TEST(1) fish-shell TEST(1) # [NAME](#NAME) test - perform tests on files and text # [SYNOPSIS](#SYNOPSIS) ``` test [EXPRESSION] [ [EXPRESSION] ] ``` # [DESCRIPTION](#DESCRIPTION) NOTE: This page documents the fish builtin **test**. To see the documentation on any non-fish versions, use **command man test**. **test** checks the given conditions and sets the exit status to 0 if they are true, 1 if they are false. The first form (**test**) is preferred. For compatibility with other shells, the second form is available: a matching pair of square brackets (**\[ \[EXPRESSION] ]**). When using a variable or command substitution as an argument with **test** you should almost always enclose it in double-quotes, as variables expanding to zero or more than one argument will most likely interact badly with **test**. **Warning:** For historical reasons, **test** supports the one-argument form (**test foo**), and this will also be triggered by e.g. **test -n $foo** if $foo is unset. We recommend you don't use the one-argument form and quote all variables or command substitutions used with **test**. This confusing misfeature will be removed in future. **test -n** without any additional argument will be false, **test -z** will be true and any other invocation with exactly one or zero arguments, including **test -d** and **test "foo"** will be an error. The same goes for **\[**, e.g. **\[ "foo" ]** and **\[ -d ]** will be errors. This can be turned on already via the **test-require-arg** feature flag <#featureflags>, and will eventually become the default and then only option. # [OPERATORS FOR FILES AND DIRECTORIES](#OPERATORS_FOR_FILES_AND_DIRECTORIES) [**-b** *FILE*](#b) Returns true if *FILE* is a block device. [**-c** *FILE*](#c) Returns true if *FILE* is a character device. [**-d** *FILE*](#d) Returns true if *FILE* is a directory. [**-e** *FILE*](#e) Returns true if *FILE* exists. [**-f** *FILE*](#f) Returns true if *FILE* is a regular file. [**-g** *FILE*](#g) Returns true if *FILE* has the set-group-ID bit set. [**-G** *FILE*](#G) Returns true if *FILE* exists and has the same group ID as the current user. [**-k** *FILE*](#k) Returns true if *FILE* has the sticky bit set. If the OS does not support the concept it returns false. See <https://en.wikipedia.org/wiki/Sticky\_bit>. [**-L** *FILE*](#L) Returns true if *FILE* is a symbolic link. [**-O** *FILE*](#O) Returns true if *FILE* exists and is owned by the current user. [**-p** *FILE*](#p) Returns true if *FILE* is a named pipe. [**-r** *FILE*](#r) Returns true if *FILE* is marked as readable. [**-s** *FILE*](#s) Returns true if the size of *FILE* is greater than zero. [**-S** *FILE*](#S) Returns true if *FILE* is a socket. [**-t** *FD*](#t) Returns true if the file descriptor *FD* is a terminal (TTY). [**-u** *FILE*](#u) Returns true if *FILE* has the set-user-ID bit set. [**-w** *FILE*](#w) Returns true if *FILE* is marked as writable; note that this does not check if the filesystem is read-only. [**-x** *FILE*](#x) Returns true if *FILE* is marked as executable. # [OPERATORS TO COMPARE FILES AND DIRECTORIES](#OPERATORS_TO_COMPARE_FILES_AND_DIRECTORIES) [*FILE1* **-nt** *FILE2*](#FILE1) Returns true if *FILE1* is newer than *FILE2*, or *FILE1* exists and *FILE2* does not. [*FILE1* **-ot** *FILE2*](#FILE1~2) Returns true if *FILE1* is older than *FILE2*, or *FILE2* exists and *FILE1* does not. [*FILE1* **-ef** *FILE1*](#FILE1~3) Returns true if *FILE1* and *FILE2* refer to the same file. # [OPERATORS FOR TEXT STRINGS](#OPERATORS_FOR_TEXT_STRINGS) [*STRING1* **=** *STRING2*](#STRING1) Returns true if the strings *STRING1* and *STRING2* are identical. [*STRING1* **!=** *STRING2*](#STRING1~2) Returns true if the strings *STRING1* and *STRING2* are not identical. [**-n** *STRING*](#n) Returns true if the length of *STRING* is non-zero. [**-z** *STRING*](#z) Returns true if the length of *STRING* is zero. # [OPERATORS TO COMPARE AND EXAMINE NUMBERS](#OPERATORS_TO_COMPARE_AND_EXAMINE_NUMBERS) [*NUM1* **-eq** *NUM2*](#NUM1) Returns true if *NUM1* and *NUM2* are numerically equal. [*NUM1* **-ne** *NUM2*](#NUM1~2) Returns true if *NUM1* and *NUM2* are not numerically equal. [*NUM1* **-gt** *NUM2*](#NUM1~3) Returns true if *NUM1* is greater than *NUM2*. [*NUM1* **-ge** *NUM2*](#NUM1~4) Returns true if *NUM1* is greater than or equal to *NUM2*. [*NUM1* **-lt** *NUM2*](#NUM1~5) Returns true if *NUM1* is less than *NUM2*. [*NUM1* **-le** *NUM2*](#NUM1~6) Returns true if *NUM1* is less than or equal to *NUM2*. Both integers and floating point numbers are supported. # [OPERATORS TO COMBINE EXPRESSIONS](#OPERATORS_TO_COMBINE_EXPRESSIONS) [*COND1* **-a** *COND2*](#COND1) Returns true if both *COND1* and *COND2* are true. [*COND1* **-o** *COND2*](#COND1~2) Returns true if either *COND1* or *COND2* are true. Expressions can be inverted using the **!** operator: **!** *EXPRESSION* Returns true if *EXPRESSION* is false, and false if *EXPRESSION* is true. Expressions can be grouped using parentheses. **(** *EXPRESSION* **)** Returns the value of *EXPRESSION*. Note that parentheses will usually require escaping with **\\** (so they appear as **\\(** and **\\)**) to avoid being interpreted as a command substitution. # [EXAMPLES](#EXAMPLES) If the **/tmp** directory exists, copy the **/etc/motd** file to it: ``` if test -d /tmp cp /etc/motd /tmp/motd end ``` If the variable **MANPATH** is defined and not empty, print the contents. (If **MANPATH** is not defined, then it will expand to zero arguments, unless quoted.) ``` if test -n "$MANPATH" echo $MANPATH end ``` Be careful with unquoted variables: ``` if test -n $MANPATH # This will also be reached if $MANPATH is unset, # because in that case we have `test -n`, so it checks if "-n" is non-empty, and it is. echo $MANPATH end ``` This will change in a future release of fish, or already with the **test-require-arg** feature flag <#featureflags> - if $MANPATH is unset, **if test -n $MANPATH** will be false. Parentheses and the **-o** and **-a** operators can be combined to produce more complicated expressions. In this example, success is printed if there is a **/foo** or **/bar** file as well as a **/baz** or **/bat** file. ``` if test \( -f /foo -o -f /bar \) -a \( -f /baz -o -f /bat \) echo Success. end ``` Numerical comparisons will fail if one of the operands is not a number: ``` if test 42 -eq "The answer to life, the universe and everything" echo So long and thanks for all the fish # will not be executed end ``` A common comparison is with **status** <#envvar-status>: ``` if test $status -eq 0 echo "Previous command succeeded" end ``` The previous test can likewise be inverted: ``` if test ! $status -eq 0 echo "Previous command failed" end ``` which is logically equivalent to the following: ``` if test $status -ne 0 echo "Previous command failed" end ``` # [STANDARDS](#STANDARDS) Unlike many things in fish, **test** implements a subset of the IEEE Std 1003.1-2008 (POSIX.1) standard <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html>. The following exceptions apply: - The **<** and **>** operators for comparing strings are not implemented. - With **test-require-arg**, the zero- and one-argument modes will behave differently. In cases such as this, one can use **command** **test** to explicitly use the system's standalone **test** rather than this **builtin** **test**. # [SEE ALSO](#SEE_ALSO) Other commands that may be useful as a condition, and are often easier to use: - string - manipulate strings <>, which can do string operations including wildcard and regular expression matching - path - manipulate and check paths <>, which can do file checks and operations, including filters on multiple paths at once # [Copyright](#Copyright) fish-shell developers October 10, 2026 4.9 --- Document: test(1) from fish 4.9.3-r1 (Chainguard OS) Source: https://github.com/fish-shell/fish-shell