provide usable examples for sudo validation

lib/ansible/modules/files/copy.py

@@ -143,14 +143,14 @@ EXAMPLES = r'''
 - copy:
     src: /mine/sudoers
     dest: /etc/sudoers
-    validate: visudo -cf %s
+    validate: /usr/sbin/visudo -cf %s
 
 # Copy a "sudoers" file on the remote machine for editing
 - copy:
     src: /etc/sudoers
     dest: /etc/sudoers.edit
     remote_src: yes
-    validate: visudo -cf %s
+    validate: /usr/sbin/visudo -cf %s
 
 # Create a CSV file from your complete inventory using an inline template
 - hosts: all

lib/ansible/modules/files/lineinfile.py

@@ -184,7 +184,7 @@ EXAMPLES = r"""
     state: present
     regexp: '^%ADMIN ALL='
     line: '%ADMIN ALL=(ALL) NOPASSWD: ALL'
-    validate: 'visudo -cf %s'
+    validate: '/usr/sbin/visudo -cf %s'
 """
 
 import re

lib/ansible/modules/files/template.py

@@ -137,7 +137,7 @@ EXAMPLES = r'''
 - template:
     src: /mine/sudoers
     dest: /etc/sudoers
-    validate: 'visudo -cf %s'
+    validate: '/usr/sbin/visudo -cf %s'
 
 # Update sshd configuration safely, avoid locking yourself out
 - template: