diffutils: Incomplete Lines

1 
1 3 Incomplete Lines
1 ******************
1 
1 When an input file ends in a non-newline character, its last line is
1 called an "incomplete line" because its last character is not a newline.
1 All other lines are called "full lines" and end in a newline character.
1 Incomplete lines do not match full lines unless differences in white
1 space are ignored (⇒White Space).
1 
1    An incomplete line is normally distinguished on output from a full
1 line by a following line that starts with '\'.  However, the RCS format
1 (⇒RCS) outputs the incomplete line as-is, without any trailing
1 newline or following line.  The side by side format normally represents
1 incomplete lines as-is, but in some cases uses a '\' or '/' gutter
1 marker.  ⇒Side by Side.  The if-then-else line format preserves a
1 line's incompleteness with '%L', and discards the newline with '%l'.
1 ⇒Line Formats.  Finally, with the 'ed' and forward 'ed' output
1 formats (⇒Output Formats) 'diff' cannot represent an incomplete
1 line, so it pretends there was a newline and reports an error.
1 
1    For example, suppose 'F' and 'G' are one-byte files that contain just
1 'f' and 'g', respectively.  Then 'diff F G' outputs
1 
1      1c1
1      < f
1      \ No newline at end of file
1      ---
1      > g
1      \ No newline at end of file
1 
1 (The exact message may differ in non-English locales.)  'diff -n F G'
1 outputs the following without a trailing newline:
1 
1      d1 1
1      a1 1
1      g
1 
1 'diff -e F G' reports two errors and outputs the following:
1 
1      1c
1      g
1      .
1