What is Unix Shell?
Unix shell is a program which works as intermediary between user input command and operating system. Shell interprets the user given command and direct the operating system what to do?
There are various type of shells. For a normal user they offer same kind of functionality but they have different syntax and capabilities.
Most shells are either of type Bourne Shell (Launched with Unix Version 7) or C shell (Launched with BSD). Most Unix machines have Bourne shell(sh) and C Shell (csh) installed.
Bourne Shell (Default prompt '$') can be further categorized as follows.
1. Bourne Shell(sh)
2. Korn Shell(ksh)
3. Bourne Again Shell(bash)
4. POSIX(sh)
The Different type of C shell as follows.
1. C Shell (csh)
2. TENEX/TOPS C Shell(tcsh)
If you want to know which shells are available for you in your Unix machine then you cat /etc/shells file. These shells are available for default login shell for any user.
$ cat /etc/shells
For Unix, Shell is like another program. Hence any program that is part of /etc/shells can be designated as a login shell of a user.
It was basic about shell. We shall delve more in to it in coming posts.
Till then keep exploring and Smile :)
Bourne Shell (Default prompt '$') can be further categorized as follows.
1. Bourne Shell(sh)
2. Korn Shell(ksh)
3. Bourne Again Shell(bash)
4. POSIX(sh)
The Different type of C shell as follows.
1. C Shell (csh)
2. TENEX/TOPS C Shell(tcsh)
If you want to know which shells are available for you in your Unix machine then you cat /etc/shells file. These shells are available for default login shell for any user.
$ cat /etc/shells
 | |||
| Fig 2.1 |
It was basic about shell. We shall delve more in to it in coming posts.
Till then keep exploring and Smile :)
Didn't know about the /etc/shells file.. Thanks for sharing!! expecting more useful posts from you.
ReplyDelete