Quick Notes for open source world

Using the GNU Compiler Collection (GCC) isn't for the faint of heart or those used to the friendlier Windows IDEs. There are a huge number of command line options available for GCC. This article brings you the most commonly used and most useful options. Writing a thousand line code is better than having to debug it. The mistakes can vary from a missing ";" error to major errors of logic. At the end of the day, code that refuses to run is merely a temp file waiting to be deleted! Given below are the most often used gcc options. Though a lot more exist, these are the most commonly used ones (26 to be specific) and can make debugging easier. For more information refer to the man pages type "man gcc" at the command line. GCC offers a host of options, some even for the AMD-K62 processor. The common syntax is gcc [option] [filename]. All options listed below are case sensitive. The option -v differs completely from -V . Also options may be put together in pairs. So, -

Meta Characters “ [ ] “ Specifies a Character class. [ aefg ] à Matches any of the character a, e, f, g. [ a-f ] à Matches any of the character in the range a to f. [ mkl $] à Matches any of the character including $. Meta characters inside character class is stripped off its special nature. [^a-z] à Complementing; Matches all the characters other than Lower case alphabets. “ \ “ Gives special meaning to various characters. Also used to escape all the meta characters from their special nature. \d à matches any decimal digit; this is equivalent to the class [0-9]. \D à matches any non-digit character; this is equivalent to the class [ˆ0-9]. \s à Matches any whitespace character; this is equivalent to the class [ \ t\n\r\f\v]. \S à matches any non- whitespace character; this is equivalent to the class [ˆ\t\n\r\f\v]. \w à matches any alphanumeric character; this is equivalent to the class [a-zA-Z0-9]. \W à matches any non-alphanumeric character; this is equivalent to

Statement -> Syntax AND / OR -> SELECT column_name(s) FROM table_name WHERE condition ANDOR condition ALTER TABLE(add column) -> ALTER TABLE table_name ADD columnname datatype ALTER TABLE(drop column) -> ALTER TABLE table_name DROP COLUMN column_name AS(alias/colum) -> SELECT column_name AS column_alias FROM table_name AS(alias/table) -> SELECT column_name FROM table_name AS table_alias BETWEEN -> SELECT column_name(s) FROM table_name WHERE column_name BETWEEN value1 AND value2 CREATE INDEX -> CREATE INDEX index_name ON table_name (column_name) CREATE TABLE -> CREATE TABLE table_name ( column_name1 data_type, column_name2 data_type, .......) CREATE UNIQUE INDEX -> CREATE UNIQUE INDEX index_name ON table_name (column_name) CREATE VIEW -> CREATE VIEW view_name AS SELECT column_name(s) FROM table_name WHERE condition DELETE FROM -> DELETE FROM table_name DELETE FROM table_name WHERE condition(Deletes entire table) DROP DATABASE -> DROP D

Make - a tutorial Table of Contents Description A simple compilation Compiling with several files Separate compilation Separate compilation steps Splitting your C Program Dependencies Dependency Graphs How dependency works How does make do it? The makefile Translating the dependency graph Listing dependencies Using the Makefile with make Shortcuts for make Macros in make Special macros Predefined rules Miscellaneous shortcuts Advanced features Special dependencies Custom suffixes and rules The Make command The make command allows you to manage large programs or groups of programs. As you begin to write larger programs, you will notice that re-compiling larger programs takes much longer than re-compiling short programs. Moreover, you notice that you usually only work on a small section of the program (such as a single function that you are debugging), and much of the rest of the program remains unchanged. The make program aids you in developing your large programs by keeping track of

Linux Kernel Hacking!! In this first of a two-part series, learn about system and environment requirements, the best ways to acquire Linux™ source code, how to configure and boot your new kernel, and how to use the printk function to print messages during bootup. Before you start Learn what these tutorials can teach you, and what you need to run the examples in them. About this series The capability of being modified is perhaps one of Linux's greatest strengths, and anyone who has dabbled with the source code has at least stood at the gates of the kingdom, if not opened them up and walked inside. These two tutorials are intended to get you started. They are for anyone who knows a little bit of programming and who wants to contribute to the development of Linux, who feels that something is missing in the kernel and wants to fix that, or who just wants to find out how a real operating system works. About this tutorial This tutorial takes a basic approach to