my program processes large errors and during development in produces large amount of output on the console. It suffers from memory corruption and I try to use valgrind to locate the error.
Unfortunately, i can't find the error messages among the output lines, and they flushing by too fast to cancel execution when they pop up. They have to be there in order to locate the error ( which element does cause the error and so on ). Redirecting then within my program doesn't work, just like piping the output does only redirect the program output, not the valgrind output.
Can you give me a hint how to solve this.
You can ask valgrind to save its output into file:
valgrind --log-file=<filename>
where <filename> is the file name for output. Later you can view this file with less or text editor.
In addition to redirecting both program and Valgrind output to a file (as already suggested), you can use --db-attach=yes flag, which will cause your program to stop in the debugger right at the error.
This has the advantage that in addition to looking at the log your program produced, you can also look at other program state (that you are not logging).
If you want it to stop in the console (not in a file), here is a way to do it :
Use the parameter : --gen-suppressions=yes
When you debug it will stops like this :
==949== Thread 2:
==949== Invalid read of size 4
==949== at 0x7B62DC0: wcslen (wcslen.S:24)
==949== by 0x7B62D7D: wcsdup (wcsdup.c:29)
==949== by 0x52D0476: de_strdup(wchar_t*) (de_string.cpp:1442)
==949== by 0x437629: void de_format<>(c_de_string&, wchar_t*) (de_string.h:368)
==949== by 0x45F4FB: int db_select_group<>(s_db*, s_pqexec_param*, wchar_t*, wchar_t*, wchar_t*, wchar_t*, int, wchar_t*) (in /corto/goinfre/code2/cortod.repo/bin/x64/Debug/cortod)
==949== by 0x45EA96: check_oldgeom(c_cartod*) (cartod_funcs.cpp:114)
==949== by 0x45EBF8: armserv_update_geom(c_cartod*) (cartod_funcs.cpp:149)
==949== by 0x455EF9: c_cortosrv_thread::on_timeout() (cartod.cpp:163)
==949== by 0x52FE500: c_de_thread::loop() (de_thread.cpp:35)
==949== by 0x52FEE97: thread_loop(void*) (de_thread_priv_linux.cpp:85)
==949== by 0x506E181: start_thread (pthread_create.c:312)
==949== by 0x7BBA47C: clone (clone.S:111)
==949== Address 0x0 is not stack'd, malloc'd or (recently) free'd
==949==
==949==
==949== ---- Print suppression ? --- [Return/N/n/Y/y/C/c] ----
Then you can go to the next one continue all etc.
The normal purpose of this parameter is to remove the false positives, by printing suppression that you can add in a file and pass it to valgrind using the parameter : --suppressions=<filename>
Valgrind outputs to stderr (fd 2) by default. You can capture stderr by redirecting file desctiptor 2:
# Output to log file.
valgrind [options] > valgrind.log 2>&1
# View output interactively.
valgrind [options] 2>&1 | less
Or you could use the --log-fd option to change where output is sent:
valgrind [options] --log-fd=1 > valgrind.log
valgrind [options] --log-fd=1 | less
Valgrind 3.14.0 has this option:
ERROR-RELATED OPTIONS top
These options are used by all tools that can report errors, e.g.
Memcheck, but not Cachegrind.
...
--exit-on-first-error=<yes|no> [default: no]
If this option is enabled, Valgrind exits on the first error. A
nonzero exit value must be defined using --error-exitcode option.
Useful if you are running regression tests or have some other
automated test machinery.
来源：https://stackoverflow.com/questions/5983746/make-valgrind-stop-immediately-after-first-error