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.

VIM with tags

Using vim coding program for a long time. It's a very good tool "ctags" to work with vim when coding.

Create tags

#ctags -R *

Naming tags

#ctags -R * -f tagName

In vim, using below command to setting PATH of tags:

:set tags=./tags,../tags

or

:set tags=tags; Add ; can recursive search tags from parent folder.

[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...)

Using mii-tool/ethtools to sniff status of network interface

When I am trying using mii-tool on my new develop environment, Some error occur, and the log message like below:

# mii-tool -V mii-tool.c 1.9 2000/04/28 00:56:08 (David Hinds) SIOCGMIIPHY on 'eth0' failed: Operation not supported no MII interfaces found

Then I google this problem find out, mii-tool has lot of bug, and some net drivers didn't support it. So, I am trying using ethtool which have more compatibility. And it work great!!

# ethtool eth0 Settings for eth0: Supported ports: [ TP MII ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full Port: MII PHYAD: 1 Transceiver: internal Auto-negotiation: on Link detected: yes

So, If just want to know about network status, Maybe ethtool is better than mii-tool, But, unfortunately, I still need to resolving mii-tool's problem for our environment. So, If you meet the trouble about "no MII interfaces found", make sure the mii-tool is follow up the newest one release. It would possible make the trouble disappear...or not...OTZ

Mac OS disable/enable .DS_Store

Mac OS will create .DS_Store on Network Disk. And it would confused the other operation system user. This is the way to disable auto create .DS_Store. defaults write com.apple.desktopservices DSDontWriteNetworkStores true

vbindiff : Good tools for compare binary files.

vbindiff is a graphical windows tools for compare binary file. It can easy find out what bytes different in ASCII or EBCDIC mode. more information in manual page :) SYNOPSIS vbindiff file1 [ file2 ] DESCRIPTION Movement Keys ------------- Up Move one line (16 bytes) towards the beginning of the file Down Move one line (16 bytes) towards the end of the file Left Move one byte towards the beginning of the file Right Move one byte towards the end of the file PageUp Move one page towards the beginning of the file PageDn Move one page towards the end of the file Home Move to the beginning of the file End Move to the end of the (shorter) file F Search for a string or byte sequence G Move to a specified file position Other Keys ---------- Enter Move to the next difference between the files Space (same as Enter) C Toggle between ASCII and EBCDIC display E Edit currently displayed section of file Esc Exit VBinDiff Q Exit VBinDiff

SD card automount for Embedded Linux

If we want to using SD card auto mount.

Please reference manual page of command "mdev".

#  mdev --helpBusyBox v1.18.4 (2011-04-01 22:32:35 CST) multi-call binary.
Usage: mdev [-s]
-s      Scan /sys and populate /dev during system boot
It can be run by kernel as a hotplug helper. To activate it: echo /sbin/mdev > /proc/sys/kernel/hotplug

It uses /etc/mdev.conf with lines[-]DEVNAME UID:GID PERM [>|=PATH] [@|$|*PROG]

 

Follow above information.

step 1. make sure build the feature "hotplug" to kernel

step 2. edit /etc/mdev.conf like below :

sd.*    0:0     660     */sbin/automount.sh     $MDEV

mmc.*   0:0     660     */sbin/automount.sh     $MDEV

step 3. add /sbin/automount.sh like below:

 

 

step 4.  Add command at /etc/rc.d/rc.sysinit

# echo /sbin/mdev > /proc/sys/kernel/hotplug

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 !

 

Cannot identify SD card partition! (mmcblk0: unknown partition table )

Situation :

When I  plug-in my SD card into some EVB board.

SD driver can detect mmcblk0, but cannot detect SD partition.

like below:

# mmc0: new high speed SDHC card at address f7c1

mmcblk0: mmc0:f7c1 SD08G 3.50 GiB

mmcblk0: unknown partition table

 

But if I want to mount SD card to some folder,

I'll need to identify partition of SD card file system.

 

Solution :

After tracing...

Only need to enable CONFIG_MSDOS_PARTITION of kernel config.

then, the partition will be identify!!

# mmc0: new high speed SDHC card at address f7c1

mmcblk0: mmc0:f7c1 SD08G 3.50 GiB

mmcblk0: p1