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aamiralikhoja
Joined: 11 Aug 2004
Posts: 88
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 28 Dec 2004 5:26 search hex values in binary file |
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dear fellows
I need c source code to find hexvalues in binary file if any body have
source code please help me
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echo47
Joined: 07 Apr 2002
Posts: 4206
Helped: 565
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| 28 Dec 2004 5:48 search hex values in binary file |
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That's a little ambiguous. Do you mean the user enters an ASCII string such as "0x12 0x34 0x56" and the program searches the file for that sequence of three bytes?
Which part of that task do you need help with? Parsing the hex input string? The file open/search routine? Does it need to be blazing fast?
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aamiralikhoja
Joined: 11 Aug 2004
Posts: 88
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| 28 Dec 2004 10:24 Re: search hex values in binary file |
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dear echo47
I want to search hex ocurecunces of hex value(not accsii string) is binary file
for example binary file has folwing format
0: 01 f0 df e9 a3 fe ff 04 00 01 85 31 30 85 34 65 43
10: 93 de af a0 43 ff 00 73 44 21 55 97 52 94 44 21 11
now if i want to find fe9a3 which occurs at first line and continue searching
the entire file and to store the position of hex value in another file how to do
that with effieient search allgo:[/i][/b][/u]
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bilgekaan
Joined: 18 Nov 2004
Posts: 118
Helped: 14
Location: Turkiye
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| 28 Dec 2004 11:22 Re: search hex values in binary file |
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this may help you
unsigned char GetNibble( BYTE* buffer , int nibbleIndex )
{
int byteIndex = nibbleIndex / 2;
if( nibbleIndex %2 )
{
return buffer[ byteIndex ] && 0x0F;
}
return ((buffer[ byteIndex ] && 0xF0)>>4);
}
unsigned char databuffer[ BUFFER_SIZE ];
unsigned char nibble_pattern[] = { 0xf , 0x0e , 0x9 , 0xa , 0x3 };
int num_nibbles = 5;
bool FindFirst( )
{
for( int i = 0 ; i < BUFFER_SIZE * 2 - num_nibbles ; i ++ )
{
if( GetNibble( databuffer , i ) == nibble_pattern[1]&&
GetNibble( databuffer , i + 1 ) == nibble_pattern[0]&&
GetNibble( databuffer , i + 2 ) == nibble_pattern[3]&&
GetNibble( databuffer , i + 3 ) == nibble_pattern[2]&&
GetNibble( databuffer , i + 4 ) == nibble_pattern[4]
)
{
return true;
}
}
return false;
}
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Always_Confused_Sudent
Joined: 26 Dec 2003
Posts: 29
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| 28 Dec 2004 12:15 Re: search hex values in binary file |
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| bilgekaan wrote: |
this may help you
unsigned char GetNibble( BYTE* buffer , int nibbleIndex )
{
int byteIndex = nibbleIndex / 2;
if( nibbleIndex %2 )
{
return buffer[ byteIndex ] && 0x0F;
}
return ((buffer[ byteIndex ] && 0xF0)>>4);
}
unsigned char databuffer[ BUFFER_SIZE ];
unsigned char nibble_pattern[] = { 0xf , 0x0e , 0x9 , 0xa , 0x3 };
int num_nibbles = 5;
bool FindFirst( )
{
for( int i = 0 ; i < BUFFER_SIZE * 2 - num_nibbles ; i ++ )
{
if( GetNibble( databuffer , i ) == nibble_pattern[1]&&
GetNibble( databuffer , i + 1 ) == nibble_pattern[0]&&
GetNibble( databuffer , i + 2 ) == nibble_pattern[3]&&
GetNibble( databuffer , i + 3 ) == nibble_pattern[2]&&
GetNibble( databuffer , i + 4 ) == nibble_pattern[4]
)
{
return true;
}
}
return false;
} |
can you explain to me why unsigned char was used to declare the function
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bilgekaan
Joined: 18 Nov 2004
Posts: 118
Helped: 14
Location: Turkiye
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| 28 Dec 2004 13:01 Re: search hex values in binary file |
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unsigned char is same as BYTE . databuffer is used to store binary file content.
Added after 28 minutes:
[quote="Always_Confused_Sudent"]
| bilgekaan wrote: |
this may help you
unsigned char GetNibble( BYTE* buffer , int nibbleIndex )
{
int byteIndex = nibbleIndex / 2;
if( nibbleIndex %2 )
{
return buffer[ byteIndex ] && 0x0F;
}
return ((buffer[ byteIndex ] && 0xF0)>>4);
}
unsigned char databuffer[ BUFFER_SIZE ];
unsigned char nibble_pattern[] = { 0xf , 0x0e , 0x9 , 0xa , 0x3 };
int num_nibbles = 5;
bool FindFirst( )
{
for( int i = 0 ; i < BUFFER_SIZE * 2 - num_nibbles ; i ++ )
{
if( GetNibble( databuffer , i ) == nibble_pattern[1]&&
GetNibble( databuffer , i + 1 ) == nibble_pattern[0]&&
GetNibble( databuffer , i + 2 ) == nibble_pattern[3]&&
GetNibble( databuffer , i + 3 ) == nibble_pattern[2]&&
GetNibble( databuffer , i + 4 ) == nibble_pattern[4]
)
{
return true;
}
}
return false;
} |
this function an prototype and never tested written in minutes. unsigned char is equal to BYTE . replace all with one of two to make code readable. I am sure there is also indexing error to access nibbles .please check
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Always_Confused_Sudent
Joined: 26 Dec 2003
Posts: 29
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| 28 Dec 2004 18:58 Re: search hex values in binary file |
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| is it equal to BYTE in all compilers?
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bilgekaan
Joined: 18 Nov 2004
Posts: 118
Helped: 14
Location: Turkiye
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| 28 Dec 2004 20:06 Re: search hex values in binary file |
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yes for most of them . but also there is unicode version of char which is 16 bit
used to represent different alphabets using different letters like turksih , chinese etc
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