segmentation fault


 
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# 1  
Old 11-24-2006
Question segmentation fault

ive written my code in C for implementation of a simple lexical analyser using singly linked list hence am making use of dynamic allocation,but when run in linux it gives a segmentation fault is it cause of the malloc function that ive made use of????any suggestions as to what i could do???
thank you!!

Last edited by rockgal; 12-03-2006 at 01:02 AM..
# 2  
Old 11-25-2006
I can't tell what your problem is from here.
The first problem is to find where in your code the segfault occurs -
compile and run your code under a debugger (gdb)
Code:
gcc -g -o myfile myfile.c
gdb myfile
gdb > r  <command line arguments>
<segfault happens here>
ba

The ba command in gdb will show a stack trace. Please post it.
# 3  
Old 11-25-2006
Ya will do that & get back to you...
thanks

Last edited by rockgal; 12-03-2006 at 01:03 AM..
# 4  
Old 11-25-2006
rockgal, please review the rules:


(9) Edit your posts if you see spelling or grammar errors (don't write in cyberchat or cyberpunk style). English only.
# 5  
Old 11-27-2006
I tried out these commands gdb >r <myfile> & gdb bt <myfile> on fedora 4.0
and this is what i got
bash: syntax error near unexpected token 'newline'
Am not sure of the syntax of the command but i picked up 'bt' from the man pages. I did try all possibilities and this is what i got for all of them...!
Please let me know if my command syntax is wrong or thats the error in my program and how can i debug it???
thank you,
rockgal

Last edited by rockgal; 12-03-2006 at 01:03 AM..
# 6  
Old 11-27-2006
Quote:
gdb > r <command-line>
refers to gdb prompt typing r + optional command-lines
Seems like you are typing this in bash "gdb >r <myfile> & gdb bt <myfile>"
# 7  
Old 11-28-2006
Crashing in linux, as in, doesn't crash in windows?

Windows lets you get away with a lot of stupid stuff sometimes, but only temporarily. Instead of crashing immediately as Linux does, it silently corrupts the heap, causing inexplicable errors in the future in code that has nothing to do with whatever your code did wrong.

It's frustrating, I know. It's only when I moved to linux did I find out how bad some of my code was!

P.S: "U" is not a word!
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