GDB commands

help List gdb command categories
help category List gdb commands of category
help command Displays description of command
apropos search-word Display commands list containing search-word in their help description
info args
i args
Displays arguments of current function
info breakpoints
info break
info b
i b
Displays list of breakpoints
info break breakpoint-number
i b breakpoint-number
Displays description of breakpoint having breakpoint-number
info watchpoints
i watchpoints
Displays list of watchpoints
info registers
i r
Display processor's register contents
info threads
i threads
Display information about current thread
info set
i set
List set-able options
r Start running program until a breakpoint or end of program
Breakpoints and Watchpoints
break funname
break line-no
break ClassName::funcName
Set a breakpoint at specified function or line number.
break +line-offset
break -line-offset
Set a breakpoint at specified number of lines forward or backward from current line of execution.
break filename:funcname Set a breapoint at specified funcname of given filename.
break filename:line-no Set a breakpoint at given line-no of specified filename.
break *address Set a breakpoint at specified instrunction address.
break line-no if condition Set a conditional breakpoint at line-no of current file. Program will suspend only when condition is true.
break line thread thread-no Set a breakpoint at line in thread with thread-no.
tbreak tbreak is similar to break but it will temporary breakpoint. i.e. Breakpoint will be deleted once it is hit.
watch condition Set a watchpoint for given condition. Program will suspend when condition is true.
clear function
clear line-number
Delete breakpoints as identified by command option.
Delete all breakpoints in function
Delete breakpoints at given line
delete Delete all breakpoints, watchpoints, or catchpoints.
delete breakpoint-number
delete range
Delete the breakpoints, watchpoints, or catchpoints specified by number or ranges.
disable breakpoint-number
disable range
enable breakpoint-number
enable range
Enable/Disable breakpoints, watchpoints or catchpoints specified by number or ranges.
enable breakpoint-number once Enables given breakpoint once. And disables it after it is hit.
Program Execution
Continues/Resumes running the program until the next breakpoint or end of program
continue number Continue but ignore current breakpoint  number times.
finish Continue until the current function is finished
step Runs the next line of the program
step N Runs the next N lines of program
next Like s, but it does not step into functions
print var Prints the current value of the variable "var"
set var=val Assign "val" value to the variable "var"
backtrace Prints a stack trace
q Quit from gdb