Add installer

README.md

@@ -119,3 +119,17 @@ in the test file.
 * `$BATS_TMPDIR` is the location to a directory that may be used to
 store temporary files.
 
+### Installing Bats
+
+Check out a copy of the Bats repository. Then, either add the Bats
+`bin` directory to your `$PATH`, or run the provided `install.sh`
+command with the location to the prefix in which you want to install
+Bats. For example, to install Bats into `/usr/local`,
+
+    $ git clone https://github.com/sstephenson/bats.git
+    $ cd bats
+    $ ./install.sh /usr/local
+
+Note that you may need to run `install.sh` with `sudo` if you do not
+have permission to write to the installation prefix.
+

install.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+set -e
+
+resolve_link() {
+  $(type -p greadlink readlink | head -1) "$1"
+}
+
+abs_dirname() {
+  local cwd="$(pwd)"
+  local path="$1"
+
+  while [ -n "$path" ]; do
+    cd "${path%/*}"
+    local name="${path##*/}"
+    path="$(resolve_link "$name" || true)"
+  done
+
+  pwd
+  cd "$cwd"
+}
+
+PREFIX="$1"
+if [ -z "$1" ]; then
+  { echo "usage: $0 <prefix>"
+    echo "  e.g. $0 /usr/local"
+  } >&2
+  exit 1
+fi
+
+BATS_ROOT="$(abs_dirname "$0")"
+mkdir -p "$PREFIX"/{bin,libexec}
+cp -R "$BATS_ROOT"/bin/* "$PREFIX"/bin
+cp -R "$BATS_ROOT"/libexec/* "$PREFIX"/libexec
+
+echo "Installed Bats to $PREFIX/bin/bats"