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YANEL - Yet Another NASM Educational Library
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	This library provides functions and macros for reading and writing. It's
written in NASM and only uses systemcalls without calling functions from libc.
Linux(amd64) is supported.

	Functions follow System V AMD64 ABI, so it's possible to link yanel.o
as a module and call the functions using other languages (C for example). More
about calling conventions you can read here:
https://github.com/hjl-tools/x86-psABI/wiki/X86-psABI

Usage
1) Functions:
_print_udec - Print unsigned decimal number from first argument. On success,
the number of bytes written is returned.  On error, -1 is returned.
_print_dec - same, but for signed decimal number.
_print_hex - same, but output is hexadecimal.
_print_bin - same, but output is binary.
_get_dec - Read decimal number from stdin and return it.
_get_hex - same but for hexadecimal.
_getchar - read 1 character from stdin with bufferization. On error, -1 is
returned, otherwise the character.
_putchar - print char (first argument) to stdout. On error, -1 is returned,
otherwise number of bytes written. It's not bufferized.
_strlen - returns length of the string ending by '\0'. Address of the first character passed
as first argument. This function is not safe.

2) Macros:

NAME; ARGUMENTS; DESCRIPTION
PRINT_UDEC ; register; Prints unsigned decimal number.
PRINT_DEC ; register; Prints signed decimal number.
PRINT_CHAR ; byte register/Immediate/Memory; Prints character.
PRINT_STRING ; Label; Print string that ends with terminating character.
NEWLINE ; - ; Prints new line symbol.
GET_DEC (GET_HEX) ; register; Places decimal (hexadecimal) integer from stdin
to the argument.
GET_CHAR ; byte register; Read 1 character to the argument
GET_STRING ; Label; Read string from stdin, ends string with '\0'.