2 * *****************************************************************************
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6 * Copyright (c) 2018-2021 Gavin D. Howard and contributors.
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36 usage: %s [options] [file...]
38 dc is a reverse-polish notation command-line calculator which supports unlimited
39 precision arithmetic. For details, use `man %s` or see the online documentation
40 at https://git.yzena.com/gavin/bc/src/tag/%s/manuals/bc/%s.1.md.
42 This dc is (mostly) compatible with the OpenBSD dc and the GNU dc. See the
43 OpenBSD man page (http://man.openbsd.org/OpenBSD-current/man1/dc.1) and the GNU
44 dc manual (https://www.gnu.org/software/bc/manual/dc-1.05/html_mono/dc.html)
47 This dc has a few differences from the two above:
49 1) When printing a byte stream (command "P"), this bc follows what the FreeBSD
51 2) This dc implements the GNU extensions for divmod ("~") and modular
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:
63 This generally means that register names will be surrounded by whitespace.
67 l idx s temp L index S temp2 < do_thing
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.
75 -e expr --expression=expr
77 Run "expr" and quit. If multiple expressions or files (see below) are
78 given, they are all run. After running, dc will exit.
82 Run the dc code in "file" and exit. See above.
86 Print this usage message and exit.
90 Put dc into interactive mode. See the man page for more details.
94 Disable line length checking.
98 Disable the prompts in interactive mode.
102 Disable the read prompt in interactive mode.
106 Print version and copyright and exit.
108 -x --extended-register
110 Enable extended register mode.
114 Enable leading zeroes on numbers greater than -1 and less than 1.
116 Environment variables:
120 Command-line arguments to use on every run.
124 If an integer, the number of characters to print on a line before
125 wrapping. Using 0 will disable line length checking.
129 If an integer and non-zero, reset on SIGINT, rather than exit, when in
132 Overrides the default, which is %s.
136 If an integer and non-zero, enable TTY mode when it is available.
138 Overrides the default, which is TTY mode %s.
142 If an integer and non-zero, enable prompt when TTY mode is possible.
144 Overrides the default, which is prompt %s.