Shell is a user interface for access to an operating system‘s services. Shells use either a command-line interface (CLI) or graphical user interface (GUI), depending on a computer’s role and particular operation.
When we speak of the command line, we are really referring to the shell.
Shell was founded by Stephen R. Bourne and It is named a shell because it is the outermost layer around the operating system kernel. Shell accepts your instruction and command in English and translate it into Computer native binary Language.
The shell is a program that provide interface to the user and takes keyboard commands and passes them to the operating system to carry out. Almost all Linux distributions supply a shell program from the GNU Project called bash. The name “bash” is an acronym for “Bourne Again SHell”, a reference to the fact bash is an enhanced replacement for sh.
When using a graphical user interface, we need another program to interact with the shell, called Terminal Emulators. If we look through our desktop menus, we will probably find one. KDE uses konsole and GNOME uses gnome-terminal, though it’s likely called simply “terminal” on our menu. There are a many other terminal emulators are available for Linux, which provides access to the shell.
After logging in to the shell using username and password above prompt will come, it means shell is ready to take input. If the last character of prompt is “#” rather than a dollar sign, it shows user has logged in via root or have superuser privileges.
Some Simple Commands
A related command is cal which, by default, displays a calendar of the current month.
To display the amount of free memory, enter the free command.
Shell ni interface ya mtumiaji kwa ajili ya upatikanaji wa huduma za mfumo wa uendeshaji. Shells kutumia ama amri-line interface (CLI) au graphical user interface (GUI), kulingana na jukumu kompyuta na operesheni maalum. Wakati sisi kuzungumza juu ya mstari wa amri, sisi ni kweli akimaanisha shell. Shell ilianzishwa na Stephen R. Bourne na inaitwa shell kwa sababu ni safu ya nje karibu na mfumo wa uendeshaji kernel. Shell inakubali maagizo yako na amri katika Kiingereza na kutafsiri katika Computer asili lugha ya binary. Shell ni programu ambayo hutoa interface kwa mtumiaji na inachukua amri keyboard na hupitisha yao kwa mfumo wa uendeshaji kutekeleza. Karibu usambazaji wote wa Linux hutoa programu ya shell kutoka Mradi wa GNU inayoitwa bash. Jina <unk>bash<unk> ni kifupi cha <unk>Bourne Again SHell<unk>, kumbukumbu ya ukweli bash ni mbadala ulioboreshwa wa sh. Wakati wa kutumia graphical user interface, tunahitaji programu nyingine ya kuingiliana na shell, aitwaye Terminal Emulators. Kama sisi kuangalia kwa njia ya menyu yetu desktop, sisi pengine kupata moja. KDE hutumia konsole na GNOME hutumia gnome-terminal, ingawa inawezekana inaitwa tu "terminal" kwenye orodha yetu. Kuna wengi wengine terminal emulators zinapatikana kwa Linux, ambayo hutoa upatikanaji wa shell. Baada ya kuingia katika shell kutumia jina la mtumiaji na nenosiri juu ya mwito utakuja, inamaanisha shell ni tayari kuchukua pembejeo. Kama tabia ya mwisho ya mwito ni <unk>#<unk> badala ya ishara ya dola, inaonyesha mtumiaji amejiunga kupitia mzizi au kuwa na haki za superuser. Baadhi ya amri rahisi amri inayohusiana ni cal ambayo, kwa default, inaonyesha kalenda ya mwezi wa sasa. Kuonyesha kiasi cha kumbukumbu ya bure, kuingia amri ya bure.