MEMFIND(start, length, value)

Searches a memory region for the first occurrence of a byte value.

Returns the address of the matching byte, or zero if the value is not found.

Examples

REM Find the first NUL byte in a buffer
 
P = MEMFIND(BUFFER, 100, 0)
 
IF P THEN
    PRINT "Found at "; P
ENDIF

REM Extract a NUL-terminated tar filename
 
ENDPOS = MEMFIND(HEADER, 100, 0)
 
IF ENDPOS = 0 THEN
    ENDPOS = HEADER + 100
ENDIF
 
NAME$ = BUFFERTOSTRING$(HEADER, ENDPOS - HEADER)
 
PRINT NAME$

REM Search for a marker byte
 
POS = MEMFIND(DATA, SIZE, &FF)
 
IF POS THEN
    PRINT "Escape byte found at "; POS
ENDIF

Notes

start is the starting memory address to search.
length is the number of bytes to scan.
value must be between 0 and 255.
Returns the address of the first matching byte.
Returns zero if the value is not found.
The search is performed using a forward linear scan.

Errors

MEMFIND: Invalid byte value
Bad Address

See also: PEEK · POKE · BUFFERTOSTRING$ · STRINGTOBUFFER