WebSVN – SvarDOS – Diff – /svarcom/trunk/helpers.c


/* This file is part of the SvarCOM project and is published under the terms
 * of the MIT license.
 *
 * Copyright (C) 2021-2022 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.
 */
 
/*
 * a variety of helper functions
 */
 
#include <i86.h>    /* MK_FP() */
#include <stdio.h>  /* sprintf() */
#include <string.h> /* memcpy() */
 
#include "svarlang.lib\svarlang.h"
 
#include "env.h"
 
#include "helpers.h"
 
 
 
/* case-insensitive comparison of strings, compares up to maxlen characters.
 * returns non-zero on equality. */
int imatchlim(const char *s1, const char *s2, unsigned short maxlen) {
  while (maxlen--) {
    char c1, c2;
    c1 = *s1;
    c2 = *s2;
    if ((c1 >= 'a') && (c1 <= 'z')) c1 -= ('a' - 'A');
    if ((c2 >= 'a') && (c2 <= 'z')) c2 -= ('a' - 'A');
    /* */
    if (c1 != c2) return(0);
    if (c1 == 0) break;
    s1++;
    s2++;
  }
  return(1);
}
 
 
/* returns zero if s1 starts with s2 */
int strstartswith(const char *s1, const char *s2) {
  while (*s2 != 0) {
    if (*s1 != *s2) return(-1);
    s1++;
    s2++;
  }
  return(0);
}
 
 
/* outputs a NULL-terminated string to handle (1=stdout 2=stderr) */
void output_internal(const char *s, unsigned char nl, unsigned char handle) {
  const static unsigned char *crlf = "\r\n";
  _asm {
    push ds
    pop es         /* make sure es=ds (scasb uses es) */
    /* get length of s into CX */
    mov ax, 0x4000 /* ah=DOS "write to file" and AL=0 for NULL matching */
    mov dx, s      /* set dx to string (required for later) */
    mov di, dx     /* set di to string (for NULL matching) */
    mov cx, 0xffff /* preset cx to 65535 (-1) */
    cld            /* clear DF so scasb increments DI */
    repne scasb    /* cmp al, es:[di], inc di, dec cx until match found */
    /* CX contains (65535 - strlen(s)) now */
    not cx         /* reverse all bits so I get (strlen(s) + 1) */
    dec cx         /* this is CX length */
    jz WRITEDONE   /* do nothing for empty strings */
 
    /* output by writing to stdout */
    /* mov ah, 0x40 */  /* DOS 2+ -- write to file via handle */
    xor bh, bh
    mov bl, handle /* set handle (1=stdout 2=stderr) */
    /* mov cx, xxx */ /* write CX bytes */
    /* mov dx, s   */ /* DS:DX is the source of bytes to "write" */
    int 0x21
    WRITEDONE:
 
    /* print out a CR/LF trailer if nl set */
    test byte ptr [nl], 0xff
    jz FINITO
    /* bx still contains handle */
    mov ah, 0x40 /* "write to file" */
    mov cx, 2
    mov dx, crlf
    int 0x21
    FINITO:
  }
}
 
 
void nls_output_internal(unsigned short id, unsigned char nl, unsigned char handle) {
  const char *NOTFOUND = "NLS_STRING_NOT_FOUND";
  const char *ptr = svarlang_strid(id);
  if ((ptr == NULL) || (ptr[0]) == 0) ptr = NOTFOUND;
  output_internal(ptr, nl, handle);
}
 
 
/* output DOS error e to stdout, if stdout is redirected then *additionally*
 * also to stderr */
void nls_outputnl_doserr(unsigned short e) {
  static char errstr[16];
  const char *ptr = NULL;
  unsigned char redirflag = 0;
  /* find string in nls block */
  if (e < 0xff) ptr = svarlang_strid(0xff00 | e);
  /* if not found, use a fallback */
  if (ptr == NULL) {
    sprintf(errstr, "DOS ERR %u", e);
    ptr = errstr;
  }
 
  /* display to stdout */
  output_internal(ptr, 1, hSTDOUT);
 
  /* is stdout redirected? */
  _asm {
    push bx
    push dx
 
    mov ax, 0x4400   /* query device flags */
    mov bx, 1        /* stdout */
    int 0x21
    /* CF set on error and AX filled with DOS error,
     * returns flags in DX on succes:
     *  bit 7 reset if handle points to a file, set if handle points to a device  */
    jc FAIL
    mov redirflag, dl
    and redirflag, 128
 
    FAIL:
    pop dx
    pop bx
  }
 
  if (redirflag == 0) output_internal(ptr, 1, hSTDERR);
}
 
 
/* find first matching files using a FindFirst DOS call
 * returns 0 on success or a DOS err code on failure */
unsigned short findfirst(struct DTA *dta, const char *pattern, unsigned short attr) {
  unsigned short res = 0;
  _asm {
    /* set DTA location */
    mov ah, 0x1a
    mov dx, dta
    int 0x21
    /* */
    mov ah, 0x4e    /* FindFirst */
    mov dx, pattern
    mov cx, attr
    int 0x21        /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */
    jnc DONE
    mov [res], ax
    DONE:
  }
  return(res);
}
 
 
/* find next matching, ie. continues an action intiated by findfirst() */
unsigned short findnext(struct DTA *dta) {
  unsigned short res = 0;
  _asm {
    mov ah, 0x4f    /* FindNext */
    mov dx, dta
    int 0x21        /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */
    jnc DONE
    mov [res], ax
    DONE:
  }
  return(res);
}
 
 
/* print s string and wait for a single key press from stdin. accepts only
 * key presses defined in the c ASCIIZ string. returns offset of pressed key
 * in string. keys in c MUST BE UPPERCASE! */
unsigned short askchoice(const char *s, const char *c) {
  unsigned short res;
  char cstr[2] = {0,0};
  char key = 0;
 
  AGAIN:
  output(s);
  output(" ");
  output("(");
  for (res = 0; c[res] != 0; res++) {
    if (res != 0) output("/");
    cstr[0] = c[res];
    output(cstr);
  }
  output(") ");
 
  _asm {
    push ax
    push dx
 
    mov ax, 0x0c01 /* clear input buffer and execute getchar (INT 21h,AH=1) */
    int 0x21
    /* if AL == 0 then this is an extended character */
    test al, al
    jnz GOTCHAR
    mov ah, 0x08   /* read again to flush extended char from input buffer */
    int 0x21
    xor al, al     /* all extended chars are ignored */
    GOTCHAR:       /* received key is in AL now */
    mov [key], al  /* save key */
 
    /* print a cr/lf */
    mov ah, 0x02
    mov dl, 0x0D
    int 0x21
    mov dl, 0x0A
    int 0x21
 
    pop dx
    pop ax
  }
 
  /* ucase() result */
  if ((key >= 'a') && (key <= 'z')) key -= ('a' - 'A');
 
  /* is there a match? */
  for (res = 0; c[res] != 0; res++) if (c[res] == key) return(res);
 
  goto AGAIN;
}
 
 
/* converts a path to its canonic representation, returns 0 on success
 * or DOS err on failure (invalid drive) */
unsigned short file_truename(const char *src, char *dst) {
  unsigned short res = 0;
  _asm {
    push es
    mov ah, 0x60  /* query truename, DS:SI=src, ES:DI=dst */
    push ds
    pop es
    mov si, src
    mov di, dst
    int 0x21
    jnc DONE
    mov [res], ax
    DONE:
    pop es
  }
  return(res);
}
 
 
/* returns DOS attributes of file, or -1 on error */
int file_getattr(const char *fname) {
  int res = -1;
  _asm {
    mov ax, 0x4300  /* query file attributes, fname at DS:DX */
    mov dx, fname
    int 0x21        /* CX=attributes if CF=0, otherwise AX=errno */
    jc DONE
    mov [res], cx
    DONE:
  }
  return(res);
}
 
 
/* returns screen's width (in columns) */
unsigned short screen_getwidth(void) {
  /* BIOS 0040:004A = word containing screen width in text columns */
  unsigned short far *scrw = MK_FP(0x40, 0x4a);
  return(*scrw);
}
 
 
/* returns screen's height (in rows) */
unsigned short screen_getheight(void) {
  /* BIOS 0040:0084 = byte containing maximum valid row value (EGA ONLY) */
  unsigned char far *scrh = MK_FP(0x40, 0x84);
  if (*scrh == 0) return(25);  /* pre-EGA adapter */
  return(*scrh + 1);
}
 
 
/* displays the "Press any key to continue" msg and waits for a keypress */
void press_any_key(void) {
  nls_output(15, 1); /* Press any key to continue... */
  _asm {
    mov ah, 0x08  /* no echo console input */
    int 0x21      /* pressed key in AL now (0 for extended keys) */
    test al, al
    jnz DONE
    int 0x21      /* executed ah=8 again to read the rest of extended key */
    DONE:
    /* output CR/LF */
    mov ah, 0x02
    mov dl, 0x0D
    int 0x21
    mov dl, 0x0A
    int 0x21
  }
}
 
 
/* validate a drive (A=0, B=1, etc). returns 1 if valid, 0 otherwise */
int isdrivevalid(unsigned char drv) {
  _asm {
    mov ah, 0x19  /* query default (current) disk */
    int 0x21      /* drive in AL (0=A, 1=B, etc) */
    mov ch, al    /* save current drive to ch */
    /* try setting up the drive as current */
    mov ah, 0x0E   /* select default drive */
    mov dl, [drv]  /* 0=A, 1=B, etc */
    int 0x21
    /* this call does not set CF on error, I must check cur drive to look for success */
    mov ah, 0x19  /* query default (current) disk */
    int 0x21      /* drive in AL (0=A, 1=B, etc) */
    mov [drv], 1  /* preset result as success */
    cmp al, dl    /* is eq? */
    je DONE
    mov [drv], 0  /* fail */
    jmp FAILED
    DONE:
    /* set current drive back to what it was initially */
    mov ah, 0x0E
    mov dl, ch
    int 0x21
    FAILED:
  }
  return(drv);
}
 
 
/* converts a 8+3 filename into 11-bytes FCB format (MYFILE  EXT) */
void file_fname2fcb(char *dst, const char *src) {
  unsigned short i;
 
  /* fill dst with 11 spaces and a NULL terminator */
  for (i = 0; i < 11; i++) dst[i] = ' ';
  dst[11] = 0;
 
  /* copy fname until dot (.) or 8 characters */
  for (i = 0; i < 8; i++) {
    if ((src[i] == '.') || (src[i] == 0)) break;
    dst[i] = src[i];
  }
 
  /* advance src until extension or end of string */
  src += i;
  for (;;) {
    if (*src == '.') {
      src++; /* next character is extension */
      break;
    }
    if (*src == 0) break;
  }
 
  /* copy extension to dst (3 chars max) */
  dst += 8;
  for (i = 0; i < 3; i++) {
    if (src[i] == 0) break;
    dst[i] = src[i];
  }
}
 
 
/* converts a 11-bytes FCB filename (MYFILE  EXT) into 8+3 format (MYFILE.EXT) */
void file_fcb2fname(char *dst, const char *src) {
  unsigned short i, end = 0;
 
  for (i = 0; i < 8; i++) {
    dst[i] = src[i];
    if (dst[i] != ' ') end = i + 1;
  }
 
  /* is there an extension? */
  if (src[8] == ' ') {
    dst[end] = 0;
  } else { /* found extension: copy it until first space */
    dst[end++] = '.';
    for (i = 8; i < 11; i++) {
      if (src[i] == ' ') break;
      dst[end++] = src[i];
    }
    dst[end] = 0;
  }
}
 
 
/* converts an ASCIIZ string into an unsigned short. returns 0 on success.
 * on error, result will contain all valid digits that were read until
 * error occurred (0 on overflow or if parsing failed immediately) */
int atous(unsigned short *r, const char *s) {
  int err = 0;
 
  _asm {
    mov si, s
    xor ax, ax  /* general purpose register */
    xor cx, cx  /* contains the result */
    mov bx, 10  /* used as a multiplicative step */
 
    NEXTBYTE:
    xchg cx, ax /* move result into cx temporarily */
    lodsb  /* AL = DS:[SI++] */
    /* is AL 0? if so we're done */
    test al, al
    jz DONE
    /* validate that AL is in range '0'-'9' */
    sub al, '0'
    jc FAIL   /* invalid character detected */
    cmp al, 9
    jg FAIL   /* invalid character detected */
    /* restore result into AX (CX contains the new digit) */
    xchg cx, ax
    /* multiply result by 10 and add cl */
    mul bx    /* DX AX = AX * BX(10) */
    jc OVERFLOW  /* overflow */
    add ax, cx
    /* if CF is set then overflow occurred (overflow part lands in DX) */
    jnc NEXTBYTE
 
    OVERFLOW:
    xor cx, cx  /* make sure result is zeroed in case overflow occured */
 
    FAIL:
    inc [err]
 
    DONE: /* save result (CX) into indirect memory address r */
    mov bx, [r]
    mov [bx], cx
  }
  return(err);
}
 
 
/* appends a backslash if path is a directory
 * returns the (possibly updated) length of path */
unsigned short path_appendbkslash_if_dir(char *path) {
  unsigned short len;
  int attr;
  for (len = 0; path[len] != 0; len++);
  if (len == 0) return(0);
  if (path[len - 1] == '\\') return(len);
  /* */
  attr = file_getattr(path);
  if ((attr > 0) && (attr & DOS_ATTR_DIR)) {
    path[len++] = '\\';
    path[len] = 0;
  }
  return(len);
}
 
 
/* get current path drive d (A=1, B=2, etc - 0 is "current drive")
 * returns 0 on success, doserr otherwise */
unsigned short curpathfordrv(char *buff, unsigned char d) {
  unsigned short r = 0;
 
  _asm {
    /* is d == 0? then I need to resolve current drive */
    cmp byte ptr [d], 0
    jne GETCWD
    /* resolve cur drive */
    mov ah, 0x19  /* get current default drive */
    int 0x21      /* al = drive (00h = A:, 01h = B:, etc) */
    inc al        /* convert to 1=A, 2=B, etc */
    mov [d], al
 
    GETCWD:
    /* prepend buff with drive:\ */
    mov si, buff
    mov dl, [d]
    mov [si], dl
    add byte ptr [si], 'A' - 1
    inc si
    mov [si], ':'
    inc si
    mov [si], '\\'
    inc si
 
    mov ah, 0x47      /* get current directory of drv DL into DS:SI */
    int 0x21
    jnc DONE
    mov [r], ax       /* copy result from ax */
 
    DONE:
  }
 
  return(r);
}
 
 
/* fills a nls_patterns struct with current NLS patterns, returns 0 on success, DOS errcode otherwise */
unsigned short nls_getpatterns(struct nls_patterns *p) {
  unsigned short r = 0;
 
  _asm {
    mov ax, 0x3800  /* DOS 2+ -- Get Country Info for current country */
    mov dx, p       /* DS:DX points to the CountryInfoRec buffer */
    int 0x21
    jnc DONE
    mov [r], ax     /* copy DOS err code to r */
    DONE:
  }
 
  return(r);
}
 
 
/* computes a formatted date based on NLS patterns found in p
 * returns length of result */
unsigned short nls_format_date(char *s, unsigned short yr, unsigned char mo, unsigned char dy, const struct nls_patterns *p) {
  unsigned short items[3];
  /* preset date/month/year in proper order depending on date format */
  switch (p->dateformat) {
    case 0:  /* USA style: m d y */
      items[0] = mo;
      items[1] = dy;
      items[2] = yr;
      break;
    case 1:  /* EU style: d m y */
      items[0] = dy;
      items[1] = mo;
      items[2] = yr;
      break;
    case 2:  /* Japan-style: y m d */
    default:
      items[0] = yr;
      items[1] = mo;
      items[2] = dy;
      break;
  }
  /* compute the string */
  return(sprintf(s, "%02u%s%02u%s%02u", items[0], p->datesep, items[1], p->datesep, items[2]));
}
 
 
/* computes a formatted time based on NLS patterns found in p, sc are ignored if set 0xff
 * returns length of result */
unsigned short nls_format_time(char *s, unsigned char ho, unsigned char mn, unsigned char sc, const struct nls_patterns *p) {
  char ampm = 0;
  unsigned short res;
 
  if (p->timefmt == 0) {
    if (ho == 12) {
      ampm = 'p';
    } else if (ho > 12) {
      ho -= 12;
      ampm = 'p';
    } else { /* ho < 12 */
      if (ho == 0) ho = 12;
      ampm = 'a';
    }
    res = sprintf(s, "%2u", ho);
  } else {
    res = sprintf(s, "%02u", ho);
  }
 
  /* append separator and minutes */
  res += sprintf(s + res, "%s%02u", p->timesep, mn);
 
  /* if seconds provided, append them, too */
  if (sc != 0xff) res += sprintf(s + res, "%s%02u", p->timesep, sc);
 
  /* finally append AM/PM char */
  if (ampm != 0) s[res++] = ampm;
  s[res] = 0;
 
  return(res);
}
 
 
/* computes a formatted integer number based on NLS patterns found in p
 * returns length of result */
unsigned short nls_format_number(char *s, unsigned long num, const struct nls_patterns *p) {
  unsigned short sl = 0, i;
  unsigned char thcount = 0;
 
  /* write the value (reverse) with thousand separators (if any defined) */
  do {
    if ((thcount == 3) && (p->thousep[0] != 0)) {
      s[sl++] = p->thousep[0];
      thcount = 0;
    }
    s[sl++] = '0' + num % 10;
    num /= 10;
    thcount++;
  } while (num > 0);
 
  /* terminate the string */
  s[sl] = 0;
 
  /* reverse the string now (has been built in reverse) */
  for (i = sl / 2 + (sl & 1); i < sl; i++) {
    thcount = s[i];
    s[i] = s[sl - (i + 1)];   /* abc'de  if i=3 then ' <-> c */
    s[sl - (i + 1)] = thcount;
  }
 
  return(sl);
}
 
 
/* reload nls ressources from svarcom.lng into svarlang_mem */
void nls_langreload(char *buff, unsigned short env) {
  const char far *nlspath;
  const char far *lang;
  static unsigned short lastlang;
 
  /* look up the LANG env variable, upcase it and copy to lang */
  lang = env_lookup_val(env, "LANG");
  if ((lang == NULL) || (lang[0] == 0)) return;
  _fmemcpy(buff, lang, 2);
  buff[2] = 0;
 
  /* check if there is need to reload at all */
  if (memcmp(&lastlang, buff, 2) == 0) return;
 
  buff[4] = 0;
  nlspath = env_lookup_val(env, "NLSPATH");
  if (nlspath != NULL) _fstrcpy(buff + 4, nlspath);
 
  if (svarlang_load("SVARCOM", buff, buff + 4) != 0) return;
 
  _fmemcpy(&lastlang, lang, 2);
}
 
 
/* locates executable fname in path and fill res with result. returns 0 on success,
 * -1 on failed match and -2 on failed match + "don't even try with other paths"
 * extptr is filled with a ptr to the extension in fname (NULL if no extension) */
int lookup_cmd(char *res, const char *fname, const char *path, const char **extptr) {
  unsigned short lastbslash = 0;
  unsigned short i, len;
  unsigned char explicitpath = 0;
 
  /* does the original fname has an explicit path prefix or explicit ext? */
  *extptr = NULL;
  for (i = 0; fname[i] != 0; i++) {
    switch (fname[i]) {
      case ':':
      case '\\':
        explicitpath = 1;
        *extptr = NULL; /* extension is the last dot AFTER all path delimiters */
        break;
      case '.':
        *extptr = fname + i + 1;
        break;
    }
  }
 
  /* normalize filename */
  if (file_truename(fname, res) != 0) return(-2);
 
  /* printf("truename: %s\r\n", res); */
 
  /* figure out where the command starts and if it has an explicit extension */
  for (len = 0; res[len] != 0; len++) {
    switch (res[len]) {
      case '?':   /* abort on any wildcard character */
      case '*':
        return(-2);
      case '\\':
        lastbslash = len;
        break;
    }
  }
 
  /* printf("lastbslash=%u\r\n", lastbslash); */
 
  /* if no path prefix was found in fname (no colon or backslash) AND we have
   * a path arg, then assemble path+filename */
  if ((!explicitpath) && (path != NULL) && (path[0] != 0)) {
    i = strlen(path);
    if (path[i - 1] != '\\') i++; /* add a byte for inserting a bkslash after path */
    /* move the filename at the place where path will end */
    memmove(res + i, res + lastbslash + 1, len - lastbslash);
    /* copy path in front of the filename and make sure there is a bkslash sep */
    memmove(res, path, i);
    res[i - 1] = '\\';
  }
 
  /* if no extension was initially provided, try matching COM, EXE, BAT */
  if (*extptr == NULL) {
    const char *ext[] = {".COM", ".EXE", ".BAT", NULL};
    len = strlen(res);
    for (i = 0; ext[i] != NULL; i++) {
      strcpy(res + len, ext[i]);
      /* printf("? '%s'\r\n", res); */
      *extptr = ext[i] + 1;
      if (file_getattr(res) >= 0) return(0);
    }
  } else { /* try finding it as-is */
    /* printf("? '%s'\r\n", res); */
    if (file_getattr(res) >= 0) return(0);
  }
 
  /* not found */
  if (explicitpath) return(-2); /* don't bother trying other paths, the caller had its own path preset anyway */
  return(-1);
}
 
 
/* fills fname with the path and filename to the linkfile related to the
 * executable link "linkname". returns 0 on success. */
int link_computefname(char *fname, const char *linkname, unsigned short env_seg) {
  unsigned short pathlen;
 
  /* fetch %DOSDIR% */
  pathlen = env_lookup_valcopy(fname, 128, env_seg, "DOSDIR");
  if (pathlen == 0) {
    outputnl("%DOSDIR% not defined");
    return(-1);
  }
 
  /* prep filename: %DOSDIR%\LINKS\PKG.LNK */
  if (fname[pathlen - 1] == '\\') pathlen--;
  sprintf(fname + pathlen, "\\LINKS\\%s.LNK", linkname);
 
  return(0);
}
 

Rev 985	Rev 1001
1	`/* This file is part of the SvarCOM project and is published under the terms`	1	`/* This file is part of the SvarCOM project and is published under the terms`
2	`* of the MIT license.`	2	`* of the MIT license.`
3	`*`	3	`*`
4	`* Copyright (C) 2021-2022 Mateusz Viste`	4	`* Copyright (C) 2021-2022 Mateusz Viste`
5	`*`	5	`*`
6	`* Permission is hereby granted, free of charge, to any person obtaining a`	6	`* Permission is hereby granted, free of charge, to any person obtaining a`
7	`* copy of this software and associated documentation files (the "Software"),`	7	`* copy of this software and associated documentation files (the "Software"),`
8	`* to deal in the Software without restriction, including without limitation`	8	`* to deal in the Software without restriction, including without limitation`
9	`* the rights to use, copy, modify, merge, publish, distribute, sublicense,`	9	`* the rights to use, copy, modify, merge, publish, distribute, sublicense,`
10	`* and/or sell copies of the Software, and to permit persons to whom the`	10	`* and/or sell copies of the Software, and to permit persons to whom the`
11	`* Software is furnished to do so, subject to the following conditions:`	11	`* Software is furnished to do so, subject to the following conditions:`
12	`*`	12	`*`
13	`* The above copyright notice and this permission notice shall be included in`	13	`* The above copyright notice and this permission notice shall be included in`
14	`* all copies or substantial portions of the Software.`	14	`* all copies or substantial portions of the Software.`
15	`*`	15	`*`
16	`* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR`	16	`* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR`
17	`* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,`	17	`* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,`
18	`* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE`	18	`* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE`
19	`* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER`	19	`* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER`
20	`* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING`	20	`* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING`
21	`* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER`	21	`* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER`
22	`* DEALINGS IN THE SOFTWARE.`	22	`* DEALINGS IN THE SOFTWARE.`
23	`*/`	23	`*/`
24		24
25	`/*`	25	`/*`
26	`* a variety of helper functions`	26	`* a variety of helper functions`
27	`*/`	27	`*/`
28		28
29	`#include <i86.h> /* MK_FP() */`	29	`#include <i86.h> /* MK_FP() */`
30	`#include <stdio.h> /* sprintf() */`	30	`#include <stdio.h> /* sprintf() */`
31	`#include <string.h> /* memcpy() */`	31	`#include <string.h> /* memcpy() */`
32		32
33	`#include "svarlang.lib\svarlang.h"`	33	`#include "svarlang.lib\svarlang.h"`
34		34
35	`#include "env.h"`	35	`#include "env.h"`
36		36
37	`#include "helpers.h"`	37	`#include "helpers.h"`
38		38
39		39
40		40
41	`/* case-insensitive comparison of strings, compares up to maxlen characters.`	41	`/* case-insensitive comparison of strings, compares up to maxlen characters.`
42	`* returns non-zero on equality. */`	42	`* returns non-zero on equality. */`
43	`int imatchlim(const char s1, const char s2, unsigned short maxlen) {`	43	`int imatchlim(const char s1, const char s2, unsigned short maxlen) {`
44	`while (maxlen--) {`	44	`while (maxlen--) {`
45	`char c1, c2;`	45	`char c1, c2;`
46	`c1 = *s1;`	46	`c1 = *s1;`
47	`c2 = *s2;`	47	`c2 = *s2;`
48	`if ((c1 >= 'a') && (c1 <= 'z')) c1 -= ('a' - 'A');`	48	`if ((c1 >= 'a') && (c1 <= 'z')) c1 -= ('a' - 'A');`
49	`if ((c2 >= 'a') && (c2 <= 'z')) c2 -= ('a' - 'A');`	49	`if ((c2 >= 'a') && (c2 <= 'z')) c2 -= ('a' - 'A');`
50	`/* */`	50	`/* */`
51	`if (c1 != c2) return(0);`	51	`if (c1 != c2) return(0);`
52	`if (c1 == 0) break;`	52	`if (c1 == 0) break;`
53	`s1++;`	53	`s1++;`
54	`s2++;`	54	`s2++;`
55	`}`	55	`}`
56	`return(1);`	56	`return(1);`
57	`}`	57	`}`
58		58
59		59
60	`/* returns zero if s1 starts with s2 */`	60	`/* returns zero if s1 starts with s2 */`
61	`int strstartswith(const char s1, const char s2) {`	61	`int strstartswith(const char s1, const char s2) {`
62	`while (*s2 != 0) {`	62	`while (*s2 != 0) {`
63	`if (s1 != s2) return(-1);`	63	`if (s1 != s2) return(-1);`
64	`s1++;`	64	`s1++;`
65	`s2++;`	65	`s2++;`
66	`}`	66	`}`
67	`return(0);`	67	`return(0);`
68	`}`	68	`}`
69		69
70		70
71	`/* outputs a NULL-terminated string to handle (1=stdout 2=stderr) */`	71	`/* outputs a NULL-terminated string to handle (1=stdout 2=stderr) */`
72	`void output_internal(const char *s, unsigned char nl, unsigned char handle) {`	72	`void output_internal(const char *s, unsigned char nl, unsigned char handle) {`
73	`const static unsigned char *crlf = "\r\n";`	73	`const static unsigned char *crlf = "\r\n";`
74	`_asm {`	74	`_asm {`
75	`push ds`	75	`push ds`
76	`pop es /* make sure es=ds (scasb uses es) */`	76	`pop es /* make sure es=ds (scasb uses es) */`
77	`/* get length of s into CX */`	77	`/* get length of s into CX */`
78	`mov ax, 0x4000 /* ah=DOS "write to file" and AL=0 for NULL matching */`	78	`mov ax, 0x4000 /* ah=DOS "write to file" and AL=0 for NULL matching */`
79	`mov dx, s /* set dx to string (required for later) */`	79	`mov dx, s /* set dx to string (required for later) */`
80	`mov di, dx /* set di to string (for NULL matching) */`	80	`mov di, dx /* set di to string (for NULL matching) */`
81	`mov cx, 0xffff /* preset cx to 65535 (-1) */`	81	`mov cx, 0xffff /* preset cx to 65535 (-1) */`
82	`cld /* clear DF so scasb increments DI */`	82	`cld /* clear DF so scasb increments DI */`
83	`repne scasb /* cmp al, es:[di], inc di, dec cx until match found */`	83	`repne scasb /* cmp al, es:[di], inc di, dec cx until match found */`
84	`/* CX contains (65535 - strlen(s)) now */`	84	`/* CX contains (65535 - strlen(s)) now */`
85	`not cx /* reverse all bits so I get (strlen(s) + 1) */`	85	`not cx /* reverse all bits so I get (strlen(s) + 1) */`
86	`dec cx /* this is CX length */`	86	`dec cx /* this is CX length */`
87	`jz WRITEDONE /* do nothing for empty strings */`	87	`jz WRITEDONE /* do nothing for empty strings */`
88		88
89	`/* output by writing to stdout */`	89	`/* output by writing to stdout */`
90	`/* mov ah, 0x40 / / DOS 2+ -- write to file via handle */`	90	`/* mov ah, 0x40 / / DOS 2+ -- write to file via handle */`
91	`xor bh, bh`	91	`xor bh, bh`
92	`mov bl, handle /* set handle (1=stdout 2=stderr) */`	92	`mov bl, handle /* set handle (1=stdout 2=stderr) */`
93	`/* mov cx, xxx / / write CX bytes */`	93	`/* mov cx, xxx / / write CX bytes */`
94	`/* mov dx, s / / DS:DX is the source of bytes to "write" */`	94	`/* mov dx, s / / DS:DX is the source of bytes to "write" */`
95	`int 0x21`	95	`int 0x21`
96	`WRITEDONE:`	96	`WRITEDONE:`
97		97
98	`/* print out a CR/LF trailer if nl set */`	98	`/* print out a CR/LF trailer if nl set */`
99	`test byte ptr [nl], 0xff`	99	`test byte ptr [nl], 0xff`
100	`jz FINITO`	100	`jz FINITO`
101	`/* bx still contains handle */`	101	`/* bx still contains handle */`
102	`mov ah, 0x40 /* "write to file" */`	102	`mov ah, 0x40 /* "write to file" */`
103	`mov cx, 2`	103	`mov cx, 2`
104	`mov dx, crlf`	104	`mov dx, crlf`
105	`int 0x21`	105	`int 0x21`
106	`FINITO:`	106	`FINITO:`
107	`}`	107	`}`
108	`}`	108	`}`
109		109
110		110
111	`void nls_output_internal(unsigned short id, unsigned char nl, unsigned char handle) {`	111	`void nls_output_internal(unsigned short id, unsigned char nl, unsigned char handle) {`
112	`const char *NOTFOUND = "NLS_STRING_NOT_FOUND";`	112	`const char *NOTFOUND = "NLS_STRING_NOT_FOUND";`
113	`const char *ptr = svarlang_strid(id);`	113	`const char *ptr = svarlang_strid(id);`
114	`if ((ptr == NULL) \|\| (ptr[0]) == 0) ptr = NOTFOUND;`	114	`if ((ptr == NULL) \|\| (ptr[0]) == 0) ptr = NOTFOUND;`
115	`output_internal(ptr, nl, handle);`	115	`output_internal(ptr, nl, handle);`
116	`}`	116	`}`
117		117
118		118
119	`/* output DOS error e to stdout, if stdout is redirected then additionally`	119	`/* output DOS error e to stdout, if stdout is redirected then additionally`
120	`* also to stderr */`	120	`* also to stderr */`
121	`void nls_outputnl_doserr(unsigned short e) {`	121	`void nls_outputnl_doserr(unsigned short e) {`
122	`static char errstr[16];`	122	`static char errstr[16];`
123	`const char *ptr = NULL;`	123	`const char *ptr = NULL;`
124	`unsigned char redirflag = 0;`	124	`unsigned char redirflag = 0;`
125	`/* find string in nls block */`	125	`/* find string in nls block */`
126	`if (e < 0xff) ptr = svarlang_strid(0xff00 \| e);`	126	`if (e < 0xff) ptr = svarlang_strid(0xff00 \| e);`
127	`/* if not found, use a fallback */`	127	`/* if not found, use a fallback */`
128	`if (ptr == NULL) {`	128	`if (ptr == NULL) {`
129	`sprintf(errstr, "DOS ERR %u", e);`	129	`sprintf(errstr, "DOS ERR %u", e);`
130	`ptr = errstr;`	130	`ptr = errstr;`
131	`}`	131	`}`
132		132
133	`/* display to stdout */`	133	`/* display to stdout */`
134	`output_internal(ptr, 1, hSTDOUT);`	134	`output_internal(ptr, 1, hSTDOUT);`
135		135
136	`/* is stdout redirected? */`	136	`/* is stdout redirected? */`
137	`_asm {`	137	`_asm {`
138	`push bx`	138	`push bx`
139	`push dx`	139	`push dx`
140		140
141	`mov ax, 0x4400 /* query device flags */`	141	`mov ax, 0x4400 /* query device flags */`
142	`mov bx, 1 /* stdout */`	142	`mov bx, 1 /* stdout */`
143	`int 0x21`	143	`int 0x21`
144	`/* CF set on error and AX filled with DOS error,`	144	`/* CF set on error and AX filled with DOS error,`
145	`* returns flags in DX on succes:`	145	`* returns flags in DX on succes:`
146	`* bit 7 reset if handle points to a file, set if handle points to a device */`	146	`* bit 7 reset if handle points to a file, set if handle points to a device */`
147	`jc FAIL`	147	`jc FAIL`
148	`mov redirflag, dl`	148	`mov redirflag, dl`
149	`and redirflag, 128`	149	`and redirflag, 128`
150		150
151	`FAIL:`	151	`FAIL:`
152	`pop dx`	152	`pop dx`
153	`pop bx`	153	`pop bx`
154	`}`	154	`}`
155		155
156	`if (redirflag == 0) output_internal(ptr, 1, hSTDERR);`	156	`if (redirflag == 0) output_internal(ptr, 1, hSTDERR);`
157	`}`	157	`}`
158		158
159		159
160	`/* find first matching files using a FindFirst DOS call`	160	`/* find first matching files using a FindFirst DOS call`
161	`* returns 0 on success or a DOS err code on failure */`	161	`* returns 0 on success or a DOS err code on failure */`
162	`unsigned short findfirst(struct DTA dta, const char pattern, unsigned short attr) {`	162	`unsigned short findfirst(struct DTA dta, const char pattern, unsigned short attr) {`
163	`unsigned short res = 0;`	163	`unsigned short res = 0;`
164	`_asm {`	164	`_asm {`
165	`/* set DTA location */`	165	`/* set DTA location */`
166	`mov ah, 0x1a`	166	`mov ah, 0x1a`
167	`mov dx, dta`	167	`mov dx, dta`
168	`int 0x21`	168	`int 0x21`
169	`/* */`	169	`/* */`
170	`mov ah, 0x4e /* FindFirst */`	170	`mov ah, 0x4e /* FindFirst */`
171	`mov dx, pattern`	171	`mov dx, pattern`
172	`mov cx, attr`	172	`mov cx, attr`
173	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`	173	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`
174	`jnc DONE`	174	`jnc DONE`
175	`mov [res], ax`	175	`mov [res], ax`
176	`DONE:`	176	`DONE:`
177	`}`	177	`}`
178	`return(res);`	178	`return(res);`
179	`}`	179	`}`
180		180
181		181
182	`/* find next matching, ie. continues an action intiated by findfirst() */`	182	`/* find next matching, ie. continues an action intiated by findfirst() */`
183	`unsigned short findnext(struct DTA *dta) {`	183	`unsigned short findnext(struct DTA *dta) {`
184	`unsigned short res = 0;`	184	`unsigned short res = 0;`
185	`_asm {`	185	`_asm {`
186	`mov ah, 0x4f /* FindNext */`	186	`mov ah, 0x4f /* FindNext */`
187	`mov dx, dta`	187	`mov dx, dta`
188	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`	188	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`
189	`jnc DONE`	189	`jnc DONE`
190	`mov [res], ax`	190	`mov [res], ax`
191	`DONE:`	191	`DONE:`
192	`}`	192	`}`
193	`return(res);`	193	`return(res);`
194	`}`	194	`}`
195		195
196		196
197	`/* print s string and wait for a single key press from stdin. accepts only`	197	`/* print s string and wait for a single key press from stdin. accepts only`
198	`* key presses defined in the c ASCIIZ string. returns offset of pressed key`	198	`* key presses defined in the c ASCIIZ string. returns offset of pressed key`
199	`* in string. keys in c MUST BE UPPERCASE! */`	199	`* in string. keys in c MUST BE UPPERCASE! */`
200	`unsigned short askchoice(const char s, const char c) {`	200	`unsigned short askchoice(const char s, const char c) {`
201	`unsigned short res;`	201	`unsigned short res;`
-		202	`char cstr[2] = {0,0};`
202	`char key = 0;`	203	`char key = 0;`
203		204
204	`AGAIN:`	205	`AGAIN:`
205	`output(s);`	206	`output(s);`
206	`output(" ");`	207	`output(" ");`
-		208	`output("(");`
-		209	`for (res = 0; c[res] != 0; res++) {`
-		210	`if (res != 0) output("/");`
-		211	`cstr[0] = c[res];`
-		212	`output(cstr);`
-		213	`}`
-		214	`output(") ");`
207		215
208	`_asm {`	216	`_asm {`
209	`push ax`	217	`push ax`
210	`push dx`	218	`push dx`
211		219
212	`mov ax, 0x0c01 /* clear input buffer and execute getchar (INT 21h,AH=1) */`	220	`mov ax, 0x0c01 /* clear input buffer and execute getchar (INT 21h,AH=1) */`
213	`int 0x21`	221	`int 0x21`
214	`/* if AL == 0 then this is an extended character */`	222	`/* if AL == 0 then this is an extended character */`
215	`test al, al`	223	`test al, al`
216	`jnz GOTCHAR`	224	`jnz GOTCHAR`
217	`mov ah, 0x08 /* read again to flush extended char from input buffer */`	225	`mov ah, 0x08 /* read again to flush extended char from input buffer */`
218	`int 0x21`	226	`int 0x21`
219	`xor al, al /* all extended chars are ignored */`	227	`xor al, al /* all extended chars are ignored */`
220	`GOTCHAR: /* received key is in AL now */`	228	`GOTCHAR: /* received key is in AL now */`
221	`mov [key], al /* save key */`	229	`mov [key], al /* save key */`
222		230
223	`/* print a cr/lf */`	231	`/* print a cr/lf */`
224	`mov ah, 0x02`	232	`mov ah, 0x02`
225	`mov dl, 0x0D`	233	`mov dl, 0x0D`
226	`int 0x21`	234	`int 0x21`
227	`mov dl, 0x0A`	235	`mov dl, 0x0A`
228	`int 0x21`	236	`int 0x21`
229		237
230	`pop dx`	238	`pop dx`
231	`pop ax`	239	`pop ax`
232	`}`	240	`}`
233		241
234	`/* ucase() result */`	242	`/* ucase() result */`
235	`if ((key >= 'a') && (key <= 'z')) key -= ('a' - 'A');`	243	`if ((key >= 'a') && (key <= 'z')) key -= ('a' - 'A');`
236		244
237	`/* is there a match? */`	245	`/* is there a match? */`
238	`for (res = 0; c[res] != 0; res++) if (c[res] == key) return(res);`	246	`for (res = 0; c[res] != 0; res++) if (c[res] == key) return(res);`
239		247
240	`goto AGAIN;`	248	`goto AGAIN;`
241	`}`	249	`}`
242		250
243		251
244	`/* converts a path to its canonic representation, returns 0 on success`	252	`/* converts a path to its canonic representation, returns 0 on success`
245	`* or DOS err on failure (invalid drive) */`	253	`* or DOS err on failure (invalid drive) */`
246	`unsigned short file_truename(const char src, char dst) {`	254	`unsigned short file_truename(const char src, char dst) {`
247	`unsigned short res = 0;`	255	`unsigned short res = 0;`
248	`_asm {`	256	`_asm {`
249	`push es`	257	`push es`
250	`mov ah, 0x60 /* query truename, DS:SI=src, ES:DI=dst */`	258	`mov ah, 0x60 /* query truename, DS:SI=src, ES:DI=dst */`
251	`push ds`	259	`push ds`
252	`pop es`	260	`pop es`
253	`mov si, src`	261	`mov si, src`
254	`mov di, dst`	262	`mov di, dst`
255	`int 0x21`	263	`int 0x21`
256	`jnc DONE`	264	`jnc DONE`
257	`mov [res], ax`	265	`mov [res], ax`
258	`DONE:`	266	`DONE:`
259	`pop es`	267	`pop es`
260	`}`	268	`}`
261	`return(res);`	269	`return(res);`
262	`}`	270	`}`
263		271
264		272
265	`/* returns DOS attributes of file, or -1 on error */`	273	`/* returns DOS attributes of file, or -1 on error */`
266	`int file_getattr(const char *fname) {`	274	`int file_getattr(const char *fname) {`
267	`int res = -1;`	275	`int res = -1;`
268	`_asm {`	276	`_asm {`
269	`mov ax, 0x4300 /* query file attributes, fname at DS:DX */`	277	`mov ax, 0x4300 /* query file attributes, fname at DS:DX */`
270	`mov dx, fname`	278	`mov dx, fname`
271	`int 0x21 /* CX=attributes if CF=0, otherwise AX=errno */`	279	`int 0x21 /* CX=attributes if CF=0, otherwise AX=errno */`
272	`jc DONE`	280	`jc DONE`
273	`mov [res], cx`	281	`mov [res], cx`
274	`DONE:`	282	`DONE:`
275	`}`	283	`}`
276	`return(res);`	284	`return(res);`
277	`}`	285	`}`
278		286
279		287
280	`/* returns screen's width (in columns) */`	288	`/* returns screen's width (in columns) */`
281	`unsigned short screen_getwidth(void) {`	289	`unsigned short screen_getwidth(void) {`
282	`/* BIOS 0040:004A = word containing screen width in text columns */`	290	`/* BIOS 0040:004A = word containing screen width in text columns */`
283	`unsigned short far *scrw = MK_FP(0x40, 0x4a);`	291	`unsigned short far *scrw = MK_FP(0x40, 0x4a);`
284	`return(*scrw);`	292	`return(*scrw);`
285	`}`	293	`}`
286		294
287		295
288	`/* returns screen's height (in rows) */`	296	`/* returns screen's height (in rows) */`
289	`unsigned short screen_getheight(void) {`	297	`unsigned short screen_getheight(void) {`
290	`/* BIOS 0040:0084 = byte containing maximum valid row value (EGA ONLY) */`	298	`/* BIOS 0040:0084 = byte containing maximum valid row value (EGA ONLY) */`
291	`unsigned char far *scrh = MK_FP(0x40, 0x84);`	299	`unsigned char far *scrh = MK_FP(0x40, 0x84);`
292	`if (scrh == 0) return(25); / pre-EGA adapter */`	300	`if (scrh == 0) return(25); / pre-EGA adapter */`
293	`return(*scrh + 1);`	301	`return(*scrh + 1);`
294	`}`	302	`}`
295		303
296		304
297	`/* displays the "Press any key to continue" msg and waits for a keypress */`	305	`/* displays the "Press any key to continue" msg and waits for a keypress */`
298	`void press_any_key(void) {`	306	`void press_any_key(void) {`
299	`nls_output(15, 1); /* Press any key to continue... */`	307	`nls_output(15, 1); /* Press any key to continue... */`
300	`_asm {`	308	`_asm {`
301	`mov ah, 0x08 /* no echo console input */`	309	`mov ah, 0x08 /* no echo console input */`
302	`int 0x21 /* pressed key in AL now (0 for extended keys) */`	310	`int 0x21 /* pressed key in AL now (0 for extended keys) */`
303	`test al, al`	311	`test al, al`
304	`jnz DONE`	312	`jnz DONE`
305	`int 0x21 /* executed ah=8 again to read the rest of extended key */`	313	`int 0x21 /* executed ah=8 again to read the rest of extended key */`
306	`DONE:`	314	`DONE:`
307	`/* output CR/LF */`	315	`/* output CR/LF */`
308	`mov ah, 0x02`	316	`mov ah, 0x02`
309	`mov dl, 0x0D`	317	`mov dl, 0x0D`
310	`int 0x21`	318	`int 0x21`
311	`mov dl, 0x0A`	319	`mov dl, 0x0A`
312	`int 0x21`	320	`int 0x21`
313	`}`	321	`}`
314	`}`	322	`}`
315		323
316		324
317	`/* validate a drive (A=0, B=1, etc). returns 1 if valid, 0 otherwise */`	325	`/* validate a drive (A=0, B=1, etc). returns 1 if valid, 0 otherwise */`
318	`int isdrivevalid(unsigned char drv) {`	326	`int isdrivevalid(unsigned char drv) {`
319	`_asm {`	327	`_asm {`
320	`mov ah, 0x19 /* query default (current) disk */`	328	`mov ah, 0x19 /* query default (current) disk */`
321	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`	329	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`
322	`mov ch, al /* save current drive to ch */`	330	`mov ch, al /* save current drive to ch */`
323	`/* try setting up the drive as current */`	331	`/* try setting up the drive as current */`
324	`mov ah, 0x0E /* select default drive */`	332	`mov ah, 0x0E /* select default drive */`
325	`mov dl, [drv] /* 0=A, 1=B, etc */`	333	`mov dl, [drv] /* 0=A, 1=B, etc */`
326	`int 0x21`	334	`int 0x21`
327	`/* this call does not set CF on error, I must check cur drive to look for success */`	335	`/* this call does not set CF on error, I must check cur drive to look for success */`
328	`mov ah, 0x19 /* query default (current) disk */`	336	`mov ah, 0x19 /* query default (current) disk */`
329	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`	337	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`
330	`mov [drv], 1 /* preset result as success */`	338	`mov [drv], 1 /* preset result as success */`
331	`cmp al, dl /* is eq? */`	339	`cmp al, dl /* is eq? */`
332	`je DONE`	340	`je DONE`
333	`mov [drv], 0 /* fail */`	341	`mov [drv], 0 /* fail */`
334	`jmp FAILED`	342	`jmp FAILED`
335	`DONE:`	343	`DONE:`
336	`/* set current drive back to what it was initially */`	344	`/* set current drive back to what it was initially */`
337	`mov ah, 0x0E`	345	`mov ah, 0x0E`
338	`mov dl, ch`	346	`mov dl, ch`
339	`int 0x21`	347	`int 0x21`
340	`FAILED:`	348	`FAILED:`
341	`}`	349	`}`
342	`return(drv);`	350	`return(drv);`
343	`}`	351	`}`
344		352
345		353
346	`/* converts a 8+3 filename into 11-bytes FCB format (MYFILE EXT) */`	354	`/* converts a 8+3 filename into 11-bytes FCB format (MYFILE EXT) */`
347	`void file_fname2fcb(char dst, const char src) {`	355	`void file_fname2fcb(char dst, const char src) {`
348	`unsigned short i;`	356	`unsigned short i;`
349		357
350	`/* fill dst with 11 spaces and a NULL terminator */`	358	`/* fill dst with 11 spaces and a NULL terminator */`
351	`for (i = 0; i < 11; i++) dst[i] = ' ';`	359	`for (i = 0; i < 11; i++) dst[i] = ' ';`
352	`dst[11] = 0;`	360	`dst[11] = 0;`
353		361
354	`/* copy fname until dot (.) or 8 characters */`	362	`/* copy fname until dot (.) or 8 characters */`
355	`for (i = 0; i < 8; i++) {`	363	`for (i = 0; i < 8; i++) {`
356	`if ((src[i] == '.') \|\| (src[i] == 0)) break;`	364	`if ((src[i] == '.') \|\| (src[i] == 0)) break;`
357	`dst[i] = src[i];`	365	`dst[i] = src[i];`
358	`}`	366	`}`
359		367
360	`/* advance src until extension or end of string */`	368	`/* advance src until extension or end of string */`
361	`src += i;`	369	`src += i;`
362	`for (;;) {`	370	`for (;;) {`
363	`if (*src == '.') {`	371	`if (*src == '.') {`
364	`src++; /* next character is extension */`	372	`src++; /* next character is extension */`
365	`break;`	373	`break;`
366	`}`	374	`}`
367	`if (*src == 0) break;`	375	`if (*src == 0) break;`
368	`}`	376	`}`
369		377
370	`/* copy extension to dst (3 chars max) */`	378	`/* copy extension to dst (3 chars max) */`
371	`dst += 8;`	379	`dst += 8;`
372	`for (i = 0; i < 3; i++) {`	380	`for (i = 0; i < 3; i++) {`
373	`if (src[i] == 0) break;`	381	`if (src[i] == 0) break;`
374	`dst[i] = src[i];`	382	`dst[i] = src[i];`
375	`}`	383	`}`
376	`}`	384	`}`
377		385
378		386
379	`/* converts a 11-bytes FCB filename (MYFILE EXT) into 8+3 format (MYFILE.EXT) */`	387	`/* converts a 11-bytes FCB filename (MYFILE EXT) into 8+3 format (MYFILE.EXT) */`
380	`void file_fcb2fname(char dst, const char src) {`	388	`void file_fcb2fname(char dst, const char src) {`
381	`unsigned short i, end = 0;`	389	`unsigned short i, end = 0;`
382		390
383	`for (i = 0; i < 8; i++) {`	391	`for (i = 0; i < 8; i++) {`
384	`dst[i] = src[i];`	392	`dst[i] = src[i];`
385	`if (dst[i] != ' ') end = i + 1;`	393	`if (dst[i] != ' ') end = i + 1;`
386	`}`	394	`}`
387		395
388	`/* is there an extension? */`	396	`/* is there an extension? */`
389	`if (src[8] == ' ') {`	397	`if (src[8] == ' ') {`
390	`dst[end] = 0;`	398	`dst[end] = 0;`
391	`} else { /* found extension: copy it until first space */`	399	`} else { /* found extension: copy it until first space */`
392	`dst[end++] = '.';`	400	`dst[end++] = '.';`
393	`for (i = 8; i < 11; i++) {`	401	`for (i = 8; i < 11; i++) {`
394	`if (src[i] == ' ') break;`	402	`if (src[i] == ' ') break;`
395	`dst[end++] = src[i];`	403	`dst[end++] = src[i];`
396	`}`	404	`}`
397	`dst[end] = 0;`	405	`dst[end] = 0;`
398	`}`	406	`}`
399	`}`	407	`}`
400		408
401		409
402	`/* converts an ASCIIZ string into an unsigned short. returns 0 on success.`	410	`/* converts an ASCIIZ string into an unsigned short. returns 0 on success.`
403	`* on error, result will contain all valid digits that were read until`	411	`* on error, result will contain all valid digits that were read until`
404	`* error occurred (0 on overflow or if parsing failed immediately) */`	412	`* error occurred (0 on overflow or if parsing failed immediately) */`
405	`int atous(unsigned short r, const char s) {`	413	`int atous(unsigned short r, const char s) {`
406	`int err = 0;`	414	`int err = 0;`
407		415
408	`_asm {`	416	`_asm {`
409	`mov si, s`	417	`mov si, s`
410	`xor ax, ax /* general purpose register */`	418	`xor ax, ax /* general purpose register */`
411	`xor cx, cx /* contains the result */`	419	`xor cx, cx /* contains the result */`
412	`mov bx, 10 /* used as a multiplicative step */`	420	`mov bx, 10 /* used as a multiplicative step */`
413		421
414	`NEXTBYTE:`	422	`NEXTBYTE:`
415	`xchg cx, ax /* move result into cx temporarily */`	423	`xchg cx, ax /* move result into cx temporarily */`
416	`lodsb /* AL = DS:[SI++] */`	424	`lodsb /* AL = DS:[SI++] */`
417	`/* is AL 0? if so we're done */`	425	`/* is AL 0? if so we're done */`
418	`test al, al`	426	`test al, al`
419	`jz DONE`	427	`jz DONE`
420	`/* validate that AL is in range '0'-'9' */`	428	`/* validate that AL is in range '0'-'9' */`
421	`sub al, '0'`	429	`sub al, '0'`
422	`jc FAIL /* invalid character detected */`	430	`jc FAIL /* invalid character detected */`
423	`cmp al, 9`	431	`cmp al, 9`
424	`jg FAIL /* invalid character detected */`	432	`jg FAIL /* invalid character detected */`
425	`/* restore result into AX (CX contains the new digit) */`	433	`/* restore result into AX (CX contains the new digit) */`
426	`xchg cx, ax`	434	`xchg cx, ax`
427	`/* multiply result by 10 and add cl */`	435	`/* multiply result by 10 and add cl */`
428	`mul bx /* DX AX = AX * BX(10) */`	436	`mul bx /* DX AX = AX * BX(10) */`
429	`jc OVERFLOW /* overflow */`	437	`jc OVERFLOW /* overflow */`
430	`add ax, cx`	438	`add ax, cx`
431	`/* if CF is set then overflow occurred (overflow part lands in DX) */`	439	`/* if CF is set then overflow occurred (overflow part lands in DX) */`
432	`jnc NEXTBYTE`	440	`jnc NEXTBYTE`
433		441
434	`OVERFLOW:`	442	`OVERFLOW:`
435	`xor cx, cx /* make sure result is zeroed in case overflow occured */`	443	`xor cx, cx /* make sure result is zeroed in case overflow occured */`
436		444
437	`FAIL:`	445	`FAIL:`
438	`inc [err]`	446	`inc [err]`
439		447
440	`DONE: /* save result (CX) into indirect memory address r */`	448	`DONE: /* save result (CX) into indirect memory address r */`
441	`mov bx, [r]`	449	`mov bx, [r]`
442	`mov [bx], cx`	450	`mov [bx], cx`
443	`}`	451	`}`
444	`return(err);`	452	`return(err);`
445	`}`	453	`}`
446		454
447		455
448	`/* appends a backslash if path is a directory`	456	`/* appends a backslash if path is a directory`
449	`* returns the (possibly updated) length of path */`	457	`* returns the (possibly updated) length of path */`
450	`unsigned short path_appendbkslash_if_dir(char *path) {`	458	`unsigned short path_appendbkslash_if_dir(char *path) {`
451	`unsigned short len;`	459	`unsigned short len;`
452	`int attr;`	460	`int attr;`
453	`for (len = 0; path[len] != 0; len++);`	461	`for (len = 0; path[len] != 0; len++);`
454	`if (len == 0) return(0);`	462	`if (len == 0) return(0);`
455	`if (path[len - 1] == '\\') return(len);`	463	`if (path[len - 1] == '\\') return(len);`
456	`/* */`	464	`/* */`
457	`attr = file_getattr(path);`	465	`attr = file_getattr(path);`
458	`if ((attr > 0) && (attr & DOS_ATTR_DIR)) {`	466	`if ((attr > 0) && (attr & DOS_ATTR_DIR)) {`
459	`path[len++] = '\\';`	467	`path[len++] = '\\';`
460	`path[len] = 0;`	468	`path[len] = 0;`
461	`}`	469	`}`
462	`return(len);`	470	`return(len);`
463	`}`	471	`}`
464		472
465		473
466	`/* get current path drive d (A=1, B=2, etc - 0 is "current drive")`	474	`/* get current path drive d (A=1, B=2, etc - 0 is "current drive")`
467	`* returns 0 on success, doserr otherwise */`	475	`* returns 0 on success, doserr otherwise */`
468	`unsigned short curpathfordrv(char *buff, unsigned char d) {`	476	`unsigned short curpathfordrv(char *buff, unsigned char d) {`
469	`unsigned short r = 0;`	477	`unsigned short r = 0;`
470		478
471	`_asm {`	479	`_asm {`
472	`/* is d == 0? then I need to resolve current drive */`	480	`/* is d == 0? then I need to resolve current drive */`
473	`cmp byte ptr [d], 0`	481	`cmp byte ptr [d], 0`
474	`jne GETCWD`	482	`jne GETCWD`
475	`/* resolve cur drive */`	483	`/* resolve cur drive */`
476	`mov ah, 0x19 /* get current default drive */`	484	`mov ah, 0x19 /* get current default drive */`
477	`int 0x21 /* al = drive (00h = A:, 01h = B:, etc) */`	485	`int 0x21 /* al = drive (00h = A:, 01h = B:, etc) */`
478	`inc al /* convert to 1=A, 2=B, etc */`	486	`inc al /* convert to 1=A, 2=B, etc */`
479	`mov [d], al`	487	`mov [d], al`
480		488
481	`GETCWD:`	489	`GETCWD:`
482	`/* prepend buff with drive:\ */`	490	`/* prepend buff with drive:\ */`
483	`mov si, buff`	491	`mov si, buff`
484	`mov dl, [d]`	492	`mov dl, [d]`
485	`mov [si], dl`	493	`mov [si], dl`
486	`add byte ptr [si], 'A' - 1`	494	`add byte ptr [si], 'A' - 1`
487	`inc si`	495	`inc si`
488	`mov [si], ':'`	496	`mov [si], ':'`
489	`inc si`	497	`inc si`
490	`mov [si], '\\'`	498	`mov [si], '\\'`
491	`inc si`	499	`inc si`
492		500

Subversion Repositories SvarDOS

(root)/svarcom/trunk/helpers.c – Rev 985 → 1001