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FindString for memory block
Posted: Mon Feb 22, 2010 3:12 am
by UserOfPure
Would be GREAT if there was a command to find a string in a memory block (perhaps called "FindStringInMemory"?), with the result being the offset from the start of the memory block. It would work just like FindString but without dying when it finds a 0-byte.
So if my memory block looked like this (hex bytes shown):
Code: Select all
41 42 43 00 44 45 46 00 47 48 49 ; ABC DEF GHI
Then the following command would return 5 because "DEF" is at offset 5:
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Debug FindStringInMemory(memory,"DEF",1)
Re: FindString for memory block
Posted: Mon Feb 22, 2010 6:43 am
by Demivec
UserOfPure wrote:Would be GREAT if there was a command to find a string in a memory block (perhaps called "FindStringInMemory"?), with the result being the offset from the start of the memory block. It would work just like FindString but without dying when it finds a 0-byte.
So if my memory block looked like this (hex bytes shown):
Code: Select all
41 42 43 00 44 45 46 00 47 48 49 ; ABC DEF GHI
Then the following command would return 5 because "DEF" is at offset 5:
Code: Select all
Debug FindStringInMemory(memory,"DEF",1)
How would the command know when to stop searching if it continued past a 0-byte? Wouldn't that cause IMA's each time the string was not found?
Re: FindString for memory block
Posted: Mon Feb 22, 2010 8:41 am
by UserOfPure
Demivec wrote:How would the command know when to stop searching
Since every allocated memory block has a set size, then obviously the search stops at the end of it. An optional "length" parameter could be used, too.
Re: FindString for memory block
Posted: Thu Feb 25, 2010 1:45 pm
by Trond
You can code this in just 8 lines:
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Procedure FindStringInMemory(String.s, Memory, MemoryLength)
Protected L = Len(String)
For I = 0 To MemoryLength-L
If CompareMemory(@String, Memory+I, L)
ProcedureReturn I+1
EndIf
Next
EndProcedure
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Memory.s = "ABC DEF GHI"
Debug FindStringInMemory("DEF", @Memory, Len(Memory))
Re: FindString for memory block
Posted: Thu Feb 25, 2010 1:50 pm
by gnozal
Re: FindString for memory block
Posted: Thu Feb 25, 2010 2:08 pm
by UserOfPure
Trond, but is that just for searching the memory of strings? I want to search a memory block that was created with AllocateMemory, which has 0 bytes in it where the required text to find is.
gnozal, thanks for the link, but I already have a custom routine written to do the job, but it's slow and I know a native command by Fred and Co would be 100% faster and more efficient.
Re: FindString for memory block
Posted: Thu Feb 25, 2010 2:21 pm
by Trond
Trond, but is that just for searching the memory of strings?
All memory are equally good memory. It really doesn't matter whether your memory area is part of a string or not. I just used a string in the example. The first parameter is always a string, which is what you asked for.