Hello!
I have to take a file and exclude the inicial part (88 positions) to a
buffer.
I try with this code, but not functioning:
fp = fopen(file,"rb" );
fseek(fp,0,SEEK _END);
size = ftell(fp);
data = malloc(size);
fseek(fp,88,SEE K_SET);
fread(data,size ,1,fp);
fclose(fp);
Where data containg the file without 88 initial positions....
Thanks for help!! 8 1624
Sorry by this messagem. I can´t edit the first topic.
I forgott to say: The file mentioned above is a binnary file.
Tks...
fp = fopen(file,"rb" );
fseek(fp,0,SEEK _END); <--I think the problem is right here, at this
instance, you move to end of the file.
size = ftell(fp);
Perhaps you can use "rewind(fp) ;"
data = malloc(size);
fseek(fp,88,SEE K_SET);
fread(data,size ,1,fp);
fclose(fp);
Just on the side note, I didn't see any error checking for null
pointers. Perhaps you didn't mention it while posting it.
For reference you take a look at following link: http://www.cplusplus.com/ref/cstdio/fread.html
Senger wrote: Hello! I have to take a file and exclude the inicial part (88 positions) to a buffer.
I try with this code, but not functioning:
fp = fopen(file,"rb" ); fseek(fp,0,SEEK _END); size = ftell(fp); data = malloc(size); fseek(fp,88,SEE K_SET); fread(data,size ,1,fp);
This line is the problem. Since you are at position 88, you can only
read "size-88" bytes into 'data'.
Hope this helps,
-shez-
I tried to do something like this:
fp = fopen(file,"rb" );
fseek(fp,0,SEEK _END);
size = ftell(fp);
data = malloc(size);
rewind (fp);
fseek(fp,88,SEE K_SET);
fread(data,tama nho-88,1,fp);
But not function....
Do I have another form to do that??
How I can exclude the 88 bytes from data after pass the values from
this variable??
I don't have problems when I use the iostream and fstream, like this:
ifstream file;
file.open(filen ame, ios::in|ios:bin ary|ios::ate);
size = file.tellg();
file.seekg (0, ios::beg);
file,seekg(88, ios::beg);
file.read (buffer, size);
file.close();
But I can't use the iostream or fstream. I have to use the stdio.h.
Thanks for help!!
What is the problem that you encounter?
I using the script to use a modified file.
But I have to exclude 88 bytes of the begining from file on my system.
In second mode, using a ifstream, I don't find any problems.
But when I use the first script (stdio) the values passed to buffer is
the complete file, and not the partial file, without 88 first bytes.
If I set the position of pointer using "fseek(fp,88,SE EK_SET);"
the "fread(data,1,s ize,fp)" it would not have to read after the 88th
byte???
With the folloing program "try.cc" I can not reproduce your problem:
// 3456789abcdefgh
#include <cstdio>
#include <cstdlib>
const char* const file = "try.cc";
const long offset = 8;
int main()
{
FILE* fp = fopen("try.cc", "rb");
fseeko(fp, 0, SEEK_END);
long size = ftell(fp);
char* data = (char*)malloc(s ize);
fseek(fp, offset, SEEK_SET);
fread(data, 1, size-offset, fp);
printf("%c\n", data[0]);
}
Running the program yields "8" as excepted.
You should check the return value of all called functions
to track down the problem.
Regards, Stephan
Thanks for all!!!!
I found the problem and made a correct. This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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