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sphinx_doc_src/cmds/contains.rst

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+\section contains contains - test if a word is present in a list
+
+\subsection contains-synopsis Synopsis
+\fish{synopsis}
+contains [OPTIONS] KEY [VALUES...]
+\endfish
+
+\subsection contains-description Description
+
+`contains` tests whether the set `VALUES` contains the string `KEY`. If so, `contains` exits with status 0; if not, it exits with status 1.
+
+The following options are available:
+
+- `-i` or `--index` print the word index
+
+Note that, like GNU tools and most of fish's builtins, `contains` interprets all arguments starting with a `-` as options to contains, until it reaches an argument that is `--` (two dashes). See the examples below.
+
+\subsection contains-example Example
+
+If $animals is a list of animals, the following will test if it contains a cat:
+
+\fish
+if contains cat $animals
+   echo Your animal list is evil!
+end
+\endfish
+
+This code will add some directories to $PATH if they aren't yet included:
+
+\fish
+for i in ~/bin /usr/local/bin
+    if not contains $i $PATH
+        set PATH $PATH $i
+    end
+end
+\endfish
+
+While this will check if `hasargs` was run with the `-q` option:
+
+\fish
+function hasargs
+    if contains -- -q $argv
+        echo '$argv contains a -q option'
+    end
+end
+\endfish
+
+The `--` here stops `contains` from treating `-q` to an option to itself. Instead it treats it as a normal string to check.