1dd9c43e12403a00af9a3ac3c3602870d42cc8f3

 1diff --git a/lib/functions.zsh b/lib/functions.zsh
 2index 63ab755cf72b1094975ef017cd71727c756e1943..aaf8a03e31e838d117ee99b076c6b5ee4fd75bb1 100644
 3--- a/lib/functions.zsh
 4+++ b/lib/functions.zsh
 5@@ -15,3 +15,61 @@ function take() {
 6   cd $1
 7 }
 8 
 9+#
10+# Get the value of an alias.
11+#
12+# Arguments:
13+#    1. alias - The alias to get its value from
14+# STDOUT:
15+#    The value of alias $1 (if it has one).
16+# Return value:
17+#    0 if the alias was found,
18+#    1 if it does not exist
19+#
20+function alias_value() {
21+    alias "$1" | sed "s/^$1='\(.*\)'$/\1/"
22+    test $(alias "$1")
23+}
24+
25+#
26+# Try to get the value of an alias,
27+# otherwise return the input.
28+#
29+# Arguments:
30+#    1. alias - The alias to get its value from
31+# STDOUT:
32+#    The value of alias $1, or $1 if there is no alias $1.
33+# Return value:
34+#    Always 0
35+#
36+function try_alias_value() {
37+    alias_value "$1" || echo "$1"
38+}
39+
40+#
41+# Set variable "$1" to default value "$2" if "$1" is not yet defined.
42+#
43+# Arguments:
44+#    1. name - The variable to set
45+#    2. val  - The default value 
46+# Return value:
47+#    0 if the variable exists, 3 if it was set
48+#
49+function default() {
50+    test `typeset +m "$1"` && return 0
51+    typeset -g "$1"="$2"   && return 3
52+}
53+
54+#
55+# Set enviroment variable "$1" to default value "$2" if "$1" is not yet defined.
56+#
57+# Arguments:
58+#    1. name - The env variable to set
59+#    2. val  - The default value 
60+# Return value:
61+#    0 if the env variable exists, 3 if it was set
62+#
63+function env_default() {
64+    env | grep -q "^$1=" && return 0 
65+    export "$1=$2"       && return 3
66+}