_off

      push es

      mov es, attr_seg

      mov al, [es:bx]              //; Looking for a BYTE that is FILE_ATTRIBUTE_LABEL only

      pop es

      and al, 0xDF              //; Ignore Archive bit

      cmp al, FILE_A_VOL

      je cleanup                //; They match, so should be true volume entry.

      mov ax, 0x4F00            //; Otherwise keep looking (findnext)

      int 0x21                  //; Execute interrupt

      jnc success               //; If carry is not set then succesful

      mov [cflag], ax           //; Set flag with error.

    cleanup:

      mov ah, 0x1A              //; Set Current DTA back to original, DS:DX

      mov dx, ds                //; Store DS, must be preserved

      pop ds                    //; Popping ES into DS since thats where we need it.

      pop bx                    //; Now DS:BX points to original DTA

      int 0x21                  //; Execute interrupt to restore.

      mov ds, dx                //; Restore DS

      pop es

      pop dx

      pop cx

      pop bx

      pop ax

    }

    /* copy over volume label, if buffer given */

    if (lpVolumeNameBuffer != NULL) {

      if (cflag != 0) {  /* error or no label */

        lpVolumeNameBuffer[0] = '\0';

      } else {                      /* copy up to buffer's size of label */

        strncpy(lpVolumeNameBuffer, finfo.ff_name, nVolumeNameSize);

        lpVolumeNameBuffer[nVolumeNameSize-1] = '\0';

        /* slide characters over if longer than 8 to remove . */

        if (lpVolumeNameBuffer[8] == '.') {

          lpVolumeNameBuffer[8] = lpVolumeNameBuffer[9];

          lpVolumeNameBuffer[9] = lpVolumeNameBuffer[10];

          lpVolumeNameBuffer[10] = lpVolumeNameBuffer[11];

          lpVolumeNameBuffer[11] = '\0';

        }

      }

    }

  }

  /* Test for no label found, which is not an error,

     Note: added the check for 0x02 as FreeDOS returns this instead

     at least for disks with LFN entries and no volume label.

  */

  if ((cflag == 0x12) || /* No more files or   */

      (cflag == 0x02)) {  /* File not found     */

    cflag = 0;       /* so assume valid drive  */

  }

  /* Get Serial Number, only supports drives mapped to letters */

  media.serial = 0;         /* set to 0, stays 0 on an error */

  {

    unsigned short media_off = FP_OFF(&media);

    unsigned short media_seg = FP_SEG(&media);

    unsigned char drv = (pathname[0] & 0xDF) - 'A' + 1;

    _asm {

      push ax

      push bx

      push cx

      push dx

      xor bh, bh

      mov bl, drv             //; Clear BH, drive in BL

      mov cx, 0x0866          //; CH=disk drive, CL=Get Serial #

      mov ax, 0x440D          //; Generic IOCTL

      mov dx, media_off       //; DS:DX pointer to media structure

      push ds

      mov ds, media_seg

      int 0x21

      pop ds

      pop dx

      pop cx

      pop bx

      pop ax

    }

  }

  if (lpVolumeSerialNumber != NULL) *lpVolumeSerialNumber = media.serial;

  /* If there was an error getting the validating drive return failure) */

  if (cflag) {  /* cflag is nonzero on any errors )*/

    return 0;   /* zero means error! */

  } else {

    return 1;   /* Success (drive exists we think anyway) */

  }

}