{"items":[{"id":"1aa274af-f80c-4993-9cce-82005808e8db","title":"UNIX Advanced System Programming-shell","slug":"unix-advanced-system-programming-shell","contentHtml":"

its the Architecture of UNIX operating systems.

( applications ( library routines ( systemcalls (( kernel )) systemcalls ) shell ) applications )

In a broad sense, an operating system is the kernel and all the other software that makes a
computer useful and gives the computer its personality

When we login into a UNIX operation system we enter our login name and our password. The system looks uo our login name and our passwaord, usually the file :

etc/paswd\n

In the password file our entry is like that: Its have 7 entries like (Example) :

sar:x:205:105:Stephen Rago:/home/sar:/bin/ksh\n

When we entering the operation system after the login then we see a shell. A shell is a command-line interpreter that reads user input and commands and executes them.

There Common shells used on UNIX systems:

Bourne-shell, C shell, Korn Shell, Tenex C shell, Bourne-again shell

Also Khazar Operation system have own system shell writed by Voctl
(check Khazar if u reading this)(https://github.com/Voctl/Khazar)

Linux uses Bourne-again shell for its default shell. In fact, /bin/sh is a link to /bin/bash.
The default shell in FreeBSD and MacOS X is the TENEX C shell, but they use the Bourne shell for their administrative shell scripts beacuse C shells programming language is notoriusly difficult to use.

","contentJson":{"type":"doc","content":[{"type":"paragraph","content":[{"text":"its the Architecture of UNIX operating systems.","type":"text"}]},{"type":"image","attrs":{"alt":null,"src":"/api/uploads/510ec12a-88e1-409d-9e32-5621466da616.webp","title":null,"width":"71%","height":null}},{"type":"paragraph","content":[{"text":"( applications ( library routines ( systemcalls (( kernel )) systemcalls ) shell ) applications )","type":"text"}]},{"type":"paragraph","content":[{"type":"hardBreak"},{"text":"In a broad sense, an operating system is the kernel and all the other software that makes a","type":"text"},{"type":"hardBreak"},{"text":"computer useful and gives the computer its personality","type":"text"}]},{"type":"paragraph","content":[{"text":"When we login into a UNIX operation system we enter our login name and our password. The system looks uo our login name and our passwaord, usually the file :","type":"text"}]},{"type":"codeBlock","attrs":{"language":null},"content":[{"text":"etc/paswd\n","type":"text"}]},{"type":"paragraph","content":[{"text":"In the password file our entry is like that: Its have 7 entries like (Example) :","type":"text"}]},{"type":"codeBlock","attrs":{"language":null},"content":[{"text":"sar:x:205:105:Stephen Rago:/home/sar:/bin/ksh\n","type":"text"}]},{"type":"paragraph","content":[{"text":"When we entering the operation system after the login then we see a shell. A shell is a command-line interpreter that reads user input and commands and executes them.","type":"text"}]},{"type":"paragraph","content":[{"text":"There Common shells used on UNIX systems:","type":"text"}]},{"type":"image","attrs":{"alt":null,"src":"/api/uploads/f6e7ae0a-d02c-44d5-83ec-6d993331f7de.webp","title":null,"width":null,"height":null}},{"type":"paragraph"},{"type":"paragraph","content":[{"text":"Bourne-shell, C shell, Korn Shell, Tenex C shell, Bourne-again shell","type":"text"}]},{"type":"paragraph","content":[{"text":"Also Khazar Operation system have own system shell writed by Voctl","type":"text"},{"type":"hardBreak"},{"text":"(check Khazar if u reading this)(","type":"text"},{"text":"https://github.com/Voctl/Khazar","type":"text","marks":[{"type":"link","attrs":{"rel":"noopener noreferrer nofollow","href":"https://github.com/Voctl/Khazar","class":null,"title":null,"target":"_blank"}}]},{"text":")","type":"text"}]},{"type":"paragraph","content":[{"text":"Linux uses Bourne-again shell for its default shell. In fact, /bin/sh is a link to /bin/bash.","type":"text"},{"type":"hardBreak"},{"text":"The default shell in FreeBSD and MacOS X is the TENEX C shell, but they use the Bourne shell for their administrative shell scripts beacuse C shells programming language is notoriusly difficult to use.","type":"text"}]}]},"remote":false,"status":"published","publishAt":null,"language":null,"summary":null,"coverUrl":null,"bannerUrl":"/api/uploads/510ec12a-88e1-409d-9e32-5621466da616.webp","coverCredit":null,"createdAt":"2026-07-28T12:41:44.102Z","updatedAt":"2026-07-28T12:41:44.102Z","author":{"id":"edd8b60c-384b-477f-aac0-7466b542fcc3","username":"denis","displayName":"Voctl","avatarUrl":"/api/uploads/b5c8fbe5-ad5a-4f26-a29a-d8c91901e014.webp","remote":false},"tags":[{"slug":"c","name":"c"},{"slug":"larp","name":"larp"},{"slug":"os","name":"os"},{"slug":"systemprogramming","name":"systemprogramming"},{"slug":"unix","name":"unix"}],"likeCount":2,"liked":false,"commentCount":2,"recommendCount":0,"recommended":false,"recommendedBy":null}],"nextCursor":null}