[EMAIL PROTECTED] (Karl Berry) writes:
> I just expected GNU tail -3 to behave the same as GNU head -3, since
> GNU is supposed to do things right :).
It depends on what you mean by "right", but I think GNU head -3
doesn't behave "right" either, if one expects options like "-3" to
"just work". For example:
$ head -v -3
head: invalid option -- 3
Try `head --help' for more information.
There is a similar problem with "head -v -34", "head -34n", and "head -3v4".
(Not to mention with "tail".)
The code to implement numeric options like "-34" is tricky due to the
desire to be backward-compatible with old, broken software and
standards. If you explore it you'll always be able to find weird
corners. I see no way to generalize them in a clean way. It's
particularly tricky with "tail", since the old and new syntaxes are
flat-out incompatible. I looked into adding support for "tail -3 a b
c", and the only way I could see to do it reliably (after about an
hour of trying to implement it in other ways) was to add a special
case for the exact usage "tail -DIGITS ARG ARG [ARG]....", where none
of the ARGs start with "-". That's no way to run a railroad.
> The error `invalid option -- 3' just confused me more, since it's not
> the -3 that is invalid.
_That_ we can fix. I installed the following.
2006-01-30 Paul Eggert <[EMAIL PROTECTED]>
* doc/coreutils.texi (tail invocation): In the obsolete usage, the
count is optional, so put square brackets around it.
* src/head.c (main): Use a better diagnostic when someone uses a
trailing numeric option in an invalid way. Problem reported by
Karl Berry.
* src/tail.c (parse_options): Likewise.
Index: doc/coreutils.texi
===================================================================
RCS file: /fetish/cu/doc/coreutils.texi,v
retrieving revision 1.307
diff -p -u -r1.307 coreutils.texi
--- doc/coreutils.texi 3 Jan 2006 00:45:06 -0000 1.307
+++ doc/coreutils.texi 31 Jan 2006 01:29:33 -0000
@@ -2551,7 +2551,7 @@ Always print file name headers.
@end table
For compatibility @command{tail} also supports an obsolete usage
[EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED], which is recognized
[EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED], which is recognized
only if it does not conflict with the usage described
above. This obsolete form uses exactly one option and at most one
file. In the option, @var{count} is an optional decimal number optionally
Index: src/head.c
===================================================================
RCS file: /fetish/cu/src/head.c,v
retrieving revision 1.104
diff -p -u -r1.104 head.c
--- src/head.c 3 Dec 2005 22:23:30 -0000 1.104
+++ src/head.c 31 Jan 2006 01:29:33 -0000
@@ -1,5 +1,5 @@
/* head -- output first part of file(s)
- Copyright (C) 89, 90, 91, 1995-2005 Free Software Foundation, Inc.
+ Copyright (C) 89, 90, 91, 1995-2006 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -973,7 +973,7 @@ main (int argc, char **argv)
break;
default:
- error (0, 0, _("unrecognized option `-%c'"), *a);
+ error (0, 0, _("invalid trailing option -- %c"), *a);
usage (EXIT_FAILURE);
}
}
@@ -992,7 +992,8 @@ main (int argc, char **argv)
argc--;
}
- while ((c = getopt_long (argc, argv, "c:n:qv", long_options, NULL)) != -1)
+ while ((c = getopt_long (argc, argv, "c:n:qv0123456789", long_options, NULL))
+ != -1)
{
switch (c)
{
@@ -1029,6 +1030,8 @@ main (int argc, char **argv)
case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
default:
+ if (ISDIGIT (c))
+ error (0, 0, _("invalid trailing option -- %c"), c);
usage (EXIT_FAILURE);
}
}
Index: src/tail.c
===================================================================
RCS file: /fetish/cu/src/tail.c,v
retrieving revision 1.248
diff -p -u -r1.248 tail.c
--- src/tail.c 24 Jan 2006 10:32:32 -0000 1.248
+++ src/tail.c 31 Jan 2006 01:29:33 -0000
@@ -1455,7 +1455,8 @@ parse_options (int argc, char **argv,
{
int c;
- while ((c = getopt_long (argc, argv, "c:n:fFqs:v", long_options, NULL))
+ while ((c = getopt_long (argc, argv, "c:n:fFqs:v0123456789",
+ long_options, NULL))
!= -1)
{
switch (c)
@@ -1553,6 +1554,11 @@ parse_options (int argc, char **argv,
case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ error (EXIT_FAILURE, 0,
+ _("option used in invalid context -- %c"), c);
+
default:
usage (EXIT_FAILURE);
}
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