https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67669
Bug ID: 67669
Summary: Wrong works fwrite or fread or both
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: beyzman at gmail dot com
Target Milestone: ---
Created attachment 36365
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36365=edit
Example of file to be processed
The program below is intended to replace every symbol with code \x00 by symbol
\x20 in some file.
The program was compiled by g++ for Windows from MinGW packet.
In the example attached there is symbols with code \x00 after every symbols
'j'.
It is intended that after program is executed, there will be symbols with code
\x20 after every symbol 'j'. But it is not so.
If I decomment 2 lines commented, the programm works as intended.
//#include
#include
#pragma hdrstop
#define min(a, b) (((a) < (b)) ? (a) : (b))
int main(int argc, char *argv[])
{
FILE *f;
int pos;
const int bufSize = 10;
int length;
int piece;
int i;
int ret;
int chSw = 0;
const char *fileName = argv[1];
char *buf;
if (argc < 1) printf("USAGE: 02space.exe \nReplaces every symbol
\\0x00 by space\n");
f = fopen(fileName,"rb+");
if (!f)
{
printf("Can not open file %s",argv[1]);
return -1;
}
fseek(f,0,SEEK_END);
length = ftell(f);
rewind (f);
ret = 0;
buf = new char[bufSize];
for(piece = (int)(min(bufSize,length)); length > 0;
length -= piece,piece = (int)(min(bufSize,length)))
{
++ret;
pos = ftell(f) ;
fread(buf,piece,1,f);
chSw = 0;
for (i = 0; i < piece; ++i)
{
if (buf[i] == '\x00')
{
buf[i] = ' ';
chSw = 1;
}
}
if (chSw)
{
fseek(f,pos,SEEK_SET);
fwrite(buf,piece,1,f);
// fseek(f,pos,SEEK_SET);
// fread(buf, piece, 1,f);
}
}
delete [] buf;
fclose(f);
return 0;
}