Login or Register to Ask a Question and Join Our Community


Programming

Good C debugger ?

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums Programming Good C debugger ?
# 8  
Old 02-02-2010
You can usually debug a CGI application like any other. The only differences are:
  • You'll have to set the CGI environment variables yourself. A script is best for that.
  • GET parameters are sent to the program using the QUERY_STRING environment variable. POST parameters are read from stdin.
# 9  
Old 02-02-2010
Quote:
Originally Posted by cyler
Yes, I have heard and used it before with no success. I'm trying to debug a CGI program written in C. It seems to segfault when using getenv. I tried running the program with Firefox and using sleep(30) to make time to attach PID but it still segfaults on this line.

Any ideas ?

PHP Code:
char DOCUMENTROOT[128] = "";
strcat(DOCUMENTROOT, getenv("DOCUMENT_ROOT")); // This line is ok, right ? I mean it is far less than 128 chars long. 
This will crash if then environment variable DOCUMENT_ROOT is not set. This may crash if DOCUMENT_ROOT is longer than 128 chars.

Cheers,
Loïc.
Last edited by Loic Domaigne; 02-02-2010 at 04:39 PM.. Reason: grammar
# 10  
Old 02-02-2010
Quote:
Originally Posted by pludi
You can usually debug a CGI application like any other. The only differences are:
  • You'll have to set the CGI environment variables yourself. A script is best for that.
  • GET parameters are sent to the program using the QUERY_STRING environment variable. POST parameters are read from stdin.
In bash I can set DOCUMENT_ROOT like this:
PHP Code:
DOCUMENT_ROOT='/path-to-folder'; export DOCUMENT_ROOT 
But how can I set stdin ?
# 11  
Old 02-02-2010
You don't set stdin, you read from it (aka "The Keyboard" or "A Pipe")
# 12  
Old 02-02-2010
Quote:
Originally Posted by pludi
You don't set stdin, you read from it (aka "The Keyboard" or "A Pipe")
How? The following will not work:

Code:
echo "field=value" | gdb myprogram

# 13  
Old 02-03-2010
AFAIK, you can't directly pipe to a program being debugged. So Option 1 is to just paste the input with the mouse, if available. Option 2 uses a FIFO, description can be found here
# 14  
Old 02-03-2010
Quote:
Originally Posted by cyler
How? The following will not work:

Code:
echo "field=value" | gdb myprogram

IMHO, you will get your results faster if you debug with print statements.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Programming

How to use a debugger a piped program ?

Hi, I have 1 program that writes in to the STDIN of another program as shown below. Both programs contain 4 or 5 lines & would terminate in under a second. $ driver.exe | program.exe How is that I can attach the debugger (gdb) to program.exe ? so that I can step through and see what all... (0 Replies)
Discussion started by: RipClaw
0 Replies

2. Programming

Alternative debugger to GNU insight debugger

GNU insight debugger is not available now a days and it is required to debug/inspect assembly code as written in the book Assembly Language Programming step by step in Linux so my question is; is there any alternative to insight that I can use instead of insight in which I can get the same... (5 Replies)
Discussion started by: vectrum
5 Replies

3. Solaris

Csharp Debugger

I want to debug my csharp project on solaris. Is anyone can tell me a program or anything else for this?? (0 Replies)
Discussion started by: dConstantine
0 Replies

4. Programming

Dbx Debugger

I have tried lots of stuff but i can't get it working, i have also found a Thread in this Forum about it but it didn't describe how the program has to be run ect. My issue is that i want to run a program with multiple arguments eg. ./myprog arg1 arg2 arg3 arg4 arg5 with dbx, but i cant get... (8 Replies)
Discussion started by: alcatros
8 Replies

5. Programming

multiprocess debugger

Hi, can somebody advise on a better multiprocess debugger? I heard with gdb we face lots of problems in multiprocess scenario currently i am using gdb debugger for a single process multithreaded project.. since i am supposed to work on a multiprocess now, i googled and came across... (1 Reply)
Discussion started by: rvan
1 Replies

6. UNIX for Dummies Questions & Answers

unix debugger

hello i'm working on cobol with unix just want to know if there is any command in unix that related to debugger i've been told something like anim command i try to search for man anim result :ERROR: Manual entry does not exist for page anim does anyone have an answer ? another thing ... (1 Reply)
Discussion started by: naamas03
1 Replies

7. UNIX for Advanced & Expert Users

Kernel debugger

hi, I want to have a debugger for my kernel and I am using kernel-2.6.11 n i am having patches kdb-v4.4-2.6.11-common-1.bz2 kdb-v4.4-2.6.11-i386-1.bz2. I applied both. I did make menuconfig with options CONFIG_KDB n CONFIG_FRAME_POINTER being set. when i tried to compile kernel. I got an... (0 Replies)
Discussion started by: sriram.ec
0 Replies

8. UNIX for Advanced & Expert Users

where to get Kernel debugger

hi , does anybody know about where to get kernel debugger for linux kernel version 2.6.11. I found it in oss.sgi.com.But there i have to download through ftp,which is not enabled here. So can anybody tell where can i get kdb(kernel debugger)through http. thanks in advance sriram (0 Replies)
Discussion started by: sriram.ec
0 Replies

9. Programming

how to use a c debugger in linux/unix

can anyone suggest tutorial sites for using c debugger in linux/unix environments (1 Reply)
Discussion started by: wojtyla
1 Replies

10. Programming

wdb debugger

Hi all, is it possible to skip a function with the wdb debugger ? could be helpful instead of compiling the whole bunch again does someone know how to do this ? thx Sven (4 Replies)
Discussion started by: Sven28
4 Replies
Login or Register to Ask a Question