checking equality of a part of two files

Question

Is it possible to check if first line of two files is equal using diff(or another easy bash command)?

[Generally checking equality of first/last k lines, or even lines i to j]

Answer 1

To diff the first k lines of two files:

$ diff <(head -k file1) <(head -k file2)

Similary, to diff the last k lines:

$ diff <(tail -k file1) <(tail -k file2)

To diff lines i to j:

diff <(sed -n 'i,jp' file1) <(sed -n 'i,jp' file2)

Answer 2

My solution seems rather basic and beginner when compared to dogbane's above, but here it is all the same!

echo "Comparing the first line from file $1 and $2 to see if they are the same."

FILE1=`head -n 1 $1`
FILE2=`head -n 1 $2`

echo $FILE1 > tempfile1.txt
echo $FILE2 > tempfile2.txt

if diff "tempfile1.txt" "tempfile2.txt"; then
    echo Success
else
    echo Fail
fi