Is the last new line on fstab important?

Question

What happens if the last line of fstab is not terminated by a newline?

Why do people get a warning when that last line is not terminated by a newline?

Basically, see [What's the point in adding a new line to the end of a file?](http://unix.stackexchange.com/questions/18743/whats-the-point-in-adding-a-new-line-to-the-end-of-a-file/18789#18789) — Gilles 'SO- stop being evil', Jul 25 '13 at 23:21

score 5 · Accepted Answer · answered Jul 25 '13 at 08:31

A line is a sequence of characters terminated by a newline character. The characters that appear after the last newline of a file are not part of a line.

Such a file that has characters after the last newline is not a text file as per the POSIX definition of a text file, and the behaviour of text utilities is unspecified in that case and in practice, behaviour varies:

Some ignore those characters completely (skip that non-terminated line)
Some consider it as a line and preserve the absence of newline (like GNU sed)
Some consider it as a line and add back the missing newline (like GNU cut)
Some utilities behaviour changes. Like read which returns a non-zero exit status when reading a non terminated line.

So even if the mount, swapon, fsck... utilities (those which typically read /etc/fstab) understand non-terminated lines, some script that process that file may still fail. You should always make sure text files are terminated by a newline character (unless they're empty). Text editors should do that by default. You generally need to go through hoops to remove that last newline characters.

Is the last new line on fstab important?

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