Subversion Repositories SvarDOS

/* This file is part of the SvarCOM project and is published under the terms

 * of the MIT license.

 *

 * Copyright (C) 2021-2024 Mateusz Viste

 *

 * 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 above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * 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

 * AUTHORS OR COPYRIGHT HOLDERS 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.

 */

/*

 * dir

 *

 * Displays a list of files and subdirectories in a directory.

 *

 * DIR [drive:][path][filename] [/P] [/W] [/A[:]attributes] [/O[[:]sortorder]] [/S] [/B] [/L]

 *

 * /P Pauses after each screenful of information.

 * /W Uses wide list format.

 *

 * /A Displays file with specified attributes:

 *     D Directories           R Read-only files     H Hidden files

 *     A Ready for archiving   S System files        - prefix meaning "not"

 *

 * /O List files in sorted order:

 *     N by name            S by size              E by extension

 *     D by date            G group dirs first     - prefix to reverse order

 *

 * /S Displays files in specified directory and all subdirectories.

 * /B Uses bare format (no heading information or summary)

 * /L Uses lowercases

 *

 * about /S - recursive DIR on specified (or current) path and subdirectories:

 * prerequisite: some sort of mechanism that works as a stack pile of DTAs

 *

 * /S logic:

 * 1. do a FindFirst on current directory

 * 2. do FindNext calls in a loop, if a DIR entry is encountered, remember its

 *    name and put a copy of the current DTA on stack, then continue the

 *    listing without further interruption

 * 3. if a new DIR was discovered, do a FindFirst on it and jmp to 2.

 *    if no DIR found, then go to 4.

 * 4. look on the stack for a DTA.

 *    if any found, pop it and jmp to 2.

 *    otherwise job is done, exit.

 */

/* NOTE: /A attributes are matched in an exclusive way, ie. only files with

 *       the specified attributes are matched. This is different from how DOS

 *       itself matches attributes hence DIR cannot rely on the attributes

 *       filter within FindFirst.

 *

 * NOTE: Multiple /A are not supported - only the last one is significant.

 */

/* width of a column in wide mode output: 15 chars is the MINIMUM because

 * directories are enclosed in [BRACKETS] and they may have an extension, too.

 * Hence "[12345678.123]" is the longest we can get. Plus a delimiter space. */

#define WCOLWIDTH 15

/* a "tiny" DTA is a DTA that is stripped from bytes that are not needed for

 * DIR operations */

_Packed struct TINYDTA {

/*  char reserved[21];

  unsigned char attr; */

  unsigned short time_sec2:5;

  unsigned short time_min:6;

  unsigned short time_hour:5;

  unsigned short date_dy:5;

  unsigned short date_mo:4;

  unsigned short date_yr:7;

  unsigned long size;

/*  char fname[13]; */

  char fname[12];

};

/* fills freebytes with free bytes for drv (A=0, B=1, etc)

 * returns DOS ERR code on failure */

static unsigned short cmd_dir_df(unsigned long *freebytes, unsigned char drv) {

  unsigned short res = 0;

  unsigned short sects_per_clust = 0, avail_clusts = 0, bytes_per_sect = 0;

  _asm {

    push ax

    push bx

    push cx

    push dx

    mov ah, 0x36  /* DOS 2+ -- Get Disk Free Space */

    mov dl, [drv] /* A=1, B=2, etc (0 = DEFAULT DRIVE) */

    inc dl

    int 0x21      /* AX=sects_per_clust, BX=avail_clusts, CX=bytes_per_sect, DX=tot_clusters */

    cmp ax, 0xffff /* AX=0xffff on error (invalid drive) */

    jne COMPUTEDF

    mov [res], 0x0f /* fill res with DOS error code 15 ("invalid drive") */

    jmp DONE

    COMPUTEDF:

    /* freebytes = AX * BX * CX */

    mov [sects_per_clust], ax

    mov [avail_clusts], bx

    mov [bytes_per_sect], cx

    DONE:

    pop dx

    pop cx

    pop bx

    pop ax

  }

  /* multiple steps to avoid uint16 overflow */

  *freebytes = sects_per_clust;

  *freebytes *= avail_clusts;

  *freebytes *= bytes_per_sect;

  return(res);

}

static void dir_pagination(unsigned short *availrows) {

  *availrows -= 1;

  if (*availrows == 0) {

    press_any_key();

    *availrows = screen_getheight() - 1;

  }

}

static void dir_print_dirprefix(const char *p) {

  unsigned char t, lastbkslash;

  char buff[2] = {0, 0};

  /* find the last backslash of path */

  lastbkslash = 0;

  for (t = 0; p[t] != 0; t++) {

    if (p[t] == '\\') lastbkslash = t;

  }

  /* print path until last bkslash */

  do {

    *buff = *p;

    output(buff);

    p++;

  } while (lastbkslash-- != 0);

}

/* print the "Directory of C:\ABC\.... string using a buffer with possible

 * file pattern garbage trailing */

static void dir_print_dirof(const char *p, unsigned short *availrows, unsigned char pagination) {

  char buff[2] = {0, 0};

  const char *dirof = svarlang_str(37,20); /* Directory of % */

  outputnl("");

  if (pagination) dir_pagination(availrows);

  /* print string until % */

  while ((*dirof != 0) && (*dirof != '%')) {

    *buff = *dirof;

    output(buff);

    dirof++;

  }

  if (*dirof != '%') return;

  dirof++;

  /* print path until last bkslash */

  dir_print_dirprefix(p);

  /* print the rest of the dirof string */

  while (*dirof != 0) {

    *buff = *dirof;

    output(buff);

    dirof++;

  }

  outputnl("");

  if (pagination) dir_pagination(availrows);

  outputnl("");

  if (pagination) dir_pagination(availrows);

}

/* add a new dirname to path, C:\XXX\*.EXE + YYY -> C:\XXX\YYY\*.EXE */

static void path_add(char *path, const char *dirname) {

  short i, ostatni = -1;

  //printf("path_add(%s,%s) -> ", path, dirname);

  /* find the last backslash */

  for (i = 0; path[i] != 0; i++) {

    if (path[i] == '\\') ostatni = i;

  }

  /* abort on error */

  if (ostatni == -1) return;

  /* do the trick */

  /* move ending to the right */

  memcpy_rtl(path + ostatni + sv_strlen(dirname) + 1, path + ostatni, sv_strlen(path + ostatni) + 1);

  /* fill in the space with dirname */

  memcpy_ltr(path + ostatni + 1, dirname, sv_strlen(dirname));

  //printf("'%s'\n", path);

}

/* take back last dir from path, C:\XXX\YYY\*.EXE -> C:\XXX\*.EXE */

static void path_back(char *path) {

  short i, ostatni = -1, przedostatni = -1;

  //printf("path_back(%s) -> ", path);

  /* find the two last backslashes */

  for (i = 0; path[i] != 0; i++) {

    if (path[i] == '\\') {

      przedostatni = ostatni;

      ostatni = i;

    }

  }

  /* abort on error */

  if (przedostatni == -1) return;

  /* do the trick */

  memcpy_ltr(path + przedostatni, path + ostatni, 1 + i - ostatni);

  //printf("'%s'\n", path);

}

/* parse an attr list like "Ar-hS" and fill bitfield into attrfilter_may and attrfilter_must.

 * /AHS   -> adds S and H to mandatory attribs ("must")

 * /A-S   -> removes S from allowed attribs ("may")

 * returns non-zero on error. */

static int dir_parse_attr_list(const char *arg, unsigned char *attrfilter_may, unsigned char *attrfilter_must) {

  for (; *arg != 0; arg++) {

    unsigned char curattr;

    char not;

    if (*arg == '-') {

      not = 1;

      arg++;

    } else {

      not = 0;

    }

    switch (*arg) {

      case 'd':

      case 'D':

        curattr = DOS_ATTR_DIR;

        break;

      case 'r':

      case 'R':

        curattr = DOS_ATTR_RO;

        break;

      case 'a':

      case 'A':

        curattr = DOS_ATTR_ARC;

        break;

      case 'h':

      case 'H':

        curattr = DOS_ATTR_HID;

        break;

      case 's':

      case 'S':

        curattr = DOS_ATTR_SYS;

        break;

      default:

        return(-1);

    }

    /* update res bitfield */

    if (not) {

      *attrfilter_may &= ~curattr;

    } else {

      *attrfilter_must |= curattr;

    }

  }

  return(0);

}

/* compare attributes in a DTA node to mandatory and optional attributes. returns 1 on match, 0 otherwise */

static int filter_attribs(const struct DTA *dta, unsigned char attrfilter_must, unsigned char attrfilter_may) {

  /* if mandatory attribs are requested, filter them now */

  if ((attrfilter_must & dta->attr) != attrfilter_must) return(0);

  /* if file contains attributes that are not allowed -> skip */

  if ((~attrfilter_may & dta->attr) != 0) return(0);

  return(1);

}

static struct {

  struct TINYDTA far *dtabuf_root;

  char order[8]; /* GNESD values (ucase = lower first ; lcase = higher first) */

  unsigned char sortownia[256]; /* collation table (used for NLS-aware sorts) */

} glob_sortcmp_dat;

/* translates an order string like "GNE-S" into values fed into the order[]

 * table of glob_sortcmp_dat. returns 0 on success, non-zero otherwise. */

static int dir_process_order_directive(const char *ordstring) {

  const char *gnesd = "gnesd"; /* must be lower case */

  int ordi, orderi = 0, i;

  /* tabula rasa */

  glob_sortcmp_dat.order[0] = 0;

  /* /O alone is a short hand for /OGN */

  if (*ordstring == 0) {

    glob_sortcmp_dat.order[0] = 'G';

    glob_sortcmp_dat.order[1] = 'N';

    glob_sortcmp_dat.order[2] = 0;

  }

  /* stupid MSDOS compatibility ("DIR /O:GNE") */

  if (*ordstring == ':') ordstring++;

  /* parsing */

  for (ordi = 0; ordstring[ordi] != 0; ordi++) {

    if (ordstring[ordi] == '-') {

      if ((ordstring[ordi + 1] == '-') || (ordstring[ordi + 1] == 0)) return(-1);

      continue;

    }

    if (orderi == sizeof(glob_sortcmp_dat.order)) return(-1);

    for (i = 0; gnesd[i] != 0; i++) {

      if ((ordstring[ordi] | 32) == gnesd[i]) { /* | 32 is lcase-ing the char */

        if ((ordi > 0) && (ordstring[ordi - 1] == '-')) {

          glob_sortcmp_dat.order[orderi] = gnesd[i];

        } else {

          glob_sortcmp_dat.order[orderi] = gnesd[i] ^ 32;

        }

        orderi++;

        break;

      }

    }

    if (gnesd[i] == 0) return(-1);

  }

  return(0);

}

static int sortcmp(const void *dtaid1, const void *dtaid2) {

  struct TINYDTA far *dta1 = &(glob_sortcmp_dat.dtabuf_root[*((unsigned short *)dtaid1)]);

  struct TINYDTA far *dta2 = &(glob_sortcmp_dat.dtabuf_root[*((unsigned short *)dtaid2)]);

  char *ordconf = glob_sortcmp_dat.order;

  /* debug stuff

  {

    int i;

    printf("%lu vs %lu | ", dta1->size, dta2->size);

    for (i = 0; dta1->fname[i] != 0; i++) printf("%c", dta1->fname[i]);

    printf(" vs ");

    for (i = 0; dta2->fname[i] != 0; i++) printf("%c", dta2->fname[i]);

    printf("\n");

  } */

  for (;;) {

    int r = -1;

    if (*ordconf & 32) r = 1;

    switch (*ordconf | 32) {

      case 'g': /* sort by type (directories first, then files) */

        if ((dta1->time_sec2 & DOS_ATTR_DIR) > (dta2->time_sec2 & DOS_ATTR_DIR)) return(0 - r);

        if ((dta1->time_sec2 & DOS_ATTR_DIR) < (dta2->time_sec2 & DOS_ATTR_DIR)) return(r);

        break;

      case ' ': /* default (last resort) sort: by name */

      case 'e': /* sort by extension */

      case 'n': /* sort by filename */

      {

        const char far *f1 = dta1->fname;

        const char far *f2 = dta2->fname;

        int i, limit = 12;

        /* special handling for '.' and '..' entries */

        if ((f1[0] == '.') && (f2[0] != '.')) return(0 - r);

        if ((f2[0] == '.') && (f1[0] != '.')) return(r);

        if ((*ordconf | 32) == 'e') {

          /* fast-forward to extension or end of filename */

          while ((*f1 != 0) && (*f1 != '.')) f1++;

          while ((*f2 != 0) && (*f2 != '.')) f2++;

          limit = 4; /* TINYDTA structs are not nul-terminated */

        }

        /* cmp */

        for (i = 0; i < limit; i++) {

          if ((glob_sortcmp_dat.sortownia[(unsigned char)(*f1)]) < (glob_sortcmp_dat.sortownia[(unsigned char)(*f2)])) return(0 - r);

          if ((glob_sortcmp_dat.sortownia[(unsigned char)(*f1)]) > (glob_sortcmp_dat.sortownia[(unsigned char)(*f2)])) return(r);

          if (*f1 == 0) break;

          f1++;

          f2++;

        }

      }

        break;

      case 's': /* sort by size */

        if (dta1->size > dta2->size) return(r);

        if (dta1->size < dta2->size) return(0 - r);

        break;

      case 'd': /* sort by date */

        if (dta1->date_yr < dta2->date_yr) return(0 - r);

        if (dta1->date_yr > dta2->date_yr) return(r);

        if (dta1->date_mo < dta2->date_mo) return(0 - r);

        if (dta1->date_mo > dta2->date_mo) return(r);

        if (dta1->date_dy < dta2->date_dy) return(0 - r);

        if (dta1->date_dy > dta2->date_dy) return(r);

        if (dta1->time_hour < dta2->time_hour) return(0 - r);

        if (dta1->time_hour > dta2->time_hour) return(r);

        if (dta1->time_min < dta2->time_min) return(0 - r);

        if (dta1->time_min > dta2->time_min) return(r);

        break;

    }

    if (*ordconf == 0) break;

    ordconf++;

  }

  return(0);

}

#define DIR_ATTR_DEFAULT (DOS_ATTR_RO | DOS_ATTR_DIR | DOS_ATTR_ARC)

struct dirrequest {

  unsigned char attrfilter_may;

  unsigned char attrfilter_must;

  const char *filespecptr;

  #define DIR_FLAG_PAUSE  1

  #define DIR_FLAG_RECUR  4

  #define DIR_FLAG_LCASE  8

  #define DIR_FLAG_SORT  16

  unsigned char flags;

  #define DIR_OUTPUT_NORM 1

  #define DIR_OUTPUT_WIDE 2

  #define DIR_OUTPUT_BARE 3

  unsigned char format;

};

static int dir_parse_cmdline(struct dirrequest *req, const char **argv) {

  for (; *argv != NULL; argv++) {

    if (*argv[0] == '/') {

      const char *arg = *argv + 1;

      char neg = 0;

      /* detect negations and get actual argument */

      if (*arg == '-') {

        neg = 1;

        arg++;

      }

      /* */

      switch (*arg) {

        case 'a':

        case 'A':

          arg++;

          /* preset defaults */

          req->attrfilter_may = DIR_ATTR_DEFAULT;

          req->attrfilter_must = 0;

          /* /-A only allowed without further parameters (used to cancel possible previous /Asmth) */

          if (neg) {

            if (*arg != 0) {

              nls_outputnl_err(0, 2); /* invalid switch */

              return(-1);

            }

          } else {

            /* skip colon if present */

            if (*arg == ':') arg++;

            /* start with "allow everything" */

            req->attrfilter_may = (DOS_ATTR_ARC | DOS_ATTR_DIR | DOS_ATTR_HID | DOS_ATTR_SYS | DOS_ATTR_RO);

            if (dir_parse_attr_list(arg, &(req->attrfilter_may), &(req->attrfilter_must)) != 0) {

              nls_outputnl_err(0, 3); /* invalid parameter format */

              return(-1);

            }

          }

          break;

        case 'b':

        case 'B':

          req->format = DIR_OUTPUT_BARE;

          break;

        case 'l':

        case 'L':

          req->flags |= DIR_FLAG_LCASE;

          break;

        case 'o':

        case 'O':

          if (neg) {

            req->flags &= (0xff ^ DIR_FLAG_SORT);

            break;

          }

          if (dir_process_order_directive(arg+1) != 0) {

            nls_output_err(0, 3); /* invalid parameter format */

            output(": ");

            outputnl(arg);

            return(-1);

          }

          req->flags |= DIR_FLAG_SORT;

          break;

        case 'p':

        case 'P':

          req->flags |= DIR_FLAG_PAUSE;

          if (neg) req->flags &= (0xff ^ DIR_FLAG_PAUSE);

          break;

        case 's':

        case 'S':

          req->flags |= DIR_FLAG_RECUR;

          break;

        case 'w':

        case 'W':

          req->format = DIR_OUTPUT_WIDE;

          break;

        default:

          nls_outputnl_err(0, 2); /* invalid switch */

          return(-1);

      }

    } else {  /* filespec */

      if (req->filespecptr != NULL) {

        nls_outputnl_err(0, 4); /* too many parameters */

        return(-1);

      }

      req->filespecptr = *argv;

    }

  }

  return(0);

}

static void dir_print_summary_files(char *buff64, unsigned short uint32maxlen, unsigned long summary_totsz, unsigned long summary_fcount, unsigned short *availrows, unsigned char flags, const struct nls_patterns *nls) {

  unsigned short i;

  /* x file(s) (maximum of files in a FAT-32 directory is 65'535) */

  sv_memset(buff64, ' ', 8);

  buff64[8] = 0;

  i = nls_format_number(buff64 + 8, summary_fcount, nls);

  output(buff64 + i);

  output(" ");

  output(svarlang_str(37,22)); /* "file(s)" */

  output(" ");

  /* xxxx bytes */

  sv_memset(buff64, ' ', 14);

  i = nls_format_number(buff64 + uint32maxlen, summary_totsz, nls);

  output(buff64 + i + 1);

  output(" ");

  nls_outputnl(37,23); /* "bytes" */

  if (flags & DIR_FLAG_PAUSE) dir_pagination(availrows);

}

#define MAX_SORTABLE_FILES 8192

static enum cmd_result cmd_dir(struct cmd_funcparam *p) {

  struct DTA *dta = (void *)0x80; /* set DTA to its default location at 80h in PSP */

  struct TINYDTA far *dtabuf = NULL; /* used to buffer results when sorting is enabled */

  unsigned short dtabufcount = 0;

  unsigned short i;

  unsigned short availrows;  /* counter of available rows on display (used for /P) */

  unsigned short screenw = screen_getwidth();

  unsigned short wcols = screenw / WCOLWIDTH; /* number of columns in wide mode */

  unsigned char wcolcount;

  struct {

    struct nls_patterns nls;

    char buff64[64];

    char path[128];

    struct DTA dtastack[64]; /* used for /S, max number of subdirs in DOS5 is 42 (A/B/C/...) */

    unsigned char dtastacklen;

    unsigned short orderidx[MAX_SORTABLE_FILES / sizeof(struct TINYDTA)];

  } *buf;

  unsigned long summary_recurs_fcount = 0; /* used for /s global summary */

  unsigned long summary_recurs_totsz = 0;  /* used for /s global summary */

  unsigned long summary_fcount;

  unsigned long summary_totsz;

  unsigned char drv = 0;

  struct dirrequest req;

  unsigned short summary_alignpos = sv_strlen(svarlang_str(37,22)) + 2;

  unsigned short uint32maxlen = 14; /* 13 is the max len of a 32 bit number with thousand separators (4'000'000'000) */

  if (screenw < 80) uint32maxlen = 10;

  if (cmd_ishlp(p)) {

    nls_outputnl(37,0); /* "Displays a list of files and subdirectories in a directory" */

    outputnl("");

    nls_outputnl(37,1); /* "DIR [drive:][path][filename] [/P] [/W] [/A[:]attributes] [/O[[:]sortorder]] [/S] [/B] [/L]" */

    outputnl("");

    nls_outputnl(37,2); /* "/P Pauses after each screenful of information" */

    nls_outputnl(37,3); /* "/W Uses wide list format" */

    outputnl("");

    nls_outputnl(37,4); /* "/A Displays files with specified attributes:" */

    nls_outputnl(37,5); /* "    D Directories            R Read-only files        H Hidden files" */

    nls_outputnl(37,6); /* "    A Ready for archiving    S System files           - prefix meaning "not"" */

    outputnl("");

    nls_outputnl(37,7); /* "/O List files in sorted order:" */

    nls_outputnl(37,8); /* "    N by name                S by size                E by extension" */

    nls_outputnl(37,9); /* "    D by date                G group dirs first       - prefix to reverse order" */

    outputnl("");

    nls_outputnl(37,10); /* "/S Displays files in specified directory and all subdirectories" */

    nls_outputnl(37,11); /* "/B Uses bare format (no heading information or summary)" */

    nls_outputnl(37,12); /* "/L Uses lowercases" */

    goto GAMEOVER;

  }

  /* allocate buf */

  buf = calloc(sizeof(*buf), 1);

  if (buf == NULL) {

    nls_output_err(255, 8); /* insufficient memory */

    goto GAMEOVER;

  }

  /* zero out glob_sortcmp_dat and init the collation table */

  sv_bzero(&glob_sortcmp_dat, sizeof(glob_sortcmp_dat));

  for (i = 0; i < 256; i++) {

    glob_sortcmp_dat.sortownia[i] = i;

    /* sorting should be case-insensitive */

    if ((i >= 'A') && (i <= 'Z')) glob_sortcmp_dat.sortownia[i] |= 32;

  }

  /* try to replace (or complement) my naive collation table with an NLS-aware

   * version provided by the kernel (or NLSFUNC)

   * see https://github.com/SvarDOS/bugz/issues/68 for some thoughts */

  {

    _Packed struct nlsseqtab {

      unsigned char id;

      unsigned short taboff;

      unsigned short tabseg;

    } collat;

    void *colptr = &collat;

    unsigned char errflag = 1;

    _asm {

      push ax

      push bx

      push cx

      push dx

      push di

      push es

      mov ax, 0x6506  /* DOS 3.3+ - Get collating sequence table */

      mov bx, 0xffff  /* code page, FFFFh = "current" */

      mov cx, 5       /* size of buffer at ES:DI */

      mov dx, 0xffff  /* country id, FFFFh = "current" */

      push ds

      pop es          /* ES:DI = address of buffer for the 5-bytes struct */

      mov di, colptr

      int 0x21

      jc FAIL

      xor al, al

      mov errflag, al

      FAIL:

      pop es

      pop di

      pop dx

      pop cx

      pop bx

      pop ax

    }

    if ((errflag == 0) && (collat.id == 6)) {

      unsigned char far *ptr = MK_FP(collat.tabseg, collat.taboff);

      unsigned short count = *(unsigned short far *)ptr;

#ifdef DIR_DUMPNLSCOLLATE

      printf("NLS AT %04X:%04X (%u elements)\n", collat.tabseg, collat.taboff, count);

#endif

      if (count <= 256) { /* you never know */

        ptr += 2; /* skip the count header */

        for (i = 0; i < count; i++) {

          glob_sortcmp_dat.sortownia[i] = ptr[i];

#ifdef DIR_DUMPNLSCOLLATE

          printf(" %03u", ptr[i]);

          if ((i & 15) == 15) {

            printf("\n");

            fflush(stdout);

          }

#endif

        }

      }

    }

  }

  i = nls_getpatterns(&(buf->nls));

  if (i != 0) nls_outputnl_doserr(i);

  /* disable usage of thousands separator on narrow screens */

  if (screenw < 80) buf->nls.thousep[0] = 0;

  /*** PARSING COMMAND LINE STARTS *******************************************/

  /* init req with some defaults */

  sv_bzero(&req, sizeof(req));

  req.attrfilter_may = DIR_ATTR_DEFAULT;

  req.format = DIR_OUTPUT_NORM;

  /* process DIRCMD first (so it can be overidden by user's cmdline) */

  {

  const char far *dircmd = env_lookup_val(p->env_seg, "DIRCMD");

  if (dircmd != NULL) {

    const char *argvptrs[32];

    cmd_explode(buf->buff64, dircmd, argvptrs);

    if ((dir_parse_cmdline(&req, argvptrs) != 0) || (req.filespecptr != NULL)) {

      nls_output(255, 10);/* bad environment */

      output(" - ");

      outputnl("DIRCMD");

      goto GAMEOVER;

    }

  }

  }

  /* parse user's command line */

  if (dir_parse_cmdline(&req, p->argv) != 0) goto GAMEOVER;

  /*** PARSING COMMAND LINE DONE *********************************************/

  /* if no filespec provided, then it's about the current directory */

  if (req.filespecptr == NULL) req.filespecptr = ".";

  availrows = screen_getheight() - 1;

  /* special case: "DIR drive:" (truename() fails on "C:" under MS-DOS 6.0) */

  if ((req.filespecptr[0] != 0) && (req.filespecptr[1] == ':') && (req.filespecptr[2] == 0)) {

    if ((req.filespecptr[0] >= 'a') && (req.filespecptr[0] <= 'z')) {

      buf->path[0] = req.filespecptr[0] - ('a' - 1);

    } else {

      buf->path[0] = req.filespecptr[0] - ('A' - 1);

    }

    i = curpathfordrv(buf->path, buf->path[0]);

  } else {

    i = file_truename(req.filespecptr, buf->path);

  }

  if (i != 0) {

    nls_outputnl_doserr(i);

    goto GAMEOVER;

  }

  /* volume label and serial */

  if (req.format != DIR_OUTPUT_BARE) {

    drv = buf->path[0];

    if (drv >= 'a') {

      drv -= 'a';

    } else {

      drv -= 'A';

    }

    cmd_vol_internal(drv, buf->buff64);

    availrows -= 2;

  }

  NEXT_ITER: /* re-entry point for /S recursing */

  summary_fcount = 0;

  summary_totsz = 0;

  /* if dir: append a backslash (also get its len) */

  i = path_appendbkslash_if_dir(buf->path);

  /* if ends with a \ then append ????????.??? */

  if (buf->path[i - 1] == '\\') sv_strcat(buf->path, "????????.???");

  /* ask DOS for list of files, but only with allowed attribs */

  i = findfirst(dta, buf->path, req.attrfilter_may);

  /* print "directory of" unless /B or /S mode with no match */

  if ((req.format != DIR_OUTPUT_BARE) && (((req.flags & DIR_FLAG_RECUR) == 0) || (i == 0))) {

    dir_print_dirof(buf->path, &availrows, req.flags & DIR_FLAG_PAUSE);

  }

  /* if no file match then abort */

  if (i != 0) {

    if (req.flags & DIR_FLAG_RECUR) goto CHECK_RECURS;

    nls_outputnl_doserr(i);

    goto GAMEOVER;

  }

  /* if sorting is involved, then let's buffer all results (and sort them) */

  if (req.flags & DIR_FLAG_SORT) {

    /* allocate a memory buffer - try several sizes until one succeeds */

    unsigned short max_dta_bufcount;

    /* compute the amount of DTAs I can buffer */