Linux Kernel Indent Rule.

This is the sample for programmer to reference. We can find the Linux Indent Rule in usr/src/linux-headers-2.6.32-35/scripts/Lindent And the indent rule is:

indent -npro -kr -i8 -ts8 -sob -l80 -ss -ncs -cp1

-npro, --ignore-profile

Do not read `.indent.pro' files.

-kr, --k-and-r-style

Use Kernighan & Ritchie coding style.

-in, --indent-leveln

Set indentation level to n spaces.

-tsn, --tab-sizen

Set tab size to n spaces.

-sob, --swallow-optional-blank-lines

Swallow optional blank lines.

-ln, --line-lengthn

Set maximum line length for non-comment lines to n.

-ss, --space-special-semicolon

On one-line for and while statements, force a blank before the semicolon.

-ncs, --no-space-after-casts

Do not put a space after cast operators.

-cpn, --else-endif-columnn

Put comments to the right of #else and #endif statements in column n.

Options

-bad, --blank-lines-after-declarations

Force blank lines after the declarations.
See BLANK LINES.

-bap, --blank-lines-after-procedures

Force blank lines after procedure bodies.
See BLANK LINES.

-bbb, --blank-lines-before-block-comments

Force blank lines before block comments.
See BLANK LINES.

-bbo, --break-before-boolean-operator

Prefer to break long lines before boolean operators.
See BREAKING LONG LINES.

-bc, --blank-lines-after-commas

Force newline after comma in declaration.
See DECLARATIONS.

-bl, --braces-after-if-line

Put braces on line after if, etc.
See STATEMENTS.

-blf, --braces-after-func-def-line

Put braces on line following function definition line.
See DECLARATIONS.

-blin, --brace-indentn

Indent braces n spaces.
See STATEMENTS.

-bls, --braces-after-struct-decl-line

Put braces on the line after struct declaration lines.
See DECLARATIONS.

-br, --braces-on-if-line

Put braces on line with if, etc.
See STATEMENTS.

-brf, --braces-on-func-def-line

Put braces on function definition line.
See DECLARATIONS.

-brs, --braces-on-struct-decl-line

Put braces on struct declaration line.
See DECLARATIONS.

-bs, --Bill-Shannon, --blank-before-sizeof

Put a space between sizeof and its argument.
See STATEMENTS.

-cn, --comment-indentationn

Put comments to the right of code in column n.
See COMMENTS.

-cbin, --case-brace-indentationn

Indent braces after a case label N spaces.
See STATEMENTS.

-cdn, --declaration-comment-columnn

Put comments to the right of the declarations in column n.
See COMMENTS.

-cdb, --comment-delimiters-on-blank-lines

Put comment delimiters on blank lines.
See COMMENTS.

-cdw, --cuddle-do-while

Cuddle while of do {} while; and preceding `}'.
See COMMENTS.

-ce, --cuddle-else

Cuddle else and preceding `}'.
See COMMENTS.

-cin, --continuation-indentationn

Continuation indent of n spaces.
See STATEMENTS.

-clin, --case-indentationn

Case label indent of n spaces.
See STATEMENTS.

-cpn, --else-endif-columnn

Put comments to the right of #else and #endif statements in column n.
See COMMENTS.

-cs, --space-after-cast

Put a space after a cast operator.
See STATEMENTS.

-dn, --line-comments-indentationn

Set indentation of comments not to the right of code to n spaces.
See COMMENTS.

-bfda, --break-function-decl-args

Break the line before all arguments in a declaration.
See DECLARATIONS.

-bfde, --break-function-decl-args

Break the line after the last argument in a declaration.
See DECLARATIONS.

-djn, --left-justify-declarations

If -cd 0 is used then comments after declarations are left justified behind the declaration.
See DECLARATIONS.

-din, --declaration-indentationn

Put variables in column n.
See DECLARATIONS.

-fc1, --format-first-column-comments

Format comments in the first column.
See COMMENTS.

-fca, --format-all-comments

Do not disable all formatting of comments.
See COMMENTS.

-gnu, --gnu-style

Use GNU coding style. This is the default.
See COMMON STYLES.

-hnl, --honour-newlines

Prefer to break long lines at the position of newlines in the input.
See BREAKING LONG LINES.

-in, --indent-leveln

Set indentation level to n spaces.
See INDENTATION.

-iln, --indent-labeln

Set offset for labels to column n.
See INDENTATION.

-ipn, --parameter-indentationn

Indent parameter types in old-style function definitions by n spaces.
See INDENTATION.

-kr, --k-and-r-style

Use Kernighan & Ritchie coding style.
See COMMON STYLES.

-ln, --line-lengthn

Set maximum line length for non-comment lines to n.
See BREAKING LONG LINES.

-lcn, --comment-line-lengthn

Set maximum line length for comment formatting to n.
See COMMENTS.

-linux, --linux-style

Use Linux coding style.
See COMMON STYLES.

-lp, --continue-at-parentheses

Line up continued lines at parentheses.
See INDENTATION.

-lps, --leave-preprocessor-space

Leave space between `#' and preprocessor directive.
See INDENTATION.

-nlps, --remove-preprocessor-space

Remove space between `#' and preprocessor directive.
See INDENTATION.

-nbad, --no-blank-lines-after-declarations

Do not force blank lines after declarations.
See BLANK LINES.

-nbap, --no-blank-lines-after-procedures

Do not force blank lines after procedure bodies.
See BLANK LINES.

-nbbo, --break-after-boolean-operator

Do not prefer to break long lines before boolean operators.
See BREAKING LONG LINES.

-nbc, --no-blank-lines-after-commas

Do not force newlines after commas in declarations.
See DECLARATIONS.

-nbfda, --dont-break-function-decl-args

Don't put each argument in a function declaration on a separate line.
See DECLARATIONS.

-ncdb, --no-comment-delimiters-on-blank-lines

Do not put comment delimiters on blank lines.
See COMMENTS.

-ncdw, --dont-cuddle-do-while

Do not cuddle } and the while of a do {} while;.
See STATEMENTS.

-nce, --dont-cuddle-else

Do not cuddle } and else.
See STATEMENTS.

-ncs, --no-space-after-casts

Do not put a space after cast operators.
See STATEMENTS.

-ndjn, --dont-left-justify-declarations

Comments after declarations are treated the same as comments after other statements.
See DECLARATIONS.

-nfc1, --dont-format-first-column-comments

Do not format comments in the first column as normal.
See COMMENTS.

-nfca, --dont-format-comments

Do not format any comments.
See COMMENTS.

-nhnl, --ignore-newlines

Do not prefer to break long lines at the position of newlines in the input.
See BREAKING LONG LINES.

-nip, --no-parameter-indentation

Zero width indentation for parameters.
See INDENTATION.

-nlp, --dont-line-up-parentheses

Do not line up parentheses.
See STATEMENTS.

-npcs, --no-space-after-function-call-names

Do not put space after the function in function calls.
See STATEMENTS.

-nprs, --no-space-after-parentheses

Do not put a space after every '(' and before every ')'.
See STATEMENTS.

-npsl, --dont-break-procedure-type

Put the type of a procedure on the same line as its name.
See DECLARATIONS.

-nsaf, --no-space-after-for

Do not put a space after every for.
See STATEMENTS.

-nsai, --no-space-after-if

Do not put a space after every if.
See STATEMENTS.

-nsaw, --no-space-after-while

Do not put a space after every while.
See STATEMENTS.

-nsc, --dont-star-comments

Do not put the `*' character at the left of comments.
See COMMENTS.

-nsob, --leave-optional-blank-lines

Do not swallow optional blank lines.
See BLANK LINES.

-nss, --dont-space-special-semicolon

Do not force a space before the semicolon after certain statements. Disables `-ss'.
See STATEMENTS.

-nut, --no-tabs

Use spaces instead of tabs.
See INDENTATION.

-nv, --no-verbosity

Disable verbose mode.
See MISCELLANEOUS OPTIONS.

-orig, --original

Use the original Berkeley coding style.
See COMMON STYLES.

-npro, --ignore-profile

Do not read `.indent.pro' files.
See INVOKING INDENT.

-pcs, --space-after-procedure-calls

Insert a space between the name of the procedure being called and the `('.
See STATEMENTS.

-pin, --paren-indentationn

Specify the extra indentation per open parentheses '(' when a statement is broken.See STATEMENTS.

-pmt, --preserve-mtime

Preserve access and modification times on output files.See MISCELLANEOUS OPTIONS.

-ppin, --preprocessor-indentationn

Specify the indentation for preprocessor conditional statements.See INDENTATION.

-prs, --space-after-parentheses

Put a space after every '(' and before every ')'.
See STATEMENTS.

-psl, --procnames-start-lines

Put the type of a procedure on the line before its name.
See DECLARATIONS.

-saf, --space-after-for

Put a space after each for.
See STATEMENTS.

-sai, --space-after-if

Put a space after each if.
See STATEMENTS.

-saw, --space-after-while

Put a space after each while.
See STATEMENTS.

-sbin, --struct-brace-indentationn

Indent braces of a struct, union or enum N spaces.
See STATEMENTS.

-sc, --start-left-side-of-comments

Put the `*' character at the left of comments.
See COMMENTS.

-sob, --swallow-optional-blank-lines

Swallow optional blank lines.
See BLANK LINES.

-ss, --space-special-semicolon

On one-line for and while statements, force a blank before the semicolon.
See STATEMENTS.

-st, --standard-output

Write to standard output.
See INVOKING INDENT.

-T

Tell indent the name of typenames.

See DECLARATIONS.

-tsn, --tab-sizen

Set tab size to n spaces.
See INDENTATION.

-ut, --use-tabs

Use tabs. This is the default.
See INDENTATION.

-v, --verbose

Enable verbose mode.
See MISCELLANEOUS OPTIONS.

-version

Output the version number of indent.
See MISCELLANEOUS OPTIONS.

[C/C++ basic] Preprocessing #if defined(SHAWN)

It's lot of usage same as #ifdef Like #if defined(...) When using #if defined(...) we can used logic AND/OR for preprocessing.

Sample 1:

#ifdef ABC
// do something
#elif DEF
// do something
#else
// do something else
#endif

Sample 1 above can be simply recoding as:

#if defined(ABC) || defined(DEF)
//do something
#else
// do something else
#endif

[C/C++ basic] Preprocessing #ifdef, #elif, #else

Today I using C/C++ preprocessor to compile my code, But I have a little confuse about "is #elif can work correctly with #ifdef"?

#ifdef TEST_IFDEF
	printf("Test #ifdef");
#elif TEST_ELIF
	printf("Test #elif");
#else
	printf("Test #else");
#endif

And after my trying. It's work well :D

[C/C++]switch-case with range?

There is an interesting discussed after today study group. Is C/C++ support switch-case with range of integer!? Let see a example :

//===================
switch (a)
{
	case 1 ... 10:
		//do somthing
		break;

	case 11 ... 20:
		//do somthing
		break;
	default:
		//do something 
		break;
}
//===================

This is successfully with gcc compiler. But not done with VC++ That's because Standard C doesn't support switch-case with range. I found the answer from http://c-faq.com/misc/nonconstcase.html If using gcc with option -pedantic, then will be error occur when compile like below: warning: range expressions in switch statements are non-standard unless you are clarify what are you doing, and understand the code portable issue. DONOT using switch-case with range! (my own suggestion...)

Bash Introduction (4/12)

4/12 Present in Alphanetworks.

 

 

The chr() in Ruby.

Cause I have to write bytes string using Ruby.

I  collation some rules of chr() to clarify my mind.

At first. create new file.

file = File.new("helloRuby", "w+")

 

There are three way to get the same result :

file.write(65.chr)

file.write(Integer(0x41).chr)

file.write("A")

upon three all get the hexdump result like :

00000000  41                                                |A|

And if using String.hex , ruby will write the string of hex number to file

file.write("A".hex)

00000000  31 30                                             |10|

 

Then, if I want to write the real hex byte to file.

I can using

file.write("A".hex.chr)

file.write(Integer(10).chr)

00000000  0a 0a                                             |..|

Important note :

chr() of Number form and chr() of String form will get the different result !

 

off_t 是32bit 還是64bit呢？

檔案位置的最大值受限於 off_t 資料型別本身的大小.
多數機器架構會定義為C的long 資料型別
若有需要將 off_t 由 32 bits 轉成 64bits
只要在 CPPFLAG 中加入 D_FILE_OFFSET_BITS=64 即可

ex:
CPPFLAG += -D_FILE_OFFSET_BITS=64

[Programming] Difference of Struct Define between C and C++

今天和 Evan 一起找 Bug 時發現了一個被我忽略的 C/C++ 小細節,

在 C++ 中, 當宣告了一個 struct 後,

可以直接用這個結構來做為型態名稱,

例如：

struct sample_struct
{

char buffer[10];

int i, j, k;

};

在 C++ 裡, 可以直接使用

sample_struct test;


而在 C 語言中較為嚴謹, 需要在每個變數宣告之前加入關鍵字 struct :

struct sample_struct test;

若直接在 C 裡用 sample_struct test; 編譯時會看見 ERROR 唷！