os

Repository to accompany me along my OS journey. This repo consists primarily of C code that ranges from the creation of basic kernel modules to code that utilizes POSIX system calls.

Random things learned:

• A good way to view the default include path for gcc is echo | gcc -E -Wp,-v -x c -
  • -E only runs the C preprocessor
  • -Wp,option flag passes option directly to the preprocessor, bypassing the compiler driver. Here -v indicates verbose
  • - indicates the input will be coming from stdin
  • -x c indicates the "C" language; this is good to do since we're accepting input from stdin
• Finding the full path of some included header can be done with echo "#include <someHeader.h>" | gcc -E -x c -| grep /someHeader.h
• System calls are found in the second section of the man pages, and therefore can be accessed via man 2 <systemCallhere>
• Wow I finally learned the UNIX filesystem permission model!
• Makefile rule/target stuff: !^@=target
• CTRL+v in insert mode in vim inserts a literal copy of the next character (https://stackoverflow.com/a/4781099/3947332)