1/* 2 * ***************************************************************************** 3 * 4 * SPDX-License-Identifier: BSD-2-Clause 5 * 6 * Copyright (c) 2018-2021 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.yzena.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 -e expr --expression=expr 76 77 Run "expr" and quit. If multiple expressions or files (see below) are 78 given, they are all run. After running, dc will exit. 79 80 -f file --file=file 81 82 Run the dc code in "file" and exit. See above. 83 84 -h --help 85 86 Print this usage message and exit. 87 88 -i --interactive 89 90 Put dc into interactive mode. See the man page for more details. 91 92 -L --no-line-length 93 94 Disable line length checking. 95 96 -P --no-prompt 97 98 Disable the prompts in interactive mode. 99 100 -R --no-read-prompt 101 102 Disable the read prompt in interactive mode. 103 104 -V --version 105 106 Print version and copyright and exit. 107 108 -x --extended-register 109 110 Enable extended register mode. 111 112 -z --leading-zeroes 113 114 Enable leading zeroes on numbers greater than -1 and less than 1. 115 116Environment variables: 117 118 DC_ENV_ARGS 119 120 Command-line arguments to use on every run. 121 122 DC_LINE_LENGTH 123 124 If an integer, the number of characters to print on a line before 125 wrapping. Using 0 will disable line length checking. 126 127 DC_SIGINT_RESET 128 129 If an integer and non-zero, reset on SIGINT, rather than exit, when in 130 interactive mode. 131 132 Overrides the default, which is %s. 133 134 DC_TTY_MODE 135 136 If an integer and non-zero, enable TTY mode when it is available. 137 138 Overrides the default, which is TTY mode %s. 139 140 DC_PROMPT 141 142 If an integer and non-zero, enable prompt when TTY mode is possible. 143 144 Overrides the default, which is prompt %s. 145