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 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
 * Copyright (C) 2021 Mateusz Viste
 */
 
#include <i86.h>    /* MK_FP() */
#include <stdio.h>  /* sprintf() */
#include <string.h> /* memcpy() */
 
#include "deflang.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 stdout */
void output_internal(const char *s, unsigned char nl) {
  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 */
    mov bx, 1      /* handle 1 is always stdout */
    /* 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 */
    or byte ptr [nl], 0
    jz FINITO
    mov ah, 0x09
    mov dx, crlf
    int 0x21
    FINITO:
  }
}
 
 
void nls_output_internal(unsigned short id, unsigned char nl) {
  const char *ptr = langblock + 4; /* first 4 bytes are lang id and lang len */
  const char *NOTFOUND = "NLS_STRING_NOT_FOUND";
  /* find the string id in langblock memory */
  for (;;) {
    if (((unsigned short *)ptr)[0] == id) {
      ptr += 3;
      break;
    }
    if (ptr[2] == 0) {
      ptr = NOTFOUND;
      break;
    }
    ptr += ptr[2] + 3;
  }
  output_internal(ptr, nl);
}
 
 
/* 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 key = 0;
 
  AGAIN:
  output(s);
  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 langblock */
void nls_langreload(char *buff, unsigned short env) {
  unsigned short i;
  const char far *nlspath;
  char *langblockptr = langblock;
  unsigned short lang;
  unsigned short errcode = 0;
 
  /* look up the LANG env variable, upcase it and copy to lang */
  nlspath = env_lookup_val(env, "LANG");
  if ((nlspath == NULL) || (nlspath[0] == 0)) return;
  buff[0] = nlspath[0];
  buff[1] = nlspath[1];
  buff[2] = 0;
 
  if (buff[0] >= 'a') buff[0] -= 'a' - 'A';
  if (buff[1] >= 'a') buff[1] -= 'a' - 'A';
  memcpy(&lang, buff, 2);
 
  /* check if there is need to reload at all */
  if (((unsigned short *)langblock)[0] == lang) return;
 
  /* printf("NLS RELOAD (curlang=%04X ; toload=%04X\r\n", ((unsigned short *)langblock)[0], lang); */
 
  nlspath = env_lookup_val(env, "NLSPATH");
  if ((nlspath == NULL) || (nlspath[0] == 0)) return;
 
  /* copy NLSPATH(far) to buff */
  for (i = 0; nlspath[i] != 0; i++) buff[i] = nlspath[i];
 
  /* terminate with a bkslash, if not already the case */
  if (buff[i - 1] != '\\') buff[i++] = '\\';
 
  /* append "svarcom.lng" */
  strcpy(buff + i, "SVARCOM.LNG");
 
  /* copy file content to langblock */
  _asm {
    push ax
    push bx
    push cx
    push dx
    push si
    push di
 
    /* make sure ES=DS and clear DF (will be useful for string matching) */
    push ds
    pop es
    cld
 
    /* preset SI to buff */
    mov si, buff
 
    /* Open File */
    mov bx, 0xffff /* bx holds the file handle (0xffff = not set) */
    mov ax, 0x3d00 /* DOS 2+ -- Open File for read */
    mov dx, si     /* fname */
    int 0x21       /* cf set on error, otherwise handle in AX */
    jnc OPENOK
    jmp FAIL
    OPENOK:
    mov bx, ax    /* save file handle to bx */
 
    /* read hdr */
    mov ah, 0x3f   /* DOS 2+ -- Read from File via Handle in BX */
    mov cx, 4      /* read 4 bytes */
    mov dx, si
    int 0x21
    jnc READHDROK
    jmp FAIL
 
    READHDROK:
 
    cmp ax, cx  /* hdr must be 4 bytes long (SvL\x1b) */
    jne FAIL
    /* check that sig is Svl\x1b */
    mov di, si
    cld         /* scasw must inc DI */
    mov ax, 'vS'
    scasw       /* cmp ax, ES:[DI] and DI += 2*/
    jne FAIL
    mov ax, 0x1B4C
    scasw       /* cmp ax, ES:[DI] and DI += 2*/
    jne FAIL
 
    READLANGID:
    /* read lang id */
    mov ah, 0x3f   /* Read from File via Handle in BX */
    /* mov bx, [i]  already set */
    mov cx, 4
    mov dx, si
    int 0x21
    jc FAIL
    cmp ax, cx
    jne FAIL
    /* is this the LANG I am looking for? */
    mov ax, [lang]
    mov di, si
    scasw       /* cmp ax, ES:[DI] and DI += 2*/
    je LOADSTRINGS
    /* skip to next lang */
    mov ax, 0x4201   /* move file pointer CX:DX bytes forward */
    /* mov bx, [i]  file handle */
    xor cx, cx
    mov dx, [di]
    int 0x21
    jc FAIL
    jmp READLANGID
 
    LOADSTRINGS:
 
    /* copy langid and langlen to langblockptr */
    mov di, langblockptr
    mov ax, [si]
    stosw   /* mov [di], ax and di += 2 */
    mov ax, [si+2]
    stosw
    /* read strings (buff+2 bytes) into langblock */
    mov ah, 0x3f   /* Read from File via Handle in BX */
    mov cx, [si+2]
    mov dx, di
    int 0x21
    jnc DONE
 
    /* on error make sure to zero out langblock's header */
    xor cx, cx
    mov [di], cx                 /* langblock id*/
    mov [di + 2], cx /* langblock len */
    mov [di + 4], cx /* 1st string id */
    mov [di + 6], cx /* 1st string len */
 
    /* cleanup and quit */
    FAIL:
    mov [errcode], ax
    DONE:
    /* close file handle if set */
    cmp bx, 0xffff
    je FNOTOPEN
    mov ah, 0x3e  /* DOS 2+ -- Close a File Handle (Handle in BX) */
    int 0x21
    FNOTOPEN:
 
    pop di
    pop si
    pop dx
    pop cx
    pop bx
    pop ax
  }
 
  if (errcode != 0) printf("AX=%04x\r\n", errcode);
}
 

Rev 445	Rev 530
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 Mateusz Viste`	4	`* Copyright (C) 2021 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	`* Copyright (C) 2021 Mateusz Viste`	27	`* Copyright (C) 2021 Mateusz Viste`
28	`*/`	28	`*/`
29		29
30	`#include <i86.h> /* MK_FP() */`	30	`#include <i86.h> /* MK_FP() */`
31	`#include <stdio.h> /* sprintf() */`	31	`#include <stdio.h> /* sprintf() */`
32	`#include <string.h> /* memcpy() */`	32	`#include <string.h> /* memcpy() */`
33		33
34	`#include "deflang.h"`	34	`#include "deflang.h"`
35		35
36	`#include "env.h"`	36	`#include "env.h"`
37		37
38	`#include "helpers.h"`	38	`#include "helpers.h"`
39		39
40		40
41	`/* case-insensitive comparison of strings, returns non-zero on equality */`	41	`/* case-insensitive comparison of strings, compares up to maxlen characters.`
-		42	`* returns non-zero on equality. */`
42	`int imatch(const char s1, const char s2) {`	43	`int imatchlim(const char s1, const char s2, unsigned short maxlen) {`
43	`for (;;) {`	44	`while (maxlen--) {`
44	`char c1, c2;`	45	`char c1, c2;`
45	`c1 = *s1;`	46	`c1 = *s1;`
46	`c2 = *s2;`	47	`c2 = *s2;`
47	`if ((c1 >= 'a') && (c1 <= 'z')) c1 -= ('a' - 'A');`	48	`if ((c1 >= 'a') && (c1 <= 'z')) c1 -= ('a' - 'A');`
48	`if ((c2 >= 'a') && (c2 <= 'z')) c2 -= ('a' - 'A');`	49	`if ((c2 >= 'a') && (c2 <= 'z')) c2 -= ('a' - 'A');`
49	`/* */`	50	`/* */`
50	`if (c1 != c2) return(0);`	51	`if (c1 != c2) return(0);`
51	`if (c1 == 0) return(1);`	52	`if (c1 == 0) break;`
52	`s1++;`	53	`s1++;`
53	`s2++;`	54	`s2++;`
54	`}`	55	`}`
-		56	`return(1);`
55	`}`	57	`}`
56		58
57		59
58	`/* returns zero if s1 starts with s2 */`	60	`/* returns zero if s1 starts with s2 */`
59	`int strstartswith(const char s1, const char s2) {`	61	`int strstartswith(const char s1, const char s2) {`
60	`while (*s2 != 0) {`	62	`while (*s2 != 0) {`
61	`if (s1 != s2) return(-1);`	63	`if (s1 != s2) return(-1);`
62	`s1++;`	64	`s1++;`
63	`s2++;`	65	`s2++;`
64	`}`	66	`}`
65	`return(0);`	67	`return(0);`
66	`}`	68	`}`
67		69
68		70
69	`/* outputs a NULL-terminated string to stdout */`	71	`/* outputs a NULL-terminated string to stdout */`
70	`void output_internal(const char *s, unsigned char nl) {`	72	`void output_internal(const char *s, unsigned char nl) {`
71	`const static unsigned char *crlf = "\r\n$";`	73	`const static unsigned char *crlf = "\r\n$";`
72	`_asm {`	74	`_asm {`
73	`push ds`	75	`push ds`
74	`pop es /* make sure es=ds (scasb uses es) */`	76	`pop es /* make sure es=ds (scasb uses es) */`
75	`/* get length of s into CX */`	77	`/* get length of s into CX */`
76	`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 */`
77	`mov dx, s /* set dx to string (required for later) */`	79	`mov dx, s /* set dx to string (required for later) */`
78	`mov di, dx /* set di to string (for NULL matching) */`	80	`mov di, dx /* set di to string (for NULL matching) */`
79	`mov cx, 0xffff /* preset cx to 65535 (-1) */`	81	`mov cx, 0xffff /* preset cx to 65535 (-1) */`
80	`cld /* clear DF so scasb increments DI */`	82	`cld /* clear DF so scasb increments DI */`
81	`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 */`
82	`/* CX contains (65535 - strlen(s)) now */`	84	`/* CX contains (65535 - strlen(s)) now */`
83	`not cx /* reverse all bits so I get (strlen(s) + 1) */`	85	`not cx /* reverse all bits so I get (strlen(s) + 1) */`
84	`dec cx /* this is CX length */`	86	`dec cx /* this is CX length */`
85	`jz WRITEDONE /* do nothing for empty strings */`	87	`jz WRITEDONE /* do nothing for empty strings */`
86		88
87	`/* output by writing to stdout */`	89	`/* output by writing to stdout */`
88	`/* mov ah, 0x40 / / DOS 2+ -- write to file via handle */`	90	`/* mov ah, 0x40 / / DOS 2+ -- write to file via handle */`
89	`mov bx, 1 /* handle 1 is always stdout */`	91	`mov bx, 1 /* handle 1 is always stdout */`
90	`/* mov cx, xxx / / write CX bytes */`	92	`/* mov cx, xxx / / write CX bytes */`
91	`/* mov dx, s / / DS:DX is the source of bytes to "write" */`	93	`/* mov dx, s / / DS:DX is the source of bytes to "write" */`
92	`int 0x21`	94	`int 0x21`
93	`WRITEDONE:`	95	`WRITEDONE:`
94		96
95	`/* print out a CR/LF trailer if nl set */`	97	`/* print out a CR/LF trailer if nl set */`
96	`or byte ptr [nl], 0`	98	`or byte ptr [nl], 0`
97	`jz FINITO`	99	`jz FINITO`
98	`mov ah, 0x09`	100	`mov ah, 0x09`
99	`mov dx, crlf`	101	`mov dx, crlf`
100	`int 0x21`	102	`int 0x21`
101	`FINITO:`	103	`FINITO:`
102	`}`	104	`}`
103	`}`	105	`}`
104		106
105		107
106	`void nls_output_internal(unsigned short id, unsigned char nl) {`	108	`void nls_output_internal(unsigned short id, unsigned char nl) {`
107	`const char ptr = langblock + 4; / first 4 bytes are lang id and lang len */`	109	`const char ptr = langblock + 4; / first 4 bytes are lang id and lang len */`
108	`const char *NOTFOUND = "NLS_STRING_NOT_FOUND";`	110	`const char *NOTFOUND = "NLS_STRING_NOT_FOUND";`
109	`/* find the string id in langblock memory */`	111	`/* find the string id in langblock memory */`
110	`for (;;) {`	112	`for (;;) {`
111	`if (((unsigned short *)ptr)[0] == id) {`	113	`if (((unsigned short *)ptr)[0] == id) {`
112	`ptr += 3;`	114	`ptr += 3;`
113	`break;`	115	`break;`
114	`}`	116	`}`
115	`if (ptr[2] == 0) {`	117	`if (ptr[2] == 0) {`
116	`ptr = NOTFOUND;`	118	`ptr = NOTFOUND;`
117	`break;`	119	`break;`
118	`}`	120	`}`
119	`ptr += ptr[2] + 3;`	121	`ptr += ptr[2] + 3;`
120	`}`	122	`}`
121	`output_internal(ptr, nl);`	123	`output_internal(ptr, nl);`
122	`}`	124	`}`
123		125
124		126
125	`/* find first matching files using a FindFirst DOS call`	127	`/* find first matching files using a FindFirst DOS call`
126	`* returns 0 on success or a DOS err code on failure */`	128	`* returns 0 on success or a DOS err code on failure */`
127	`unsigned short findfirst(struct DTA dta, const char pattern, unsigned short attr) {`	129	`unsigned short findfirst(struct DTA dta, const char pattern, unsigned short attr) {`
128	`unsigned short res = 0;`	130	`unsigned short res = 0;`
129	`_asm {`	131	`_asm {`
130	`/* set DTA location */`	132	`/* set DTA location */`
131	`mov ah, 0x1a`	133	`mov ah, 0x1a`
132	`mov dx, dta`	134	`mov dx, dta`
133	`int 0x21`	135	`int 0x21`
134	`/* */`	136	`/* */`
135	`mov ah, 0x4e /* FindFirst */`	137	`mov ah, 0x4e /* FindFirst */`
136	`mov dx, pattern`	138	`mov dx, pattern`
137	`mov cx, attr`	139	`mov cx, attr`
138	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`	140	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`
139	`jnc DONE`	141	`jnc DONE`
140	`mov [res], ax`	142	`mov [res], ax`
141	`DONE:`	143	`DONE:`
142	`}`	144	`}`
143	`return(res);`	145	`return(res);`
144	`}`	146	`}`
145		147
146		148
147	`/* find next matching, ie. continues an action intiated by findfirst() */`	149	`/* find next matching, ie. continues an action intiated by findfirst() */`
148	`unsigned short findnext(struct DTA *dta) {`	150	`unsigned short findnext(struct DTA *dta) {`
149	`unsigned short res = 0;`	151	`unsigned short res = 0;`
150	`_asm {`	152	`_asm {`
151	`mov ah, 0x4f /* FindNext */`	153	`mov ah, 0x4f /* FindNext */`
152	`mov dx, dta`	154	`mov dx, dta`
153	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`	155	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`
154	`jnc DONE`	156	`jnc DONE`
155	`mov [res], ax`	157	`mov [res], ax`
156	`DONE:`	158	`DONE:`
157	`}`	159	`}`
158	`return(res);`	160	`return(res);`
159	`}`	161	`}`
160		162
161		163
162	`/* print s string and wait for a single key press from stdin. accepts only`	164	`/* print s string and wait for a single key press from stdin. accepts only`
163	`* key presses defined in the c ASCIIZ string. returns offset of pressed key`	165	`* key presses defined in the c ASCIIZ string. returns offset of pressed key`
164	`* in string. keys in c MUST BE UPPERCASE! */`	166	`* in string. keys in c MUST BE UPPERCASE! */`
165	`unsigned short askchoice(const char s, const char c) {`	167	`unsigned short askchoice(const char s, const char c) {`
166	`unsigned short res;`	168	`unsigned short res;`
167	`char key = 0;`	169	`char key = 0;`
168		170
169	`AGAIN:`	171	`AGAIN:`
170	`output(s);`	172	`output(s);`
171	`output(" ");`	173	`output(" ");`
172		174
173	`_asm {`	175	`_asm {`
174	`push ax`	176	`push ax`
175	`push dx`	177	`push dx`
176		178
177	`mov ax, 0x0c01 /* clear input buffer and execute getchar (INT 21h,AH=1) */`	179	`mov ax, 0x0c01 /* clear input buffer and execute getchar (INT 21h,AH=1) */`
178	`int 0x21`	180	`int 0x21`
179	`/* if AL == 0 then this is an extended character */`	181	`/* if AL == 0 then this is an extended character */`
180	`test al, al`	182	`test al, al`
181	`jnz GOTCHAR`	183	`jnz GOTCHAR`
182	`mov ah, 0x08 /* read again to flush extended char from input buffer */`	184	`mov ah, 0x08 /* read again to flush extended char from input buffer */`
183	`int 0x21`	185	`int 0x21`
184	`xor al, al /* all extended chars are ignored */`	186	`xor al, al /* all extended chars are ignored */`
185	`GOTCHAR: /* received key is in AL now */`	187	`GOTCHAR: /* received key is in AL now */`
186	`mov [key], al /* save key */`	188	`mov [key], al /* save key */`
187		189
188	`/* print a cr/lf */`	190	`/* print a cr/lf */`
189	`mov ah, 0x02`	191	`mov ah, 0x02`
190	`mov dl, 0x0D`	192	`mov dl, 0x0D`
191	`int 0x21`	193	`int 0x21`
192	`mov dl, 0x0A`	194	`mov dl, 0x0A`
193	`int 0x21`	195	`int 0x21`
194		196
195	`pop dx`	197	`pop dx`
196	`pop ax`	198	`pop ax`
197	`}`	199	`}`
198		200
199	`/* ucase() result */`	201	`/* ucase() result */`
200	`if ((key >= 'a') && (key <= 'z')) key -= ('a' - 'A');`	202	`if ((key >= 'a') && (key <= 'z')) key -= ('a' - 'A');`
201		203
202	`/* is there a match? */`	204	`/* is there a match? */`
203	`for (res = 0; c[res] != 0; res++) if (c[res] == key) return(res);`	205	`for (res = 0; c[res] != 0; res++) if (c[res] == key) return(res);`
204		206
205	`goto AGAIN;`	207	`goto AGAIN;`
206	`}`	208	`}`
207		209
208		210
209	`/* converts a path to its canonic representation, returns 0 on success`	211	`/* converts a path to its canonic representation, returns 0 on success`
210	`* or DOS err on failure (invalid drive) */`	212	`* or DOS err on failure (invalid drive) */`
211	`unsigned short file_truename(const char src, char dst) {`	213	`unsigned short file_truename(const char src, char dst) {`
212	`unsigned short res = 0;`	214	`unsigned short res = 0;`
213	`_asm {`	215	`_asm {`
214	`push es`	216	`push es`
215	`mov ah, 0x60 /* query truename, DS:SI=src, ES:DI=dst */`	217	`mov ah, 0x60 /* query truename, DS:SI=src, ES:DI=dst */`
216	`push ds`	218	`push ds`
217	`pop es`	219	`pop es`
218	`mov si, src`	220	`mov si, src`
219	`mov di, dst`	221	`mov di, dst`
220	`int 0x21`	222	`int 0x21`
221	`jnc DONE`	223	`jnc DONE`
222	`mov [res], ax`	224	`mov [res], ax`
223	`DONE:`	225	`DONE:`
224	`pop es`	226	`pop es`
225	`}`	227	`}`
226	`return(res);`	228	`return(res);`
227	`}`	229	`}`
228		230
229		231
230	`/* returns DOS attributes of file, or -1 on error */`	232	`/* returns DOS attributes of file, or -1 on error */`
231	`int file_getattr(const char *fname) {`	233	`int file_getattr(const char *fname) {`
232	`int res = -1;`	234	`int res = -1;`
233	`_asm {`	235	`_asm {`
234	`mov ax, 0x4300 /* query file attributes, fname at DS:DX */`	236	`mov ax, 0x4300 /* query file attributes, fname at DS:DX */`
235	`mov dx, fname`	237	`mov dx, fname`
236	`int 0x21 /* CX=attributes if CF=0, otherwise AX=errno */`	238	`int 0x21 /* CX=attributes if CF=0, otherwise AX=errno */`
237	`jc DONE`	239	`jc DONE`
238	`mov [res], cx`	240	`mov [res], cx`
239	`DONE:`	241	`DONE:`
240	`}`	242	`}`
241	`return(res);`	243	`return(res);`
242	`}`	244	`}`
243		245
244		246
245	`/* returns screen's width (in columns) */`	247	`/* returns screen's width (in columns) */`
246	`unsigned short screen_getwidth(void) {`	248	`unsigned short screen_getwidth(void) {`
247	`/* BIOS 0040:004A = word containing screen width in text columns */`	249	`/* BIOS 0040:004A = word containing screen width in text columns */`
248	`unsigned short far *scrw = MK_FP(0x40, 0x4a);`	250	`unsigned short far *scrw = MK_FP(0x40, 0x4a);`
249	`return(*scrw);`	251	`return(*scrw);`
250	`}`	252	`}`
251		253
252		254
253	`/* returns screen's height (in rows) */`	255	`/* returns screen's height (in rows) */`
254	`unsigned short screen_getheight(void) {`	256	`unsigned short screen_getheight(void) {`
255	`/* BIOS 0040:0084 = byte containing maximum valid row value (EGA ONLY) */`	257	`/* BIOS 0040:0084 = byte containing maximum valid row value (EGA ONLY) */`
256	`unsigned char far *scrh = MK_FP(0x40, 0x84);`	258	`unsigned char far *scrh = MK_FP(0x40, 0x84);`
257	`if (scrh == 0) return(25); / pre-EGA adapter */`	259	`if (scrh == 0) return(25); / pre-EGA adapter */`
258	`return(*scrh + 1);`	260	`return(*scrh + 1);`
259	`}`	261	`}`
260		262
261		263
262	`/* displays the "Press any key to continue" msg and waits for a keypress */`	264	`/* displays the "Press any key to continue" msg and waits for a keypress */`
263	`void press_any_key(void) {`	265	`void press_any_key(void) {`
264	`nls_output(15, 1); /* Press any key to continue... */`	266	`nls_output(15, 1); /* Press any key to continue... */`
265	`_asm {`	267	`_asm {`
266	`mov ah, 0x08 /* no echo console input */`	268	`mov ah, 0x08 /* no echo console input */`
267	`int 0x21 /* pressed key in AL now (0 for extended keys) */`	269	`int 0x21 /* pressed key in AL now (0 for extended keys) */`
268	`test al, al`	270	`test al, al`
269	`jnz DONE`	271	`jnz DONE`
270	`int 0x21 /* executed ah=8 again to read the rest of extended key */`	272	`int 0x21 /* executed ah=8 again to read the rest of extended key */`
271	`DONE:`	273	`DONE:`
272	`/* output CR/LF */`	274	`/* output CR/LF */`
273	`mov ah, 0x02`	275	`mov ah, 0x02`
274	`mov dl, 0x0D`	276	`mov dl, 0x0D`
275	`int 0x21`	277	`int 0x21`
276	`mov dl, 0x0A`	278	`mov dl, 0x0A`
277	`int 0x21`	279	`int 0x21`
278	`}`	280	`}`
279	`}`	281	`}`
280		282
281		283
282	`/* validate a drive (A=0, B=1, etc). returns 1 if valid, 0 otherwise */`	284	`/* validate a drive (A=0, B=1, etc). returns 1 if valid, 0 otherwise */`
283	`int isdrivevalid(unsigned char drv) {`	285	`int isdrivevalid(unsigned char drv) {`
284	`_asm {`	286	`_asm {`
285	`mov ah, 0x19 /* query default (current) disk */`	287	`mov ah, 0x19 /* query default (current) disk */`
286	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`	288	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`
287	`mov ch, al /* save current drive to ch */`	289	`mov ch, al /* save current drive to ch */`
288	`/* try setting up the drive as current */`	290	`/* try setting up the drive as current */`
289	`mov ah, 0x0E /* select default drive */`	291	`mov ah, 0x0E /* select default drive */`
290	`mov dl, [drv] /* 0=A, 1=B, etc */`	292	`mov dl, [drv] /* 0=A, 1=B, etc */`
291	`int 0x21`	293	`int 0x21`
292	`/* this call does not set CF on error, I must check cur drive to look for success */`	294	`/* this call does not set CF on error, I must check cur drive to look for success */`
293	`mov ah, 0x19 /* query default (current) disk */`	295	`mov ah, 0x19 /* query default (current) disk */`
294	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`	296	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`
295	`mov [drv], 1 /* preset result as success */`	297	`mov [drv], 1 /* preset result as success */`
296	`cmp al, dl /* is eq? */`	298	`cmp al, dl /* is eq? */`
297	`je DONE`	299	`je DONE`
298	`mov [drv], 0 /* fail */`	300	`mov [drv], 0 /* fail */`
299	`jmp FAILED`	301	`jmp FAILED`
300	`DONE:`	302	`DONE:`
301	`/* set current drive back to what it was initially */`	303	`/* set current drive back to what it was initially */`
302	`mov ah, 0x0E`	304	`mov ah, 0x0E`
303	`mov dl, ch`	305	`mov dl, ch`
304	`int 0x21`	306	`int 0x21`
305	`FAILED:`	307	`FAILED:`
306	`}`	308	`}`
307	`return(drv);`	309	`return(drv);`
308	`}`	310	`}`
309		311
310		312
311	`/* converts a 8+3 filename into 11-bytes FCB format (MYFILE EXT) */`	313	`/* converts a 8+3 filename into 11-bytes FCB format (MYFILE EXT) */`
312	`void file_fname2fcb(char dst, const char src) {`	314	`void file_fname2fcb(char dst, const char src) {`
313	`unsigned short i;`	315	`unsigned short i;`
314		316
315	`/* fill dst with 11 spaces and a NULL terminator */`	317	`/* fill dst with 11 spaces and a NULL terminator */`
316	`for (i = 0; i < 11; i++) dst[i] = ' ';`	318	`for (i = 0; i < 11; i++) dst[i] = ' ';`
317	`dst[11] = 0;`	319	`dst[11] = 0;`
318		320
319	`/* copy fname until dot (.) or 8 characters */`	321	`/* copy fname until dot (.) or 8 characters */`
320	`for (i = 0; i < 8; i++) {`	322	`for (i = 0; i < 8; i++) {`
321	`if ((src[i] == '.') \|\| (src[i] == 0)) break;`	323	`if ((src[i] == '.') \|\| (src[i] == 0)) break;`
322	`dst[i] = src[i];`	324	`dst[i] = src[i];`
323	`}`	325	`}`
324		326
325	`/* advance src until extension or end of string */`	327	`/* advance src until extension or end of string */`
326	`src += i;`	328	`src += i;`
327	`for (;;) {`	329	`for (;;) {`
328	`if (*src == '.') {`	330	`if (*src == '.') {`
329	`src++; /* next character is extension */`	331	`src++; /* next character is extension */`
330	`break;`	332	`break;`
331	`}`	333	`}`
332	`if (*src == 0) break;`	334	`if (*src == 0) break;`
333	`}`	335	`}`
334		336
335	`/* copy extension to dst (3 chars max) */`	337	`/* copy extension to dst (3 chars max) */`
336	`dst += 8;`	338	`dst += 8;`
337	`for (i = 0; i < 3; i++) {`	339	`for (i = 0; i < 3; i++) {`
338	`if (src[i] == 0) break;`	340	`if (src[i] == 0) break;`
339	`dst[i] = src[i];`	341	`dst[i] = src[i];`
340	`}`	342	`}`
341	`}`	343	`}`
342		344
343		345
344	`/* converts a 11-bytes FCB filename (MYFILE EXT) into 8+3 format (MYFILE.EXT) */`	346	`/* converts a 11-bytes FCB filename (MYFILE EXT) into 8+3 format (MYFILE.EXT) */`
345	`void file_fcb2fname(char dst, const char src) {`	347	`void file_fcb2fname(char dst, const char src) {`
346	`unsigned short i, end = 0;`	348	`unsigned short i, end = 0;`
347		349
348	`for (i = 0; i < 8; i++) {`	350	`for (i = 0; i < 8; i++) {`
349	`dst[i] = src[i];`	351	`dst[i] = src[i];`
350	`if (dst[i] != ' ') end = i + 1;`	352	`if (dst[i] != ' ') end = i + 1;`
351	`}`	353	`}`
352		354
353	`/* is there an extension? */`	355	`/* is there an extension? */`
354	`if (src[8] == ' ') {`	356	`if (src[8] == ' ') {`
355	`dst[end] = 0;`	357	`dst[end] = 0;`
356	`} else { /* found extension: copy it until first space */`	358	`} else { /* found extension: copy it until first space */`
357	`dst[end++] = '.';`	359	`dst[end++] = '.';`
358	`for (i = 8; i < 11; i++) {`	360	`for (i = 8; i < 11; i++) {`
359	`if (src[i] == ' ') break;`	361	`if (src[i] == ' ') break;`
360	`dst[end++] = src[i];`	362	`dst[end++] = src[i];`
361	`}`	363	`}`
362	`dst[end] = 0;`	364	`dst[end] = 0;`
363	`}`	365	`}`
364	`}`	366	`}`
365		367
366		368
367	`/* converts an ASCIIZ string into an unsigned short. returns 0 on success.`	369	`/* converts an ASCIIZ string into an unsigned short. returns 0 on success.`
368	`* on error, result will contain all valid digits that were read until`	370	`* on error, result will contain all valid digits that were read until`
369	`* error occurred (0 on overflow or if parsing failed immediately) */`	371	`* error occurred (0 on overflow or if parsing failed immediately) */`
370	`int atous(unsigned short r, const char s) {`	372	`int atous(unsigned short r, const char s) {`
371	`int err = 0;`	373	`int err = 0;`
372		374
373	`_asm {`	375	`_asm {`
374	`mov si, s`	376	`mov si, s`
375	`xor ax, ax /* general purpose register */`	377	`xor ax, ax /* general purpose register */`
376	`xor cx, cx /* contains the result */`	378	`xor cx, cx /* contains the result */`
377	`mov bx, 10 /* used as a multiplicative step */`	379	`mov bx, 10 /* used as a multiplicative step */`
378		380
379	`NEXTBYTE:`	381	`NEXTBYTE:`
380	`xchg cx, ax /* move result into cx temporarily */`	382	`xchg cx, ax /* move result into cx temporarily */`
381	`lodsb /* AL = DS:[SI++] */`	383	`lodsb /* AL = DS:[SI++] */`
382	`/* is AL 0? if so we're done */`	384	`/* is AL 0? if so we're done */`
383	`test al, al`	385	`test al, al`
384	`jz DONE`	386	`jz DONE`
385	`/* validate that AL is in range '0'-'9' */`	387	`/* validate that AL is in range '0'-'9' */`
386	`sub al, '0'`	388	`sub al, '0'`
387	`jc FAIL /* invalid character detected */`	389	`jc FAIL /* invalid character detected */`
388	`cmp al, 9`	390	`cmp al, 9`
389	`jg FAIL /* invalid character detected */`	391	`jg FAIL /* invalid character detected */`
390	`/* restore result into AX (CX contains the new digit) */`	392	`/* restore result into AX (CX contains the new digit) */`
391	`xchg cx, ax`	393	`xchg cx, ax`
392	`/* multiply result by 10 and add cl */`	394	`/* multiply result by 10 and add cl */`
393	`mul bx /* DX AX = AX * BX(10) */`	395	`mul bx /* DX AX = AX * BX(10) */`
394	`jc OVERFLOW /* overflow */`	396	`jc OVERFLOW /* overflow */`
395	`add ax, cx`	397	`add ax, cx`
396	`/* if CF is set then overflow occurred (overflow part lands in DX) */`	398	`/* if CF is set then overflow occurred (overflow part lands in DX) */`
397	`jnc NEXTBYTE`	399	`jnc NEXTBYTE`
398		400
399	`OVERFLOW:`	401	`OVERFLOW:`
400	`xor cx, cx /* make sure result is zeroed in case overflow occured */`	402	`xor cx, cx /* make sure result is zeroed in case overflow occured */`
401		403
402	`FAIL:`	404	`FAIL:`
403	`inc [err]`	405	`inc [err]`
404		406
405	`DONE: /* save result (CX) into indirect memory address r */`	407	`DONE: /* save result (CX) into indirect memory address r */`
406	`mov bx, [r]`	408	`mov bx, [r]`
407	`mov [bx], cx`	409	`mov [bx], cx`
408	`}`	410	`}`
409	`return(err);`	411	`return(err);`
410	`}`	412	`}`
411		413
412		414
413	`/* appends a backslash if path is a directory`	415	`/* appends a backslash if path is a directory`
414	`* returns the (possibly updated) length of path */`	416	`* returns the (possibly updated) length of path */`
415	`unsigned short path_appendbkslash_if_dir(char *path) {`	417	`unsigned short path_appendbkslash_if_dir(char *path) {`
416	`unsigned short len;`	418	`unsigned short len;`
417	`int attr;`	419	`int attr;`
418	`for (len = 0; path[len] != 0; len++);`	420	`for (len = 0; path[len] != 0; len++);`
419	`if (len == 0) return(0);`	421	`if (len == 0) return(0);`
420	`if (path[len - 1] == '\\') return(len);`	422	`if (path[len - 1] == '\\') return(len);`
421	`/* */`	423	`/* */`
422	`attr = file_getattr(path);`	424	`attr = file_getattr(path);`
423	`if ((attr > 0) && (attr & DOS_ATTR_DIR)) {`	425	`if ((attr > 0) && (attr & DOS_ATTR_DIR)) {`
424	`path[len++] = '\\';`	426	`path[len++] = '\\';`
425	`path[len] = 0;`	427	`path[len] = 0;`
426	`}`	428	`}`
427	`return(len);`	429	`return(len);`
428	`}`	430	`}`
429		431
430		432
431	`/* get current path drive d (A=1, B=2, etc - 0 is "current drive")`	433	`/* get current path drive d (A=1, B=2, etc - 0 is "current drive")`
432	`* returns 0 on success, doserr otherwise */`	434	`* returns 0 on success, doserr otherwise */`
433	`unsigned short curpathfordrv(char *buff, unsigned char d) {`	435	`unsigned short curpathfordrv(char *buff, unsigned char d) {`
434	`unsigned short r = 0;`	436	`unsigned short r = 0;`
435		437
436	`_asm {`	438	`_asm {`
437	`/* is d == 0? then I need to resolve current drive */`	439	`/* is d == 0? then I need to resolve current drive */`
438	`cmp byte ptr [d], 0`	440	`cmp byte ptr [d], 0`
439	`jne GETCWD`	441	`jne GETCWD`
440	`/* resolve cur drive */`	442	`/* resolve cur drive */`
441	`mov ah, 0x19 /* get current default drive */`	443	`mov ah, 0x19 /* get current default drive */`
442	`int 0x21 /* al = drive (00h = A:, 01h = B:, etc) */`	444	`int 0x21 /* al = drive (00h = A:, 01h = B:, etc) */`
443	`inc al /* convert to 1=A, 2=B, etc */`	445	`inc al /* convert to 1=A, 2=B, etc */`
444	`mov [d], al`	446	`mov [d], al`
445		447
446	`GETCWD:`	448	`GETCWD:`
447	`/* prepend buff with drive:\ */`	449	`/* prepend buff with drive:\ */`
448	`mov si, buff`	450	`mov si, buff`
449	`mov dl, [d]`	451	`mov dl, [d]`
450	`mov [si], dl`	452	`mov [si], dl`
451	`add byte ptr [si], 'A' - 1`	453	`add byte ptr [si], 'A' - 1`
452	`inc si`	454	`inc si`
453	`mov [si], ':'`	455	`mov [si], ':'`
454	`inc si`	456	`inc si`
455	`mov [si], '\\'`	457	`mov [si], '\\'`
456	`inc si`	458	`inc si`
457		459
458	`mov ah, 0x47 /* get current directory of drv DL into DS:SI */`	460	`mov ah, 0x47 /* get current directory of drv DL into DS:SI */`
459	`int 0x21`	461	`int 0x21`
460	`jnc DONE`	462	`jnc DONE`
461	`mov [r], ax /* copy result from ax */`	463	`mov [r], ax /* copy result from ax */`
462		464
463	`DONE:`	465	`DONE:`
464	`}`	466	`}`
465		467
466	`return(r);`	468	`return(r);`
467	`}`	469	`}`
468		470
469		471
470	`/* fills a nls_patterns struct with current NLS patterns, returns 0 on success, DOS errcode otherwise */`	472	`/* fills a nls_patterns struct with current NLS patterns, returns 0 on success, DOS errcode otherwise */`
471	`unsigned short nls_getpatterns(struct nls_patterns *p) {`	473	`unsigned short nls_getpatterns(struct nls_patterns *p) {`
472	`unsigned short r = 0;`	474	`unsigned short r = 0;`
473		475
474	`_asm {`	476	`_asm {`
475	`mov ax, 0x3800 /* DOS 2+ -- Get Country Info for current country */`	477	`mov ax, 0x3800 /* DOS 2+ -- Get Country Info for current country */`
476	`mov dx, p /* DS:DX points to the CountryInfoRec buffer */`	478	`mov dx, p /* DS:DX points to the CountryInfoRec buffer */`
477	`int 0x21`	479	`int 0x21`
478	`jnc DONE`	480	`jnc DONE`
479	`mov [r], ax /* copy DOS err code to r */`	481	`mov [r], ax /* copy DOS err code to r */`
480	`DONE:`	482	`DONE:`
481	`}`	483	`}`
482		484
483	`return(r);`	485	`return(r);`
484	`}`	486	`}`
485		487
486		488
487	`/* computes a formatted date based on NLS patterns found in p`	489	`/* computes a formatted date based on NLS patterns found in p`
488	`* returns length of result */`	490	`* returns length of result */`
489	`unsigned short nls_format_date(char s, unsigned short yr, unsigned char mo, unsigned char dy, const struct nls_patterns p) {`	491	`unsigned short nls_format_date(char s, unsigned short yr, unsigned char mo, unsigned char dy, const struct nls_patterns p) {`
490	`unsigned short items[3];`	492	`unsigned short items[3];`
491	`/* preset date/month/year in proper order depending on date format */`	493	`/* preset date/month/year in proper order depending on date format */`
492	`switch (p->dateformat) {`	494	`switch (p->dateformat) {`
493	`case 0: /* USA style: m d y */`	495	`case 0: /* USA style: m d y */`
494	`items[0] = mo;`	496	`items[0] = mo;`
495	`items[1] = dy;`	497	`items[1] = dy;`
496	`items[2] = yr;`	498	`items[2] = yr;`
497	`break;`	499	`break;`
498	`case 1: /* EU style: d m y */`	500	`case 1: /* EU style: d m y */`

Subversion Repositories SvarDOS

(root)/svarcom/trunk/helpers.c – Rev 445 → 530