The crontab (cron derives fromÂ chronos, Greek for time; tab stands forÂ table) command, found in Unix and Unix-like operating systems, is used to schedule commands to be executed periodically. To see what crontabs are currently running on your system, you can open a terminal and run: sudo crontab -l To edit the list ofÂ cronjobs you can [...]
Hi Morning to all of my Readers, I found one ineresting script to monitor the CPU . The script found on the following siteÂ http://bashcurescancer.com TheÂ a script is called monitorCpuUsage.sh. It is meant to be called from crontab and to inform you of processes or users who maybe using excessive amounts of cpu. Here is the [...]
Sometime it is necessary to block incoming connection or traffic from specific remote host. iptables is administration tool for IPv4 packet filtering and NAT under Linux kernel. Following tip will help you to block attacker or spammers IP address. Â The blocklist is create with an API I wrote and you can use wget to update [...]
Webalizer is a fast, free web server log file analysis program. It produces highly detailed, easily configurable usage reports in HTML format, for viewing with a standard web browser. It was written to solve several problems with currently available analysis packages. A vast majority of them were written in Perl or some other scripting language, [...]
Lots of programmers like PHP for its ability to code and develop web applications fast. Code-debugging is a lot easier than with PERL or C. However, there is one thing a lot of developers are puzzled about, â€œHow to run PHP Scripts with crontab?â€ Cron is normally available on all Unix and Linux distributions; if [...]
E-Mail delivery can be invoked by issuing the command “sendmail -q”. For those who are interested in what sendmail actually does, “sendmail -q -v” will give a more verbose version of the delivery process.
It is very convenient to automate the process of e-mail delivery. A tool commonly used for this process is cron.
Below are ways to list out and remove user’s cron job, as superuser # crontab -u username -l to list out the current cron job by the particular username account. Deleting them is as easy as # crontab -u username -r Curious for pending jobs issued by that particular user? # su username # jobs [...]
1. How to know which ports are listening from your IP address? # nmap -sT -O your-ip-address 2. How to grep an exact match? # grep -w textfile.txt 3. How to reverse grep matches? # grep -v textfile.txt # 4. How to know which service name is what port? Assuming port 443 # cat testfile.txt [...]
Linux systems are capable of running scheduled jobs. Server administrative task are done on regular basis even while sysads are away or during sleeping hours. This keeps a fully working production server do unattended jobs on periodical basis. cron is a linux utility that schedules and automates jobs. This blog entry covers how to do [...]
There are times that a server does not need to listen and process any TCP/UDP request for a long list of consecutive local IP addresses. This blog entry provides a starting point of creating server scripts to block a long list of consecutive IP address from the server for permanent blocking. To start, launch your [...]
Fighting spam email is a worldwide daily combat challenge. Email spam fight is just another daily server wide monitoring function of any sysad administering those email servers. Global spam email attacks and happens everyday regardless of country, server setup, domains, geolocation and public IP address you might have. Take a look of the top country [...]
Monitoring mailbox users can be done in many serveral ways via web interface or via terminal or via bash scripts. With the usual mbox type emails, incoming new email messages are automatically redirected to each users’ own spool file. This spool mail is by default located and stored in /var/spool/mail. From there, the spool file [...]
This document entry however covers a foundation approach and mostly used tar arguments on backing up data using the linux command tar. ============================================= Data backup samples using Tar Linux command ============================================= A very simple usage of tar # tar cvf backup.tar * Legend: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -c create a new tar file -v verbose mode -f select [...]
The Multi Router Traffic Grapher (MRTG) is a tool to monitor the traffic load on network-links. MRTG generates HTML pages containing PNG images which provide a LIVE visual representation of this traffic. MRTG is basically used for generating graphs to a device, network host, IP-based appliances for monitoring usage, live data and statistics usage. This [...]