Ever been troubled by segmentation faults .. now use gdb to take a closer inspection..
GDB stands for GNU Debugger which is a debugger for C and C++ .For any file you need to add -g to enable default debugging support.For enabling gdb just type gdb or gdb <filename> .If you did not mention the file earlier you can mention it by using the file command.
(gdb) file prog1.x
To run the program:
(gdb)run
If the program does have issues you will get information about where the program crashed i.e the line number and parameters to the function that caused the error.
The break command is used for setting the breakpoints in the program.For setting breakpoints in the file line pair use:
(gdb) break file.c:8
For breaking at a particular function use:
(gdb)break fib_func
To proceed to the next breakpoint use the continue statement:
(gdb)continue
To proceed one step at a time use the step statement:
(gdb)step
To print the value of the variables at any given time use the print command which prints the value of the variables and the print/x which gives the value of the variables mentioned in the program as hexadecimal.
Breakpoints stop the program at the points in the program ..whereas watchpoints watch over changes in the variables .
(gdb) watch i
whenever i is modified the program interrupts and prints out the old and the new values.Other useful commands are:
backtrace - produces a stack trace of the function calls that lead to a seg fault
finish - runs until the current function is finished
delete - deletes a specified breakpoint
info breakpoints - shows information about all declared breakpoints
Breakpoints are a tedious task of getting data always out of programs.To get specific
parts you can use conditional breakpoints like:
(gdb)break file1.c:6 if i >= ARRAYSIZE
So now you can try out various commands in your terminal and check out the gdb
manual for more details.
GDB stands for GNU Debugger which is a debugger for C and C++ .For any file you need to add -g to enable default debugging support.For enabling gdb just type gdb or gdb <filename> .If you did not mention the file earlier you can mention it by using the file command.
(gdb) file prog1.x
To run the program:
(gdb)run
If the program does have issues you will get information about where the program crashed i.e the line number and parameters to the function that caused the error.
The break command is used for setting the breakpoints in the program.For setting breakpoints in the file line pair use:
(gdb) break file.c:8
For breaking at a particular function use:
(gdb)break fib_func
To proceed to the next breakpoint use the continue statement:
(gdb)continue
To proceed one step at a time use the step statement:
(gdb)step
To print the value of the variables at any given time use the print command which prints the value of the variables and the print/x which gives the value of the variables mentioned in the program as hexadecimal.
Breakpoints stop the program at the points in the program ..whereas watchpoints watch over changes in the variables .
(gdb) watch i
whenever i is modified the program interrupts and prints out the old and the new values.Other useful commands are:
backtrace - produces a stack trace of the function calls that lead to a seg fault
finish - runs until the current function is finished
delete - deletes a specified breakpoint
info breakpoints - shows information about all declared breakpoints
Breakpoints are a tedious task of getting data always out of programs.To get specific
parts you can use conditional breakpoints like:
(gdb)break file1.c:6 if i >= ARRAYSIZE
So now you can try out various commands in your terminal and check out the gdb
manual for more details.
