diff-utils

[Neal H Walfield]

There is a small error in the output of `diff --help.'  It claims the
following:

  -c  -C NUM  --context[=NUM]  Output NUM (default 2) lines of copied context.
  -u  -U NUM  --unified[=NUM]  Output NUM (default 2) lines of unified-context.

First, this is wrong, the second version of the Single Unix
Specification specifically says that there must be three lines of
context by default:

        Diff -c or -C Output Format

        With the -c or -C option, the output format will consist of
        affected lines along with surrounding lines of context. The
        affected lines will show which ones need to be deleted or
        changed in file1, and those added from file2. With the -c
        option, three lines of context, if available, will be written
        before and after the affected lines.

This, however, agrees with the both the info manual and the
implementation.

Here is a patch to correct this discrepancy:

2001-12-12  Neal H Walfield  <address@hidden>

        * diff.c (option_help): Correct the desciption of the `-c' and
        `-u' to match the info manual and the implementation.


diff -upr diffutils-2.7.orig/diff.c diffutils-2.7/diff.c
--- diffutils-2.7.orig/diff.c   Thu Sep 22 18:47:00 1994
+++ diffutils-2.7/diff.c        Wed Dec 12 21:38:47 2001
@@ -1,5 +1,5 @@
 /* GNU DIFF main routine.
-   Copyright (C) 1988, 1989, 1992, 1993, 1994 Free Software Foundation, Inc.
+   Copyright (C) 1988, 1989, 1992, 1993, 1994, 2001 Free Software Foundation, 
Inc.
 
 This file is part of GNU DIFF.
 
@@ -687,8 +701,8 @@ static char const * const option_help[] 
 "--binary  Read and write data in binary mode.",
 #endif
 "-a  --text  Treat all files as text.\n",
-"-c  -C NUM  --context[=NUM]  Output NUM (default 2) lines of copied context.",
-"-u  -U NUM  --unified[=NUM]  Output NUM (default 2) lines of unified 
context.",
+"-c  -C NUM  --context[=NUM]  Output NUM (default 3) lines of copied context.",
+"-u  -U NUM  --unified[=NUM]  Output NUM (default 3) lines of unified 
context.",
 "  -NUM  Use NUM context lines.",
 "  -L LABEL  --label LABEL  Use LABEL instead of file name.",
 "  -p  --show-c-function  Show which C function each change is in.",