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 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:
  }
}
 
 
static const char *nlsblock_findstr(unsigned short id) {
  const char *ptr = langblock + 4; /* first 4 bytes are lang id and lang len */
  /* find the string id in langblock memory */
  for (;;) {
    if (((unsigned short *)ptr)[0] == id) {
      ptr += 3;
      return(ptr);
    }
    if (ptr[2] == 0) return(NULL);
    ptr += ptr[2] + 3;
  }
}
 
 
void nls_output_internal(unsigned short id, unsigned char nl, unsigned char handle) {
  const char *NOTFOUND = "NLS_STRING_NOT_FOUND";
  const char *ptr = nlsblock_findstr(id);
  if (ptr == NULL) ptr = NOTFOUND;
  output_internal(ptr, nl, handle);
}
 
 
/* output DOS error e to stderr */
void nls_outputnl_doserr(unsigned short e) {
  static char errstr[16];
  const char *ptr = NULL;
  /* find string in nls block */
  if (e < 0xff) ptr = nlsblock_findstr(0xff00 | e);
  /* if not found, use a fallback */
  if (ptr == NULL) {
    sprintf(errstr, "DOS ERR %u", e);
    ptr = errstr;
  }
  /* display */
  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 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);
}
 
 
/* 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 542	Rev 571
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, 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	`static const char *nlsblock_findstr(unsigned short id) {`	111	`static const char *nlsblock_findstr(unsigned short id) {`
112	`const char ptr = langblock + 4; / first 4 bytes are lang id and lang len */`	112	`const char ptr = langblock + 4; / first 4 bytes are lang id and lang len */`
113	`/* find the string id in langblock memory */`	113	`/* find the string id in langblock memory */`
114	`for (;;) {`	114	`for (;;) {`
115	`if (((unsigned short *)ptr)[0] == id) {`	115	`if (((unsigned short *)ptr)[0] == id) {`
116	`ptr += 3;`	116	`ptr += 3;`
117	`return(ptr);`	117	`return(ptr);`
118	`}`	118	`}`
119	`if (ptr[2] == 0) return(NULL);`	119	`if (ptr[2] == 0) return(NULL);`
120	`ptr += ptr[2] + 3;`	120	`ptr += ptr[2] + 3;`
121	`}`	121	`}`
122	`}`	122	`}`
123		123
124		124
125	`void nls_output_internal(unsigned short id, unsigned char nl, unsigned char handle) {`	125	`void nls_output_internal(unsigned short id, unsigned char nl, unsigned char handle) {`
126	`const char *NOTFOUND = "NLS_STRING_NOT_FOUND";`	126	`const char *NOTFOUND = "NLS_STRING_NOT_FOUND";`
127	`const char *ptr = nlsblock_findstr(id);`	127	`const char *ptr = nlsblock_findstr(id);`
128	`if (ptr == NULL) ptr = NOTFOUND;`	128	`if (ptr == NULL) ptr = NOTFOUND;`
129	`output_internal(ptr, nl, handle);`	129	`output_internal(ptr, nl, handle);`
130	`}`	130	`}`
131		131
132		132
133	`/* output DOS error e to stderr */`	133	`/* output DOS error e to stderr */`
134	`void nls_outputnl_doserr(unsigned short e) {`	134	`void nls_outputnl_doserr(unsigned short e) {`
135	`static char errstr[16];`	135	`static char errstr[16];`
136	`const char *ptr = NULL;`	136	`const char *ptr = NULL;`
137	`/* find string in nls block */`	137	`/* find string in nls block */`
138	`if (e < 0xff) ptr = nlsblock_findstr(0xff00 \| e);`	138	`if (e < 0xff) ptr = nlsblock_findstr(0xff00 \| e);`
139	`/* if not found, use a fallback */`	139	`/* if not found, use a fallback */`
140	`if (ptr == NULL) {`	140	`if (ptr == NULL) {`
141	`sprintf(errstr, "DOS ERR %u", e);`	141	`sprintf(errstr, "DOS ERR %u", e);`
142	`ptr = errstr;`	142	`ptr = errstr;`
143	`}`	143	`}`
144	`/* display */`	144	`/* display */`
145	`output_internal(ptr, 1, hSTDERR);`	145	`output_internal(ptr, 1, hSTDERR);`
146	`}`	146	`}`
147		147
148		148
149	`/* find first matching files using a FindFirst DOS call`	149	`/* find first matching files using a FindFirst DOS call`
150	`* returns 0 on success or a DOS err code on failure */`	150	`* returns 0 on success or a DOS err code on failure */`
151	`unsigned short findfirst(struct DTA dta, const char pattern, unsigned short attr) {`	151	`unsigned short findfirst(struct DTA dta, const char pattern, unsigned short attr) {`
152	`unsigned short res = 0;`	152	`unsigned short res = 0;`
153	`_asm {`	153	`_asm {`
154	`/* set DTA location */`	154	`/* set DTA location */`
155	`mov ah, 0x1a`	155	`mov ah, 0x1a`
156	`mov dx, dta`	156	`mov dx, dta`
157	`int 0x21`	157	`int 0x21`
158	`/* */`	158	`/* */`
159	`mov ah, 0x4e /* FindFirst */`	159	`mov ah, 0x4e /* FindFirst */`
160	`mov dx, pattern`	160	`mov dx, pattern`
161	`mov cx, attr`	161	`mov cx, attr`
162	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`	162	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`
163	`jnc DONE`	163	`jnc DONE`
164	`mov [res], ax`	164	`mov [res], ax`
165	`DONE:`	165	`DONE:`
166	`}`	166	`}`
167	`return(res);`	167	`return(res);`
168	`}`	168	`}`
169		169
170		170
171	`/* find next matching, ie. continues an action intiated by findfirst() */`	171	`/* find next matching, ie. continues an action intiated by findfirst() */`
172	`unsigned short findnext(struct DTA *dta) {`	172	`unsigned short findnext(struct DTA *dta) {`
173	`unsigned short res = 0;`	173	`unsigned short res = 0;`
174	`_asm {`	174	`_asm {`
175	`mov ah, 0x4f /* FindNext */`	175	`mov ah, 0x4f /* FindNext */`
176	`mov dx, dta`	176	`mov dx, dta`
177	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`	177	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`
178	`jnc DONE`	178	`jnc DONE`
179	`mov [res], ax`	179	`mov [res], ax`
180	`DONE:`	180	`DONE:`
181	`}`	181	`}`
182	`return(res);`	182	`return(res);`
183	`}`	183	`}`
184		184
185		185
186	`/* print s string and wait for a single key press from stdin. accepts only`	186	`/* print s string and wait for a single key press from stdin. accepts only`
187	`* key presses defined in the c ASCIIZ string. returns offset of pressed key`	187	`* key presses defined in the c ASCIIZ string. returns offset of pressed key`
188	`* in string. keys in c MUST BE UPPERCASE! */`	188	`* in string. keys in c MUST BE UPPERCASE! */`
189	`unsigned short askchoice(const char s, const char c) {`	189	`unsigned short askchoice(const char s, const char c) {`
190	`unsigned short res;`	190	`unsigned short res;`
191	`char key = 0;`	191	`char key = 0;`
192		192
193	`AGAIN:`	193	`AGAIN:`
194	`output(s);`	194	`output(s);`
195	`output(" ");`	195	`output(" ");`
196		196
197	`_asm {`	197	`_asm {`
198	`push ax`	198	`push ax`
199	`push dx`	199	`push dx`
200		200
201	`mov ax, 0x0c01 /* clear input buffer and execute getchar (INT 21h,AH=1) */`	201	`mov ax, 0x0c01 /* clear input buffer and execute getchar (INT 21h,AH=1) */`
202	`int 0x21`	202	`int 0x21`
203	`/* if AL == 0 then this is an extended character */`	203	`/* if AL == 0 then this is an extended character */`
204	`test al, al`	204	`test al, al`
205	`jnz GOTCHAR`	205	`jnz GOTCHAR`
206	`mov ah, 0x08 /* read again to flush extended char from input buffer */`	206	`mov ah, 0x08 /* read again to flush extended char from input buffer */`
207	`int 0x21`	207	`int 0x21`
208	`xor al, al /* all extended chars are ignored */`	208	`xor al, al /* all extended chars are ignored */`
209	`GOTCHAR: /* received key is in AL now */`	209	`GOTCHAR: /* received key is in AL now */`
210	`mov [key], al /* save key */`	210	`mov [key], al /* save key */`
211		211
212	`/* print a cr/lf */`	212	`/* print a cr/lf */`
213	`mov ah, 0x02`	213	`mov ah, 0x02`
214	`mov dl, 0x0D`	214	`mov dl, 0x0D`
215	`int 0x21`	215	`int 0x21`
216	`mov dl, 0x0A`	216	`mov dl, 0x0A`
217	`int 0x21`	217	`int 0x21`
218		218
219	`pop dx`	219	`pop dx`
220	`pop ax`	220	`pop ax`
221	`}`	221	`}`
222		222
223	`/* ucase() result */`	223	`/* ucase() result */`
224	`if ((key >= 'a') && (key <= 'z')) key -= ('a' - 'A');`	224	`if ((key >= 'a') && (key <= 'z')) key -= ('a' - 'A');`
225		225
226	`/* is there a match? */`	226	`/* is there a match? */`
227	`for (res = 0; c[res] != 0; res++) if (c[res] == key) return(res);`	227	`for (res = 0; c[res] != 0; res++) if (c[res] == key) return(res);`
228		228
229	`goto AGAIN;`	229	`goto AGAIN;`
230	`}`	230	`}`
231		231
232		232
233	`/* converts a path to its canonic representation, returns 0 on success`	233	`/* converts a path to its canonic representation, returns 0 on success`
234	`* or DOS err on failure (invalid drive) */`	234	`* or DOS err on failure (invalid drive) */`
235	`unsigned short file_truename(const char src, char dst) {`	235	`unsigned short file_truename(const char src, char dst) {`
236	`unsigned short res = 0;`	236	`unsigned short res = 0;`
237	`_asm {`	237	`_asm {`
238	`push es`	238	`push es`
239	`mov ah, 0x60 /* query truename, DS:SI=src, ES:DI=dst */`	239	`mov ah, 0x60 /* query truename, DS:SI=src, ES:DI=dst */`
240	`push ds`	240	`push ds`
241	`pop es`	241	`pop es`
242	`mov si, src`	242	`mov si, src`
243	`mov di, dst`	243	`mov di, dst`
244	`int 0x21`	244	`int 0x21`
245	`jnc DONE`	245	`jnc DONE`
246	`mov [res], ax`	246	`mov [res], ax`
247	`DONE:`	247	`DONE:`
248	`pop es`	248	`pop es`
249	`}`	249	`}`
250	`return(res);`	250	`return(res);`
251	`}`	251	`}`
252		252
253		253
254	`/* returns DOS attributes of file, or -1 on error */`	254	`/* returns DOS attributes of file, or -1 on error */`
255	`int file_getattr(const char *fname) {`	255	`int file_getattr(const char *fname) {`
256	`int res = -1;`	256	`int res = -1;`
257	`_asm {`	257	`_asm {`
258	`mov ax, 0x4300 /* query file attributes, fname at DS:DX */`	258	`mov ax, 0x4300 /* query file attributes, fname at DS:DX */`
259	`mov dx, fname`	259	`mov dx, fname`
260	`int 0x21 /* CX=attributes if CF=0, otherwise AX=errno */`	260	`int 0x21 /* CX=attributes if CF=0, otherwise AX=errno */`
261	`jc DONE`	261	`jc DONE`
262	`mov [res], cx`	262	`mov [res], cx`
263	`DONE:`	263	`DONE:`
264	`}`	264	`}`
265	`return(res);`	265	`return(res);`
266	`}`	266	`}`
267		267
268		268
269	`/* returns screen's width (in columns) */`	269	`/* returns screen's width (in columns) */`
270	`unsigned short screen_getwidth(void) {`	270	`unsigned short screen_getwidth(void) {`
271	`/* BIOS 0040:004A = word containing screen width in text columns */`	271	`/* BIOS 0040:004A = word containing screen width in text columns */`
272	`unsigned short far *scrw = MK_FP(0x40, 0x4a);`	272	`unsigned short far *scrw = MK_FP(0x40, 0x4a);`
273	`return(*scrw);`	273	`return(*scrw);`
274	`}`	274	`}`
275		275
276		276
277	`/* returns screen's height (in rows) */`	277	`/* returns screen's height (in rows) */`
278	`unsigned short screen_getheight(void) {`	278	`unsigned short screen_getheight(void) {`
279	`/* BIOS 0040:0084 = byte containing maximum valid row value (EGA ONLY) */`	279	`/* BIOS 0040:0084 = byte containing maximum valid row value (EGA ONLY) */`
280	`unsigned char far *scrh = MK_FP(0x40, 0x84);`	280	`unsigned char far *scrh = MK_FP(0x40, 0x84);`
281	`if (scrh == 0) return(25); / pre-EGA adapter */`	281	`if (scrh == 0) return(25); / pre-EGA adapter */`
282	`return(*scrh + 1);`	282	`return(*scrh + 1);`
283	`}`	283	`}`
284		284
285		285
286	`/* displays the "Press any key to continue" msg and waits for a keypress */`	286	`/* displays the "Press any key to continue" msg and waits for a keypress */`
287	`void press_any_key(void) {`	287	`void press_any_key(void) {`
288	`nls_output(15, 1); /* Press any key to continue... */`	288	`nls_output(15, 1); /* Press any key to continue... */`
289	`_asm {`	289	`_asm {`
290	`mov ah, 0x08 /* no echo console input */`	290	`mov ah, 0x08 /* no echo console input */`
291	`int 0x21 /* pressed key in AL now (0 for extended keys) */`	291	`int 0x21 /* pressed key in AL now (0 for extended keys) */`
292	`test al, al`	292	`test al, al`
293	`jnz DONE`	293	`jnz DONE`
294	`int 0x21 /* executed ah=8 again to read the rest of extended key */`	294	`int 0x21 /* executed ah=8 again to read the rest of extended key */`
295	`DONE:`	295	`DONE:`
296	`/* output CR/LF */`	296	`/* output CR/LF */`
297	`mov ah, 0x02`	297	`mov ah, 0x02`
298	`mov dl, 0x0D`	298	`mov dl, 0x0D`
299	`int 0x21`	299	`int 0x21`
300	`mov dl, 0x0A`	300	`mov dl, 0x0A`
301	`int 0x21`	301	`int 0x21`
302	`}`	302	`}`
303	`}`	303	`}`
304		304
305		305
306	`/* validate a drive (A=0, B=1, etc). returns 1 if valid, 0 otherwise */`	306	`/* validate a drive (A=0, B=1, etc). returns 1 if valid, 0 otherwise */`
307	`int isdrivevalid(unsigned char drv) {`	307	`int isdrivevalid(unsigned char drv) {`
308	`_asm {`	308	`_asm {`
309	`mov ah, 0x19 /* query default (current) disk */`	309	`mov ah, 0x19 /* query default (current) disk */`
310	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`	310	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`
311	`mov ch, al /* save current drive to ch */`	311	`mov ch, al /* save current drive to ch */`
312	`/* try setting up the drive as current */`	312	`/* try setting up the drive as current */`
313	`mov ah, 0x0E /* select default drive */`	313	`mov ah, 0x0E /* select default drive */`
314	`mov dl, [drv] /* 0=A, 1=B, etc */`	314	`mov dl, [drv] /* 0=A, 1=B, etc */`
315	`int 0x21`	315	`int 0x21`
316	`/* this call does not set CF on error, I must check cur drive to look for success */`	316	`/* this call does not set CF on error, I must check cur drive to look for success */`
317	`mov ah, 0x19 /* query default (current) disk */`	317	`mov ah, 0x19 /* query default (current) disk */`
318	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`	318	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`
319	`mov [drv], 1 /* preset result as success */`	319	`mov [drv], 1 /* preset result as success */`
320	`cmp al, dl /* is eq? */`	320	`cmp al, dl /* is eq? */`
321	`je DONE`	321	`je DONE`
322	`mov [drv], 0 /* fail */`	322	`mov [drv], 0 /* fail */`
323	`jmp FAILED`	323	`jmp FAILED`
324	`DONE:`	324	`DONE:`
325	`/* set current drive back to what it was initially */`	325	`/* set current drive back to what it was initially */`
326	`mov ah, 0x0E`	326	`mov ah, 0x0E`
327	`mov dl, ch`	327	`mov dl, ch`
328	`int 0x21`	328	`int 0x21`
329	`FAILED:`	329	`FAILED:`
330	`}`	330	`}`
331	`return(drv);`	331	`return(drv);`
332	`}`	332	`}`
333		333
334		334
335	`/* converts a 8+3 filename into 11-bytes FCB format (MYFILE EXT) */`	335	`/* converts a 8+3 filename into 11-bytes FCB format (MYFILE EXT) */`
336	`void file_fname2fcb(char dst, const char src) {`	336	`void file_fname2fcb(char dst, const char src) {`
337	`unsigned short i;`	337	`unsigned short i;`
338		338
339	`/* fill dst with 11 spaces and a NULL terminator */`	339	`/* fill dst with 11 spaces and a NULL terminator */`
340	`for (i = 0; i < 11; i++) dst[i] = ' ';`	340	`for (i = 0; i < 11; i++) dst[i] = ' ';`
341	`dst[11] = 0;`	341	`dst[11] = 0;`
342		342
343	`/* copy fname until dot (.) or 8 characters */`	343	`/* copy fname until dot (.) or 8 characters */`
344	`for (i = 0; i < 8; i++) {`	344	`for (i = 0; i < 8; i++) {`
345	`if ((src[i] == '.') \|\| (src[i] == 0)) break;`	345	`if ((src[i] == '.') \|\| (src[i] == 0)) break;`
346	`dst[i] = src[i];`	346	`dst[i] = src[i];`
347	`}`	347	`}`
348		348
349	`/* advance src until extension or end of string */`	349	`/* advance src until extension or end of string */`
350	`src += i;`	350	`src += i;`
351	`for (;;) {`	351	`for (;;) {`
352	`if (*src == '.') {`	352	`if (*src == '.') {`
353	`src++; /* next character is extension */`	353	`src++; /* next character is extension */`
354	`break;`	354	`break;`
355	`}`	355	`}`
356	`if (*src == 0) break;`	356	`if (*src == 0) break;`
357	`}`	357	`}`
358		358
359	`/* copy extension to dst (3 chars max) */`	359	`/* copy extension to dst (3 chars max) */`
360	`dst += 8;`	360	`dst += 8;`
361	`for (i = 0; i < 3; i++) {`	361	`for (i = 0; i < 3; i++) {`
362	`if (src[i] == 0) break;`	362	`if (src[i] == 0) break;`
363	`dst[i] = src[i];`	363	`dst[i] = src[i];`
364	`}`	364	`}`
365	`}`	365	`}`
366		366
367		367
368	`/* converts a 11-bytes FCB filename (MYFILE EXT) into 8+3 format (MYFILE.EXT) */`	368	`/* converts a 11-bytes FCB filename (MYFILE EXT) into 8+3 format (MYFILE.EXT) */`
369	`void file_fcb2fname(char dst, const char src) {`	369	`void file_fcb2fname(char dst, const char src) {`
370	`unsigned short i, end = 0;`	370	`unsigned short i, end = 0;`
371		371
372	`for (i = 0; i < 8; i++) {`	372	`for (i = 0; i < 8; i++) {`
373	`dst[i] = src[i];`	373	`dst[i] = src[i];`
374	`if (dst[i] != ' ') end = i + 1;`	374	`if (dst[i] != ' ') end = i + 1;`
375	`}`	375	`}`
376		376
377	`/* is there an extension? */`	377	`/* is there an extension? */`
378	`if (src[8] == ' ') {`	378	`if (src[8] == ' ') {`
379	`dst[end] = 0;`	379	`dst[end] = 0;`
380	`} else { /* found extension: copy it until first space */`	380	`} else { /* found extension: copy it until first space */`
381	`dst[end++] = '.';`	381	`dst[end++] = '.';`
382	`for (i = 8; i < 11; i++) {`	382	`for (i = 8; i < 11; i++) {`
383	`if (src[i] == ' ') break;`	383	`if (src[i] == ' ') break;`
384	`dst[end++] = src[i];`	384	`dst[end++] = src[i];`
385	`}`	385	`}`
386	`dst[end] = 0;`	386	`dst[end] = 0;`
387	`}`	387	`}`
388	`}`	388	`}`
389		389
390		390
391	`/* converts an ASCIIZ string into an unsigned short. returns 0 on success.`	391	`/* converts an ASCIIZ string into an unsigned short. returns 0 on success.`
392	`* on error, result will contain all valid digits that were read until`	392	`* on error, result will contain all valid digits that were read until`
393	`* error occurred (0 on overflow or if parsing failed immediately) */`	393	`* error occurred (0 on overflow or if parsing failed immediately) */`
394	`int atous(unsigned short r, const char s) {`	394	`int atous(unsigned short r, const char s) {`
395	`int err = 0;`	395	`int err = 0;`
396		396
397	`_asm {`	397	`_asm {`
398	`mov si, s`	398	`mov si, s`
399	`xor ax, ax /* general purpose register */`	399	`xor ax, ax /* general purpose register */`
400	`xor cx, cx /* contains the result */`	400	`xor cx, cx /* contains the result */`
401	`mov bx, 10 /* used as a multiplicative step */`	401	`mov bx, 10 /* used as a multiplicative step */`
402		402
403	`NEXTBYTE:`	403	`NEXTBYTE:`
404	`xchg cx, ax /* move result into cx temporarily */`	404	`xchg cx, ax /* move result into cx temporarily */`
405	`lodsb /* AL = DS:[SI++] */`	405	`lodsb /* AL = DS:[SI++] */`
406	`/* is AL 0? if so we're done */`	406	`/* is AL 0? if so we're done */`
407	`test al, al`	407	`test al, al`
408	`jz DONE`	408	`jz DONE`
409	`/* validate that AL is in range '0'-'9' */`	409	`/* validate that AL is in range '0'-'9' */`
410	`sub al, '0'`	410	`sub al, '0'`
411	`jc FAIL /* invalid character detected */`	411	`jc FAIL /* invalid character detected */`
412	`cmp al, 9`	412	`cmp al, 9`
413	`jg FAIL /* invalid character detected */`	413	`jg FAIL /* invalid character detected */`
414	`/* restore result into AX (CX contains the new digit) */`	414	`/* restore result into AX (CX contains the new digit) */`
415	`xchg cx, ax`	415	`xchg cx, ax`
416	`/* multiply result by 10 and add cl */`	416	`/* multiply result by 10 and add cl */`
417	`mul bx /* DX AX = AX * BX(10) */`	417	`mul bx /* DX AX = AX * BX(10) */`
418	`jc OVERFLOW /* overflow */`	418	`jc OVERFLOW /* overflow */`
419	`add ax, cx`	419	`add ax, cx`
420	`/* if CF is set then overflow occurred (overflow part lands in DX) */`	420	`/* if CF is set then overflow occurred (overflow part lands in DX) */`
421	`jnc NEXTBYTE`	421	`jnc NEXTBYTE`
422		422
423	`OVERFLOW:`	423	`OVERFLOW:`
424	`xor cx, cx /* make sure result is zeroed in case overflow occured */`	424	`xor cx, cx /* make sure result is zeroed in case overflow occured */`
425		425
426	`FAIL:`	426	`FAIL:`
427	`inc [err]`	427	`inc [err]`
428		428
429	`DONE: /* save result (CX) into indirect memory address r */`	429	`DONE: /* save result (CX) into indirect memory address r */`
430	`mov bx, [r]`	430	`mov bx, [r]`
431	`mov [bx], cx`	431	`mov [bx], cx`
432	`}`	432	`}`
433	`return(err);`	433	`return(err);`
434	`}`	434	`}`
435		435
436		436
437	`/* appends a backslash if path is a directory`	437	`/* appends a backslash if path is a directory`
438	`* returns the (possibly updated) length of path */`	438	`* returns the (possibly updated) length of path */`
439	`unsigned short path_appendbkslash_if_dir(char *path) {`	439	`unsigned short path_appendbkslash_if_dir(char *path) {`
440	`unsigned short len;`	440	`unsigned short len;`
441	`int attr;`	441	`int attr;`
442	`for (len = 0; path[len] != 0; len++);`	442	`for (len = 0; path[len] != 0; len++);`
443	`if (len == 0) return(0);`	443	`if (len == 0) return(0);`
444	`if (path[len - 1] == '\\') return(len);`	444	`if (path[len - 1] == '\\') return(len);`
445	`/* */`	445	`/* */`
446	`attr = file_getattr(path);`	446	`attr = file_getattr(path);`
447	`if ((attr > 0) && (attr & DOS_ATTR_DIR)) {`	447	`if ((attr > 0) && (attr & DOS_ATTR_DIR)) {`
448	`path[len++] = '\\';`	448	`path[len++] = '\\';`
449	`path[len] = 0;`	449	`path[len] = 0;`
450	`}`	450	`}`
451	`return(len);`	451	`return(len);`
452	`}`	452	`}`
453		453
454		454
455	`/* get current path drive d (A=1, B=2, etc - 0 is "current drive")`	455	`/* get current path drive d (A=1, B=2, etc - 0 is "current drive")`
456	`* returns 0 on success, doserr otherwise */`	456	`* returns 0 on success, doserr otherwise */`
457	`unsigned short curpathfordrv(char *buff, unsigned char d) {`	457	`unsigned short curpathfordrv(char *buff, unsigned char d) {`
458	`unsigned short r = 0;`	458	`unsigned short r = 0;`
459		459
460	`_asm {`	460	`_asm {`
461	`/* is d == 0? then I need to resolve current drive */`	461	`/* is d == 0? then I need to resolve current drive */`
462	`cmp byte ptr [d], 0`	462	`cmp byte ptr [d], 0`
463	`jne GETCWD`	463	`jne GETCWD`
464	`/* resolve cur drive */`	464	`/* resolve cur drive */`
465	`mov ah, 0x19 /* get current default drive */`	465	`mov ah, 0x19 /* get current default drive */`
466	`int 0x21 /* al = drive (00h = A:, 01h = B:, etc) */`	466	`int 0x21 /* al = drive (00h = A:, 01h = B:, etc) */`
467	`inc al /* convert to 1=A, 2=B, etc */`	467	`inc al /* convert to 1=A, 2=B, etc */`
468	`mov [d], al`	468	`mov [d], al`
469		469
470	`GETCWD:`	470	`GETCWD:`
471	`/* prepend buff with drive:\ */`	471	`/* prepend buff with drive:\ */`
472	`mov si, buff`	472	`mov si, buff`
473	`mov dl, [d]`	473	`mov dl, [d]`
474	`mov [si], dl`	474	`mov [si], dl`
475	`add byte ptr [si], 'A' - 1`	475	`add byte ptr [si], 'A' - 1`
476	`inc si`	476	`inc si`
477	`mov [si], ':'`	477	`mov [si], ':'`
478	`inc si`	478	`inc si`
479	`mov [si], '\\'`	479	`mov [si], '\\'`
480	`inc si`	480	`inc si`
481		481
482	`mov ah, 0x47 /* get current directory of drv DL into DS:SI */`	482	`mov ah, 0x47 /* get current directory of drv DL into DS:SI */`
483	`int 0x21`	483	`int 0x21`
484	`jnc DONE`	484	`jnc DONE`
485	`mov [r], ax /* copy result from ax */`	485	`mov [r], ax /* copy result from ax */`
486		486
487	`DONE:`	487	`DONE:`
488	`}`	488	`}`
489		489
490	`return(r);`	490	`return(r);`
491	`}`	491	`}`
492		492
493		493
494	`/* fills a nls_patterns struct with current NLS patterns, returns 0 on success, DOS errcode otherwise */`	494	`/* fills a nls_patterns struct with current NLS patterns, returns 0 on success, DOS errcode otherwise */`
495	`unsigned short nls_getpatterns(struct nls_patterns *p) {`	495	`unsigned short nls_getpatterns(struct nls_patterns *p) {`
496	`unsigned short r = 0;`	496	`unsigned short r = 0;`
497		497
498	`_asm {`	498	`_asm {`
499	`mov ax, 0x3800 /* DOS 2+ -- Get Country Info for current country */`	499	`mov ax, 0x3800 /* DOS 2+ -- Get Country Info for current country */`
500	`mov dx, p /* DS:DX points to the CountryInfoRec buffer */`	500	`mov dx, p /* DS:DX points to the CountryInfoRec buffer */`

Subversion Repositories SvarDOS

(root)/svarcom/trunk/helpers.c – Rev 542 → 571