Node:Incomplete Lines, Next:Comparing Directories, Previous:Output Formats, Up:Top
When an input file ends in a non-newline character, its last line is called an incomplete line because its last character is not a newline. All other lines are called full lines and end in a newline character. Incomplete lines do not match full lines unless differences in white space are ignored (see White Space).
An incomplete line is normally distinguished on output from a full line
by a following line that starts with \. However, the RCS format
(see RCS) outputs the incomplete line as-is, without any trailing
newline or following line. The side by side format normally represents
incomplete lines as-is, but in some cases uses a \ or /
gutter marker; See Side by Side. The if-then-else line format
preserves a line's incompleteness with %L, and discards the
newline with %l; See Line Formats. Finally, with the
ed and forward ed output formats (see Output Formats)
diff cannot represent an incomplete line, so it pretends there
was a newline and reports an error.
For example, suppose F and G are one-byte files that
contain just f and g, respectively. Then diff F G
outputs
1c1 < f \ No newline at end of file --- > g \ No newline at end of file
(The exact message may differ in non-English locales.)
diff -n F G outputs the following without a trailing newline:
d1 1 a1 1 g
diff -e F G reports two errors and outputs the following:
1c g .