On older systems, @command{head} supports an obsolete option
@option{-@var{count}@var{options}}, which is recognized only 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
+by a size letter (@samp{b}, @samp{k}, @samp{m}) as in @option{-c}, or
@samp{l} to mean count by lines, or other option letters (@samp{cqv}).
@acronym{POSIX} 1003.1-2001 (@pxref{Standards conformance}) does not allow
this; use @option{-c @var{count}} or @option{-n @var{count}} instead.
@sc{gnu} @command{tail} can output any amount of data (some other versions of
@command{tail} cannot). It also has no @option{-r} option (print in
reverse), since reversing a file is really a different job from printing
-the end of a file; BSD @command{tail} (which is the one with @code{-r}) can
+the end of a file; BSD @command{tail} (which is the one with @option{-r}) can
only reverse files that are at most as large as its buffer, which is
typically 32 KiB. A more reliable and versatile way to reverse files is
the @sc{gnu} @command{tac} command.
On older systems, @command{tail} supports an obsolete option
@option{-@var{count}@var{options}}, which is recognized only 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
+by a size letter (@samp{b}, @samp{k}, @samp{m}) as in @option{-c}, or
@samp{l} to mean count by lines, or other option letters
(@samp{cfqv}). Some older @command{tail} implementations also support
an obsolete option @option{+@var{count}} with the same meaning as
@noindent
prints both the byte counts and the word counts.
-With the @code{--max-line-length} option, @command{wc} prints the length
+With the @option{--max-line-length} option, @command{wc} prints the length
of the longest line per file, and if there is more than one file it
prints the maximum (not the sum) of those lengths.
This makes it easy for Emacs to find the names, even when they contain
unusual characters such as space or newline, without fancy searching.
-If directories are being listed recursively (@code{-R}), output a similar
+If directories are being listed recursively (@option{-R}), output a similar
line with offsets for each subdirectory name:
@example
//SUBDIRED// @var{beg1} @var{end1} @dots{}
By default, @command{unlink} honors the @option{--help} and @option{--version}
options. That makes it a little harder to remove files named
-@code{--help} and @code{--version}, so when the environment variable
+@option{--help} and @option{--version}, so when the environment variable
@env{POSIXLY_CORRECT} is set, @command{unlink} treats such a command line
arguments not as an option, but as an operand.
If a file being written to does not already exist, it is created. If a
file being written to already exists, the data it previously contained
-is overwritten unless the @code{-a} option is used.
+is overwritten unless the @option{-a} option is used.
The program accepts the following options. Also see @ref{Common options}.
@item cbreak
@opindex cbreak
-Same as @code{-icanon}. May be negated. If negated, same as
+Same as @option{-icanon}. May be negated. If negated, same as
@code{icanon}.
@item pass8
@item litout
@opindex litout
-Same as @code{-parenb -istrip -opost cs8}. May be negated.
+Same as @option{-parenb -istrip -opost cs8}. May be negated.
If negated, same as @code{parenb istrip opost cs7}.
@item decctlq
@opindex decctlq
-Same as @code{-ixany}. Non-@acronym{POSIX}. May be negated.
+Same as @option{-ixany}. Non-@acronym{POSIX}. May be negated.
@item tabs
@opindex tabs
@item min @var{n}
@opindex min
Set the minimum number of characters that will satisfy a read until
-the time value has expired, when @code{-icanon} is set.
+the time value has expired, when @option{-icanon} is set.
@item time @var{n}
@opindex time
Set the number of tenths of a second before reads time out if the minimum
-number of characters have not been read, when @code{-icanon} is set.
+number of characters have not been read, when @option{-icanon} is set.
@item ispeed @var{n}
@opindex ispeed
of: 0 50 75 110 134 134.5 150 200 300 600 1200 1800 2400 4800 9600
19200 38400 @code{exta} @code{extb}. @code{exta} is the same as
19200; @code{extb} is the same as 38400. 0 hangs up the line if
-@code{-clocal} is set.
+@option{-clocal} is set.
@end table
@opindex -n
@opindex --name
Print the user or group name instead of the ID number. Requires
-@code{-u}, @code{-g}, or @code{-G}.
+@option{-u}, @option{-g}, or @option{-G}.
@item -r
@itemx --real
@opindex -r
@opindex --real
Print the real, instead of effective, user or group id. Requires
-@code{-u}, @code{-g}, or @code{-G}.
+@option{-u}, @option{-g}, or @option{-G}.
@item -u
@itemx --user
@cindex formatting times
If given an argument that starts with a @samp{+}, @command{date} prints the
current time and date (or the time and date specified by the
-@code{--date} option, see below) in the format defined by that argument,
+@option{--date} option, see below) in the format defined by that argument,
which is the same as in the @code{strftime} function. Except for
directives, which start with @samp{%}, characters in the format string
are printed unchanged. The directives are described below.
@command{uname} prints information about the machine and operating system
it is run on. If no options are given, @command{uname} acts as if the
-@code{-s} option were given. Synopsis:
+@option{-s} option were given. Synopsis:
@example
uname [@var{option}]@dots{}
@end example
-If multiple options or @code{-a} are given, the selected information is
+If multiple options or @option{-a} are given, the selected information is
printed in this order:
@example
@cindex @option{-su}
GNU @command{su} does not treat @file{/bin/sh} or any other shells specially
-(e.g., by setting @code{argv[0]} to @option{-su}, passing @code{-c} only
+(e.g., by setting @code{argv[0]} to @option{-su}, passing @option{-c} only
to certain shells, etc.).
@findex syslog
@opindex -c
@opindex --command
Pass @var{command}, a single command line to run, to the shell with
-a @code{-c} option instead of starting an interactive shell.
+a @option{-c} option instead of starting an interactive shell.
@item -f
@itemx --fast
@flindex .cshrc
@cindex file name pattern expansion, disabled
@cindex globbing, disabled
-Pass the @code{-f} option to the shell. This probably only makes sense
-if the shell run is @command{csh} or @command{tcsh}, for which the @code{-f}
+Pass the @option{-f} option to the shell. This probably only makes sense
+if the shell run is @command{csh} or @command{tcsh}, for which the @option{-f}
option prevents reading the startup file (@file{.cshrc}). With
-Bourne-like shells, the @code{-f} option disables file name pattern
+Bourne-like shells, the @option{-f} option disables file name pattern
expansion (globbing), which is not likely to be useful.
@item -
@var{user}'s shell is restricted. A @dfn{restricted shell} is one that
is not listed in the file @file{/etc/shells}, or in a compiled-in list
if that file does not exist. Parts of what this option does can be
-overridden by @code{--login} and @code{--shell}.
+overridden by @option{--login} and @option{--shell}.
@item -s @var{shell}
@itemx --shell=@var{shell}
@command{seq} prints a sequence of numbers to standard output. Synopses:
@example
-seq [@var{option}]@dots{} [@var{first} [@var{increment}]] @var{last}
+seq [@var{option}]@dots{} @var{last}
+seq [@var{option}]@dots{} @var{first} @var{last}
+seq [@var{option}]@dots{} @var{first} @var{increment} @var{last}
@end example
@command{seq} prints the numbers from @var{first} to @var{last} by
-@var{increment}. By default, @var{first} and @var{increment} are both 1,
-and each number is printed on its own line. Any floating-point number
+@var{increment}. By default, each number is printed on a separate line.
+When @var{increment} is not specified, it defaults to @samp{1},
+even when @var{first} is larger than @var{last}.
+@var{first} also defaults to @samp{1}. So @code{seq 1} prints
+@samp{1}, but @code{seq 0} and @code{seq 10 5} produce no output.
+Floating-point numbers
may be specified (using a period before any fractional digits).
The program accepts the following options. Also see @ref{Common options}.
implemented using binary floating point arithmetic (via the C
@code{double} type) -- which means some decimal numbers like @code{.1}
cannot be represented exactly. That in turn means some nonintuitive
-conditions like @code{.1 * 3 > .3} will end up being true.
+conditions like @w{@code{.1 * 3 > .3}} will end up being true.
To work around that in the above example, use a slightly larger number as
the @var{last} value:
projects / thirdparty / coreutils.git / commitdiff
