Question

[Edit1:]

For the seqName, I declare it as a global parameter at the beginning of the file as

char seqName[20];

[Edit2:]

Aren’t those number of passing to the program during the actual execution? I got the following message just by using the valgrind tool. The command I input is:

jl@ubuntu:~/work/dsr_analysis$ valgrind –tool=memcheck –leak-check=yes ./test

[Edit3:]

Sorry, since I am a new user of Valgrind, when I use it, I only typing the command in Edit2.

However, my program dose have some command-line parameters.

Therefore, I think I’d better to debug my program by the new command:

valgrind –tool=memcheck –leak-check=yes ./test foreman.cif 352 288

---

There is a piece of my program:

height = atoi(argv[3]);

width = atoi(argv[2]);

sprintf(seqName,"%s", argv[1]);

// strcpy(seqName, argv[1]);

After compiling it, a exe file test is generated, then I use Valgrind to check it.
Then I got the following message, however I cannot understand what it tends to tell me.
Can anyone provide some kind help, Thanks.

jl@ubuntu:~/work/dsr_analysis$ valgrind –tool=memcheck –leak-check=yes ./test

==28940== Memcheck, a memory error detector

==28940== Copyright (C) 2002-2009, and GNU GPL’d, by Julian Seward et al.

==28940== Using Valgrind-3.6.0.SVN-Debian and LibVEX;

rerun with -h for copyright info

==28940== Command: ./test

==28940==

==28940== Invalid read of size 1

==28940== at 0x40260CA: strcpy (mc_replace_strmem.c:311)

==28940== by 0x804A5C6: main (me_search.c:1428)

==28940== Address 0x0 is not stack’d, malloc’d or (recently) free’d

==28940==

==28940==

==28940== Process terminating with default action of signal 11 (SIGSEGV)

==28940== Access not within mapped region at address 0x0

==28940== at 0x40260CA: strcpy (mc_replace_strmem.c:311)

==28940== by 0x804A5C6: main (me_search.c:1428)

==28940== If you believe this happened as a result of a stack

==28940== overflow in your program’s main thread (unlikely but

==28940== possible), you can try to increase the size of the

==28940== main thread stack using the –main-stacksize= flag.

==28940== The main thread stack size used in this run was 8388608.

==28940==

==28940== HEAP SUMMARY:

==28940== in use at exit: 0 bytes in 0 blocks

==28940== total heap usage: 0 allocs, 0 frees, 0 bytes allocated

==28940==

==28940== All heap blocks were freed — no leaks are possible

==28940==

==28940== For counts of detected and suppressed errors, rerun with: -v

==28940== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 13 from 8)1 contexts
(suppressed: 13 from 8)

1 contexts (suppressed: 13 from 8)

Answer 1

You really haven’t posted clear enough code to be sure, but if you call your executable with no command-line parameters, then argv[1] will contain a NULL pointer, and argv[2], argv[3] etc. will contain undefined values.

Edit: You need to provide the program with parameters on the valgrind command line (I guess – I don’t use valgrind myself). Something like:

valgrind ... ./test foo bar zod

And BTW, calling an executable test is a bad idea on Linux/Unix as it is very easy to get confused with the shell built-in of the same name