Using the C Debugger

The GBD Tutorial, Online Docs

Compile your program with '-g'

gcc -g main.c

run gbd

gdb a.out

exit gbd

(gdb) quit

Common Commands

help List gdb command categories
help category List gdb commands of category
help command Displays description of command
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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
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r Start running program until a breakpoint or end of program
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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.
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tbreak tbreak is similar to break but it will temporary breakpoint. i.e. Breakpoint will be deleted once it is hit.
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watch condition Set a watchpoint for given condition. Program will suspend when condition is true.
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clear
clear function
clear line-number Delete breakpoints as identified by command option.
Delete all breakpoints in function
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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.
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disable breakpoint-number
disable range
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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.
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continue
c Continues/Resumes running the program until the next breakpoint or end of program
continue number Continue but ignore current breakpoint number times.
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finish Continue until the current function is finished
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step Runs the next line of the program
step N Runs the next N lines of program
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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

External Links

Debugging with GDB, Edition.pdf - Free download books

http:///wiki/?gbddebugger

15sep22

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