kolibrios/programs/demos/aclock/trunk/strtok.inc

126 lines
3.4 KiB
PHP
Raw Permalink Normal View History

; some strtok-like function
;
; Copyright (c) 2003 Thomas Mathys
; killer@vantage.ch
;
; This program is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation; either version 2 of the License, or
; (at your option) any later version.
;
; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
; GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with this program; if not, write to the Free Software
; Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
;
%ifndef _STRTOK_INC
%define _STRTOK_INC
;********************************************************************
; strtok
; this function works like strtok from a c runtime library.
; note that it is not threadsafe. it would be an easy task
; to make it threadsafe, though:
; .adx must be removed, instead the last search address is
; stored at some location provided by the user (passed as
; a third parameter in ecx or so)
;
; input:
;
; eax : address of string to be searched (asciiz), or
; 0 to get the next token of the current string
; ebx : address of delimiter list (asciiz)
;
; output:
;
; eax : pointer to the next token, or 0 if there
; aren't any tokens anymore.
;
; destroys: nothing
;
;********************************************************************
strtok:
pushad
pushfd
; get start address
; if the new start address is 0, and the old address (.adx)
; is also 0, then there's nothing to do and we return 0.
or eax,eax ; new address = 0 ?
jz .nonewstring ; nope -> use old string
mov [.adx],eax ; yeah -> store new string adx
.nonewstring:
mov esi,[.adx] ; load string address
or esi,esi ; 0 ?
jnz .startadxok ; nope -> ok
xor eax,eax ; yeah -> return 0
je .bye
.startadxok:
; skip leading delimiters
.skipdelimiters:
lodsb ; read character
mov edi,ebx ; edi -> delimiter list
.foo:
mov cl,[edi] ; get delimiter
inc edi
or cl,cl ; end of delimiter list
jz .endofdelimiterlist
cmp al,cl ; if AL is a delimiter, then
je .skipdelimiters ; we need to skip it too...
jmp .foo ; otherwise try next delimiter
.endofdelimiterlist:
; end of string reached without finding any non-delimiters ?
or al,al ; character = 0 ?
jnz .bar ; nope -> continue
mov dword [.adx],0 ; yeah -> remember this
xor eax,eax ; and return 0
jmp .bye
.bar:
; found the start of a token, let's store its address
mov edx,esi
dec edx ; edx = start address of token
; find the end of the token
.abraham:
lodsb ; get character
mov edi,ebx ; edi -> delimiter list
.bebraham:
mov cl,[edi] ; get delimiter
inc edi
cmp al,cl ; is AL a delimiter ?
jne .cebraham ; nope -> continue
or al,al ; terminating zero found ?
jnz .argle
xor esi,esi ; yeah -> remember this
jmp .bargle
.argle:
mov byte [esi-1],0 ; nope -> mark end of token
.bargle:
mov [.adx],esi ; remember search address
mov eax,edx ; return token address
jmp .bye
.cebraham:
or cl,cl ; end of delimiter list ?
jnz .bebraham ; nope -> try next delimiter
jmp .abraham
; write return value into stack, so that when popad
; gets executed, eax will receive the return value.
.bye:
mov [esp+4*8],eax
popfd
popad
ret
.adx dd 0
%endif