Programmers interact with the Unix shell via a terminal emulator. However, nowadays, direct operations through serial hardware have become quite common. A shell doesn’t show the operating system details and gets the system kernel details well managed. Unix shells include features, such as filename wildcarding, command substitution, piping, here documents, control structures, and variables for iteration and condition-testing.
Various Unix shells have been created over time, but BASH and CSH were the most influential and widely distributed. Both of these have been used as models and the coding base for many derivatives and similar works. In spite of the fact that BASH and CSH are both Unix shells, there are not exactly the same.
Fundamental Differences
Bourne Shell, sh, written by Stephen Bourne. Bourne Shell introduced the basic Unix shell features, such as command substitution, here documents, more generic variables, and built-in control structures. The path of ‘sh’ in Unix is written as /bin/sh. Being inspired by sh, BASH was created by Brian Fox for the popular GNU Project.
Fox released BASH as a beta in 1989 after writing its code for more than a year. Brian Fox remained the maintainer of this Unix shell until around 1994, when Chet Ramey became the primary maintainer of BASH. From this time onwards, BASH achieved the highest popularity and became the default shell on various distributions. Its full-path is /bin/bash.
Later BASH was ported to Windows and distributed with MinGW and Cygwin, to DOS, to OpenVMS, to Novell NetWare, to ArcaOS, and finally to Android through different terminal emulators.
Coming to CSH, it was written in C language by Bill Joy. It was first released in 1978. The expression grammar and the control structures were included. CSH was distributed with BSD Unix. BSD or Berkeley Software Distribution was an operating system built upon Research Unix. The term BSD commonly represents its successors, including OpenBSD, FreeBSD, DragonFly BSD, and NetBSD.
CSH introduced a whole set of features for interactive work, such as aliases, directory stacks, history and editing mechanisms, cdpath, job control, tilde notation, and path hashing. Although these features were copied to various other shells, the main language structure has never been copied. The only similar work is the Hamilton C shell. The command full-path is /bin/csh.
On some systems, CSH may be a hard link (directory entry) to TENEX C Shell, also known as TCSH. TCSH is an enhanced version of the original Joy’s CSH.
Different Characteristics
This section of the article takes you through CSH vs. BASH in terms of different parameters.
Bourne Compatibility: BASH is compatible with the Bourne shell. CSH isn’t compatible with the Bourne shell.
Speed: BASH is faster and C shell.
Features: BASH and C shell work both on Linux and Unix. CSH has its unique features, and BASH incorporated other shell features like CSH and KSH (Korn Shell) along with its own unique features. This made BASH widely used shell having more features than CSH.
Configuration Files: Configuration files that work on CSH but not on BASH include /etc/.login, /etc/csh.cshrc, /etc/csh.login, ~/.cshrc, ~/.login, ~/.logout. Files that work on BASH but not CSH are $ENV (typically ~/.kshrc), /etc/profile, ~/.profile, ~/.bash_profile, ~/.bash_login, ~/.bash_logout, ~/.bashrc.
Popularity: BASH is more popular than C shell.
How They Work
Below are some examples and work instances in BASH and CSH. This makes it easier to differentiate the two Nix shells.
Few Instances in CSH
- ^H signifies a backspace, use ^? to perform delete, ^U represents the kill character
- A command is followed by an argument, such as the flag argument. It’s initiated by the ‘-’ symbol. If the command is given, it defines file size too.
- Special characters are used. They have a syntactic and semantic illustration of shells.
- Filenames are separated by ‘/’. Each section specifies its place within the directory.
- ‘*’ can be used in CSH.
- Command termination can be done.
- Each shell has its own set of variables.
- Inputs can be transformed via Aliases.
- To form a directory, type “mkdir” in the terminal.
- Separate directories can be created to make your search faster and easier. You only need to remember the folder while writing the command.
Few Instances in BASH
- Anything you type after echo will be displayed as an output. For example, if you type “sky” after echo, the sky will be the output.
- There are some default commands in BASH. For example, cal is used for the calendar; date gives the current date, etc.
- In BASH, the “pwd” command signifies the print working directory. Command this in the terminal, and the current directory shows up as the output.
- The “ls” command shows information about the latest emails, files, folders that you’re working with. This command pulls out the data stored in the home directory.
- ‘$’ signifies you have signed in as the standard user
- Use “cd” to navigate to a folder.
Summary
In this article, you have learned about CSH vs. BASH. To sum it up, the main differences between these two mainstream Unix shells would be as follows.
- CSH commands begin with a hash (#), but BASH commands begin with a semicolon (;)
- CSH is interactive. BASH is considered to be a non-interactive terminal.
- Bill Joy developed CSH. BASH was re-created by Brian Fox
- CSH initially came in the 1970s. BASH was restructured in 1989
- BASH is more used by working professionals than CSH.
Hope this article serves your purpose of understanding the differences between BASH and the C shell, and you can find all the information you want.
