Homework & Coursework Questions

#!/bin/bash

#copy the content of file.txt to a temporary file
cat file.txt > tmp.txt

#get today's month and day
today=`date +%m'/'%d`

#insert a dummy row, with todays date and time in the temporary file
dummy="test 0,123456789,1800/$today"

echo "$dummy" >> tmp.txt

#sort the file by month and day and output to another temp file
sort -t'/' -k2,3 tmp.txt > tmp2.txt

#no of birthdays today, apart from the dummy row
matches_today=`grep "$today" tmp2.txt | grep -v "$dummy" | wc -l`


#if there are no matches for today, check to see if the dummy is the last record; 
#if it is the next birthday is top of the list, otherwise it's the next row; otherwise, 
#if there are matches for today echo them

if test $matches_today -eq 0
        then
                if test "`tail -1 tmp2.txt`" == "$dummy"
                        then
                                echo "`head -1 tmp2.txt`"
                        else
                                echo "`grep -A1 "$dummy" tmp2.txt | grep -v "$dummy"`"
                fi
        else
                echo "`grep "$today" tmp2.txt | grep -v "$dummy"`"

fi