/*
* *****************************************************************************
*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2018-2025 Gavin D. Howard and contributors.
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* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
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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://github.com/gavinhoward/bc/tree/%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:
-C --no-digit-clamp
Disables clamping of digits that are larger than or equal to the current
ibase when parsing numbers.
This means that the value added to a number from a digit is always that
digit's value multiplied by the value of ibase raised to the power of the
digit's position, which starts from 0 at the least significant digit.
If multiple of this option and the -c option are given, the last is used.
-c --digit-clamp
Enables clamping of digits that are larger than or equal to the current
ibase when parsing numbers.
This means that digits that the value added to a number from a digit that
is greater than or equal to the ibase is the value of ibase minus 1 all
multiplied by the value of ibase raised to the power of the digit's
position, which starts from 0 at the least significant digit.
If multiple of this option and the -C option are given, the last is used.
{{ A H N HN }}
-E seed --seed=seed
Sets the builtin variable seed to the given value assuming that the given
value is in base 10. It is a fatal error if the given value is not a valid
number.
{{ end }}
-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 ibase --ibase=ibase
Sets the builtin variable ibase to the given value assuming that the given
value is in base 10. It is a fatal error if the given value is not a valid
number.
-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.
-O obase --obase=obase
Sets the builtin variable obase to the given value assuming that the given
value is in base 10. It is a fatal error if the given value is not a valid
number.
-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 scale --scale=scale
Sets the builtin variable scale to the given value assuming that the given
value is in base 10. It is a fatal error if the given value is not a valid
number.
-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.
If zero, disable the banner.
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.
If zero, do not reset on SIGINT in all cases, but exit instead.
Overrides the default, which is %s.
BC_TTY_MODE
If an integer and non-zero, enable TTY mode when it is available.
If zero, disable TTY mode in all cases.
Overrides the default, which is TTY mode %s.
BC_PROMPT
If an integer and non-zero, enable prompt when TTY mode is possible.
If zero, disable prompt in all cases.
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.
BC_DIGIT_CLAMP
If an integer and non-zero, clamp digits larger than or equal to the
current ibase when parsing numbers.
Overrides the default, which is %s.
