Introduction export command in Linux marks an environment variable to be exported with any newly forked child processes and thus it allows a child process to inherit all marked variables. Frequently Used Options -p : List of all names that are exported in the current shell-n : Remove names from [...]
The source command read and execute commands from the filename argument in the current shell context. When a script is run using source it runs within the existing shell, any variables created or modified by the script will remain available after the script completes. In contrast if the script is [...]
The time command in Linux runs the specified program command with the given arguments. When command finishes, time writes a message to standard error giving timing statistics about this program run. It shows Elapsed real time between invocation and terminationUser CPU time, i.e. amount of CPU time spent in user [...]
The /dev/null device is a special file that discards all data written to it but reports that the write operation succeeded. It is typically used for disposing of unwanted output streams of a process. This is usually done by redirection. /dev/null is creaetd every time on system boot. From the [...]
Hard link and Soft link (Symbolic link) in Linux are two different methods to refer to a file in the hard drive. Inode Each file has one inode that contains information about that file, including the location of the data belonging to that file. Every file must have at least [...]
The chown command in Linux is used to modify the owner and group of files, directories and links. By default, the owner of a filesystem object is the user that created it. The group is a set of users that share the same access permissions (i.e., read, write and execute) [...]
Permission Groups There are below three permission groups for each file and directory Owner : The Owner permissions apply only the owner of the file or directory.Group : This permissions apply only to the group that has been assigned to the file or directory.Others : This permissions apply to all [...]
CD Command The cd (change directory) command is used to change the current working directory in Linux and other Unix-like operating systems. The current working directory is the directory in which the user is currently working in. The syntax for the cd command is as follows: cd [OPTIONS] directory Absolute [...]
A service is an application (or set of applications) that runs in the background waiting to be used, or carrying out essential tasks. They are not interactive. It is detached from the keyboard and display of any interactive user. Process is a running program. At a particular instant of time, [...]
Ubuntu follows the filesystem hierarchy structure. The location where software gets installed depends on how you install it. According to the FHS, /usr hierarchy is reserved for the software provided by the Linux distribution. By convention, /usr/local is reserved for software compiled and installed manually. The /usr/local directory should contain [...]