Pete's Place

A BASH script to monitor disk usage in Linux

Someone asked me if disk space usage can be monitored via a bash script. Yes, it can. The following script can be copied to the host to be monitored, then executed periodically (once an hour?) via a crontab. Keep in mind there are bigger better ways out there to do this, but this isn't bad for a small simple solution. It's also a good exercise for you if you are learning Linux!

#!/bin/bash
# A script to keep an eye on disk use. Mutt must be installed

# and the host must be able to send SMTP mail.

# Alert Recipient
ADMIN="linux-admin@example.com"

# Alert Threshhold

ALERT=85

df -h -P | grep -vE '^Filesystem|tmpfs|cdrom|iso|nfs|140.139' | awk '{ print $5 " " $1 }' | while read OUTPUT;
do
        USAGE=$(echo $OUTPUT | awk '{ print $1 }' | cut -d'%' -f1 )
        PARTITION=$(echo $OUTPUT | awk '{ print $2 }')

        if [ $USAGE -ge $ALERT ] ; then
                echo -e "WARNING: Filesystem on \"$PARTITION\" is ${USAGE}% full.\n Threshold is 85% \n HOST: $HOSTNAME\nDATE: $(date)\nThis message generated by /admin-scripts/SpaceWatch on $HOSTNAME" | \
                mutt -s "Alert: Disk space warning on $HOSTNAME" ${ADMIN}
        fi

done

exit 0

2018 University of Nebraska Cornhuskers Football Schedule

What D&D character am I?

I Am A: True Neutral Human Ranger (7th Level)

Ability Scores:
Strength-12
Dexterity-11
Constitution-12
Intelligence-12
Wisdom-11
Charisma-12

Alignment:
True Neutral A true neutral character does what seems to be a good idea. He doesn't feel strongly one way or the other when it comes to good vs. evil or law vs. chaos. Most true neutral characters exhibit a lack of conviction or bias rather than a commitment to neutrality. Such a character thinks of good as better than evil after all, he would rather have good neighbors and rulers than evil ones. Still, he's not personally committed to upholding good in any abstract or universal way. Some true neutral characters, on the other hand, commit themselves philosophically to neutrality. They see good, evil, law, and chaos as prejudices and dangerous extremes. They advocate the middle way of neutrality as the best, most balanced road in the long run. True neutral is the best alignment you can be because it means you act naturally, without prejudice or compulsion. However, true neutral can be a dangerous alignment when it represents apathy, indifference, and a lack of conviction.

Race:
Humans are the most adaptable of the common races. Short generations and a penchant for migration and conquest have made them physically diverse as well. Humans are often unorthodox in their dress, sporting unusual hairstyles, fanciful clothes, tattoos, and the like.

Class:
Rangers are skilled stalkers and hunters who make their home in the woods. Their martial skill is nearly the equal of the fighter, but they lack the latter's dedication to the craft of fighting. Instead, the ranger focuses his skills and training on a specific enemy a type of creature he bears a vengeful grudge against and hunts above all others. Rangers often accept the role of protector, aiding those who live in or travel through the woods. His skills allow him to move quietly and stick to the shadows, especially in natural settings, and he also has special knowledge of certain types of creatures. Finally, an experienced ranger has such a tie to nature that he can actually draw on natural power to cast divine spells, much as a druid does, and like a druid he is often accompanied by animal companions. A ranger's Wisdom score should be high, as this determines the maximum spell level that he can cast.

Find out What Kind of Dungeons and Dragons Character Would You Be?, courtesy of Easydamus (e-mail)

2016 Nebraska Cornhuskers Football Schedule

2016 Nebraska Cornhuskers Football Schedule: The 2016 Nebraska Cornhuskers Football Schedule with dates, times, TV network, and links to tickets.

CentOS7: HOWTO show running services

[root@tony ~]# systemctl --no-page -t service -a --state running --no-legend
auditd.service loaded active running Security Auditing Service
crond.service loaded active running Command Scheduler
dbus.service loaded active running D-Bus System Message Bus
dovecot.service loaded active running Dovecot IMAP/POP3 email server
getty@tty1.service loaded active running Getty on tty1
gssproxy.service loaded active running GSSAPI Proxy Daemon
lvm2-lvmetad.service loaded active running LVM2 metadata daemon
NetworkManager.service loaded active running Network Manager
ntpd.service loaded active running Network Time Service
polkit.service loaded active running Authorization Manager
postfix.service loaded active running Postfix Mail Transport Agent
rsyslog.service loaded active running System Logging Service
sshd.service loaded active running OpenSSH server daemon
systemd-journald.service loaded active running Journal Service
systemd-logind.service loaded active running Login Service
systemd-udevd.service loaded active running udev Kernel Device Manager
tuned.service loaded active running Dynamic System Tuning Daemon
vmtoolsd.service loaded active running Service for virtual machines hosted on VMware
wpa_supplicant.service loaded active running WPA Supplicant daemon
[root@tony ~]#

Ginger loves her Daddy!

Here's a fun little script using the Google Maps Geocoding API:

[pete@server1 ~]# cat latlong.sh
#!/bin/bash

if [[ -z $@ ]]; then 
  echo "Works better with an address..."
  exit 1
fi
if [[ ! -x /usr/bin/curl ]]; then 
  echo "ERROR: Can't work without /usr/bin/curl"
  exit 1
fi
if [ ! -x /usr/bin/xml2 ]; then 
  echo "ERROR: Please install package xml2 from the EPEL repo first."
  exit 1
fi

address="$(echo $@ | sed 's/ /+/g')"

curl -s "http://maps.googleapis.com/maps/api/geocode/xml?address=${address}" \

     -o /tmp/file.xml

eval $(xml2 < /tmp/file.xml | tr '/, ' '___' | grep =)

if [[ $_GeocodeResponse_status == "OK" ]]; then
  echo "Address: $(echo $address | sed 's/+/ /g')"
  echo "Lattitude: $_GeocodeResponse_result_geometry_location_lat"
  echo "Longitude: $_GeocodeResponse_result_geometry_location_lng"
else
  echo "No results"
fi

exit 0

[pete@server1 ~]# ./latlong.sh 1600 Pennsylvania Ave, Washington, DC
Address: 1600 Pennsylvania Ave, Washington, DC
Lattitude: 38.8791981
Longitude: -76.9818437
[pete@server1 ~]#

Awesome!

Pete's Holiday Wish Lists for 2015

People have asked, so here it is for your Holiday shopping convinience:

Merry Christmas!

How to download all the RHEL7 docs

You can easily download all of the available Red Hat Enterprise Linux 7 Documentation (in PDF format) from a BASH prompt, by using the following command line:

curl -s 
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/ |
 grep -o '[^"]*Linux/7/pdf[^"]*' | xargs -I{} wget 
https://access.redhat.com{}

This is very handy when you are studying for RHEL 7 Certification (RHCSA/RHCE). All the answers to the test are in these docs... :-)

Official RHEL7 Information

Here's a list of links to Official Red Hat Enterprise Linux information:

Red Hat website provides the official documentation*,
Red Hat Enterprise Linux blog gives general information,
Red Hat Developer blog offers information to developers,
Red Hat Community blog communicates about general events,
Red Hat Security blog talks about security,
Red Hat Storage blog discusses storage topics (Big Data, Ceph, GlusterFS, etc),
Red Hat Services blog provides information for IT professionals,
Red Hat customer portal provides a place for discussions on technical topics,
Red Hat Certified Professionals Facebook account gives information about trainings and certifications,
Red Hat LinkedIn group is a place to meet other Red Hat Certified Professionals,
CentOS 7 blog offers the last news about CentOS 7,
Oracle Linux provides an Administrator’s Guide for Release 7,
Red Hat offers a RHEL 7 Network Performance Tuning Guide and a RHEL 7 Real-Time Installation Guide.

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