Published on November 25th 2024 by Felix Halim

If you’re working with Bash command-line interface, you’re likely to come across a variety of metacharacters that can make your life easier. In this article, we’ll explore some of the most useful metacharacters in Bash and provide examples for each of them.

Exploring Metacharacters in Bash

Let’s start by reviewing some of the metacharacters we’ve already covered in previous article:

These metacharacters are commonly used in Bash and can help you perform a variety of tasks, such as redirecting input and output, piping commands, and separating commands.

But there are many other metacharacters in Bash that can be equally useful. Let’s take a closer look at some of them.

Pattern Matching

Pattern matching is a powerful feature in Bash that allows you to match files and directories based on specific patterns. Here are some of the most commonly used pattern matching metacharacters:

Here are some examples of how you can use these metacharacters:

# Match all files with a .txt extension
felixhalim@learning-bytes:[~]$ ls *.txt
# Create files with names file0, file1, file2, ..., file10
felixhalim@learning-bytes:[~]$ touch file{0..10}
# Match all files with a name starting with "file" and ending with a number
felixhalim@learning-bytes:[~]$ ls file[0-9]*
file0  file1  file10  file2  file3  file4  file5  file6  file7  file8  file9
# Create files with names fileA, fileB, fileC, ..., fileZ
felixhalim@learning-bytes:[~]$ touch file{A..Z}
# Match all files with a name starting with "file" and ending with a letter
felixhalim@learning-bytes:[~]$ ls file[[:alpha:]]*
fileA  fileC  fileE  fileG  fileI  fileK  fileM  fileO  fileQ  fileS  fileU  fileW  fileY
fileB  fileD  fileF  fileH  fileJ  fileL  fileN  fileP  fileR  fileT  fileV  fileX  fileZ

# Match all files with a name starting with "file" and ending with either a number or a letter
felixhalim@learning-bytes:[~]$ ls file[[:alnum:]]*
file0   file2  file5  file8  fileB  fileE  fileH  fileK  fileN  fileQ  fileT  fileW  fileZ
file1   file3  file6  file9  fileC  fileF  fileI  fileL  fileO  fileR  fileU  fileX
file10  file4  file7  fileA  fileD  fileG  fileJ  fileM  fileP  fileS  fileV  fileY

# Match all files with a name starting with "file" and ending with two characters
felixhalim@learning-bytes:[~]$ ls file??
file10

# Remove all files with a name starting with "file"
felixhalim@learning-bytes:[~]$ rm file*
felixhalim@learning-bytes:[~]$ echo gic-{tg,dsg,iig}
gic-tg gic-dsg gic-iig

felixhalim@learning-bytes:[~]$ echo {a..f}-profile
a-profile b-profile c-profile d-profile e-profile f-profile

felixhalim@learning-bytes:[~]$ echo rank-{1..5}
rank-1 rank-2 rank-3 rank-4 rank-5

If you are constructing strings, use a brace expansion. If you are matching filenames, use a filename pattern.

Other Metacharacters

Escape Characters

Escape characters are used to escape special characters in Bash. Here’s an example:

# Match all files with a name containing a space
ls file\\ with\\ space.txt