diff --git a/docs/kickstart/file/contains.md b/docs/kickstart/file/contains.md
new file mode 100644
index 0000000..c2762d5
--- /dev/null
+++ b/docs/kickstart/file/contains.md
@@ -0,0 +1,11 @@
+# kickstart.file.contains file_name string_to_search
+Searchs for `string_to_search` on `file_name`.
+Returns 0 if there the file contains the string, and 1 otherwise.
+
+### Example
+
+```bash
+$ kickstart.file.contains /etc/groups wheel && echo yup
+$ kickstart.file.contains /etc/groups banana || echo nope
+```
+
diff --git a/docs/kickstart/stream/contains.md b/docs/kickstart/stream/contains.md
new file mode 100644
index 0000000..e22ced3
--- /dev/null
+++ b/docs/kickstart/stream/contains.md
@@ -0,0 +1,11 @@
+# kickstart.stream.contains string_to_search
+Searchs for `string_to_search` on STDIN
+Returns 0 if there the stream contains the string, and 1 otherwise.
+
+### Example
+
+```bash
+$ echo weee | kickstart.stream.contains wee && echo yup
+$ echo weee | kickstart.stream.contains ahh || echo nope
+```
+
diff --git a/kickstart/recipes/kickstart/file.sh b/kickstart/recipes/kickstart/file.sh
index 3931f47..960de3d 100644
--- a/kickstart/recipes/kickstart/file.sh
+++ b/kickstart/recipes/kickstart/file.sh
@@ -2,3 +2,7 @@ kickstart.file.link() {
   rm -rf $2 2>/dev/null
   ln -s $1 $2
 }
+
+kickstart.file.contains() {
+  grep -q $2 $1 2>/dev/null
+}
diff --git a/kickstart/recipes/kickstart/group.sh b/kickstart/recipes/kickstart/group.sh
index c7c8cdd..9b2e192 100644
--- a/kickstart/recipes/kickstart/group.sh
+++ b/kickstart/recipes/kickstart/group.sh
@@ -1,4 +1,4 @@
 kickstart.group.create() {
   kickstart.info "Creating group $1"
-  grep -q $1 /etc/group || groupadd $1
+  kickstart.file.contains /etc/group $1 || groupadd $1
 }
diff --git a/kickstart/recipes/kickstart/module.sh b/kickstart/recipes/kickstart/module.sh
index 0f74d0b..21c098f 100644
--- a/kickstart/recipes/kickstart/module.sh
+++ b/kickstart/recipes/kickstart/module.sh
@@ -7,7 +7,7 @@ kickstart.module.apply_recipe() {
 }
 
 kickstart.module.apply_() {
-  local cur_dir=`pwd`;
+  local cur_dir=`pwd`
   cd modules/$1
   source $3/$2.sh
   cd $cur_dir
diff --git a/kickstart/recipes/kickstart/os.sh b/kickstart/recipes/kickstart/os.sh
index f8b50bf..31cf4e4 100644
--- a/kickstart/recipes/kickstart/os.sh
+++ b/kickstart/recipes/kickstart/os.sh
@@ -1,6 +1,6 @@
 kickstart.os() {
-  ( uname -a | grep -q Ubuntu ) && echo "Ubuntu"
-  ( uname -a | grep -q Darwin ) && echo "Mac"
+  uname -a | kickstart.stream.contains Ubuntu && echo "Ubuntu"
+  uname -a | kickstart.stream.contains Darwin && echo "Mac"
 }
 
 kickstart.os.is() {
diff --git a/kickstart/recipes/kickstart/package.sh b/kickstart/recipes/kickstart/package.sh
index e02c210..92617a8 100644
--- a/kickstart/recipes/kickstart/package.sh
+++ b/kickstart/recipes/kickstart/package.sh
@@ -6,8 +6,8 @@ kickstart.package.manager() {
 
 kickstart.package.installed() {
   local pkg_manager=`kickstart.package.manager`
-  [ $pkg_manager = 'apt-get' ] && dpkg -s $@ >/dev/null 2>&1 && return $?
-  [ $pkg_manager = 'brew' ] && ! $(brew info $@ | grep -q "Not installed") && return $?
+  [ $pkg_manager = 'apt-get' ] && dpkg -s "$@" >/dev/null 2>&1 && return $?
+  [ $pkg_manager = 'brew' ] && ! $(brew info "$@" | kickstart.stream.contains "Not installed") && return $?
 }
 
 kickstart.package.install() {
diff --git a/kickstart/recipes/kickstart/profile.sh b/kickstart/recipes/kickstart/profile.sh
index e13dd74..b468d3e 100644
--- a/kickstart/recipes/kickstart/profile.sh
+++ b/kickstart/recipes/kickstart/profile.sh
@@ -15,7 +15,7 @@ kickstart.profile.source_on_configuration_file() {
   local file=$1
   local profile_d=$2
   local configuration=$3
-  grep -q $file $configuration 2>/dev/null || ( echo "[[ -f $profile_d/$file ]] && source $profile_d/$file" >> $configuration )
+  kickstart.file.contains $configuration $file || ( echo "[[ -f $profile_d/$file ]] && source $profile_d/$file" >> $configuration )
 }
 
 kickstart.profile.location.profile_d() {
diff --git a/kickstart/recipes/kickstart/stream.sh b/kickstart/recipes/kickstart/stream.sh
new file mode 100644
index 0000000..db5be72
--- /dev/null
+++ b/kickstart/recipes/kickstart/stream.sh
@@ -0,0 +1,3 @@
+kickstart.stream.contains() {
+  grep -q $1 2>/dev/null
+}
diff --git a/kickstart/recipes/kickstart/user.sh b/kickstart/recipes/kickstart/user.sh
index ef5fe2d..9ce7960 100644
--- a/kickstart/recipes/kickstart/user.sh
+++ b/kickstart/recipes/kickstart/user.sh
@@ -3,7 +3,7 @@ kickstart.user.create() {
 }
 
 kickstart.user.is_on_group() {
-  grep -q $2 <(id -nG $1)
+  id -nG $1 | kickstart.stream.contains $2
 }
 
 kickstart.user.add_group() {