Interesting article on Linux permissions. It explains how to recognise which permission system might be in use (SELinux, ACLs), the meaning of the spe[……]
Author: Andrea
AWS dynamic IP ranges
Need to know the dynamic IP ranges used by AWS in a specific region? AWS publishes this as a JSON file.
curl -s https://ip-ranges.amazonaws.com/ip-ra[......]
Sys admin levels explained
Interesting article on the different levels and skill sets of System Administrators. It breaks down what separates a junior sysadmin from a senior one[……]
The politics of the Linux desktop
Open Source software was becoming more and more popular in 2009, even though many of these applications were still little known. According to PCWorld,[……]
How to soft reset Linux disks
Sometimes disks stop responding and cause system slowness because the kernel is waiting for a response that never comes. The disk appears 100% utilise[……]
Find sdx device/ATAx mappings
When dealing with hardware, you often see log messages like:
ata9: hard resetting link
ata9: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
To map[……]
Convert Squid/timestamps to a human readable format
Somebody had the brilliant idea of using Unix timestamps in Squid log files. It makes parsing easy but reading them is not so human-friendly.
This is[……]
bash – remove first line with tail and last line with head
Say you have a file called test.txt:
line 1
line 2
line 3
Remove the first line:
tail -n +2 test.txt
Remove the last line:
head -n -1 test.txt
R[……]
sed – match and replace BIND/DNS serial number programmatically
I had to make modifications to several BIND zone files. Sed proved itself invaluable once again.
The zone files looked like this:
domain.com. IN SOA[......]
Remove all non-ascii characters with perl
Sometimes when creating one-liners, the source contains non-ASCII characters that make parsing harder. To strip them all out, use Perl:
cat dirty-sou[......]