Helper functions to test if in requirements used for checking for mercurial install and for pylibmc

bin/compile

@@ -173,7 +173,7 @@ set -e
 source $BIN_DIR/steps/pylibmc
 
 # Install Mercurial if it appears to be required.
-if (grep -Fiq "hg+" requirements.txt) then
+if (in-req "hg+" requirements.txt) then
   pip install --use-mirrors mercurial | cleanup | indent
 fi
 

bin/steps/pylibmc

@@ -1,10 +1,10 @@
 #!/usr/bin/env bash
 
 # This script serves as the Pylibmc build step of the
-# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python) 
-# compiler. 
-# 
-# A [buildpack](http://devcenter.heroku.com/articles/buildpacks) is an 
+# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
+# compiler.
+#
+# A [buildpack](http://devcenter.heroku.com/articles/buildpacks) is an
 # adapter between a Python application and Heroku's runtime.
 #
 # This script is invoked by [`bin/compile`](/).
@@ -12,8 +12,11 @@
 # The location of the pre-compiled libmemcached binary.
 VENDORED_MEMCACHED="http://cl.ly/0a191R3K160t1w1P0N25/vendor-libmemcached.tar.gz"
 
+# Syntax sugar.
+source $BIN_DIR/utils
+
 # If pylibmc exists within requirements, use vendored libmemcached.
-if (grep -Fiq "pylibmc" requirements.txt) then
+if (in-req "pylibmc" requirements.txt) then
   echo "-----> Noticed pylibmc. Bootstrapping libmemcached."
   cd .heroku
 

bin/utils

@@ -49,4 +49,26 @@ function deep-mv (){
 
   rm -fr $1/!(tmp)
   find -H $1 -maxdepth 1 -name '.*' -a \( -type d -o -type f -o -type l \) -exec rm -fr '{}' \;
-}
+}
+
+# Recursively finds requirements.txt files
+function list-req (){
+  echo $@
+  for req in $(grep -Fie "-r " $@ | sed 's/-r //g')
+    do
+      path="$(dirname $@)/$req"
+      list-req $path
+    done
+}
+
+# Find pattern in requirements files recursively
+# Usage: $ in-req pattern file
+function in-req (){
+  for file in $(list-req $2)
+    do
+      if (grep -Fiqe "$1" "$file") then
+        return 0
+      fi
+    done
+  return 1
+}