Keeping track of your CPU’s performance is extremely important. In UNIX, you can accomplish this task by using the system utilities and commands. For those who would like to find out their CPU utilization, one command is extremely important. It is called SAR – System Activity Reporter. The SAR commands make accessing CPU performance quite …
The grep command is a search command built into a variety of Unix based operating systems. This command line utility, whose name stems from the original Unix term which means “search globally for lines matching the regular expression, and print them,” can be accessed using the command line or terminal from anywhere in the Unix …
Linux is a free, open source operating system that competes with the Windows Operating Systems and Mac OS X. Linux is widely used on a number of devices such as servers, desktops, laptops, smartphones, PDAs, game consoles, tablet computers, supercomputers, and mainframes. Linux controls only about 4.9% of the market share of desktop computers while …
Unix users write, edit, list, and remove cron jobs using the `crontab` command. `crontab -e` takes users into their default editor to edit their crontab entries. `crontab -l` lists their crontab. `crontab -r` removes their crontab. crontab Security If the cron.allow file exists, then the user must be listed in that file in order to …
The Unix sort command is a command for the Unix family of operating systems. It is designed to sort whatever information you give it. The command can be used for a variety of purposes, but it is most frequently employed when there are a number of different files which need to be ordered in some …
umask is a Unix shell built-in command that automatically sets file permissions on newly created files. The umask command can be confusing to use because it does work as a mask. In other words, the user sets the permissions that he/she does not want in the umask. To calculate permissions that will result from specific …
A rootkit is a type of computer malware that is created to hide programs or other computer processes from detection from both users and antivirus software programs. Once installed, a rootkit will typically obtain administrator or higher-level permissions on the infected computer. Although rootkits originated with the UNIX operating system by providing root access to …
DHCP is the dynamic host configuration protocol. In other words, it describes how your computer is connected to networks. Assigning an IP address dynamically is a basic task assigned to DHCP along with domain name, name server, gateway, host name and net mask. DHCP can provide other information like time server and has a capability …
Unix Shell Scripting Tutorials This Unix shell scripting tutorial provides samples and instructional materials that are easy to understand and useful for Unix shell scripting. It also offers illustrated samples that will helps users explore different avenues of Unix shell scripting. Bourne Shell Programming Tutorial Learn how to use the Unix shell with this …
The idea of a restricted shell first arose in the Unix operating system in order to prevent the end-user from doing as many operations as a normal shell allows. A restricted shell lets the administrator control the end-user’s computing environment by only permitting explicitly used commands to be used. The Linux restricted shell (rssh) is …