How to find the main() function using IDAPython

Question

I don't know how to find the main() function using IDAPython.

How can I do this?

Answer 1

Run this in the python console of IDA, and it will print the address of a function named main

for funcAddr in idautils.Functions():
    funcName = idc.get_func_name(funcAddr)
    if funcName == 'main':
        print(f"{funcAddr:#x}")

Answer 2

Your question is a little unclear, to be honest. You write main function, but I wonder if you mean the C runtime's main or the (main) entry point of the binary?

These are two different things. The idautils module offers an Entries() function and a Names() function.

The documentation for both is slightly misleading. They return generators, not a list -- as documented.

By using Names() you can do what the other answer suggests. Using a list comprehension makes it a little more concise:

import idautils

# by looking for "main", we look anywhere in the tuple
mainfunc = [name for name in idautils.Names() if "main" in name]
# mainfunc is a list of tuples of (ea, name)
# NB: if there is just a single match, it's a single list element
print(mainfunc)

... might yield an output like: [(5368942248, 'main')]

import idautils

# by accessing index 3, we access the name
mainfunc = [name for name in idautils.Entries() if "main" in name[3]]
# mainfunc is a list of tuples of (index, ordinal, ea, name)
print(mainfunc)

... might yield an output of [(0, 5369098092, 5369098092, 'wmainCRTStartup')]