Subversion Repositories SvarDOS

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

  TREE - Graphically displays the directory structure of a drive or path

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

#define VERSION "1.04"

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

  Written by: Kenneth J. Davis

  Date:       August, 2000

  Updated:    September, 2000; October, 2000; November, 2000; January, 2001;

              May, 2004; Sept, 2005

  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.

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

/* Include files */

#include <dos.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include "stack.h"

#include "svarlang/svarlang.h"

/* The default extended forms of the lines used. */

#define VERTBAR_STR  "\xB3   "                 /* |    */

#define TBAR_HORZBAR_STR "\xC3\xC4\xC4\xC4"    /* +--- */

#define CBAR_HORZBAR_STR "\xC0\xC4\xC4\xC4"    /* \--- */

/* Global flags */

#define SHOWFILESON    1  /* Display names of files in directories       */

#define SHOWFILESOFF   0  /* Don't display names of files in directories */

#define ASCIICHARS     1  /* Use ASCII [7bit] characters                 */

#define EXTENDEDCHARS  0  /* Use extended ASCII [8bit] characters        */

#define NOPAUSE        0  /* Default, don't pause after screenfull       */

#define PAUSE          1  /* Wait for keypress after each page           */

/* Global variables */

short showFiles = SHOWFILESOFF;

short charSet = EXTENDEDCHARS;

short pause = NOPAUSE;

short dspAll = 0;  /* if nonzero includes HIDDEN & SYSTEM files in output */

short dspSize = 0; /* if nonzero displays filesizes                       */

short dspAttr = 0; /* if nonzero displays file attributes [DACESHRBP]     */

short dspSumDirs = 0; /* show count of subdirectories  (per dir and total)*/

/* maintains total count, for > 4billion dirs, use a __int64 */

unsigned long totalSubDirCnt = 0;

/* text window size, used to determine when to pause,

   Note: rows is total rows available - 2

   1 is for pause message and then one to prevent auto scroll up

*/

short cols=80, rows=23;   /* determined these on startup (when possible)  */

/* Global constants */

#define SERIALLEN 16      /* Defines max size of volume & serial number   */

#define VOLLEN 16

static char path[PATH_MAX];   /* Path to begin search from, default=current   */

#define MAXPADLEN (PATH_MAX*2) /* Must be large enough to hold the maximum padding */

/* (PATH_MAX/2)*4 == (max path len / min 2chars dirs "?\") * 4chars per padding    */

/* The maximum size any line of text output can be, including room for '\0'*/

#define MAXLINE 160        /* Increased to fit two lines for translations  */

/* The hard coded strings used by the following show functions.            */

/* common to many functions [Set 1] */

char newLine[MAXLINE] = "\n";

/* Procedures */

/* returns the current drive (A=0, B=1, etc) */

static unsigned char getdrive(void);

#pragma aux getdrive = \

"mov ah, 0x19" \

"int 0x21" \

modify [ah] \

value [al]

/* waits for a keypress, flushes keyb buffer, returns nothing */

static void waitkey(void);

#pragma aux waitkey = \

"mov ah, 0x08" \

"int 0x21" \

/* flush keyb buffer in case it was an extended key */ \

"mov ax, 0x0C0B" \

"int 0x21" \

modify [ax]

/* checks if stdout appears to be redirected. returns 0 if not, non-zero otherwise. */

static unsigned char is_stdout_redirected(void);

#pragma aux is_stdout_redirected = \

"mov ax, 0x4400"    /* DOS 2+, IOCTL Get Device Info */            \

"mov bx, 0x0001"    /* file handle (stdout) */                     \

"int 0x21" \

"jc DONE"           /* on error AL contains a non-zero err code */ \

"and dl, 0x80"      /* bit 7 of DL is the "CHAR" flag */           \

"xor dl, 0x80"      /* return 0 if CHAR bit is set */              \

"mov al, dl" \

"DONE:" \

modify [ax bx dx] \

value [al]

static _Packed struct {

  unsigned short infolevel;

  unsigned short serial2;

  unsigned short serial1;

  char label[11];

  short fstype[8];

} glob_drv_info;

/* drv is 1-based (A=1, B=2, ...) */

static void getdrvserial(unsigned char drv) {

  unsigned short drvinfo_seg = FP_SEG(&glob_drv_info);

  _asm {

    push ax

    push bx

    push dx

    mov ax, 0x6900

    xor bh, bh

    mov bl, drv

    mov dx, offset glob_drv_info

    push ds

    mov ds, drvinfo_seg

    int 0x21

    pop ds

    pop dx

    pop bx

    pop ax

  }

}

static int truename(char *path, const char *origpath) {

  unsigned short origpath_seg = FP_SEG(origpath);

  unsigned short origpath_off = FP_OFF(origpath);

  unsigned short dstpath_seg = FP_SEG(path);

  unsigned short dstpath_off = FP_OFF(path);

  unsigned char cflag = 0;

  /* resolve path with truename */

  _asm {

    push ax

    push si

    push di

    push es

    push ds

    mov ah, 0x60          /* AH = 0x60 -> TRUENAME */

    mov di, dstpath_off   /* ES:DI -> dst buffer */

    mov es, dstpath_seg

    mov si, origpath_off  /* DS:SI -> src path */

    mov ds, origpath_seg

    int 0x21

    jnc DONE

    mov cflag, 1

    DONE:

    pop ds

    pop es

    pop di

    pop si

    pop ax

  }

  return(cflag);

}

/* sets rows & cols to size of actual console window

 * force NOPAUSE if appears output redirected to a file or

 * piped to another program

 * Uses hard coded defaults and leaves pause flag unchanged

 * if unable to obtain information.

 */

static void getConsoleSize(void) {

  unsigned short far *bios_cols = (unsigned short far *)MK_FP(0x40,0x4A);

  unsigned short far *bios_size = (unsigned short far *)MK_FP(0x40,0x4C);

  if (is_stdout_redirected() != 0) {

    /* e.g. redirected to a file, tree > filelist.txt */

    /* Output to a file or program, so no screen to fill (no max cols or rows) */

      pause = NOPAUSE;   /* so ignore request to pause */

  } else { /* e.g. the console */

    if ((*bios_cols == 0) || (*bios_size == 0)) { /* MDA does not report size */

      cols = 80;

      rows = 23;

    } else {

      cols = *bios_cols;

      rows = *bios_size / cols / 2;

      if (rows > 2) rows -= 2; /* necessary to keep screen from scrolling */

    }

  }

}

/* when pause == NOPAUSE then identical to printf,

   otherwise counts lines printed and pauses as needed.

   Should be used for all messages printed that do not

   immediately exit afterwards (else printf may be used).

   May display N too many lines before pause if line is

   printed that exceeds cols [N=linelen%cols] and lacks

   any newlines (but this should not occur in tree).

*/

#include <stdarg.h>  /* va_list, va_start, va_end */

static int pprintf(const char *msg, ...) {

  static int lineCnt = -1;

  static int lineCol = 0;

  va_list argptr;

  int cnt;

  char buffer[MAXLINE];

  if (lineCnt == -1) lineCnt = rows;

  va_start(argptr, msg);

  cnt = vsprintf(buffer, msg, argptr);

  va_end(argptr);

  if (pause == PAUSE)

  {

    char *l = buffer;

    char *t;

    /* cycle through counting newlines and lines > cols */

    for (t = strchr(l, '\n'); t != NULL; t = strchr(l, '\n'))

    {

      char c;

      t++;             /* point to character after newline */

      c = *t;          /* store current value */

      *t = '\0';       /* mark as end of string */

      /* print all but last line of a string that wraps across rows */

      /* adjusting for partial lines printed without the newlines   */

      while (strlen(l)+lineCol > cols)

      {

        char c = l[cols-lineCol];

        l[cols-lineCol] = '\0';

        printf("%s", l);

        l[cols-lineCol] = c;

        l += cols-lineCol;

        lineCnt--;  lineCol = 0;

        if (!lineCnt) { lineCnt= rows;  fflush(NULL);  fprintf(stderr, "%s", svarlang_strid(0x0106));  waitkey(); }

      }

      printf("%s", l); /* print out this line */

      *t = c;          /* restore value */

      l = t;           /* mark beginning of next line */

      lineCnt--;  lineCol = 0;

      if (!lineCnt) { lineCnt= rows;  fflush(NULL);  fprintf(stderr, "%s", svarlang_strid(0x0106));  waitkey(); }

    }

    printf("%s", l);   /* print rest of string that lacks newline */

    lineCol = strlen(l);

  }

  else  /* NOPAUSE */

    printf("%s", buffer);

  return cnt;

}

/* Displays to user valid options then exits program indicating no error */

static void showUsage(void) {

  puts(svarlang_strid(0x0201));

  puts("");

  puts(svarlang_strid(0x0202));

  puts("");

  puts(svarlang_strid(0x0203));

  puts(svarlang_strid(0x0204));

  exit(1);

}

/* Displays error message then exits indicating error */

static void showInvalidUsage(char * badOption) {

  printf(svarlang_strid(0x0301), badOption); /* invalid switch - ... */

  printf("%s%s", svarlang_strid(0x0302), newLine); /* use TREE /? for usage info */

  exit(1);

}

/* Displays author, copyright, etc info, then exits indicating no error. */

static void showVersionInfo(void) {

  printf(svarlang_strid(0x0201));

  printf(svarlang_strid(0x0202));

  printf(svarlang_strid(0x0403), VERSION);

  printf(svarlang_strid(0x0404));

  printf(svarlang_strid(0x0407));

  exit(1);

}

/* Displays error messge for invalid drives and exits */

static void showInvalidDrive(void) {

  printf(svarlang_strid(0x0501)); /* invalid drive spec */

  exit(1);

}

/**

 * Takes a given path, strips any \ or / that may appear on the end.

 * Returns a pointer to its static buffer containing path

 * without trailing slash and any necessary display conversions.

 */

static char *fixPathForDisplay(char *path);

/* Displays error message for invalid path; Does NOT exit */

static void showInvalidPath(const char *badpath) {

  pprintf("%s\n", badpath);

  pprintf(svarlang_strid(0x0601), badpath); /* invalid path - ... */

}

/* Displays error message for out of memory; Does NOT exit */

static void showOutOfMemory(const char *path) {

  pprintf(svarlang_strid(0x0702), path); /* out of memory on subdir ... */

}

/* Parses the command line and sets global variables. */

static void parseArguments(int argc, char **argv) {

  int i;

  /* if no drive specified on command line, use current */

  if (truename(path, ".") != 0) showInvalidDrive();

  for (i = 1; i < argc; i++) {

    /* Check if user is giving an option or drive/path */

    if ((argv[i][0] != '/') && (argv[i][0] != '-') ) {

      if (truename(path, argv[i]) != 0) showInvalidPath(argv[i]);

      continue;

    }

    /* must be an option then */

    /* check multi character options 1st */

    if (argv[i][1] & 0xDF == 'D') {

      switch(argv[i][2] & 0xDF) {

        case 'A' :       /*  /DA  display attributes */

          dspAttr = 1;

          break;

        case 'F' :       /*  /DF  display filesizes  */

          dspSize = 1;

          break;

        case 'H' :       /*  /DH  display hidden & system files (normally not shown) */

          dspAll = 1;

          break;

        case 'R' :       /*  /DR  display results at end */

          dspSumDirs = 1;

          break;

        default:

          showInvalidUsage(argv[i]);

      }

      continue;

    }

    /* a 1 character option (or invalid) */

    if (argv[i][2] != 0) showInvalidUsage(argv[i]);

    switch(argv[i][1] & 0xDF) { /* upcase */

      case 'F': /* show files */

        showFiles = SHOWFILESON; /* set file display flag appropriately */

        break;

      case 'A': /* use ASCII only (7-bit) */

        charSet = ASCIICHARS;    /* set charset flag appropriately      */

        break;

      case 'V': /* Version information */

        showVersionInfo();       /* show version info and exit          */

        break;

      case 'P': /* wait for keypress after each page (pause) */

        pause = PAUSE;

        break;

      case '?' & 0xDF:

        showUsage();             /* show usage info and exit            */

        break;

      default: /* Invalid or unknown option */

        showInvalidUsage(argv[i]);

    }

  }

}

/**

 * Fills in the serial and volume variables with the serial #

 * and volume found using path.

 */

static void GetVolumeAndSerial(char *volume, char *serial, char *path) {

  getdrvserial((path[0] & 0xDF) - '@');

  memcpy(volume, glob_drv_info.label, 12);

  volume[11] = 0;

  sprintf(serial, "%04X:%04X", glob_drv_info.serial1, glob_drv_info.serial2);

}

/**

 * Stores directory information obtained from FindFirst/Next that

 * we may wish to make use of when displaying directory entry.

 * e.g. attribute, dates, etc.

 */

typedef struct DIRDATA {

  unsigned long subdirCnt;  /* how many subdirectories we have */

  unsigned long fileCnt;    /* how many [normal] files we have */

  unsigned int attrib;      /* Directory attributes            */

} DIRDATA;

/**

 * Contains the information stored in a Stack necessary to allow

 * non-recursive function to display directory tree.

 */

struct SUBDIRINFO {

  struct SUBDIRINFO *parent; /* points to parent subdirectory                */

  char *currentpath;    /* Stores the full path this structure represents     */

  char *subdir;         /* points to last subdir within currentpath           */

  char *dsubdir;        /* Stores a display ready directory name              */

  long subdircnt;       /* Initially a count of how many subdirs in this dir  */

  struct find_t *findnexthnd; /* The handle returned by findfirst, used in findnext */

  struct DIRDATA ddata; /* Maintain directory information, eg attributes      */

};

/**

 * Returns 0 if no subdirectories, count if has subdirs.

 * Path must end in slash \ or /

 * On error (invalid path) displays message and returns -1L.

 * Stores additional directory data in ddata if non-NULL

 * and path is valid.

 */

static long hasSubdirectories(char *path, DIRDATA *ddata) {

  struct find_t findData;

  char buffer[PATH_MAX + 4];

  unsigned short hasSubdirs = 0;

  /* get the handle to start with (using wildcard spec) */

  strcpy(buffer, path);

  strcat(buffer, "*.*");

  if (_dos_findfirst(buffer, 0x37, &findData) != 0) {

    showInvalidPath(path); /* Display error message */

    return(-1);

  }

  /*  cycle through entries counting directories found until no more entries */

  do {

    if ((findData.attrib & _A_SUBDIR) == 0) continue; /* not a DIR */

      /* filter out system and hidden files, unless dspAll is on */

    if (dspAll == 0) {

      if (findData.attrib & _A_HIDDEN) continue;

      if (findData.attrib & _A_SYSTEM) continue;

    }

    if (findData.name[0] != '.') { /* ignore '.' and '..' */

      hasSubdirs++;      /* subdir of initial path found, so increment counter */

    }

  } while(_dos_findnext(&findData) == 0);

  /* prevent resource leaks, close the handle. */

  _dos_findclose(&findData);

  if (ddata != NULL)  // don't bother if user doesn't want them

  {

    /* The root directory of a volume (including non root paths

       corresponding to mount points) may not have a current (.) and

       parent (..) entry.  So we can't get attributes for initial

       path in above loop from the FindFile call as it may not show up

       (no . entry).  So instead we explicitly get them here.

    */

    if (_dos_getfileattr(path, &(ddata->attrib)) != 0) {

      //printf("ERROR: unable to get file attr, %i\n", GetLastError());

      ddata->attrib = 0;

    }

    /* a curiosity, for showing sum of directories process */

    ddata->subdirCnt = hasSubdirs;

  }

  totalSubDirCnt += hasSubdirs;

  return hasSubdirs;

}

/**

 * Allocates memory and stores the necessary stuff to allow us to

 * come back to this subdirectory after handling its subdirectories.

 * parentpath must end in \ or / or be NULL, however

 * parent should only be NULL for initialpath

 * if subdir does not end in slash, one is added to stored subdir

 * dsubdir is subdir already modified so ready to display to user

 */

static struct SUBDIRINFO *newSubdirInfo(struct SUBDIRINFO *parent, char *subdir, char *dsubdir) {

  int parentLen, subdirLen;

  struct SUBDIRINFO *temp;

  /* Get length of parent directory */

  if (parent == NULL)

    parentLen = 0;

  else

    parentLen = strlen(parent->currentpath);

  /* Get length of subdir, add 1 if does not end in slash */

  subdirLen = strlen(subdir);

  if ((subdirLen < 1) || ( (*(subdir+subdirLen-1) != '\\') && (*(subdir+subdirLen-1) != '/') ) )

    subdirLen++;

  temp = malloc(sizeof(struct SUBDIRINFO));

  if (temp == NULL) {

    showOutOfMemory(subdir);

    return NULL;

  }

  if ( ((temp->currentpath = (char *)malloc(parentLen+subdirLen+1)) == NULL) ||

       ((temp->dsubdir = (char *)malloc(strlen(dsubdir)+1)) == NULL) )

  {

    showOutOfMemory(subdir);

    if (temp->currentpath != NULL) free(temp->currentpath);

    free(temp);

    return NULL;

  }

  temp->parent = parent;

  if (parent == NULL)

    strcpy(temp->currentpath, "");

  else

    strcpy(temp->currentpath, parent->currentpath);

  strcat(temp->currentpath, subdir);

  /* if subdir[subdirLen-1] == '\0' then we must append a slash */

  if (*(subdir+subdirLen-1) == '\0')

    strcat(temp->currentpath, "\\");

  temp->subdir = temp->currentpath+parentLen;

  strcpy(temp->dsubdir, dsubdir);

  if ((temp->subdircnt = hasSubdirectories(temp->currentpath, &(temp->ddata))) == -1L)

  {

    free (temp->currentpath);

    free (temp->dsubdir);

    free(temp);

    return NULL;

  }

  temp->findnexthnd = NULL;

  return temp;

}

/**

 * Extends the padding with the necessary 4 characters.

 * Returns the pointer to the padding.

 * padding should be large enough to hold the additional

 * characters and '\0', moreSubdirsFollow specifies if

 * this is the last subdirectory in a given directory

 * or if more follow (hence if a | is needed).

 * padding must not be NULL

 */

static char * addPadding(char *padding, int moreSubdirsFollow) {

  if (moreSubdirsFollow) {

    /* 1st char is | or a vertical bar */

    if (charSet == EXTENDEDCHARS) {

      strcat(padding, VERTBAR_STR);

    } else {

      strcat(padding, "|   ");

    }

  } else {

    strcat(padding, "    ");

  }

  return(padding);

}

/**

 * Removes the last padding added (last 4 characters added).

 * Does nothing if less than 4 characters in string.

 * padding must not be NULL

 * Returns the pointer to padding.

 */

static char *removePadding(char *padding) {

  size_t len = strlen(padding);

  if (len < 4) return padding;

  *(padding + len - 4) = '\0';

  return padding;

}

/**

 * Displays the current path, with necessary padding before it.

 * A \ or / on end of currentpath is not shown.

 * moreSubdirsFollow should be nonzero if this is not the last

 * subdirectory to be displayed in current directory, else 0.

 * Also displays additional information, such as attributes or

 * sum of size of included files.

 * currentpath is an ASCIIZ string of path to display

 *             assumed to be a displayable path (ie. OEM or UTF-8)

 * padding is an ASCIIZ string to display prior to entry.

 * moreSubdirsFollow is -1 for initial path else >= 0.

 */

static void showCurrentPath(char *currentpath, char *padding, int moreSubdirsFollow, DIRDATA *ddata) {

  if (padding != NULL)

    pprintf("%s", padding);

  /* print lead padding except for initial directory */

  if (moreSubdirsFollow >= 0)

  {

    if (charSet == EXTENDEDCHARS)

    {

      if (moreSubdirsFollow)

        pprintf("%s", TBAR_HORZBAR_STR);

      else

        pprintf("%s", CBAR_HORZBAR_STR);

    } else {

      if (moreSubdirsFollow)

        pprintf("+---");

      else

        pprintf("\\---");

    }

  }

  /* optional display data */

  if (dspAttr)  /* attributes */

    pprintf("[%c%c%c%c%c] ",

      (ddata->attrib & _A_SUBDIR)?'D':' ',  /* keep this one? its always true */

      (ddata->attrib & _A_ARCH)?'A':' ',

      (ddata->attrib & _A_SYSTEM)?'S':' ',

      (ddata->attrib & _A_HIDDEN)?'H':' ',

      (ddata->attrib & _A_RDONLY)?'R':' '

    );

  /* display directory name */

  pprintf("%s\n", currentpath);

}

/**

 * Displays summary information about directory.

 * Expects to be called after displayFiles (optionally called)

 */

static void displaySummary(char *padding, int hasMoreSubdirs, DIRDATA *ddata) {

  addPadding(padding, hasMoreSubdirs);

  if (dspSumDirs) {

    if (showFiles == SHOWFILESON) {

      /* print File summary with lead padding, add filesize to it */

      pprintf("%s%lu files\n", padding, ddata->fileCnt);

    }

    /* print Directory summary with lead padding */

    pprintf("%s%lu subdirectories\n", padding, ddata->subdirCnt);

    /* show [nearly] blank line after summary */

    pprintf("%s\n", padding);

  }

  removePadding(padding);

}

/**

 * Displays files in directory specified by path.

 * Path must end in slash \ or /

 * Returns -1 on error,

 *          0 if no files, but no errors either,

 *      or  1 if files displayed, no errors.

 */

static int displayFiles(const char *path, char *padding, int hasMoreSubdirs, DIRDATA *ddata) {

  char buffer[PATH_MAX + 4];

  struct find_t entry;   /* current directory entry info    */

  unsigned long filesShown = 0;

  /* get handle for files in current directory (using wildcard spec) */

  strcpy(buffer, path);

  strcat(buffer, "*.*");

  if (_dos_findfirst(buffer, 0x37, &entry) != 0) return(-1);

  addPadding(padding, hasMoreSubdirs);

  /* cycle through directory printing out files. */

  do

  {

    /* print padding followed by filename */

    if ( ((entry.attrib & _A_SUBDIR) == 0) &&

         ( ((entry.attrib & (_A_HIDDEN | _A_SYSTEM)) == 0)  || dspAll) )

    {

      /* print lead padding */

      pprintf("%s", padding);

      /* optional display data */

      if (dspAttr)  /* file attributes */

        pprintf("[%c%c%c%c] ",

          (entry.attrib & _A_ARCH)?'A':' ',

          (entry.attrib & _A_SYSTEM)?'S':' ',

          (entry.attrib & _A_HIDDEN)?'H':' ',

          (entry.attrib & _A_RDONLY)?'R':' '

        );

      if (dspSize) { /* file size */

        if (entry.size < 1048576ul)  /* if less than a MB, display in bytes */

          pprintf("%10lu ", entry.size);

        else                               /* otherwise display in KB */

          pprintf("%8luKB ", entry.size / 1024ul);

      }

      /* print filename */

      pprintf("%s\n", entry.name);

      filesShown++;

    }

  } while(_dos_findnext(&entry) == 0);

  if (filesShown)

  {

    pprintf("%s\n", padding);

  }

  removePadding(padding);

  /* store for summary display */

  if (ddata != NULL) ddata->fileCnt = filesShown;

  return (filesShown)? 1 : 0;

}

/**

 * Common portion of findFirstSubdir and findNextSubdir

 * Checks current FindFile results to determine if a valid directory

 * was found, and if so copies appropriate data into subdir and dsubdir.

 * It will repeat until a valid subdirectory is found or no more

 * are found, at which point it closes the FindFile search handle and

 * return NULL.  If successful, returns FindFile handle.

 */

static struct find_t *cycleFindResults(struct find_t *entry, char *subdir, char *dsubdir) {

  /* cycle through directory until 1st non . or .. directory is found. */

  for (;;) {

    /* skip files & hidden or system directories */

    if ((((entry->attrib & _A_SUBDIR) == 0) ||

         ((entry->attrib &

          (_A_HIDDEN | _A_SYSTEM)) != 0  && !dspAll) ) ||

        (entry->name[0] == '.')) {

      if (_dos_findnext(entry) != 0) {

        _dos_findclose(entry);      // prevent resource leaks

        return(NULL); // no subdirs found

      }

    } else {

      /* set display name */

      strcpy(dsubdir, entry->name);

      strcpy(subdir, entry->name);

      strcat(subdir, "\\");

      return(entry);

    }

  }

  return entry;

}

/**