@ifinfo
This file documents the GNU command line utilities.
-Copyright (C) 1994, 1995, 1996, 2000, 2001 Free Software Foundation, Inc.
+Copyright (C) 1994, 1995, 1996, 2000, 2001, 2002 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
@page
@vskip 0pt plus 1filll
-Copyright @copyright{} 1994, 1995, 1996, 2000, 2001 Free Software
+Copyright @copyright{} 1994, 1995, 1996, 2000, 2001, 2002 Free Software
Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
involved in improving this manual. The entire @sc{gnu} community will
benefit.
-@cindex @sc{posix.2}
+@cindex @sc{posix}
The @sc{gnu} utilities documented here are mostly compatible with the
-@sc{posix.2} standard.
+@sc{posix} standard.
@cindex bugs, reporting
Please report bugs to @email{bug-coreutils@@gnu.org}. Remember
to include the version number, machine architecture, input files, and
interpret a trailing slash as a request to dereference the symbolic link
and so must rename the indirectly referenced @emph{directory} and not
the symbolic link. Although it may seem surprising that such behavior
-be the default, it is required by @sc{posix.2} and is consistent with
+be the default, it is required by @sc{posix} and is consistent with
other parts of that standard.
@node Output of entire files
@example
tail [@var{option}]@dots{} [@var{file}]@dots{}
tail -@var{number} [@var{option}]@dots{} [@var{file}]@dots{}
-tail +@var{number} [@var{option}]@dots{} [@var{file}]@dots{} # obsolescent
@end example
If more than one @var{file} is specified, @code{tail} prints a
typically 32k. A more reliable and versatile way to reverse files is
the @sc{gnu} @code{tac} command.
-@code{tail} accepts two option formats: the new one, in which numbers
-are arguments to the options (@option{-n 1}), and the obsolescent one, in
-which the number precedes any option letters (@option{-1} or @samp{+1}).
-Warning: support for the @samp{+1} form will be withdrawn, as future
-versions of @sc{posix} will not allow it.
+@code{tail} accepts two option formats: the standard one, in which
+numbers are arguments to the options (@option{-n 1}), and the
+obsolescent one, in which the number precedes any option letters
+(@option{-1}). On older systems @command{tail} also supports an
+obsolete option format @option{+@var{count}} with the same meaning as
+@option{-+@var{count}}, but @sc{posix} no longer allows this; use
+@option{-n +@var{count}} instead.
If any option-argument is a number @var{n} starting with a @samp{+},
@code{tail} begins printing with the @var{n}th item from the start of
@table @samp
@item -@var{count}
-@itemx +@var{count}
@opindex -@var{count}
-@opindex +@var{count}
This option is only recognized if it is specified first. @var{count} is
a decimal number optionally followed by a size letter (@samp{b},
@samp{k}, @samp{m}) as in @code{-c}, or @samp{l} to mean count by lines,
or other option letters (@samp{cfqv}).
-Warning: the @samp{+@var{count}} usage is obsolescent. Future versions
-of @sc{posix} will require that support for it be withdrawn. Use
-@option{-n +@var{count}} instead.
-
@item -c @var{bytes}
@itemx --bytes=@var{bytes}
@opindex -c
@code{cksum} output for the original files (typically given in the
distribution).
-The CRC algorithm is specified by the @sc{posix.2} standard. It is not
+The CRC algorithm is specified by the @sc{posix} standard. It is not
compatible with the BSD or System V @code{sum} algorithms (see the
previous section); it is more robust.
input line length or restrictions on bytes allowed within lines. In
addition, if the final byte of an input file is not a newline, @sc{gnu}
@code{sort} silently supplies one. A line's trailing newline is not
-part of the line for comparison purposes.@footnote{@sc{posix}.2-1992
-requires that the trailing newline be part of the comparison, and some
-@code{sort} implementations obey this requirement, but it is widely
-considered to be a bug in the standard and the next version of
-@sc{posix}.2 will likely remove this requirement.}
+part of the line for comparison purposes.
Upon any error, @code{sort} exits with a status of @samp{2}.
commands like @code{sort -o F F} and @code{cat F | sort -o F}.
@vindex POSIXLY_CORRECT
-If @option{-c} is not also specified, @option{-o} may appear after an
-input file even if @env{POSIXLY_CORRECT} is set, e.g., @samp{sort F -o
-F}. Warning: this usage is obsolescent. Future versions of @sc{posix}
-will require that support for it be withdrawn. Portable scripts should
-specify @option{-o @var{output-file}} before any input files.
+On newer systems, @option{-o} cannot appear after an input file if
+@env{POSIXLY_CORRECT} is set, e.g., @samp{sort F -o F}. Portable
+scripts should specify @option{-o @var{output-file}} before any input
+files.
@item -S @var{size}
@itemx --buffer-size=@var{size}
reliably handle arbitrary pathnames (even those which contain Line Feed
characters.)
-@item +@var{pos1} [-@var{pos2}]
-The obsolescent, traditional option for specifying a sort field. The field
-consists of the line between @var{pos1} and up to but @emph{not including}
-@var{pos2} (or the end of the line if @var{pos2} is omitted). Fields
-and character positions are numbered starting with 0. See below.
-
-Warning: the @samp{+@var{pos1}} usage is obsolescent. Future versions of
-@sc{posix} will require that support for it be withdrawn. Use
-@option{--key} (@option{-k}) instead.
-
@end table
Historical (BSD and System V) implementations of @code{sort} have
affect the meaning of character positions in field specifications in
obscure cases. The only fix is to add an explicit @option{-b}.
-A position in a sort field specified with the @option{-k} or @samp{+}
+A position in a sort field specified with the @option{-k}
option has the form @samp{@var{f}.@var{c}}, where @var{f} is the number
of the field to use and @var{c} is the number of the first character
-from the beginning of the field (for @samp{+@var{pos}}) or from the end
-of the previous field (for @option{-@var{pos}}). If the @samp{.@var{c}}
-is omitted, it is taken to be the first character in the field. If the
+from the beginning of the field. In a start position, an omitted
+@samp{.@var{c}} stands for the field's first character. In an end
+position, an omitted or zero @samp{.@var{c}} stands for the field's
+last character. If the
@option{-b} option was specified, the @samp{.@var{c}} part of a field
-specification is counted from the first nonblank character of the field
-(for @samp{+@var{pos}}) or from the first nonblank character following
-the previous field (for @option{-@var{pos}}).
+specification is counted from the first nonblank character of the field.
-A sort key option may also have any of the option letters @samp{Mbdfinr}
+A sort key position may also have any of the option letters @samp{Mbdfinr}
appended to it, in which case the global ordering options are not used
for that particular field. The @option{-b} option may be independently
-attached to either or both of the @samp{+@var{pos}} and
-@option{-@var{pos}} parts of a field specification, and if it is inherited
+attached to either or both of the start and
+end positions of a field specification, and if it is inherited
from the global options it will be attached to both.
Keys may span multiple fields.
+On older systems @command{sort} supports an obsolete origin-zero
+syntax @samp{+@var{pos1} [-@var{pos2}]} for specifying sort keys, but
+@sc{posix} no longer allows this. Use @option{-k} instead.
+
Here are some examples to illustrate various combinations of options.
-In them, the @sc{posix} @option{-k} option is used to specify sort keys rather
-than the obsolescent @samp{+@var{pos1}-@var{pos2}} syntax.
@itemize @bullet
are sequences of non-space non-tab characters that are separated from
each other by at least one space or tab.
-@item +@var{n}
-@itemx -s @var{n}
+@item -s @var{n}
@itemx --skip-chars=@var{n}
-@opindex +@var{n}
@opindex -s
@opindex --skip-chars
Skip @var{n} characters before checking for uniqueness. If you use both
the field and character skipping options, fields are skipped over first.
-
-Warning: the @samp{+@var{n}} usage is obsolescent. Future versions of
-@sc{posix} will require that support for it be withdrawn. Use
-@option{-s @var{n}} instead.
+On older systems, @command{uniq} also supports an obsolete option
+format @option{+@var{n}}, but @sc{posix} no longer allows this format;
+use @option{-s @var{n}} instead.
@item -c
@itemx --count
@var{set2}, the extra characters at the end of @var{set2} are ignored.
On the other hand, making @var{set1} longer than @var{set2} is not
-portable; @sc{posix.2} says that the result is undefined. In this situation,
+portable; @sc{posix} says that the result is undefined. In this situation,
BSD @code{tr} pads @var{set2} to the length of @var{set1} by repeating
the last character of @var{set2} as many times as necessary. System V
@code{tr} truncates @var{set1} to the length of @var{set2}.
@vindex POSIXLY_CORRECT
Setting the environment variable @env{POSIXLY_CORRECT} turns off the
following warning and error messages, for strict compliance with
-@sc{posix.2}. Otherwise, the following diagnostics are issued:
+@sc{posix}. Otherwise, the following diagnostics are issued:
@enumerate
copies the file @file{a/b/c} to @file{existing_dir/a/b/c}, creating
any missing intermediate directories.
-Warning: the meaning of @option{-P} will change in the future to conform
-to @sc{posix}. Use @option{--parents} for the old meaning, and
-@option{--no-dereference} for the new.
-
@item -r
@cindex directories, copying recursively
@cindex copying directories recursively
touch [@var{option}]@dots{} @var{file}@dots{}
@end example
+Older systems support an obsolete variant syntax, as follows.
If the first @var{file} would be a valid argument to the @option{-t}
option and no timestamp is given with any of the @option{-d}, @option{-r},
or @option{-t} options and the @samp{--} argument is not given, that
argument is interpreted as the time for the other files instead of
-as a file name. Warning: this usage is obsolescent, and future versions
-of @sc{posix} will require that support for it be withdrawn. Use
-@option{-t} instead.
+as a file name. This usage is obsolete; use @option{-t} instead.
@cindex empty files, creating
Any @var{file} that does not exist is created empty.
@opindex --portability
Instead of performing length checks on the underlying filesystem,
test the length of each file name and its components against the
-@sc{posix.1} minimum limits for portability. Also check that the file
+@sc{posix} minimum limits for portability. Also check that the file
name contains no characters not in the portable file name character set.
@end table
projects / thirdparty / coreutils.git / commitdiff
