I've been banging my head against the monitor for the past nine hours and
narrowed a problem down to the following.
I've found that for certain data, the read() function will return a short
byte count.
Take the following test file: http://xffm.org/test.dbh and compile and
execute the following program:
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
int main(int argc, char **argv){
int fd = open("test.dbh",O_RDWR);
void *data = malloc(256);
size_t bytes = read(fd, data, 256);
printf("bytes read=%ld\n", (long)bytes);
printf("errno=%s\n", strerror(errno));
close(fd);
FILE *f = fopen("test.dbh", "r");
bytes = fread(data, 1, 256, f);
printf("bytes fread=%ld\n", (long)bytes);
return 1;
}
This is the output of the above program compiled with mingw gcc:
bytes read=255
errno=No error
bytes fread=256
Which is wrong. I get the same broken result with both:
gcc.exe (rev5, Built by MinGW-W64 project) 4.8.1
and
gcc.exe (GCC) 4.6.2 (from mingw-32)
Linux, of course, reads the 256 bytes correctly.
So there is something in the file which breaks the read on Windows.
What could possibly be wrong?
Is there some Windows trick you need apply to make read() work as it is
intended?
Or would it be a bug of the mingw gcc port?
Any help is appreciated.
--
------------------------------------------------------------------------------------
Dr. Edscott Wilson Garcia
Applied Mathematics and Computing
Mexican Petroleum Institute
------------------------------------------------------------------------------
October Webinars: Code for Performance
Free Intel webinars can help you accelerate application performance.
Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from
the latest Intel processors and coprocessors. See abstracts and register >
http://pubads.g.doubleclick.net/gampad/clk?id=60135031&iu=/4140/ostg.clktrk
_______________________________________________
Mingw-w64-public mailing list
Mingw-w64-public@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
