Tag Archives: Code

The Curious Case of Missing Quota Report on Volume

A week ago one of my old colleagues ask some help with an error he has on one of his servers, I was happy to oblige.

He had several servers all working exactly the same, same hardware, same OS and same configuration (apart from IP’s).
One of his server crashed and after the reboot one of his batch scripts stopped working specifically on this server.
The script tried to determind if a specific volume (for example: /mnt/volA) exist and have enougth free space,
This he did by invoking the “df” command and the “quota” command (Or their equivalent in the specific language).

What he found was:
While running: “df -k /mnt/volA” he got the correct line and response,
But on the other hand when he tried to run “quota -v |grep “/mnt/volA” the quota command didn’t return the volume.
This was particulary wierd because this volume was NFS volume with specified quota (set on the NFS server) – moreover the volume did apeer on the other servers when you looked for it when you’ve used “quota” Continue reading The Curious Case of Missing Quota Report on Volume

Python textwrap – Wrap your text to terminal size

Following the last post “Python textwrap – Fix Your Multiline Strings Indentations” – where we learned how to fix the indentation caused by the python indentation standards.
In this post I want to show you how to create a wrap to your text that support multiline and smart indent.

This might sound old to you but the original terminal (standard) was and still is 80 characters width. Long ago when I’ve started working on CLI applications and scripts my boss asked me to see the “usage/help” of one of them, then he looked at me and said – This is not 80 characters width! This is not terminal standard – Fix this!”
Back then I’ve just trimmed my lined and fix this.
More then 500 scripts later and 4 languages into the future I’ve looked at this and thought – There might be a better way to do this.
And there in python was the answer.

Let’s start with example:

>>> import textwrap
>>> x = "This is the first line of the text - This line is far more then then 80 characters and will need to be wraped to 80 characters width"
>>> print x
This is the first line of the text - This line is far more then then 80 characters and will need to be wraped to 80 characters width
>>> #Lets wrap it to 80 characters
>>> print textwrap.fill(x, width=80)
This is the first line of the text - This line is far more then then 80
characters and will need to be wraped to 80 characters width
SyntaxError: invalid syntax
>>> #See that the words won't break (Unless this is a long word)

Now let’s try that with a multiline string:

>>> x = '''
This is a mltiline string, now this is the first line and it will be more then 50 characters width for the example.
Now we create a new line with more then 50 width as the second line'''
>>> print textwrap.fill(x, width=50)
 This is a mltiline string, now this is the first
line and it will be more then 50 characters width
for the example. Now we create a new line with
more then 50 width as the second line
>>>

As you can see the second line was integrated into the first line instead of being on it’s own line – This is one of the problems with textwrap – it works only on a single line. Continue reading Python textwrap – Wrap your text to terminal size

Python textwrap – Fix Your Multiline Strings Indentation

I’ve been writing a lot in python the last couple of months and most of my code is for a CLI oriented environment (Mostly Linux/Unix shell).

One of the most important things when you create CLI is the help and usage string – Mostly because other people will try to use it – But lets face it, that script you’ve written a month ago? You’ve probably completely forgotten how it works.

So writing help or usage usually means that you work with an external file or multiline string. Continue reading Python textwrap – Fix Your Multiline Strings Indentation