Nemiver - Unable to direct standard input

Question

I like the idea of nemiver, but i can't get this basic function of nemiver to work: redirect standard input to program. so as my program needs file input instead of manual input, it usually takes the form:

./program < list.txt

but apparently, nemiver does not recognize this simple redirection. and thinks "<" and "list.txt" as separate arguments. this frustrates me greatly. is there a solution to this? Thank you guys so much!

related: [Input redirection in gdb (MinGW)](http://stackoverflow.com/questions/3544325/input-redirection-in-gdb-mingw) — Brent Bradburn, Jun 18 '13 at 18:58
kdbg supports redirection. Unfortunately, [kdbg is DOA](https://bugs.launchpad.net/ubuntu/+source/kdbg/+bug/1072300) in recent Ubuntu releases. — Brent Bradburn, Jun 18 '13 at 19:03

score 0 · Answer 1 · answered Apr 08 '14 at 17:03

If you just want to do a postmortem analysis (and don't need to single-step), you can load a crash-dump (core) file which can be generated under any kind of pipelining/redirection scenario.

( ulimit -c unlimited && ./yourapp <in.txt >out.txt ) || nemiver --load-core=core ./yourapp

This only launches the debugger if a crash or assert occurs.

score -1 · Answer 2 · answered Nov 06 '13 at 14:51

As a quick-and-dirty solution, you can add something like the following at the beginning of main()...

    {
 // programmatically redirect stdio
    const char * stdin_filename="input.txt", * stdout_filename="output.txt";
    assert( dup2(open(stdin_filename ,O_RDONLY),0) != -1 );
    assert( dup2(open(stdout_filename,O_WRONLY),1) != -1 );
    asm(" int3"); // optional breakpoint -- kills program when not debugging
    }

Just make sure that you disable this when not debugging (since presumably you want to use the normal method of redirection in that case).

You also need the following...

#include <unistd.h>
#include <fcntl.h>

Nemiver - Unable to direct standard input

2 Answers2