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/* This file is part of the SvarCOM project and is published under the terms
* of the MIT license.
*
* Copyright (C) 2021-2024 Mateusz Viste
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/*
* a variety of helper functions
*/
#include <i86.h> /* MK_FP() */
#include <stdio.h> /* sprintf() */
#include "svarlang.lib\svarlang.h"
#include "env.h"
#include "rmodinit.h"
#include "helpers.h"
void dos_get_date(unsigned short *y, unsigned char *m, unsigned char *d) {
/* get cur date */
_asm {
mov ah, 0x2a /* DOS 1+ -- Query DOS Date */
int 0x21 /* CX=year DH=month DL=day */
mov bx, y
mov [bx], cx
mov bx, m
mov [bx], dh
mov bx, d
mov [bx], dl
}
}
void dos_get_time(unsigned char *h, unsigned char *m, unsigned char *s) {
_asm {
mov ah, 0x2c /* DOS 1+ -- Query DOS Time */
int 0x21 /* CH=hour CL=minutes DH=seconds DL=1/100sec */
mov bx, h
mov [bx], ch
mov bx, m
mov [bx], cl
mov bx, s
mov [bx], dh
}
}
/* like strlen() */
unsigned short sv_strlen(const char *s) {
unsigned short len = 0;
while (*s != 0) {
s++;
len++;
}
return(len);
}
/* case-insensitive comparison of strings, compares up to maxlen characters.
* returns non-zero on equality. */
int imatchlim(const char *s1, const char *s2, unsigned short maxlen) {
while (maxlen--) {
char c1, c2;
c1 = *s1;
c2 = *s2;
if ((c1 >= 'a') && (c1 <= 'z')) c1 -= ('a' - 'A');
if ((c2 >= 'a') && (c2 <= 'z')) c2 -= ('a' - 'A');
/* */
if (c1 != c2) return(0);
if (c1 == 0) break;
s1++;
s2++;
}
return(1);
}
/* returns zero if s1 starts with s2 */
int strstartswith(const char *s1, const char *s2) {
while (*s2 != 0) {
if (*s1 != *s2) return(-1);
s1++;
s2++;
}
return(0);
}
/* outputs a NULL-terminated string to handle (1=stdout 2=stderr) */
void output_internal(const char *s, unsigned char nl, unsigned char handle) {
const static unsigned char *crlf = "\r\n";
_asm {
push ds
pop es /* make sure es=ds (scasb uses es) */
/* get length of s into CX */
mov ax, 0x4000 /* ah=DOS "write to file" and AL=0 for NULL matching */
mov dx, s /* set dx to string (required for later) */
mov di, dx /* set di to string (for NULL matching) */
mov cx, 0xffff /* preset cx to 65535 (-1) */
cld /* clear DF so scasb increments DI */
repne scasb /* cmp al, es:[di], inc di, dec cx until match found */
/* CX contains (65535 - strlen(s)) now */
not cx /* reverse all bits so I get (strlen(s) + 1) */
dec cx /* this is CX length */
jz WRITEDONE /* do nothing for empty strings */
/* output by writing to stdout */
/* mov ah, 0x40 */ /* DOS 2+ -- write to file via handle */
xor bh, bh
mov bl, handle /* set handle (1=stdout 2=stderr) */
/* mov cx, xxx */ /* write CX bytes */
/* mov dx, s */ /* DS:DX is the source of bytes to "write" */
int 0x21
WRITEDONE:
/* print out a CR/LF trailer if nl set */
test byte ptr [nl], 0xff
jz FINITO
/* bx still contains handle */
mov ah, 0x40 /* "write to file" */
mov cx, 2
mov dx, crlf
int 0x21
FINITO:
}
}
void nls_output_internal(unsigned short id, unsigned char nl, unsigned char handle) {
const char *NOTFOUND = "NLS_STRING_NOT_FOUND";
const char *ptr = svarlang_strid(id);
if ((ptr == NULL) || (ptr[0]) == 0) ptr = NOTFOUND;
output_internal(ptr, nl, handle);
}
/* output DOS error e to stdout, if stdout is redirected then *additionally*
* also to stderr */
void nls_outputnl_doserr(unsigned short e) {
static char errstr[16];
const char *ptr = NULL;
unsigned char redirflag = 0;
/* find string in nls block */
if (e < 0xff) ptr = svarlang_strid(0xff00 | e);
/* if not found, use a fallback */
if ((ptr == NULL) || (ptr[0] == 0)) {
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 {
/* set DTA location */
mov ah, 0x1a
mov dx, dta
int 0x21
/* FindNext */
mov ah, 0x4f
int 0x21 /* CF set on error + err code in AX, DTA filled with FileInfoRec on success */
jnc DONE
mov [res], ax
DONE:
}
return(res);
}
static unsigned char _dos_getkey_noecho(void);
#pragma aux _dos_getkey_noecho = \
"mov ax, 0x0c08" /* clear input buffer and execute getchar (INT 21h,AH=8) */ \
"int 0x21" \
"test al, al" /* if AL == 0 then this is an extended character */ \
"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 */ \
modify [ah] \
value [al]
/* 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! ENTER chooses the FIRST choice */
unsigned short askchoice(const char *s, const char *c) {
unsigned short res;
char cstr[2] = {0,0};
char key = 0;
output(s);
output(" ");
output("(");
for (res = 0; c[res] != 0; res++) {
if (res != 0) output("/");
cstr[0] = c[res];
output(cstr);
}
output(") ");
AGAIN:
key = _dos_getkey_noecho();
if (key == '\r') key = c[0]; /* ENTER is synonym for the first key */
/* 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) {
cstr[0] = key;
output(cstr);
output("\r\n");
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);
}
/* like strcpy() but returns the string's length */
unsigned short sv_strcpy(char *dst, const char *s) {
unsigned short len = 0;
for (;;) {
*dst = *s;
if (*s == 0) return(len);
dst++;
s++;
len++;
}
}
/* like sv_strcpy() but operates on far pointers */
unsigned short sv_strcpy_far(char far *dst, const char far *s) {
unsigned short len = 0;
for (;;) {
*dst = *s;
if (*s == 0) return(len);
dst++;
s++;
len++;
}
}
/* like strcat() */
void sv_strcat(char *dst, const char *s) {
/* advance dst to end of string */
while (*dst != 0) dst++;
/* append string */
sv_strcpy(dst, s);
}
/* like strcat() but operates on far pointers */
void sv_strcat_far(char far *dst, const char far *s) {
/* advance dst to end of string */
while (*dst != 0) dst++;
/* append string */
sv_strcpy_far(dst, s);
}
/* 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);
}
/* capitalize an ASCIZ string following country-dependent rules */
void nls_strtoup(char *buff) {
unsigned short errcode = 0;
/* requires DOS 4+ */
_asm {
push ax
push dx
mov ax, 0x6522 /* country-dependent capitalize string (DOS 4+) */
mov dx, buff /* DS:DX -> string to capitalize */
int 0x21
jnc DONE
mov errcode, ax /* set errcode on failure */
DONE:
pop dx
pop ax
}
/* do a naive upcase if DOS has no NLS support */
if (errcode != 0) {
while (*buff) {
if (*buff < 128) { /* apply only to 7bit (low ascii) values */
*buff &= 0xDF;
}
buff++;
}
}
}
/* reload nls ressources from svarcom.lng into svarlang_mem and rmod */
void nls_langreload(char *buff, unsigned short rmodseg) {
const char far *dosdir;
const char far *lang;
static unsigned short lastlang;
unsigned short dosdirlen;
unsigned short rmodenvseg = *(unsigned short far *)MK_FP(rmodseg, RMOD_OFFSET_ENVSEG);
unsigned char far *rmodcritmsg = MK_FP(rmodseg, RMOD_OFFSET_CRITMSG);
int i;
/* look up the LANG env variable, upcase it and copy to lang */
lang = env_lookup_val(rmodenvseg, "LANG");
if ((lang == NULL) || (lang[0] == 0)) return;
memcpy_ltr_far(buff, lang, 2);
buff[2] = 0;
/* check if there is need to reload at all */
if (lastlang == *((unsigned short *)buff)) return;
buff[4] = 0;
dosdir = env_lookup_val(rmodenvseg, "DOSDIR");
if (dosdir == NULL) return;
sv_strcpy_far(buff + 4, dosdir);
dosdirlen = sv_strlen(buff + 4);
if (buff[4 + dosdirlen - 1] == '\\') dosdirlen--;
memcpy_ltr(buff + 4 + dosdirlen, "\\SVARCOM.LNG", 13);
/* try loading %DOSDIR%\SVARCOM.LNG */
if (svarlang_load(buff + 4, buff) != 0) {
/* failed! try %DOSDIR%\BIN\SVARCOM.LNG */
memcpy_ltr(buff + 4 + dosdirlen, "\\BIN\\SVARCOM.LNG", 17);
if (svarlang_load(buff + 4, buff) != 0) return;
}
memcpy_ltr_far(&lastlang, lang, 2);
/* update RMOD's critical handler with new strings */
for (i = 0; i < 9; i++) {
int len;
len = sv_strlen(svarlang_str(3, i));
if (len > 15) len = 15;
memcpy_ltr_far(rmodcritmsg + (i * 16), svarlang_str(3, i), len);
memcpy_ltr_far(rmodcritmsg + (i * 16) + len, "$", 1);
}
/* The ARIF string is special: always 4 bytes long and no $ terminator */
memcpy_ltr_far(rmodcritmsg + (9 * 16), svarlang_str(3,9), 4);
}
/* 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;
const char *exec_ext[] = {"COM", "EXE", "BAT", NULL};
/* 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;
}
}
/* if explicit ext found, make sure it is executable */
if (*extptr != NULL) {
for (i = 0; exec_ext[i] != NULL; i++) if (imatch(*extptr, exec_ext[i])) break;
if (exec_ext[i] == NULL) return(-2); /* bad extension - don't try running it ever */
}
/* normalize filename */
if (file_truename(fname, res) != 0) return(-2);
/* printf("truename: %s\r\n", res); */
/* figure out where the command starts */
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 = sv_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 */
memcpy_rtl(res + i, res + lastbslash + 1, len - lastbslash);
/* copy path in front of the filename and make sure there is a bkslash sep */
memcpy_ltr(res, path, i);
res[i - 1] = '\\';
}
/* if no extension was initially provided, try matching COM, EXE, BAT */
if (*extptr == NULL) {
int attr;
len = sv_strlen(res);
res[len++] = '.';
for (i = 0; exec_ext[i] != NULL; i++) {
sv_strcpy(res + len, exec_ext[i]);
/* printf("? '%s'\r\n", res); */
*extptr = exec_ext[i];
attr = file_getattr(res);
if (attr < 0) continue; /* file not found */
if (attr & DOS_ATTR_DIR) continue; /* this is a directory */
if (attr & DOS_ATTR_VOL) continue; /* this is a volume */
return(0);
}
} else { /* try finding it as-is */
/* printf("? '%s'\r\n", res); */
int attr = file_getattr(res);
if ((attr >= 0) && /* file exists */
((attr & DOS_ATTR_DIR) == 0) && /* is not a directory */
((attr & DOS_ATTR_VOL) == 0)) { /* is not a volume */
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, doserr = 0;
/* fetch %DOSDIR% */
pathlen = env_lookup_valcopy(fname, 128, env_seg, "DOSDIR");
if (pathlen == 0) return(-1);
/* prep filename: %DOSDIR%\LINKS\PKG.LNK */
if (fname[pathlen - 1] == '\\') pathlen--;
pathlen += sprintf(fname + pathlen, "\\LINKS");
/* create \LINKS if not exists */
if (file_getattr(fname) < 0) {
_asm {
push dx
mov ah, 0x39
mov dx, fname
int 0x21
jnc DONE
mov doserr, ax
DONE:
pop dx
}
if (doserr) {
output(fname);
output(" - ");
nls_outputnl(255, doserr);
return(-1);
}
}
/* quit early if dir does not exist (or is not a dir) */
if (file_getattr(fname) != DOS_ATTR_DIR) {
output(fname);
output(" - ");
nls_outputnl(255,3); /* path not found */
return(-1);
}
sprintf(fname + pathlen, "\\%s.LNK", linkname);
return(0);
}
/* like memcpy() but guarantees to copy from left to right */
void memcpy_ltr(void *d, const void *s, unsigned short len) {
unsigned char const *ss = s;
unsigned char *dd = d;
while (len--) {
*dd = *ss;
ss++;
dd++;
}
}
/* like memcpy_ltr() but operates on far pointers */
void memcpy_ltr_far(void far *d, const void far *s, unsigned short len) {
unsigned char const far *ss = s;
unsigned char far *dd = d;
while (len--) {
*dd = *ss;
ss++;
dd++;
}
}
/* like memcpy() but guarantees to copy from right to left */
void memcpy_rtl(void *d, const void *s, unsigned short len) {
unsigned char const *ss = s;
unsigned char *dd = d;
dd += len - 1;
ss += len - 1;
while (len--) {
*dd = *ss;
ss--;
dd--;
}
}
/* like bzero(), but accepts far pointers */
void sv_bzero(void far *dst, unsigned short len) {
char far *d = dst;
while (len--) {
*d = 0;
d++;
}
}
/* like memset() */
void sv_memset(void *dst, unsigned char c, unsigned short len) {
unsigned char *d = dst;
while (len--) {
*d = c;
d++;
}
}