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This commit is contained in:
James Gregory 2013-12-30 18:34:31 +11:00
commit 18011c595a
352 changed files with 6040 additions and 6040 deletions
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32
09-04.md
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@ -32,9 +32,9 @@
.code
public _FindString
_FindStringprocnear
push bp ;preserve caller’s stack frame
push bp ;preserve caller's stack frame
mov bp,sp ;point to our stack frame
push si ;preserve caller’s register variables
push si ;preserve caller's register variables
push di
cld ;make string instructions increment pointers
mov si,[bp+SearchString] ;pointer to string to search for
@ -62,7 +62,7 @@
FindStringLoop:
mov cx,dx ;put remaining buffer search length in CX
repnz scasb ;scan for the scan byte
jnz FindStringNotFound ;not found, so there’s no match
jnz FindStringNotFound ;not found, so there's no match
;found, so we have a potential match-check the
; rest of this candidate location
push di ;remember the address of the next byte to scan
@ -75,13 +75,13 @@
shr cx,1 ;convert to word for faster search
jnc FindStringWord ;do word search if no odd byte
cmpsb ;compare the odd byte
jnz FindStringNoMatch ;odd byte doesn’t match, so we
; haven’t found the search string here
jnz FindStringNoMatch ;odd byte doesn't match, so we
; haven't found the search string here
FindStringWord:
jcxz FindStringFound ;if the string is only 1 byte long,
; we’ve found a match
; we've found a match
repz cmpsw ;check the rest of the string a word at a time
jz FindStringFound ;it’s a match
jz FindStringFound ;it's a match
FindStringNoMatch:
pop di ;get back pointer to the next byte to scan
and dx,dx ;is there anything left to check?
@ -94,9 +94,9 @@
sub ax,bx ; string was found (earlier we pushed the
; address of the byte after the scan match)
FindStringDone:
pop di ;restore caller’s register variables
pop di ;restore caller's register variables
pop si
pop bp ;restore caller’s stack frame
pop bp ;restore caller's stack frame
ret
_FindStringendp
end
@ -111,26 +111,26 @@
extern unsigned char * FindString(unsigned char *, unsigned int,
unsigned char *, unsigned int, unsigned int);
void main(void);
static unsigned char TestBuffer[] = “When, in the course of human \
static unsigned char TestBuffer[] = "When, in the course of human \
events, it becomes necessary for one people to dissolve the \
political bands which have connected them with another, and to \
assume among the powers of the earth the separate and equal station \
to which the laws of nature and of nature’s God entitle them...”;
to which the laws of nature and of nature's God entitle them...";
void main() {
static unsigned char TestString[] = “equal”;
static unsigned char TestString[] = "equal";
unsigned char TempBuffer[DISPLAY_LENGTH+1];
unsigned char *MatchPtr;
/* Search for TestString and report the results */
if ((MatchPtr = FindString(TestBuffer,
(unsigned int) strlen(TestBuffer), TestString,
(unsigned int) strlen(TestString), 1)) == NULL) {
/* TestString wasn’t found */
printf(“\”%s\“ not found\n”, TestString);
/* TestString wasn't found */
printf("\"%s\" not found\n", TestString);
} else {
/* TestString was found. Zero-terminate TempBuffer; strncpy
won’t do it if DISPLAY_LENGTH characters are copied */
won't do it if DISPLAY_LENGTH characters are copied */
TempBuffer[DISPLAY_LENGTH] = 0;
printf(“\”%s\“ found. Next %d characters at match:\n\”%s\“\n”,
printf("\"%s\" found. Next %d characters at match:\n\"%s\"\n",
TestString, DISPLAY_LENGTH,
strncpy(TempBuffer, MatchPtr, DISPLAY_LENGTH));
}