Mohan Cheema's Online Diary

Often we need to list just the column name of the table without displaying the metadata. However, Until before MySQL 5.0 there was no way to get just the column names for any given table. Since MySQL 5.0 new table has been added information_schema. INFORMATION_SCHEMA provides access to database metadata.

Metadata is data about the data, such as the name of a database or table, the data type of a column, or access privileges. Other terms that sometimes are used for this information are data dictionary and system catalog.  Read more...

As SVN admin we are asked to send an email to release managers and testers for all the commits made to the repository so that release managers can update their release sheet and testers can do the testing. This is small post-commit hook for SVN which sends out an email to release manager and testers.

#!/bin/sh

REPOS="$1"
REV="$2"

SVNLOOK=/usr/bin/svnlook

auth=`$SVNLOOK author -r $REV $REPOS`
dt=`$SVNLOOK date -r $REV $REPOS | sed 's/\,//g'`
changed=`$SVNLOOK changed -r $REV $REPOS`
log=`$SVNLOOK log -r $REV $REPOS`
n=$'\n'

LISTID="releasemanagers@yourdomain.com testers@yourdomain.com"

echo "$n $n====Status:PROJECT INTEGRATION svncommit: $DATTIM====$n Changeset [Revision ID ${REV}] by $auth.$n$n On Date $dt.$n$n With Comment $n$log.$n$n Files Changed$n $changed.$n $n" | mailx -s "New Commit in $REPOS" $LISTID

I hope this will be helpful for someone.

As SVN admin we need to make sure any commits made to the repository should have comments associated it with. The reason to have comments during commits is simple to know what has been fixed or what new has been added to the repository. Here is the simple shell script I have written to stop the commits if comments has not been added.  Read more...

Linux has a supposedly good memory management feature that will use up any “extra” RAM you have to cache stuff. This section of the memory being used is supposed to be freely available to be taken over by any other process that actually needs it, but unfortunately some Linux distros think that cache memory is too important to move over for anything else that actually needs it.

I have 16 GB RAM in my Server. Whenever there is no cache being stored in the memory (i.e. when I first boot / restart the server), response time is great. But as soon as it fills up with cache, my server response is terrible.  Read more...

It often happens when we install vsftpd on newly installed system and configure it properly still sometimes we get one of the following error.

1. vsftpd:  Error 553 – Could not create file
2. vsftpd:  Error 530 – Login Incorrect (Even if username and password are correct)

So what is the problem and how to resolve.

The problem is often due to SElinux. To resolve this you will need to disable SElinux protection for FTP , from SElinux settings. For this you just have to run the following command:

setsebool -P ftp_home_dir 1  Read more...