Thursday, July 18, 2013

behave yourself

useful for sysadmins


very very useful to restrict your users

Wednesday, July 3, 2013

Flexjson vs GSON

GSON is prettier, but flexjson deals with cycles.

So I usually go flexjson. It's not pretty to die by stack overflow.

Booleans in OpenJPA


    @ExternalValues({"true=1", "false=0"})
    boolean val;

or MySQL will use a single bit to store this

So you want a mail server to play with, try apache james

Forget sendmail. Download apache james, and

1. vi bin/ and add a JAVA_HOME pointing to some non-IBM JVM such as sun's

#   JAVA_HOME          Must point at your Java Development Kit installation.
#export JAVA_HOME=/home/leoks/ibm-java-i386-70/
export JAVA_HOME=/opt/j2sdk1.4.2_19/

just because IBM JVM does not have the encryption algorithm you'll need.

2. vi apps/james/SAR-INF/config.xml and change all the ports to something higher, so you don't have to be root to start it (basically POP3=9110, NNTP=9119 and SMTP=9025)

3. start it up

[leoks@xxx bin]$ ./
Using PHOENIX_HOME:   /home/leoks/Downloads/james-2.3.2
Using PHOENIX_TMPDIR: /home/leoks/Downloads/james-2.3.2/temp
Using JAVA_HOME:      /opt/j2sdk1.4.2_19/
Running Phoenix:

Phoenix 4.2

James Mail Server 2.3.2
Remote Manager Service started plain:4555
POP3 Service started plain:9110
SMTP Service started plain:9025
NNTP Service started plain:9119
FetchMail Disabled

[1]+  Stopped                 ./
[leoks@xxx bin]$ bg

4. then add your users (user and password are root/root)

[leoks@xxx bin]$ telnet localhost 4555
Connected to localhost.
Escape character is '^]'.
JAMES Remote Administration Tool 2.3.2
Please enter your login and password
Login id:
Welcome root. HELP for a list of commands
adduser leoks xxx
User leoks added
Connection closed by foreign host.

and you're good to go