1/* 2 * ***************************************************************************** 3 * 4 * SPDX-License-Identifier: BSD-2-Clause 5 * 6 * Copyright (c) 2018-2023 Gavin D. Howard and contributors. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions are met: 10 * 11 * * Redistributions of source code must retain the above copyright notice, this 12 * list of conditions and the following disclaimer. 13 * 14 * * Redistributions in binary form must reproduce the above copyright notice, 15 * this list of conditions and the following disclaimer in the documentation 16 * and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 * 30 * ***************************************************************************** 31 * 32 * The dc help text. 33 * 34 */ 35 36usage: %s [options] [file...] 37 38dc is a reverse-polish notation command-line calculator which supports unlimited 39precision arithmetic. For details, use `man %s` or see the online documentation 40at https://git.gavinhoward.com/gavin/bc/src/tag/%s/manuals/bc/%s.1.md. 41 42This dc is (mostly) compatible with the OpenBSD dc and the GNU dc. See the 43OpenBSD man page (http://man.openbsd.org/OpenBSD-current/man1/dc.1) and the GNU 44dc manual (https://www.gnu.org/software/bc/manual/dc-1.05/html_mono/dc.html) 45for details. 46 47This dc has a few differences from the two above: 48 49 1) When printing a byte stream (command "P"), this bc follows what the FreeBSD 50 dc does. 51 2) This dc implements the GNU extensions for divmod ("~") and modular 52 exponentiation ("|"). 53 3) This dc implements all FreeBSD extensions, except for "J" and "M". 54 4) This dc does not implement the run command ("!"), for security reasons. 55 5) Like the FreeBSD dc, this dc supports extended registers. However, they are 56 implemented differently. When it encounters whitespace where a register 57 should be, it skips the whitespace. If the character following is not 58 a lowercase letter, an error is issued. Otherwise, the register name is 59 parsed by the following regex: 60 61 [a-z][a-z0-9_]* 62 63 This generally means that register names will be surrounded by whitespace. 64 65 Examples: 66 67 l idx s temp L index S temp2 < do_thing 68 69 Also note that, unlike the FreeBSD dc, extended registers are not even 70 parsed unless the "-x" option is given. Instead, the space after a command 71 that requires a register name is taken as the register name. 72 73Options: 74 75 -C --no-digit-clamp 76 77 Disables clamping of digits that are larger than or equal to the current 78 ibase when parsing numbers. 79 80 This means that the value added to a number from a digit is always that 81 digit's value multiplied by the value of ibase raised to the power of the 82 digit's position, which starts from 0 at the least significant digit. 83 84 If multiple of this option and the -c option are given, the last is used. 85 86 -c --digit-clamp 87 88 Enables clamping of digits that are larger than or equal to the current 89 ibase when parsing numbers. 90 91 This means that digits that the value added to a number from a digit that 92 is greater than or equal to the ibase is the value of ibase minus 1 all 93 multiplied by the value of ibase raised to the power of the digit's 94 position, which starts from 0 at the least significant digit. 95 96 If multiple of this option and the -C option are given, the last is used. 97{{ A H N HN }} 98 99 -E seed --seed=seed 100 101 Sets the builtin variable seed to the given value assuming that the given 102 value is in base 10. It is a fatal error if the given value is not a valid 103 number. 104{{ end }} 105 106 -e expr --expression=expr 107 108 Run "expr" and quit. If multiple expressions or files (see below) are 109 given, they are all run. After running, dc will exit. 110 111 -f file --file=file 112 113 Run the dc code in "file" and exit. See above. 114 115 -h --help 116 117 Print this usage message and exit. 118 119 -I ibase --ibase=ibase 120 121 Sets the builtin variable ibase to the given value assuming that the given 122 value is in base 10. It is a fatal error if the given value is not a valid 123 number. 124 125 -i --interactive 126 127 Put dc into interactive mode. See the man page for more details. 128 129 -L --no-line-length 130 131 Disable line length checking. 132 133 -O obase --obase=obase 134 135 Sets the builtin variable obase to the given value assuming that the given 136 value is in base 10. It is a fatal error if the given value is not a valid 137 number. 138 139 -P --no-prompt 140 141 Disable the prompts in interactive mode. 142 143 -R --no-read-prompt 144 145 Disable the read prompt in interactive mode. 146 147 -S scale --scale=scale 148 149 Sets the builtin variable scale to the given value assuming that the given 150 value is in base 10. It is a fatal error if the given value is not a valid 151 number. 152 153 -V --version 154 155 Print version and copyright and exit. 156 157 -x --extended-register 158 159 Enable extended register mode. 160 161 -z --leading-zeroes 162 163 Enable leading zeroes on numbers greater than -1 and less than 1. 164 165Environment variables: 166 167 DC_ENV_ARGS 168 169 Command-line arguments to use on every run. 170 171 DC_LINE_LENGTH 172 173 If an integer, the number of characters to print on a line before 174 wrapping. Using 0 will disable line length checking. 175 176 DC_SIGINT_RESET 177 178 If an integer and non-zero, reset on SIGINT, rather than exit, when in 179 interactive mode. 180 181 If zero, do not reset on SIGINT in all cases, but exit instead. 182 183 Overrides the default, which is %s. 184 185 DC_TTY_MODE 186 187 If an integer and non-zero, enable TTY mode when it is available. 188 189 If zero, disable TTY mode in all cases. 190 191 Overrides the default, which is TTY mode %s. 192 193 DC_PROMPT 194 195 If an integer and non-zero, enable prompt when TTY mode is possible. 196 197 If zero, disable prompt in all cases. 198 199 Overrides the default, which is prompt %s. 200 201 DC_EXPR_EXIT 202 203 If an integer and non-zero, exit when expressions or expression files are 204 given on the command-line, and does not exit when an integer and zero. 205 206 Overrides the default, which is %s. 207 208 DC_DIGIT_CLAMP 209 210 If an integer and non-zero, clamp digits larger than or equal to the 211 current ibase when parsing numbers. 212 213 Overrides the default, which is %s. 214