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 …
The total number of Unix commands is immense. No normal user or system administrator would ever need to know them all. The Unix commands available to you will vary based upon several factors: The version of Unix you are using (FreeBSD, Linux, Solaris, AIX, HP-UX, OpenBSD, etc…) The Unix shell you are using (sh, csh, …
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 …
Solaris makes it unreasonably difficult to change an installed server’s hostname. To change the hostname on a Solaris system, edit all of these files: /etc/hosts /etc/nodename /etc/hostname.* /etc/inet/ipnodes When file editing is complete, reboot the server to test the changes and ensure that they operate correctly. Note that changing the hostname only changes the name …
To audit Unix passwords, you must compare each encrypted password in the Unix password file with a set of potential encrypted passwords. These potential encrypted passwords are created by encrypting every password in a list of plaintext passwords. This is an example of a dictionary attack. The Unix passwd File Location The traditional location for …
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 …
List Logged In Unix Users Unix has many commands to list users who are logged in. These commands include ‘w,’ ‘who,’ and ‘users:’ $ w 9:51PM up 99 days, 5:39, 2 users, load averages: 0.83, 0.90, 0.90 USER TTY FROM LOGIN@ IDLE WHAT will p0 c-66-164-235-73. 8:11AM – w spencer p3 c-66-164-235-73. 8:26PM 1:24 pine …
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 …
For those computer users that have both Unix and Window’s operating systems, you should know that you can easily copy your Unix files from a Unix computer and transfer them to a Windows computer. Using Client for NFS, you can transfer any existing Unix files from your Unix server to a Windows based server. It …
Bootable distributions of the Linux operating system are becoming very popular for use in securing networks, testing network security, and conducting forensics after suspected intrusions. Local Area Security Linux Local Area Security Linux is a ‘Live CD’ distribution with a small footprint. Containing over 200 information security and administration related tools, as well as a …