lec3vid4

#!/bin/bash

#display uid and username of the user executing the script 
#diplay if the user is a vagrant user or not 

#display the uid 
echo "your uID is ${UID}"

#only display if the uid does not match 1000
UID_TO_TEST_FOR='1000'
if [ $UID_TO_TEST_FOR != ${UID} ]
then
  echo "your uid does not match $UID_TO_TEST_FOR to avoid don't run it as sudo"
  exit 1 #when script or a program exit successfully it returns a exit status 0 by convention , if it doesnt execute successfully it returns a non zero staus to see exit statuses 'man useradd'
fi  

#display the username
USER_NAME=$(id -un dklafd)

#test if the command succeeded
if [ ${?} -ne 0 ] # ? holds the exit status of most recentlty executed command which is $(id -un)
then 
  echo 'THE ID COMMAND DID NOT EXECUTE SUCCESFULLY BECAUSE EXIT STATUS OF A FAILED PROGRAM IS NOT 0' #if we fail the id someway these line will execute
  exit 1 # exit terminate the whole script
fi  
echo "your user name is ${USER_NAME}"
  

#you can use a string test conditional 
USER_NAME_TO_TEST_FOR='devfedora'
if [ $(id -un) = $USER_NAME_TO_TEST_FOR ] # == sign used for pattern matching 
then 
  echo "your user name matches $USER_NAME_TO_TEST_FOR"
fi  

#test for != (not equal) for the string  
if [ $(id -un) != $USER_NAME_TO_TEST_FOR ] # == sign used for pattern matching 
then 
  echo "your user name does not matches $USER_NAME_TO_TEST_FOR"
  exit 1
fi  

exit 0 # if you dont specify the exit status it will take the previous exit status as exit status