RFC 2142 - Mailbox Names for Common Services, Roles and Functions

RFC stands for Request For Comments. Not all RFC documents end up as standards. But it is indeed a good read to find out how standards works. For example, RFC 2142 list emails that should be reserve for its purpose :

Perl - How to upgrade perl modules

Now we've know how to deal with Perl modules :

• installing em' (the no-brainer way)
• list em' (even the core ones)
• remove em'

How about upgrading Perl modules?

FreeBSD - How to change time zone

Platform :
FreeBSD

Objective :
Change the FreeBSD system clock time zone

Command :

tzsetup

Perl - How to uninstall / delete Perl module

Installing Perl modules can use the cpanm utility, but how about removing Perl modules? App::pmuninstall module is the answer!

Installation :

$ cpanm App::pmuninstall
--> Working on App::pmuninstall
Fetching http://search.cpan.org/CPAN/authors/id/X/XA/XAICRON/App-
pmuninstall-0.16.tar.gz ... OK
Configuring App-pmuninstall-0.16 ... OK
Building and testing App-pmuninstall-0.16 ... OK
Successfully installed App-pmuninstall-0.16

Usage :

vim - How to stop vim creating "tilde" backup files

Vim, aka the Programmer's Editor, by default creates backup files (ends with a tilde character) whenever editing file. E.g. myfile~, another_file~, yet_another_file~ and etc.

After some time, this generates too many backup laying around the file system. Too messy. This is how to stop vim create these backup files :

Perl - How to find out what Core Modules installed

Perl comes with a set of core modules. Perl core modules comes with default installation.
E.g. :
- Env
- File::Spec
- File::Basename
- Time::localtime

These are just some of the gems to a system administrator. So, how to find out what core modules are included with your perl installation?




Here's how :

FreeBSD - How to change screen to use BASH

Purpose :
Make screen, the virtual terminal program, changes the user's default shell from tcsh to BASH when starting.

Command :

FreeBSD - How to create big huge files

Platform :
FreeBSD

Purpose :
Create big files for testing purpose.

Command :

dd

Bash - How to output all (stdout & stderr) into log file in Bash

Purpose :
When scripting Bash scripts, often we'll need to output all stdout & stderr of a particular command into a log file, for logging purposes or diagnostic purposes.






Command :

FreeBSD - How to check device or CPU performance

Platform :
FreeBSD

Purpose :
Monitoring disk read/write activity.

Command :
iostat


Installation :
The "iostat" command comes with the base installation.

Useful switches :
-w == update frequency, in seconds
-d == only show devices, hdd related
-C == show CPU activity only

Example :

ssh - How to pipe output from local to remote server

In Bash, with pipe (the "|" symbol) and ssh makes a good combination of server administration tool, securely. Some examples :

FreeBSD - How to reduce TIME_WAIT connections

Routinely, I did a "netstat -an" on a FreeBSD box, a DNS server. The screen then shower with hundreds of "TIME_WAIT" connections. Seems like some malware infected clients are querying the server and causes the terminated TCP socket waiting to be shutdown, but not fast enough, to be efficient. Fortunately, the numbers of TIME_WAIT sockets accumulated are insignificant.

In order to reduce the number of socket waiting, tune the system value :

FreeBSD - How to make changes to sendmail, FreeBSD styled

Sendmail is the default MTA in FreeBSD. FreeBSD has its own way in managing sendmail's configuration files. Instead of making changes to sendmail.mc, changes should be made to $(hostname).mc. Similarly for submit.mc, changes should be $(hostname).submit.mc.

Here's how :

FreeBSD - How to test newsyslog for systax error

Platform :
FreeBSD

Purpose :
Syntax checking after creating a new logrotate in "newsyslog"

Command :
newsyslog


Installation :
The "newsyslog" log rotation program comes with the base installation.

Useful switches :
-n == DO NOT actually do the logrotate. Instead, show what will be perform
-vv == verbose on what newsyslog is doing

Example :

BIND - Error "loading from master file managed-keys.bind failed: file not found"

Platform :
FreeBSD

Error message :
Every time restarting the BIND DNS server, the log file will have this entry :

general: error: managed-keys-zone ./IN: loading from master file managed-keys.bind failed: file not found

BIND DNS continue to work though.

Solution :
Create a empty file in /var/named/etc/namedb, name "managed-keys.bind":

touch /var/named/etc/namedb/managed-keys.bind

Why :
The file "managed-keys.bind" is used for managing keys in DNSSEC. By default, BIND is looking for it. Even though you might not be using this feature, creating the file in empty will make the error message go away.


Sayonara !!!

FreeBSD - How to get information on hardware details

Platform :
FreeBSD

Purpose :
Print out information about hardware, e.g. CPU, memory, network card & etc

OSX - How to maximize window using keyboard shortcut

By default, OSX does not comes with a shortcut, though there's a function for it. To make use of it, we'll need to assign a keyboard shortcut key to maximize or un-maximize window.








Here's how to do it :

1. Open the "System Preferences"
2. Under the "Hardware" section, click on "Keyboard"
3. Next, click on "Keyboard Shortcuts" then "Application Shortcuts" (on the left hand box)
4. Add a shortcut key by clicking on "+" symbol, on the bottom of the right hand box
5. At the next dialog box, choose "All Applications" for "Application:"
6. In the "Menu Title :" column, type in "Zoom"
7. Click on the next column, "Keyboard Shortcut:", then press your preferred keyboard shortcut.
   E.g. Control + Option + Command + m (you didn't read wrongly, is 4 keys there :p)
   
   *** Avoid popular shortcut key, e.g. Command + v

Now, open an application and try the new keyboard shortcut key. Press the first time for maximized and the second time to return the previous size.

Nemaste !!!

FreeBSD - portupgrade php5 got hiccups with security/php5-filter

During the routing upgrading of ports, caught a hiccups while upgrading php5 related packages.

One of the port failed to upgrade after issuing "portupgrade -vr php5*".







The errors :

===>  Building for php5-filter-5.3.4
/bin/sh /usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/libtool --mode=compile cc  -I. -I/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter -DPHP_ATOM_INC -I/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/include -I/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/main -I/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter -I/usr/local/include/php -I/usr/local/include/php/main -I/usr/local/include/php/TSRM -I/usr/local/include/php/Zend -I/usr/local/include/php/ext -I/usr/local/include/php/ext/date/lib  -DHAVE_CONFIG_H  -O2 -fno-strict-aliasing -pipe   -c /usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c -o logical_filters.lo
 cc -I. -I/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter -DPHP_ATOM_INC -I/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/include -I/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/main -I/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter -I/usr/local/include/php -I/usr/local/include/php/main -I/usr/local/include/php/TSRM -I/usr/local/include/php/Zend -I/usr/local/include/php/ext -I/usr/local/include/php/ext/date/lib -DHAVE_CONFIG_H -O2 -fno-strict-aliasing -pipe -c /usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c  -fPIC -DPIC -o .libs/logical_filters.o
In file included from /usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c:25:
/usr/local/include/php/ext/pcre/php_pcre.h:29:18: error: pcre.h: No such file or directory
In file included from /usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c:25:
/usr/local/include/php/ext/pcre/php_pcre.h:37: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
/usr/local/include/php/ext/pcre/php_pcre.h:38: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
/usr/local/include/php/ext/pcre/php_pcre.h:44: error: expected specifier-qualifier-list before 'pcre'
/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c: In function 'php_filter_validate_regexp':
/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c:411: error: 'pcre' undeclared (first use in this function)
/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c:411: error: (Each undeclared identifier is reported only once
/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c:411: error: for each function it appears in.)
/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c:411: error: 're' undeclared (first use in this function)
/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c:412: error: 'pcre_extra' undeclared (first use in this function)
/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c: In function 'php_filter_validate_email':
/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c:527: error: 'pcre' undeclared (first use in this function)
/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c:527: error: 're' undeclared (first use in this function)
/usr/ports/security/php5-filter/work/php-5.3.4/ext/filter/logical_filters.c:528: error: 'pcre_extra' undeclared (first use in this function)
*** Error code 1
1 error
*** Error code 1

Stop in /usr/ports/security/php5-filter.
** Command failed [exit code 1]: /usr/bin/script -qa /tmp/portupgrade20101224-47314-9ktu04-0 env UPGRADE_TOOL=portupgrade UPGRADE_PORT=php5-filter-5.2.11_1 UPGRADE_PORT_VER=5.2.11_1 make
** Fix the problem and try again.
--->  Build of security/php5-filter ended at: Fri, 24 Dec 2010 09:36:27 +0800 (consumed 00:00:43)
--->  Upgrade of security/php5-filter ended at: Fri, 24 Dec 2010 09:36:27 +0800 (consumed 00:00:43)
--->  ** Upgrade tasks 1: 0 done, 0 ignored, 0

Checking out /usr/ports/UPDATING and /usr/ports/MOVED doesn't seems to give a hint. Next try on Forum.FreeBSD.org shed light on this :

Bash - How to check the exit status of pipe command

Piping in bash commands are common.
Checking exit status of a command in bash scripting is essential.
How about checking exit status of the commands in a pipe?





Example:

FreeBSD - Port p5-Encode-Detect error

While patching one of the FreeBSD box, a perl module port, converters/p5-Encode-Detect-1.01, failed to compile. This is the abstract of the error message :

===>  Extracting for p5-Encode-Detect-1.01
=> SHA256 Checksum OK for Encode-Detect-1.01.tar.gz.
===>   p5-Encode-Detect-1.01 depends on file: /usr/local/bin/perl5.8.9 - found
===>  Patching for p5-Encode-Detect-1.01
===>   p5-Encode-Detect-1.01 depends on file: /usr/local/bin/perl5.8.9 - found
===>   p5-Encode-Detect-1.01 depends on file: /usr/local/lib/perl5/site_perl/5.8.9/ExtUtils/CBuilder.pm - found
===>   p5-Encode-Detect-1.01 depends on file: /usr/local/lib/perl5/site_perl/5.8.9/Module/Build.pm - found
===>   p5-Encode-Detect-1.01 depends on file: /usr/local/bin/perl5.8.9 - found
===>  Configuring for p5-Encode-Detect-1.01
Warning: ExtUtils::CBuilder not installed or no compiler detected
Proceeding with configuration, but compilation may fail during Build

Creating new 'MYMETA.yml' with configuration results
Creating new 'Build' script for 'Encode-Detect' version '1.01'
===>  Building for p5-Encode-Detect-1.01
Building Encode-Detect
Error: no compiler detected to compile 'src/LangBulgarianModel.cpp'.  Aborting
*** Error code 2

Stop in /usr/ports/converters/p5-Encode-Detect.

It seems like the port devel/p5-ExtUtils-CBuilder didn't quite compile it's option and installed properly. Reinstalling devel/p5-ExtUtils-CBuilder didn't help. Re-compile all of the dependency of converters/p5-Encode-Detect & devel/p5-ExtUtils-CBuilder also didn't work as well.

The error message does strongly suggest that there's problem with devel/p5-ExtUtils-CBuilder. It's time to get my hands dirty, by manually compiling the port devel/p5-ExtUtils-CBuilder :