Description: A bashism is a feature or syntax that is specific to the Bash shell, a widely used command interpreter in Unix-like operating systems. Bash, which stands for ‘Bourne Again SHell’, was created by Brian Fox in 1987 as an enhancement of the original Bourne shell. Bashisms can include commands, functions, variables, and control structures that are not compatible with other shells, such as sh or csh. This specificity allows users to take full advantage of Bash’s capabilities, facilitating task automation and the creation of more complex scripts. Bashisms are particularly valued for their flexibility and power, enabling developers and system administrators to write scripts that can perform tasks ranging from file manipulation to process management and interaction with other programs. Understanding bashisms is essential for anyone working with Bash, as it allows for greater efficiency and effectiveness in command line and script programming.
History: The term ‘bashism’ originated with the creation of the Bash shell in 1987 by Brian Fox. Bash was designed to be compatible with the Bourne shell but also introduced new features and enhancements that were not present in its predecessor. As Bash became the default shell in many Linux distributions, bashisms began to be widely used by developers and system administrators. Over time, the Bash user community has grown, and bashisms have become integrated into the Linux scripting culture, becoming an essential part of daily work in command-line environments.
Uses: Bashisms are primarily used in creating shell scripts to automate tasks in Unix-like systems. They allow users to write commands and functions that leverage Bash’s specific features, such as variable expansion, string manipulation, and flow control. This is particularly useful in system administration, where scripts can be created to perform backups, manage users, or implement scheduled tasks. Additionally, bashisms are used in development environments to facilitate the building and deployment of applications.
Examples: An example of a bashism is the use of the ‘[[ … ]]’ syntax for conditional evaluations, which is more powerful than the ‘[ … ]’ syntax used in other shells. Another example is the use of array expansion, which allows multiple values to be stored in a single variable, something that is not possible in older shells. Bashisms can also be found in the use of anonymous functions and advanced string manipulation, such as pattern substitution.
