From dbef8b1a92f789f4109435a3b7278f899e328767 Mon Sep 17 00:00:00 2001
From: mapc <musikmichael@web.de>
Date: Sat, 5 May 2012 10:39:05 +0200
Subject: [PATCH 1/2] Add helper to get the value of an alias only

---
 lib/functions.zsh | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/lib/functions.zsh b/lib/functions.zsh
index d2dcadd0..b4d89a64 100644
--- a/lib/functions.zsh
+++ b/lib/functions.zsh
@@ -15,3 +15,33 @@ function take() {
   cd $1
 }
 
+#
+# Get the value of an alias.
+#
+# Arguments:
+#    1. alias - The alias to get its value from
+# STDOUT:
+#    The value of alias $1 (if it has one).
+# Return value:
+#    0 if the alias was found,
+#    1 if it does not exist
+#
+function alias_value() {
+    alias "$1" | sed "s/^$1='\(.*\)'$/\1/"
+    test $(alias "$1")
+}
+
+#
+# Try to get the value of an alias,
+# otherwise return the input.
+#
+# Arguments:
+#    1. alias - The alias to get its value from
+# STDOUT:
+#    The value of alias $1, or $1 if there is no alias $1.
+# Return value:
+#    Always 0
+#
+function try_alias_value() {
+    alias_value "$1" || echo "$1"
+}
\ No newline at end of file

From 8f71efc09b42d69cc053649fade92485d282a561 Mon Sep 17 00:00:00 2001
From: mapc <musikmichael@web.de>
Date: Sat, 5 May 2012 10:39:31 +0200
Subject: [PATCH 2/2] Add helper to easily define default values for variables
 and env variables.

---
 lib/functions.zsh | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/lib/functions.zsh b/lib/functions.zsh
index b4d89a64..3770d4e8 100644
--- a/lib/functions.zsh
+++ b/lib/functions.zsh
@@ -44,4 +44,32 @@ function alias_value() {
 #
 function try_alias_value() {
     alias_value "$1" || echo "$1"
+}
+
+#
+# Set variable "$1" to default value "$2" if "$1" is not yet defined.
+#
+# Arguments:
+#    1. name - The variable to set
+#    2. val  - The default value 
+# Return value:
+#    0 if the variable exists, 3 if it was set
+#
+function default() {
+    test `typeset +m "$1"` && return 0
+    typeset -g "$1"="$2"   && return 3
+}
+
+#
+# Set enviroment variable "$1" to default value "$2" if "$1" is not yet defined.
+#
+# Arguments:
+#    1. name - The env variable to set
+#    2. val  - The default value 
+# Return value:
+#    0 if the env variable exists, 3 if it was set
+#
+function env_default() {
+    env | grep -q "^$1=" && return 0 
+    export "$1=$2"       && return 3
 }
\ No newline at end of file