Q. Delete or remove last line from a file.
This can be achieved with SED command.
sed -i '$d' filename
Let me explain this command. SED is a stream editor which is useful for editing stream of characters. here -i option say's to insert the data in to the original file, ie modify original file. $ indicates last line and d for deleting that line and update to the file.
There are other methods to delete last lines
head -n -1 file1 > file2;mv file2 file1
Here I used head command to list all the lines but not the last line, redirected the output of this to a new file then moved file1 to file2.