nolibc

Warning

Still a work in progress

My poor attempt of re-writting a small portion of libc without libc but syscalls
This is not intended for any use.
Purely written out of fun and for demo purposes.

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Compile

Edit src/main.c

Install dependencies

sudo pacman -S make gcc     # Archlinux
sudo apt install make gcc   # Debian based 
sudo dnf install make gcc   # Red Hat based

Compile

make        # compiles binary
make run    # run's binary

Run tests

make test

Targets in Makefile

• test = compile lib in all formats (.so,.a,.c) for testing
• static_lib = creates static lib no_libc.a in static_lib/ dir
• shared_lib = creates shared objects (.so) in shared_lib/ ( it is the default target )
• all = uses raw c files in include/src/ and links them to src/main.c

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Note

• The default make compiles the header files to .so files in lib/ which are then used to link src/main.c
• compiled binary is located in bin/

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DIRECTORIES

libc source codes

• include/ = header include files
• include/src/ = source include files for the header include files
• src/ = source file(s), that's where main.c is located ( Program Entry )

Compiled source codes

• shared_iib/ = compiled shared object files ( .so files )
• static_lib/ = contains no_libc.a for static linking
• bin = ouput binary is placed

others

• scripts/ ( no longer in use ) = scripts to compile shared files and check shared files ( used in old makefile )

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Available Functions

• _read
• _write
• _print
• _println
• _scanline
• _scan
• _printf
• _scanf
• _exit
• _free
• _malloc
• _memset
• _brk
• _sbrk
• _strlen
• _reverse
• _itoa
• _stoa
• _memcpy
• _memcmp
• _format
• _sprintf
• _snprintf
• _open
• _creat
• _close
• _mmap
• _munmap