Shell Programming and Scripting

if grep -w "Hi"\|"Hello" /home/my.log 2>&1 > /dev/null 
then
    EMAIL_ADDR="aaa@gmail.com"
    echo "Please view the error messages on attached file " | mutt -a ~/error_report.txt -s "hi `date +"%d-%m-%Y"`" "$EMAIL_ADDR"
  fi

$ grep -q "Hello" file || { grep -q "Hi" file && echo "fine" ; }
                       ^--- if NOT found      ^--- if found

if grep -wq "Hi" file && ! grep -wq "Hello" file
then
  echo "Hi, but not hello"
fi

if grep -wq "Hi" file && ! grep -wq "Hello" file
one kid of email
if grep -wq "Hi" file &&  grep -wq "Hello" file
 other kind of mail

if grep -w "Hi"\|"Hello" /home/my.log 2>&1 > /dev/null
then
 one kid of email
else 
   if if grep -wq "Hi" /home/my.log 2>&1 > /dev/null
  then
   other kind of mail
      fi
fi

if condition 1; then
  action 1
elif condition 2; then
  action 2
fi

egrep -wq "Hi|Hello" /home/my.log
if [ "$?" -eq 0]
then
           one kind of email
else
     grep -wq "Hi" /home/my.log
     if [ "$?" -eq 0] 
    then    
        other kind of mail       
    fi
fi

grep -qw hello file; TMP=$?; grep -qw hi file; RES=$((2-2*$?+1-TMP))

case $RES in
        0) echo mail: no occurrence;;
        1) echo mail: hello occurrence;;
        2) echo mail: hi occurrence;;
        3) echo mail: both occurrences;;
    esac