Detect OS to use proper grep options

2 files changed, 12 insertions, 4 deletions

diff --git a/README.md b/README.md
index 13c1fe5..d6fbbf0 100644
--- a/README.md
+++ b/README.md
@@ -1129,9 +1129,13 @@ Rootly Powers and Processes
   a. Find entries that have UID 0.
 
     ```bash
-    #!/bin/sh
+    #!/bin/bash
 
-    cat /etc/passwd | grep -P '^\w+:[x]:\d+:0.*$'
+    if [[ "$OSTYPE" == "darwin"* ]]; then
+      cat /etc/passwd | cut -d: -f1,3 | grep ':0'
+    else
+      cat /etc/passwd | grep -P '^\w+:[x]:\d+:0.*$'
+    fi
     ```
 
   b. Find entries that have that have no password (needs /etc/shadow).
diff --git a/bin/uid-zero b/bin/uid-zero
index 129d587..2976cbb 100755
--- a/bin/uid-zero
+++ b/bin/uid-zero
@@ -1,3 +1,7 @@
-#!/bin/sh
+#!/bin/bash
 
-cat /etc/passwd | grep -P '^\w+:[x]:\d+:0.*$'
+if [[ "$OSTYPE" == "darwin"* ]]; then
+  cat /etc/passwd | cut -d: -f1,3 | grep ':0'
+else
+  cat /etc/passwd | grep -P '^\w+:[x]:\d+:0.*$'
+fi