debug

Instructions for the "debug" exercise

• compile, run, see the crash
• run it in gdb
• inspect backtrace, variables to understand the problem
• try stepping through the code using 'step' and 'next', use breakpoints and continue to get familiar with gdb
• fix the bug

Some useful gdb commands

Command	Effect
gdb ./randomize	launch the debugger with the given executable
gdb --tui ./randomize	same as above, but with terminal user interface enabled
tui enable	enabled the terminal user interface
run	runs the program
bt, backtrace	show a backtrace (list of stack frames) of the current thread
up	navigate one stack frame up
down	navigate one stack frame down
s, step	execute current line, stop at earliest next occasion
n, next	continue until next line or function exits
c, continue	continue execution
print <var>	show current value of variable
info locals	show the values of all local variables
info args	show the values of all function arguments
br <linenr>	put a breakpoint at line
info br:	list active breakpoints
enable/disable/delete #	enable/disable/delete breakpoints