case Statement

case lets you compare one value against several possible patterns and run different code for whichever one matches, without writing a long chain of if/elif.

In this page:

Basic case Syntax
Matching Multiple Patterns with |
Glob Patterns in case
Fallthrough with ;;&

Basic case Syntax

case compares a single value against a list of patterns in order and runs the commands under the first pattern that matches, ending each branch with ;;. The whole statement is closed with esac.

Example: Basic case Syntax

bash

#!/bin/bash
fruit="banana"
case $fruit in
    apple)
        echo "It's an apple"
        ;;
    banana)
        echo "It's a banana"
        ;;
    *)
        echo "Unknown fruit"
        ;;
esac

Matching Multiple Patterns with |

A single branch can match several alternative patterns by separating them with | (pipe), which acts as an or between patterns. This avoids duplicating the same commands under multiple separate branches.

Example: Matching Multiple Patterns with |

bash

#!/bin/bash
answer="y"
case $answer in
    y|Y|yes|YES)
        echo "Confirmed"
        ;;
    n|N|no|NO)
        echo "Declined"
        ;;
    *)
        echo "Unrecognized response"
        ;;
esac

Glob Patterns in case

case patterns use the same glob wildcards as filename matching: * matches any string, ? matches a single character, and [abc] matches any one of the listed characters. This makes case convenient for classifying things like file extensions.

Example: Glob Patterns in case

bash

#!/bin/bash
filename="archive.tar.gz"
case $filename in
    *.txt)
        echo "Text file"
        ;;
    *.tar.gz|*.tgz)
        echo "Compressed tarball"
        ;;
    *)
        echo "Unknown type"
        ;;
esac

Fallthrough with ;;&

Normally case stops after running the first matching branch, but the Bash-specific ;;& terminator lets execution keep testing later patterns even after a match, rather than exiting the statement. This is useful when more than one branch might legitimately apply to the same value.

Example: Fallthrough with ;;&

bash

#!/bin/bash
value="15"
case $value in
    [0-9]*)
        echo "Starts with a digit"
        ;;&
    1*)
        echo "Starts with a 1"
        ;;
esac

Common Mistakes

Forgetting the double semicolon ;; at the end of each pattern's commands; without it Bash keeps looking for the next ;; and merges branches together unexpectedly.
Thinking case patterns are regular expressions; they are actually glob-style wildcard patterns (*, ?, [...]), not full regex syntax.
Forgetting the closing esac (case spelled backwards) to end the statement.

Chapter Summary

Syntax: case value in pattern1) commands ;; pattern2) commands ;; esac.
Patterns support glob wildcards (*, ?, [abc]) and can be combined with | to match multiple alternatives in one branch, e.g. y|Y).
*) as the final pattern acts as a catch-all default branch, matching anything not caught earlier.
;;& (Bash extension) lets execution continue testing subsequent patterns even after a match, instead of stopping at the first match.

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case Statement

Basic case Syntax

Matching Multiple Patterns with |

Glob Patterns in case

Fallthrough with ;;&

Chapter Quiz — Complete all 14 topics to unlock

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