Is Bash Scripting the Same as Shell Scripting?

No, the bash scripting is not similar to the shell script, because both have different syntax and features. The bash script is executed specifically in bash, while the shell script can be executed in any shell, such as bash, zsh, ksh, etc. 

Moreover, the bash script is the file that contains a set of commands with variables, loops, and, if else, conditions based on the requirement. On the other side, the shell is the command line interpreter that executes commands in an interface. 

This blog will clear the doubt of the user about the query “Is Bash Scripting the Same as Shell Scripting?” in Linux.

• Bash Script
  • Example
  • Key Features
• Shell Script
  • Example
  • Key Features
• Difference Between Shell Script and Bash Script

The Bash Script in Linux

The bash script is just like the programing language starts with the “#!/bin/bash” shebang. It is the extended shell version used to manipulate repetitive tasks in Linux. Let’s implement an example of the bash script:

Example:

In the following script, a “string” variable is initialized with “itslinuxfoss” and printing it on the screen using the echo statement:

#!/bin/bash

#initializing variable
string="itslinuxfoss"

#printing the variable
echo $string

Save the above bash script file.

Run the bash script file in the terminal to see the output:

$ bash bash-script.sh

The “string” variable is printed with the message “itslinuxfoss” stored in it.

Key Features of Bash Script

The following features can be obtained from the bash script:

• “Multi-characters Option”: Apart from the single characters options (i.e., a,-b,-c), bash script supports multi-characters options like “–debugger,” “–help,” “–login,” etc.
• “Start-up Files”: bash script helps create the startup files to create an environment.
• “Conditional Statements”: In the bash script, the user can create conditional statements to check and perform tasks accordingly.
• “Arrays and Loops”: The user can also create arrays for creating multiple printed variables using the loops (for and while).
• “Directory Stack”: Bash script can also facilitate the user to check the directory stack list containing recently visited directories’ information.

The Shell Script in Linux

The shell script starts with the “#!/bin/sh” shebang representing the default system shell. It was linked with the bash file in the old version of Debian and Ubuntu. But it has been linked with the “dash” shell in the previous few years. The dash shell is based on the POSIX-Standard that doesn’t implement the bash-specific tasks. Let’s clear the discussion by checking the symbolic link of the “/bin/sh” directory: 

$ ls -l /bin/sh
$ ls -l /bin/dash

The “/bin/sh” directory is symbolically linked to the “dash” shell as shown.

Example: 

The following is the script that represents the shell script in which a variable “string” is initialized with “itslinuxfoss” and displaying it on the screen:

#!/bin/sh

#initializing variable
string="itslinuxfoss"

#printing the variable
echo $string

Save the above shell script file.

Run the shells script file in the terminal:

$ bash shell-script.sh

The “string” variable is printed with the message “itslinuxfoss” stored in it.

Key Features of Shell Script

The shell script provide the following features:

• Pipping: In the shell script, the user can use the link more than one command through pipe (|) to generate combined output.
• Background Processing: The user can send the tasks in lengthy tasks in the background using the “bg” command. 
• Variable Substitutions: The shell script supports variable substitutions such as storing the data in a built-in or user-defined variable.
• Pattern Matching: Shell script also provides the pattern matching facility to find the specific file using the pattern.

Difference Between Shell Script and Bash Script

The difference between shell and bash script is described in the following table:

Conclusion

Bash and shell scripting seem similar, but bash is only executable in bash shell while shell script can be executed in any shell. The shell can be bash, zsh, ksh, etc. The bash script starts with the shebang “#!/bin/bash” while the shell script with the “#!/bin/sh”. Moreover, the features for both bash and shell scripting are different such as multi-character options, variable substitutions, etc. 

This query, “Is Bash Scripting the Same as Shell Scripting?” has been answered with a brief demonstration of both bash and shell script.

Henry