GDB Cheat Sheet

Using Enhanced GDB

It's recommended to use enhanced version of GDB such as GEF. These have some extended features.

Start Debugger

chmod +x ./example
gdb ./example

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Commands in GDB

Debug

# Start the program
run
r

# Continue until the next breakpoint or the end
continue
c

# Execute the next line of code but do not enter any function calls on that line.
next
n

# Execute the next line of code
step
s

# Jump to specific address
j *0x01234

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Disassemble

# Disassemble the main function
disass main

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Breakpoints

# Set a breakpoint at a specified line number, function, or address.
break main
b main
break *0x12345678
# Add a breakpoint to the relative address position from the main function.
b *main+25

# Information about breakpoints
info breakpoints
i breakpoints
i b

# Delete all breakpoints
delete breakpoints
d breakpoints
# Delete the specified breakpoint
delete <breakpoint_number>
delete 1
d 1

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View Values

# Print value of expression at specific address
p 0x01234

# Examine the memory as specific address as addresses
x/a 0x01234
# Examine the memory at specific address as 10 characters
x/10c 0x01234
# Examine the memory as specific address as string
x/s 0x01234
# Examine
x/g 0x01234

# Display information of registers
info registers
i r
# Display information of the stack frame
i f

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Change Values

# Set N characters to specific address
set {char [5]} 0x01234 = "Hello"

# Set the value stored at memory address `0x01234` to `0x5678`
set *0x01234 = 0x5678

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