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Diffstat (limited to 'man/man1/dc.1')
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diff --git a/man/man1/dc.1 b/man/man1/dc.1 new file mode 100644 index 00000000..0f2c13a5 --- /dev/null +++ b/man/man1/dc.1 @@ -0,0 +1,257 @@ +.TH DC 1 +.SH NAME +dc \- desk calculator +.SH SYNOPSIS +.B dc +[ +.I file +] +.SH DESCRIPTION +.I Dc +is an arbitrary precision desk calculator. +Ordinarily it operates on decimal integers, +but one may specify an input base, output base, +and a number of fractional digits to be maintained. +The overall structure of +.I dc +is +a stacking (reverse Polish) calculator. +If an argument is given, +input is taken from that file until its end, +then from the standard input. +The following constructions are recognized: +.TP +number +The value of the number is pushed on the stack. +A number is an unbroken string of the digits +.B 0-9A-F +or +.BR 0-9a-f . +A hexadecimal number beginning with a lower case +letter must be preceded by a zero to distinguish it +from the command associated with the letter. +It may be preceded by an underscore +.B _ +to input a +negative number. +Numbers may contain decimal points. +.TP +.L ++ - / * % ^ +Add +.LR + , +subtract +.LR - , +multiply +.LR * , +divide +.LR / , +remainder +.LR % , +or exponentiate +.L ^ +the top two values on the stack. +The two entries are popped off the stack; +the result is pushed on the stack in their place. +Any fractional part of an exponent is ignored. +.TP +.BI s x +.br +.ns +.TP +.BI S x +Pop the top of the stack and store into +a register named +.IR x , +where +.I x +may be any character. +Under operation +.B S +register +.I x +is treated as a stack and the value is pushed on it. +.TP +.BI l x +.br +.ns +.TP +.BI L x +Push the value in register +.I x +onto the stack. +The register +.I x +is not altered. +All registers start with zero value. +Under operation +.B L +register +.I x +is treated as a stack and its top value is popped onto the main stack. +.TP +.B d +Duplicate the +top value on the stack. +.TP +.B p +Print the top value on the stack. +The top value remains unchanged. +.B P +interprets the top of the stack as an +text +string, +removes it, and prints it. +.TP +.B f +Print the values on the stack. +.TP +.B q +.br +.ns +.TP +.B Q +Exit the program. +If executing a string, the recursion level is +popped by two. +Under operation +.B Q +the top value on the stack is popped and the string execution level is popped +by that value. +.TP +.B x +Treat the top element of the stack as a character string +and execute it as a string of +.I dc +commands. +.TP +.B X +Replace the number on the top of the stack with its scale factor. +.TP +.B "[ ... ]" +Put the bracketed +text +string on the top of the stack. +.TP +.PD0 +.BI < x +.TP +.BI > x +.TP +.BI = x +.PD +Pop and compare the +top two elements of the stack. +Register +.I x +is executed if they obey the stated +relation. +.TP +.B v +Replace the top element on the stack by its square root. +Any existing fractional part of the argument is taken +into account, but otherwise the scale factor is ignored. +.TP +.B ! +Interpret the rest of the line as a shell command. +.TP +.B c +Clear the stack. +.TP +.B i +The top value on the stack is popped and used as the +number base for further input. +.TP +.B I +Push the input base on the top of the stack. +.TP +.B o +The top value on the stack is popped and used as the +number base for further output. +In bases larger than 10, each `digit' prints as a group of decimal digits. +.TP +.B O +Push the output base on the top of the stack. +.TP +.B k +Pop the top of the stack, and use that value as +a non-negative scale factor: +the appropriate number of places +are printed on output, +and maintained during multiplication, division, and exponentiation. +The interaction of scale factor, +input base, and output base will be reasonable if all are changed +together. +.TP +.B z +Push the stack level onto the stack. +.TP +.B Z +Replace the number on the top of the stack with its length. +.TP +.B ? +A line of input is taken from the input source (usually the terminal) +and executed. +.TP +.B "; :" +Used by +.I bc +for array operations. +.PP +The scale factor set by +.B k +determines how many digits are kept to the right of +the decimal point. +If +.I s +is the current scale factor, +.I sa +is the scale of the first operand, +.I sb +is the scale of the second, +and +.I b +is the (integer) second operand, +results are truncated to the following scales. +.IP +.nf +\fL+\fR,\fL-\fR max(\fIsa,sb\fR) +\fL*\fR min(\fIsa\fR+\fIsb \fR, max\fR(\fIs,sa,sb\fR)) +\fL/\fI s +\fL%\fR so that dividend = divisor*quotient + remainder; remainder has sign of dividend +\fL^\fR min(\fIsa\fR\(mu|\fIb\fR|, max(\fIs,sa\fR)) +\fLv\fR max(\fIs,sa\fR) +.fi +.SH EXAMPLES +.EX +[la1+dsa*pla10>y]sy +0sa1 +lyx +.EE +.ns +.IP +Print the first ten values of +.IR n ! +.SH SOURCE +.B /sys/src/cmd/dc.c +.SH "SEE ALSO" +.IR bc (1), +.IR hoc (1) +.SH DIAGNOSTICS +.I x +.LR "is unimplemented" , +where +.I x +is an octal number: an internal error. +.br +`Out of headers' +for too many numbers being kept around. +.br +`Nesting depth' +for too many levels of nested execution. +.SH BUGS +When the input base exceeds 16, +there is no notation for digits greater than +.BR F . +.PP +Past its time. |