bash get filename without extension with code examples

Bash is a command-line interface used in Unix-based operating systems for scripting and automation purposes. In Bash, it is common to work with filenames and their extensions. Sometimes it might be necessary to extract the filename without its extension. In this article, we will explore various techniques and code examples for getting filename without extension in Bash.

Techniques for getting filename without extension:

1. Using Parameter Expansion:
   Parameter expansion is a feature in Bash that allows manipulating variables and their values.

${var%pattern}
This expression returns the value of the variable ‘var’ after cutting down the shortest substring that matches the ‘pattern.’

${var%%pattern}
This expression returns the value of the variable ‘var’ after cutting down the longest substring that matches the ‘pattern.’

The pattern used in these expressions is generally of the form ‘.’, where ‘’ represents any number of characters, and ‘’ represents the file extension. We can use this pattern to extract the filename without its extension.

Example:
The following code snippet retrieves the filename without extension from an absolute path and stores in the variable ‘filename.’

path="/home/user/dir/file.txt"
filename="${path##/}"
filename="${filename%.}"

2. Using ‘basename’ command:
   The ‘basename’ command is used to extract the filename from a fully qualified or absolute path. We can use the ‘basename’ command along with the extension to get the filename without its extension.

Example:
The following code snippet retrieves the filename without extension using the ‘basename’ command and stores it in the variable ‘filename.’

path="/home/user/dir/file.txt"
filename="$(basename $path .txt)"

3. Using ‘sed’ command:
   The ‘sed’ command is used for text manipulation in Bash. We can use the ‘sed’ command along with a regex pattern to extract the filename without extension.

Example:
The following code snippet retrieves the filename without extension using the ‘sed’ command and stores it in the variable ‘filename.’

path="/home/user/dir/file.txt"
filename="$(echo $path | sed 's/.[^.]*$//')"

Code examples:

1. Using Parameter Expansion:

path="/home/user/dir/file.txt"
filename="${path##/}"
filename="${filename%.}"
echo $filename

Output:
file

2. Using ‘basename’ command:

path="/home/user/dir/file.txt"
filename="$(basename $path .txt)"
echo $filename

Output:
file

3. Using ‘sed’ command:

path="/home/user/dir/file.txt"
filename="$(echo $path | sed 's/.[^.]*$//')"
echo $filename

Output:
file

Conclusion:
In Bash, we have various techniques for extracting the filename without its extension. We can use parameter expansion, ‘basename’ command, and ‘sed’ command for this purpose. We have demonstrated these techniques with the help of code examples to make it easier for understanding and learning. These techniques will be helpful in automating tasks involving filenames.

Sure! Here's some more information about the previous topics covered in the Bash script article:

1. Parameter Expansion:

Parameter expansion is a powerful feature in Bash that allows us to manipulate variables and their values in various ways. It is a way to perform substitution and concatenation operations on the variables.

There are many different forms of parameter expansion in Bash, but some of the most commonly used ones include:

• ${var} – expands to the value of the variable.
• ${var:-word} – expands to the value of the variable if it is set, or to the default value "word" if it is not set.
• ${var:=word} – sets the variable to the default value "word" if it is not set, and then expands to the value of the variable.
• ${var%pattern} – removes the shortest substring that matches "pattern" from the end of the variable.
• ${var%%pattern} – removes the longest substring that matches "pattern" from the end of the variable.
• ${var#pattern} – removes the shortest substring that matches "pattern" from the beginning of the variable.
• ${var##pattern} – removes the longest substring that matches "pattern" from the beginning of the variable.

2. basename:

basename is a command-line utility in Unix and Unix-like operating systems that is used to extract the filename from a fully qualified or absolute path. It takes a path as an argument and returns the filename at the end of that path.

The basic syntax of the basename command is as follows:

$ basename path [suffix]

The "path" argument is the file path that we want to extract the filename from, and the optional "suffix" argument is the extension that we want to remove from the file name.

If the "suffix" argument is provided, the basename command will remove it from the end of the filename. If "suffix" is not provided, or if the filename doesn't have the suffix, basename will return the filename as it is.

3. sed:

sed, short for Stream Editor, is another powerful tool for text manipulation in Unix and Unix-like systems. It is a non-interactive editor that reads data from a file or standard input, processes it line by line, and then prints the result to standard output.

In its most basic form, the sed command takes the following syntax:

$ sed 'command' filename

Here, "command" refers to the instruction that sed should apply to the lines of the file, and "filename" is the file that we want to process.

The "command" can be a complex set of regular expressions, substitution patterns, and other sed constructs that allow us to perform a wide variety of text manipulation tasks.

Overall, Bash is a powerful tool for scripting and automation, and understanding its various features and utilities can help you automate tedious manual tasks, save time and effort, and make your workflow more efficient.

Popular questions

1. What is Bash?
   Bash is a command-line interface used in Unix-based operating systems for scripting and automation purposes.

2. What is Parameter Expansion in Bash?
   Parameter expansion is a feature in Bash that allows manipulating variables and their values.

3. What is the basename command used for?
   The ‘basename’ command is used to extract the filename from a fully qualified or absolute path.

4. What is the ‘sed’ command used for?
   The ‘sed’ command is used for text manipulation in Bash. It is a way to perform substitution and concatenation operations on the variables.

5. How can we extract the filename without extension using Parameter Expansion in Bash?
   We can use the ${var%pattern} or ${var%%pattern} expression to extract the filename without its extension. The pattern used in these expressions is generally of the form ‘.’, where ‘’ represents any number of characters, and ‘’ represents the file extension.

Tag

FilenameParsing