/*
 * *****************************************************************************
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2018-2021 Gavin D. Howard and contributors.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
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 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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 * *****************************************************************************
 *
 * The bc help text.
 *
 */

usage: %s [options] [file...]

bc is a command-line, arbitrary-precision calculator with a Turing-complete
language. For details, use `man %s` or see the online documentation at
https://git.yzena.com/gavin/bc/src/tag/%s/manuals/bc/%s.1.md.

This bc is compatible with both the GNU bc and the POSIX bc spec. See the GNU bc
manual (https://www.gnu.org/software/bc/manual/bc.html) and bc spec
(http://pubs.opengroup.org/onlinepubs/9699919799/utilities/bc.html)
for details.

This bc has three differences to the GNU bc:

  1) Arrays can be passed to the builtin "length" function to get the number of
     elements currently in the array. The following example prints "1":

       a[0] = 0
       length(a[])

  2) The precedence of the boolean "not" operator (!) is equal to that of the
     unary minus (-), or negation, operator. This still allows POSIX-compliant
     scripts to work while somewhat preserving expected behavior (versus C) and
     making parsing easier.
  3) This bc has many more extensions than the GNU bc does. For details, see the
     man page or online documentation.

This bc also implements the dot (.) extension of the BSD bc.

Options:

  -e  expr  --expression=expr

      Run "expr" and quit. If multiple expressions or files (see below) are
      given, they are all run before executing from stdin.

  -f  file  --file=file

      Run the bc code in "file" and exit. See above as well.

  -g  --global-stacks

      Turn scale, ibase, and obase into stacks. This makes the value of each be
      be restored on returning from functions. See the man page or online
      documentation for more details.

  -h  --help

      Print this usage message and exit.

  -i  --interactive

      Force interactive mode.

  -L  --no-line-length

      Disable line length checking.

  -l  --mathlib

      Use predefined math routines:

          s(expr)  =  sine of expr in radians
          c(expr)  =  cosine of expr in radians
          a(expr)  =  arctangent of expr, returning radians
          l(expr)  =  natural log of expr
          e(expr)  =  raises e to the power of expr
          j(n, x)  =  Bessel function of integer order n of x

      This bc may load more functions with these options. See the manpage or
      online documentation for details.

  -P  --no-prompt

      Disable the prompts in interactive mode.

  -R  --no-read-prompt

      Disable the read prompt in interactive mode.

  -r  keyword  --redefine=keyword

      Redefines "keyword" and allows it to be used as a function, variable, and
      array name. This is useful when this bc gives parse errors on scripts
      meant for other bc implementations.

      Only keywords that are not in the POSIX bc spec may be redefined.

      It is a fatal error to attempt to redefine a keyword that cannot be
      redefined or does not exist.

  -q  --quiet

      Don't print version and copyright.

  -s  --standard

      Error if any non-POSIX extensions are used.

  -w  --warn

      Warn if any non-POSIX extensions are used.

  -v  --version

      Print version information and copyright and exit.

  -z  --leading-zeroes

      Enable leading zeroes on numbers greater than -1 and less than 1.

Environment variables:

  POSIXLY_CORRECT

      Error if any non-POSIX extensions are used.

  BC_ENV_ARGS

      Command-line arguments to use on every run.

  BC_LINE_LENGTH

      If an integer, the number of characters to print on a line before
      wrapping. Using 0 will disable line length checking.

  BC_BANNER

      If an integer and non-zero, display the copyright banner in interactive
      mode.

      Overrides the default, which is %s print the banner.

  BC_SIGINT_RESET

      If an integer and non-zero, reset on SIGINT, rather than exit, when in
      interactive mode.

      Overrides the default, which is %s.

  BC_TTY_MODE

      If an integer and non-zero, enable TTY mode when it is available.

      Overrides the default, which is TTY mode %s.

  BC_PROMPT

      If an integer and non-zero, enable prompt when TTY mode is possible.

      Overrides the default, which is prompt %s.

  BC_EXPR_EXIT

      If an integer and non-zero, exit when expressions or expression files are
      given on the command-line, and does not exit when an integer and zero.

      Overrides the default, which is %s.