Recently I wanted to print disassembled main funciton of the program to the file so I can read it in my Emacs, but it turned out I can’t simply redirect the GDB output to the file with disassemble main > main.asm command in gdb command line.

But there is -ex option exists in gdb command so we can execute some gdb commands right after gdb is initialized.

Looks like this:

gdb <file> -ex 'disassemble main' -ex 'quit' > main.asm