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


/* This file is part of the SvarCOM project and is published under the terms
 * of the MIT license.
 *
 * Copyright (C) 2021-2022 Mateusz Viste
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
 
/*
 * a variety of helper functions
 */
 
#include <i86.h>    /* MK_FP() */
#include <stdio.h>  /* sprintf() */
#include <string.h> /* memcpy() */
 
 
 
#include "env.h"
 
#include "helpers.h"
 
 
/* supplied through DEFLANG.C */
extern char svarlang_mem[];
extern const unsigned short svarlang_memsz;
 
 
/* 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 = svarlang_mem;
  /* find the string id in langblock memory */
  for (;;) {
    if (((unsigned short *)ptr)[0] == id) {
 
      return(ptr + 4);
    }
    if (ptr[2] == 0) return(NULL);
    ptr += ((unsigned short *)ptr)[1] + 4;
  }
}
 
 
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 stdout, if stdout is redirected then *additionally*
 * also to stderr */
void nls_outputnl_doserr(unsigned short e) {
  static char errstr[16];
  const char *ptr = NULL;
  unsigned char redirflag = 0;
  /* find string in nls block */
  if (e < 0xff) ptr = nlsblock_findstr(0xff00 | e);
  /* if not found, use a fallback */
  if (ptr == NULL) {
    sprintf(errstr, "DOS ERR %u", e);
    ptr = errstr;
  }
 
  /* display to stdout */
  output_internal(ptr, 1, hSTDOUT);
 
  /* is stdout redirected? */
  _asm {
    push bx
    push dx
 
    mov ax, 0x4400   /* query device flags */
    mov bx, 1        /* stdout */
    int 0x21
    /* CF set on error and AX filled with DOS error,
     * returns flags in DX on succes:
     *  bit 7 reset if handle points to a file, set if handle points to a device  */
    jc FAIL
    mov redirflag, dl
    and redirflag, 128
 
    FAIL:
    pop dx
    pop bx
  }
 
  if (redirflag == 0) output_internal(ptr, 1, hSTDERR);
}
 
 
/* find first matching files using a FindFirst DOS call
 * returns 0 on success or a DOS err code on failure */
unsigned short findfirst(struct DTA *dta, const char *pattern, unsigned short attr) {
  unsigned short res = 0;
  _asm {
    /* set DTA location */
    mov ah, 0x1a
    mov dx, dta
    int 0x21
    /* */
    mov ah, 0x4e    /* FindFirst */
    mov dx, pattern
    mov cx, attr
    int 0x21        /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */
    jnc DONE
    mov [res], ax
    DONE:
  }
  return(res);
}
 
 
/* find next matching, ie. continues an action intiated by findfirst() */
unsigned short findnext(struct DTA *dta) {
  unsigned short res = 0;
  _asm {
    mov ah, 0x4f    /* FindNext */
    mov dx, dta
    int 0x21        /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */
    jnc DONE
    mov [res], ax
    DONE:
  }
  return(res);
}
 
 
/* print s string and wait for a single key press from stdin. accepts only
 * key presses defined in the c ASCIIZ string. returns offset of pressed key
 * in string. keys in c MUST BE UPPERCASE! */
unsigned short askchoice(const char *s, const char *c) {
  unsigned short res;
  char 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 svarlang_mem */
void nls_langreload(char *buff, unsigned short env) {
  unsigned short i;
  const char far *nlspath;
  char *langblockptr = svarlang_mem;
  unsigned short lang;
  unsigned short errcode = 0;
  static unsigned short lastlang;
 
  /* 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] & 0xDF;
  buff[1] = nlspath[1] & 0xDF;
  buff[2] = 0;
 
 
 
  memcpy(&lang, buff, 2);
 
  /* check if there is need to reload at all */
  if (lastlang == lang) return;
 
  /* printf("NLS RELOAD (curlang=%04X ; toload=%04X\r\n", lastlang, 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 svarlang_mem */
  _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:
 
 
 
 
 
 
 
    /* read strings (buff+2 bytes) into langblock */
    mov di, langblockptr
    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) lastlang = lang;
}
 
 
/* 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 959	Rev 965
1	`/* This file is part of the SvarCOM project and is published under the terms`	1	`/* This file is part of the SvarCOM project and is published under the terms`
2	`* of the MIT license.`	2	`* of the MIT license.`
3	`*`	3	`*`
4	`* Copyright (C) 2021-2022 Mateusz Viste`	4	`* Copyright (C) 2021-2022 Mateusz Viste`
5	`*`	5	`*`
6	`* Permission is hereby granted, free of charge, to any person obtaining a`	6	`* Permission is hereby granted, free of charge, to any person obtaining a`
7	`* copy of this software and associated documentation files (the "Software"),`	7	`* copy of this software and associated documentation files (the "Software"),`
8	`* to deal in the Software without restriction, including without limitation`	8	`* to deal in the Software without restriction, including without limitation`
9	`* the rights to use, copy, modify, merge, publish, distribute, sublicense,`	9	`* the rights to use, copy, modify, merge, publish, distribute, sublicense,`
10	`* and/or sell copies of the Software, and to permit persons to whom the`	10	`* and/or sell copies of the Software, and to permit persons to whom the`
11	`* Software is furnished to do so, subject to the following conditions:`	11	`* Software is furnished to do so, subject to the following conditions:`
12	`*`	12	`*`
13	`* The above copyright notice and this permission notice shall be included in`	13	`* The above copyright notice and this permission notice shall be included in`
14	`* all copies or substantial portions of the Software.`	14	`* all copies or substantial portions of the Software.`
15	`*`	15	`*`
16	`* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR`	16	`* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR`
17	`* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,`	17	`* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,`
18	`* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE`	18	`* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE`
19	`* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER`	19	`* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER`
20	`* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING`	20	`* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING`
21	`* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER`	21	`* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER`
22	`* DEALINGS IN THE SOFTWARE.`	22	`* DEALINGS IN THE SOFTWARE.`
23	`*/`	23	`*/`
24		24
25	`/*`	25	`/*`
26	`* a variety of helper functions`	26	`* a variety of helper functions`
27	`*/`	27	`*/`
28		28
29	`#include <i86.h> /* MK_FP() */`	29	`#include <i86.h> /* MK_FP() */`
30	`#include <stdio.h> /* sprintf() */`	30	`#include <stdio.h> /* sprintf() */`
31	`#include <string.h> /* memcpy() */`	31	`#include <string.h> /* memcpy() */`
32		32
33	`#include "deflang.h"`	-
34		-
35	`#include "env.h"`	33	`#include "env.h"`
36		34
37	`#include "helpers.h"`	35	`#include "helpers.h"`
38		36
39		37
-		38	`/* supplied through DEFLANG.C */`
-		39	`extern char svarlang_mem[];`
-		40	`extern const unsigned short svarlang_memsz;`
-		41
-		42
40	`/* case-insensitive comparison of strings, compares up to maxlen characters.`	43	`/* case-insensitive comparison of strings, compares up to maxlen characters.`
41	`* returns non-zero on equality. */`	44	`* returns non-zero on equality. */`
42	`int imatchlim(const char s1, const char s2, unsigned short maxlen) {`	45	`int imatchlim(const char s1, const char s2, unsigned short maxlen) {`
43	`while (maxlen--) {`	46	`while (maxlen--) {`
44	`char c1, c2;`	47	`char c1, c2;`
45	`c1 = *s1;`	48	`c1 = *s1;`
46	`c2 = *s2;`	49	`c2 = *s2;`
47	`if ((c1 >= 'a') && (c1 <= 'z')) c1 -= ('a' - 'A');`	50	`if ((c1 >= 'a') && (c1 <= 'z')) c1 -= ('a' - 'A');`
48	`if ((c2 >= 'a') && (c2 <= 'z')) c2 -= ('a' - 'A');`	51	`if ((c2 >= 'a') && (c2 <= 'z')) c2 -= ('a' - 'A');`
49	`/* */`	52	`/* */`
50	`if (c1 != c2) return(0);`	53	`if (c1 != c2) return(0);`
51	`if (c1 == 0) break;`	54	`if (c1 == 0) break;`
52	`s1++;`	55	`s1++;`
53	`s2++;`	56	`s2++;`
54	`}`	57	`}`
55	`return(1);`	58	`return(1);`
56	`}`	59	`}`
57		60
58		61
59	`/* returns zero if s1 starts with s2 */`	62	`/* returns zero if s1 starts with s2 */`
60	`int strstartswith(const char s1, const char s2) {`	63	`int strstartswith(const char s1, const char s2) {`
61	`while (*s2 != 0) {`	64	`while (*s2 != 0) {`
62	`if (s1 != s2) return(-1);`	65	`if (s1 != s2) return(-1);`
63	`s1++;`	66	`s1++;`
64	`s2++;`	67	`s2++;`
65	`}`	68	`}`
66	`return(0);`	69	`return(0);`
67	`}`	70	`}`
68		71
69		72
70	`/* outputs a NULL-terminated string to handle (1=stdout 2=stderr) */`	73	`/* outputs a NULL-terminated string to handle (1=stdout 2=stderr) */`
71	`void output_internal(const char *s, unsigned char nl, unsigned char handle) {`	74	`void output_internal(const char *s, unsigned char nl, unsigned char handle) {`
72	`const static unsigned char *crlf = "\r\n";`	75	`const static unsigned char *crlf = "\r\n";`
73	`_asm {`	76	`_asm {`
74	`push ds`	77	`push ds`
75	`pop es /* make sure es=ds (scasb uses es) */`	78	`pop es /* make sure es=ds (scasb uses es) */`
76	`/* get length of s into CX */`	79	`/* get length of s into CX */`
77	`mov ax, 0x4000 /* ah=DOS "write to file" and AL=0 for NULL matching */`	80	`mov ax, 0x4000 /* ah=DOS "write to file" and AL=0 for NULL matching */`
78	`mov dx, s /* set dx to string (required for later) */`	81	`mov dx, s /* set dx to string (required for later) */`
79	`mov di, dx /* set di to string (for NULL matching) */`	82	`mov di, dx /* set di to string (for NULL matching) */`
80	`mov cx, 0xffff /* preset cx to 65535 (-1) */`	83	`mov cx, 0xffff /* preset cx to 65535 (-1) */`
81	`cld /* clear DF so scasb increments DI */`	84	`cld /* clear DF so scasb increments DI */`
82	`repne scasb /* cmp al, es:[di], inc di, dec cx until match found */`	85	`repne scasb /* cmp al, es:[di], inc di, dec cx until match found */`
83	`/* CX contains (65535 - strlen(s)) now */`	86	`/* CX contains (65535 - strlen(s)) now */`
84	`not cx /* reverse all bits so I get (strlen(s) + 1) */`	87	`not cx /* reverse all bits so I get (strlen(s) + 1) */`
85	`dec cx /* this is CX length */`	88	`dec cx /* this is CX length */`
86	`jz WRITEDONE /* do nothing for empty strings */`	89	`jz WRITEDONE /* do nothing for empty strings */`
87		90
88	`/* output by writing to stdout */`	91	`/* output by writing to stdout */`
89	`/* mov ah, 0x40 / / DOS 2+ -- write to file via handle */`	92	`/* mov ah, 0x40 / / DOS 2+ -- write to file via handle */`
90	`xor bh, bh`	93	`xor bh, bh`
91	`mov bl, handle /* set handle (1=stdout 2=stderr) */`	94	`mov bl, handle /* set handle (1=stdout 2=stderr) */`
92	`/* mov cx, xxx / / write CX bytes */`	95	`/* mov cx, xxx / / write CX bytes */`
93	`/* mov dx, s / / DS:DX is the source of bytes to "write" */`	96	`/* mov dx, s / / DS:DX is the source of bytes to "write" */`
94	`int 0x21`	97	`int 0x21`
95	`WRITEDONE:`	98	`WRITEDONE:`
96		99
97	`/* print out a CR/LF trailer if nl set */`	100	`/* print out a CR/LF trailer if nl set */`
98	`test byte ptr [nl], 0xff`	101	`test byte ptr [nl], 0xff`
99	`jz FINITO`	102	`jz FINITO`
100	`/* bx still contains handle */`	103	`/* bx still contains handle */`
101	`mov ah, 0x40 /* "write to file" */`	104	`mov ah, 0x40 /* "write to file" */`
102	`mov cx, 2`	105	`mov cx, 2`
103	`mov dx, crlf`	106	`mov dx, crlf`
104	`int 0x21`	107	`int 0x21`
105	`FINITO:`	108	`FINITO:`
106	`}`	109	`}`
107	`}`	110	`}`
108		111
109		112
110	`static const char *nlsblock_findstr(unsigned short id) {`	113	`static const char *nlsblock_findstr(unsigned short id) {`
111	`const char ptr = langblock + 4; / first 4 bytes are lang id and lang len */`	114	`const char *ptr = svarlang_mem;`
112	`/* find the string id in langblock memory */`	115	`/* find the string id in langblock memory */`
113	`for (;;) {`	116	`for (;;) {`
114	`if (((unsigned short *)ptr)[0] == id) {`	117	`if (((unsigned short *)ptr)[0] == id) {`
115	`ptr += 3;`	-
116	`return(ptr);`	118	`return(ptr + 4);`
117	`}`	119	`}`
118	`if (ptr[2] == 0) return(NULL);`	120	`if (ptr[2] == 0) return(NULL);`
119	`ptr += ptr[2] + 3;`	121	`ptr += ((unsigned short *)ptr)[1] + 4;`
120	`}`	122	`}`
121	`}`	123	`}`
122		124
123		125
124	`void nls_output_internal(unsigned short id, unsigned char nl, unsigned char handle) {`	126	`void nls_output_internal(unsigned short id, unsigned char nl, unsigned char handle) {`
125	`const char *NOTFOUND = "NLS_STRING_NOT_FOUND";`	127	`const char *NOTFOUND = "NLS_STRING_NOT_FOUND";`
126	`const char *ptr = nlsblock_findstr(id);`	128	`const char *ptr = nlsblock_findstr(id);`
127	`if (ptr == NULL) ptr = NOTFOUND;`	129	`if (ptr == NULL) ptr = NOTFOUND;`
128	`output_internal(ptr, nl, handle);`	130	`output_internal(ptr, nl, handle);`
129	`}`	131	`}`
130		132
131		133
132	`/* output DOS error e to stdout, if stdout is redirected then additionally`	134	`/* output DOS error e to stdout, if stdout is redirected then additionally`
133	`* also to stderr */`	135	`* also to stderr */`
134	`void nls_outputnl_doserr(unsigned short e) {`	136	`void nls_outputnl_doserr(unsigned short e) {`
135	`static char errstr[16];`	137	`static char errstr[16];`
136	`const char *ptr = NULL;`	138	`const char *ptr = NULL;`
137	`unsigned char redirflag = 0;`	139	`unsigned char redirflag = 0;`
138	`/* find string in nls block */`	140	`/* find string in nls block */`
139	`if (e < 0xff) ptr = nlsblock_findstr(0xff00 \| e);`	141	`if (e < 0xff) ptr = nlsblock_findstr(0xff00 \| e);`
140	`/* if not found, use a fallback */`	142	`/* if not found, use a fallback */`
141	`if (ptr == NULL) {`	143	`if (ptr == NULL) {`
142	`sprintf(errstr, "DOS ERR %u", e);`	144	`sprintf(errstr, "DOS ERR %u", e);`
143	`ptr = errstr;`	145	`ptr = errstr;`
144	`}`	146	`}`
145		147
146	`/* display to stdout */`	148	`/* display to stdout */`
147	`output_internal(ptr, 1, hSTDOUT);`	149	`output_internal(ptr, 1, hSTDOUT);`
148		150
149	`/* is stdout redirected? */`	151	`/* is stdout redirected? */`
150	`_asm {`	152	`_asm {`
151	`push bx`	153	`push bx`
152	`push dx`	154	`push dx`
153		155
154	`mov ax, 0x4400 /* query device flags */`	156	`mov ax, 0x4400 /* query device flags */`
155	`mov bx, 1 /* stdout */`	157	`mov bx, 1 /* stdout */`
156	`int 0x21`	158	`int 0x21`
157	`/* CF set on error and AX filled with DOS error,`	159	`/* CF set on error and AX filled with DOS error,`
158	`* returns flags in DX on succes:`	160	`* returns flags in DX on succes:`
159	`* bit 7 reset if handle points to a file, set if handle points to a device */`	161	`* bit 7 reset if handle points to a file, set if handle points to a device */`
160	`jc FAIL`	162	`jc FAIL`
161	`mov redirflag, dl`	163	`mov redirflag, dl`
162	`and redirflag, 128`	164	`and redirflag, 128`
163		165
164	`FAIL:`	166	`FAIL:`
165	`pop dx`	167	`pop dx`
166	`pop bx`	168	`pop bx`
167	`}`	169	`}`
168		170
169	`if (redirflag == 0) output_internal(ptr, 1, hSTDERR);`	171	`if (redirflag == 0) output_internal(ptr, 1, hSTDERR);`
170	`}`	172	`}`
171		173
172		174
173	`/* find first matching files using a FindFirst DOS call`	175	`/* find first matching files using a FindFirst DOS call`
174	`* returns 0 on success or a DOS err code on failure */`	176	`* returns 0 on success or a DOS err code on failure */`
175	`unsigned short findfirst(struct DTA dta, const char pattern, unsigned short attr) {`	177	`unsigned short findfirst(struct DTA dta, const char pattern, unsigned short attr) {`
176	`unsigned short res = 0;`	178	`unsigned short res = 0;`
177	`_asm {`	179	`_asm {`
178	`/* set DTA location */`	180	`/* set DTA location */`
179	`mov ah, 0x1a`	181	`mov ah, 0x1a`
180	`mov dx, dta`	182	`mov dx, dta`
181	`int 0x21`	183	`int 0x21`
182	`/* */`	184	`/* */`
183	`mov ah, 0x4e /* FindFirst */`	185	`mov ah, 0x4e /* FindFirst */`
184	`mov dx, pattern`	186	`mov dx, pattern`
185	`mov cx, attr`	187	`mov cx, attr`
186	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`	188	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`
187	`jnc DONE`	189	`jnc DONE`
188	`mov [res], ax`	190	`mov [res], ax`
189	`DONE:`	191	`DONE:`
190	`}`	192	`}`
191	`return(res);`	193	`return(res);`
192	`}`	194	`}`
193		195
194		196
195	`/* find next matching, ie. continues an action intiated by findfirst() */`	197	`/* find next matching, ie. continues an action intiated by findfirst() */`
196	`unsigned short findnext(struct DTA *dta) {`	198	`unsigned short findnext(struct DTA *dta) {`
197	`unsigned short res = 0;`	199	`unsigned short res = 0;`
198	`_asm {`	200	`_asm {`
199	`mov ah, 0x4f /* FindNext */`	201	`mov ah, 0x4f /* FindNext */`
200	`mov dx, dta`	202	`mov dx, dta`
201	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`	203	`int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */`
202	`jnc DONE`	204	`jnc DONE`
203	`mov [res], ax`	205	`mov [res], ax`
204	`DONE:`	206	`DONE:`
205	`}`	207	`}`
206	`return(res);`	208	`return(res);`
207	`}`	209	`}`
208		210
209		211
210	`/* print s string and wait for a single key press from stdin. accepts only`	212	`/* print s string and wait for a single key press from stdin. accepts only`
211	`* key presses defined in the c ASCIIZ string. returns offset of pressed key`	213	`* key presses defined in the c ASCIIZ string. returns offset of pressed key`
212	`* in string. keys in c MUST BE UPPERCASE! */`	214	`* in string. keys in c MUST BE UPPERCASE! */`
213	`unsigned short askchoice(const char s, const char c) {`	215	`unsigned short askchoice(const char s, const char c) {`
214	`unsigned short res;`	216	`unsigned short res;`
215	`char key = 0;`	217	`char key = 0;`
216		218
217	`AGAIN:`	219	`AGAIN:`
218	`output(s);`	220	`output(s);`
219	`output(" ");`	221	`output(" ");`
220		222
221	`_asm {`	223	`_asm {`
222	`push ax`	224	`push ax`
223	`push dx`	225	`push dx`
224		226
225	`mov ax, 0x0c01 /* clear input buffer and execute getchar (INT 21h,AH=1) */`	227	`mov ax, 0x0c01 /* clear input buffer and execute getchar (INT 21h,AH=1) */`
226	`int 0x21`	228	`int 0x21`
227	`/* if AL == 0 then this is an extended character */`	229	`/* if AL == 0 then this is an extended character */`
228	`test al, al`	230	`test al, al`
229	`jnz GOTCHAR`	231	`jnz GOTCHAR`
230	`mov ah, 0x08 /* read again to flush extended char from input buffer */`	232	`mov ah, 0x08 /* read again to flush extended char from input buffer */`
231	`int 0x21`	233	`int 0x21`
232	`xor al, al /* all extended chars are ignored */`	234	`xor al, al /* all extended chars are ignored */`
233	`GOTCHAR: /* received key is in AL now */`	235	`GOTCHAR: /* received key is in AL now */`
234	`mov [key], al /* save key */`	236	`mov [key], al /* save key */`
235		237
236	`/* print a cr/lf */`	238	`/* print a cr/lf */`
237	`mov ah, 0x02`	239	`mov ah, 0x02`
238	`mov dl, 0x0D`	240	`mov dl, 0x0D`
239	`int 0x21`	241	`int 0x21`
240	`mov dl, 0x0A`	242	`mov dl, 0x0A`
241	`int 0x21`	243	`int 0x21`
242		244
243	`pop dx`	245	`pop dx`
244	`pop ax`	246	`pop ax`
245	`}`	247	`}`
246		248
247	`/* ucase() result */`	249	`/* ucase() result */`
248	`if ((key >= 'a') && (key <= 'z')) key -= ('a' - 'A');`	250	`if ((key >= 'a') && (key <= 'z')) key -= ('a' - 'A');`
249		251
250	`/* is there a match? */`	252	`/* is there a match? */`
251	`for (res = 0; c[res] != 0; res++) if (c[res] == key) return(res);`	253	`for (res = 0; c[res] != 0; res++) if (c[res] == key) return(res);`
252		254
253	`goto AGAIN;`	255	`goto AGAIN;`
254	`}`	256	`}`
255		257
256		258
257	`/* converts a path to its canonic representation, returns 0 on success`	259	`/* converts a path to its canonic representation, returns 0 on success`
258	`* or DOS err on failure (invalid drive) */`	260	`* or DOS err on failure (invalid drive) */`
259	`unsigned short file_truename(const char src, char dst) {`	261	`unsigned short file_truename(const char src, char dst) {`
260	`unsigned short res = 0;`	262	`unsigned short res = 0;`
261	`_asm {`	263	`_asm {`
262	`push es`	264	`push es`
263	`mov ah, 0x60 /* query truename, DS:SI=src, ES:DI=dst */`	265	`mov ah, 0x60 /* query truename, DS:SI=src, ES:DI=dst */`
264	`push ds`	266	`push ds`
265	`pop es`	267	`pop es`
266	`mov si, src`	268	`mov si, src`
267	`mov di, dst`	269	`mov di, dst`
268	`int 0x21`	270	`int 0x21`
269	`jnc DONE`	271	`jnc DONE`
270	`mov [res], ax`	272	`mov [res], ax`
271	`DONE:`	273	`DONE:`
272	`pop es`	274	`pop es`
273	`}`	275	`}`
274	`return(res);`	276	`return(res);`
275	`}`	277	`}`
276		278
277		279
278	`/* returns DOS attributes of file, or -1 on error */`	280	`/* returns DOS attributes of file, or -1 on error */`
279	`int file_getattr(const char *fname) {`	281	`int file_getattr(const char *fname) {`
280	`int res = -1;`	282	`int res = -1;`
281	`_asm {`	283	`_asm {`
282	`mov ax, 0x4300 /* query file attributes, fname at DS:DX */`	284	`mov ax, 0x4300 /* query file attributes, fname at DS:DX */`
283	`mov dx, fname`	285	`mov dx, fname`
284	`int 0x21 /* CX=attributes if CF=0, otherwise AX=errno */`	286	`int 0x21 /* CX=attributes if CF=0, otherwise AX=errno */`
285	`jc DONE`	287	`jc DONE`
286	`mov [res], cx`	288	`mov [res], cx`
287	`DONE:`	289	`DONE:`
288	`}`	290	`}`
289	`return(res);`	291	`return(res);`
290	`}`	292	`}`
291		293
292		294
293	`/* returns screen's width (in columns) */`	295	`/* returns screen's width (in columns) */`
294	`unsigned short screen_getwidth(void) {`	296	`unsigned short screen_getwidth(void) {`
295	`/* BIOS 0040:004A = word containing screen width in text columns */`	297	`/* BIOS 0040:004A = word containing screen width in text columns */`
296	`unsigned short far *scrw = MK_FP(0x40, 0x4a);`	298	`unsigned short far *scrw = MK_FP(0x40, 0x4a);`
297	`return(*scrw);`	299	`return(*scrw);`
298	`}`	300	`}`
299		301
300		302
301	`/* returns screen's height (in rows) */`	303	`/* returns screen's height (in rows) */`
302	`unsigned short screen_getheight(void) {`	304	`unsigned short screen_getheight(void) {`
303	`/* BIOS 0040:0084 = byte containing maximum valid row value (EGA ONLY) */`	305	`/* BIOS 0040:0084 = byte containing maximum valid row value (EGA ONLY) */`
304	`unsigned char far *scrh = MK_FP(0x40, 0x84);`	306	`unsigned char far *scrh = MK_FP(0x40, 0x84);`
305	`if (scrh == 0) return(25); / pre-EGA adapter */`	307	`if (scrh == 0) return(25); / pre-EGA adapter */`
306	`return(*scrh + 1);`	308	`return(*scrh + 1);`
307	`}`	309	`}`
308		310
309		311
310	`/* displays the "Press any key to continue" msg and waits for a keypress */`	312	`/* displays the "Press any key to continue" msg and waits for a keypress */`
311	`void press_any_key(void) {`	313	`void press_any_key(void) {`
312	`nls_output(15, 1); /* Press any key to continue... */`	314	`nls_output(15, 1); /* Press any key to continue... */`
313	`_asm {`	315	`_asm {`
314	`mov ah, 0x08 /* no echo console input */`	316	`mov ah, 0x08 /* no echo console input */`
315	`int 0x21 /* pressed key in AL now (0 for extended keys) */`	317	`int 0x21 /* pressed key in AL now (0 for extended keys) */`
316	`test al, al`	318	`test al, al`
317	`jnz DONE`	319	`jnz DONE`
318	`int 0x21 /* executed ah=8 again to read the rest of extended key */`	320	`int 0x21 /* executed ah=8 again to read the rest of extended key */`
319	`DONE:`	321	`DONE:`
320	`/* output CR/LF */`	322	`/* output CR/LF */`
321	`mov ah, 0x02`	323	`mov ah, 0x02`
322	`mov dl, 0x0D`	324	`mov dl, 0x0D`
323	`int 0x21`	325	`int 0x21`
324	`mov dl, 0x0A`	326	`mov dl, 0x0A`
325	`int 0x21`	327	`int 0x21`
326	`}`	328	`}`
327	`}`	329	`}`
328		330
329		331
330	`/* validate a drive (A=0, B=1, etc). returns 1 if valid, 0 otherwise */`	332	`/* validate a drive (A=0, B=1, etc). returns 1 if valid, 0 otherwise */`
331	`int isdrivevalid(unsigned char drv) {`	333	`int isdrivevalid(unsigned char drv) {`
332	`_asm {`	334	`_asm {`
333	`mov ah, 0x19 /* query default (current) disk */`	335	`mov ah, 0x19 /* query default (current) disk */`
334	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`	336	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`
335	`mov ch, al /* save current drive to ch */`	337	`mov ch, al /* save current drive to ch */`
336	`/* try setting up the drive as current */`	338	`/* try setting up the drive as current */`
337	`mov ah, 0x0E /* select default drive */`	339	`mov ah, 0x0E /* select default drive */`
338	`mov dl, [drv] /* 0=A, 1=B, etc */`	340	`mov dl, [drv] /* 0=A, 1=B, etc */`
339	`int 0x21`	341	`int 0x21`
340	`/* this call does not set CF on error, I must check cur drive to look for success */`	342	`/* this call does not set CF on error, I must check cur drive to look for success */`
341	`mov ah, 0x19 /* query default (current) disk */`	343	`mov ah, 0x19 /* query default (current) disk */`
342	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`	344	`int 0x21 /* drive in AL (0=A, 1=B, etc) */`
343	`mov [drv], 1 /* preset result as success */`	345	`mov [drv], 1 /* preset result as success */`
344	`cmp al, dl /* is eq? */`	346	`cmp al, dl /* is eq? */`
345	`je DONE`	347	`je DONE`
346	`mov [drv], 0 /* fail */`	348	`mov [drv], 0 /* fail */`
347	`jmp FAILED`	349	`jmp FAILED`
348	`DONE:`	350	`DONE:`
349	`/* set current drive back to what it was initially */`	351	`/* set current drive back to what it was initially */`
350	`mov ah, 0x0E`	352	`mov ah, 0x0E`
351	`mov dl, ch`	353	`mov dl, ch`
352	`int 0x21`	354	`int 0x21`
353	`FAILED:`	355	`FAILED:`
354	`}`	356	`}`
355	`return(drv);`	357	`return(drv);`
356	`}`	358	`}`
357		359
358		360
359	`/* converts a 8+3 filename into 11-bytes FCB format (MYFILE EXT) */`	361	`/* converts a 8+3 filename into 11-bytes FCB format (MYFILE EXT) */`
360	`void file_fname2fcb(char dst, const char src) {`	362	`void file_fname2fcb(char dst, const char src) {`
361	`unsigned short i;`	363	`unsigned short i;`
362		364
363	`/* fill dst with 11 spaces and a NULL terminator */`	365	`/* fill dst with 11 spaces and a NULL terminator */`
364	`for (i = 0; i < 11; i++) dst[i] = ' ';`	366	`for (i = 0; i < 11; i++) dst[i] = ' ';`
365	`dst[11] = 0;`	367	`dst[11] = 0;`
366		368
367	`/* copy fname until dot (.) or 8 characters */`	369	`/* copy fname until dot (.) or 8 characters */`
368	`for (i = 0; i < 8; i++) {`	370	`for (i = 0; i < 8; i++) {`
369	`if ((src[i] == '.') \|\| (src[i] == 0)) break;`	371	`if ((src[i] == '.') \|\| (src[i] == 0)) break;`
370	`dst[i] = src[i];`	372	`dst[i] = src[i];`
371	`}`	373	`}`
372		374
373	`/* advance src until extension or end of string */`	375	`/* advance src until extension or end of string */`
374	`src += i;`	376	`src += i;`
375	`for (;;) {`	377	`for (;;) {`
376	`if (*src == '.') {`	378	`if (*src == '.') {`
377	`src++; /* next character is extension */`	379	`src++; /* next character is extension */`
378	`break;`	380	`break;`
379	`}`	381	`}`
380	`if (*src == 0) break;`	382	`if (*src == 0) break;`
381	`}`	383	`}`
382		384
383	`/* copy extension to dst (3 chars max) */`	385	`/* copy extension to dst (3 chars max) */`
384	`dst += 8;`	386	`dst += 8;`
385	`for (i = 0; i < 3; i++) {`	387	`for (i = 0; i < 3; i++) {`
386	`if (src[i] == 0) break;`	388	`if (src[i] == 0) break;`
387	`dst[i] = src[i];`	389	`dst[i] = src[i];`
388	`}`	390	`}`
389	`}`	391	`}`
390		392
391		393
392	`/* converts a 11-bytes FCB filename (MYFILE EXT) into 8+3 format (MYFILE.EXT) */`	394	`/* converts a 11-bytes FCB filename (MYFILE EXT) into 8+3 format (MYFILE.EXT) */`
393	`void file_fcb2fname(char dst, const char src) {`	395	`void file_fcb2fname(char dst, const char src) {`
394	`unsigned short i, end = 0;`	396	`unsigned short i, end = 0;`
395		397
396	`for (i = 0; i < 8; i++) {`	398	`for (i = 0; i < 8; i++) {`
397	`dst[i] = src[i];`	399	`dst[i] = src[i];`
398	`if (dst[i] != ' ') end = i + 1;`	400	`if (dst[i] != ' ') end = i + 1;`
399	`}`	401	`}`
400		402
401	`/* is there an extension? */`	403	`/* is there an extension? */`
402	`if (src[8] == ' ') {`	404	`if (src[8] == ' ') {`
403	`dst[end] = 0;`	405	`dst[end] = 0;`
404	`} else { /* found extension: copy it until first space */`	406	`} else { /* found extension: copy it until first space */`
405	`dst[end++] = '.';`	407	`dst[end++] = '.';`
406	`for (i = 8; i < 11; i++) {`	408	`for (i = 8; i < 11; i++) {`
407	`if (src[i] == ' ') break;`	409	`if (src[i] == ' ') break;`
408	`dst[end++] = src[i];`	410	`dst[end++] = src[i];`
409	`}`	411	`}`
410	`dst[end] = 0;`	412	`dst[end] = 0;`
411	`}`	413	`}`
412	`}`	414	`}`
413		415
414		416
415	`/* converts an ASCIIZ string into an unsigned short. returns 0 on success.`	417	`/* converts an ASCIIZ string into an unsigned short. returns 0 on success.`
416	`* on error, result will contain all valid digits that were read until`	418	`* on error, result will contain all valid digits that were read until`
417	`* error occurred (0 on overflow or if parsing failed immediately) */`	419	`* error occurred (0 on overflow or if parsing failed immediately) */`
418	`int atous(unsigned short r, const char s) {`	420	`int atous(unsigned short r, const char s) {`
419	`int err = 0;`	421	`int err = 0;`
420		422
421	`_asm {`	423	`_asm {`
422	`mov si, s`	424	`mov si, s`
423	`xor ax, ax /* general purpose register */`	425	`xor ax, ax /* general purpose register */`
424	`xor cx, cx /* contains the result */`	426	`xor cx, cx /* contains the result */`
425	`mov bx, 10 /* used as a multiplicative step */`	427	`mov bx, 10 /* used as a multiplicative step */`
426		428
427	`NEXTBYTE:`	429	`NEXTBYTE:`
428	`xchg cx, ax /* move result into cx temporarily */`	430	`xchg cx, ax /* move result into cx temporarily */`
429	`lodsb /* AL = DS:[SI++] */`	431	`lodsb /* AL = DS:[SI++] */`
430	`/* is AL 0? if so we're done */`	432	`/* is AL 0? if so we're done */`
431	`test al, al`	433	`test al, al`
432	`jz DONE`	434	`jz DONE`
433	`/* validate that AL is in range '0'-'9' */`	435	`/* validate that AL is in range '0'-'9' */`
434	`sub al, '0'`	436	`sub al, '0'`
435	`jc FAIL /* invalid character detected */`	437	`jc FAIL /* invalid character detected */`
436	`cmp al, 9`	438	`cmp al, 9`
437	`jg FAIL /* invalid character detected */`	439	`jg FAIL /* invalid character detected */`
438	`/* restore result into AX (CX contains the new digit) */`	440	`/* restore result into AX (CX contains the new digit) */`
439	`xchg cx, ax`	441	`xchg cx, ax`
440	`/* multiply result by 10 and add cl */`	442	`/* multiply result by 10 and add cl */`
441	`mul bx /* DX AX = AX * BX(10) */`	443	`mul bx /* DX AX = AX * BX(10) */`
442	`jc OVERFLOW /* overflow */`	444	`jc OVERFLOW /* overflow */`
443	`add ax, cx`	445	`add ax, cx`
444	`/* if CF is set then overflow occurred (overflow part lands in DX) */`	446	`/* if CF is set then overflow occurred (overflow part lands in DX) */`
445	`jnc NEXTBYTE`	447	`jnc NEXTBYTE`
446		448
447	`OVERFLOW:`	449	`OVERFLOW:`
448	`xor cx, cx /* make sure result is zeroed in case overflow occured */`	450	`xor cx, cx /* make sure result is zeroed in case overflow occured */`
449		451
450	`FAIL:`	452	`FAIL:`
451	`inc [err]`	453	`inc [err]`
452		454
453	`DONE: /* save result (CX) into indirect memory address r */`	455	`DONE: /* save result (CX) into indirect memory address r */`
454	`mov bx, [r]`	456	`mov bx, [r]`
455	`mov [bx], cx`	457	`mov [bx], cx`
456	`}`	458	`}`
457	`return(err);`	459	`return(err);`
458	`}`	460	`}`
459		461
460		462
461	`/* appends a backslash if path is a directory`	463	`/* appends a backslash if path is a directory`
462	`* returns the (possibly updated) length of path */`	464	`* returns the (possibly updated) length of path */`
463	`unsigned short path_appendbkslash_if_dir(char *path) {`	465	`unsigned short path_appendbkslash_if_dir(char *path) {`
464	`unsigned short len;`	466	`unsigned short len;`
465	`int attr;`	467	`int attr;`
466	`for (len = 0; path[len] != 0; len++);`	468	`for (len = 0; path[len] != 0; len++);`
467	`if (len == 0) return(0);`	469	`if (len == 0) return(0);`
468	`if (path[len - 1] == '\\') return(len);`	470	`if (path[len - 1] == '\\') return(len);`
469	`/* */`	471	`/* */`
470	`attr = file_getattr(path);`	472	`attr = file_getattr(path);`
471	`if ((attr > 0) && (attr & DOS_ATTR_DIR)) {`	473	`if ((attr > 0) && (attr & DOS_ATTR_DIR)) {`
472	`path[len++] = '\\';`	474	`path[len++] = '\\';`
473	`path[len] = 0;`	475	`path[len] = 0;`
474	`}`	476	`}`
475	`return(len);`	477	`return(len);`
476	`}`	478	`}`
477		479
478		480
479	`/* get current path drive d (A=1, B=2, etc - 0 is "current drive")`	481	`/* get current path drive d (A=1, B=2, etc - 0 is "current drive")`
480	`* returns 0 on success, doserr otherwise */`	482	`* returns 0 on success, doserr otherwise */`
481	`unsigned short curpathfordrv(char *buff, unsigned char d) {`	483	`unsigned short curpathfordrv(char *buff, unsigned char d) {`
482	`unsigned short r = 0;`	484	`unsigned short r = 0;`
483		485
484	`_asm {`	486	`_asm {`
485	`/* is d == 0? then I need to resolve current drive */`	487	`/* is d == 0? then I need to resolve current drive */`
486	`cmp byte ptr [d], 0`	488	`cmp byte ptr [d], 0`
487	`jne GETCWD`	489	`jne GETCWD`
488	`/* resolve cur drive */`	490	`/* resolve cur drive */`
489	`mov ah, 0x19 /* get current default drive */`	491	`mov ah, 0x19 /* get current default drive */`
490	`int 0x21 /* al = drive (00h = A:, 01h = B:, etc) */`	492	`int 0x21 /* al = drive (00h = A:, 01h = B:, etc) */`
491	`inc al /* convert to 1=A, 2=B, etc */`	493	`inc al /* convert to 1=A, 2=B, etc */`
492	`mov [d], al`	494	`mov [d], al`
493		495
494	`GETCWD:`	496	`GETCWD:`
495	`/* prepend buff with drive:\ */`	497	`/* prepend buff with drive:\ */`

Subversion Repositories SvarDOS

(root)/svarcom/trunk/helpers.c – Rev 959 → 965