From 058b0118a52061ad57694c01fc8763b22b789c4d Mon Sep 17 00:00:00 2001 From: rsc Date: Mon, 3 Jan 2005 06:40:20 +0000 Subject: Some man pages. --- man/man1/bc.1 | 292 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 292 insertions(+) create mode 100644 man/man1/bc.1 (limited to 'man/man1/bc.1') diff --git a/man/man1/bc.1 b/man/man1/bc.1 new file mode 100644 index 00000000..9bb0f08e --- /dev/null +++ b/man/man1/bc.1 @@ -0,0 +1,292 @@ +.TH BC 1 +.SH NAME +bc \- arbitrary-precision arithmetic language +.SH SYNOPSIS +.B bc +[ +.B -c +] +[ +.B -l +] +[ +.B -s +] +[ +.I file ... +] +.SH DESCRIPTION +.I Bc +is an interactive processor for a language that resembles +C but provides arithmetic on numbers of arbitrary length with up +to 100 digits right of the decimal point. +It takes input from any files given, then reads +the standard input. +The +.B -l +argument stands for the name +of an arbitrary precision math library. +The +.B -s +argument suppresses the automatic display +of calculation results; all output is via the +.B print +command. +.PP +The following syntax for +.I bc +programs is like that of C; +.I L +means letter +.BR a - z , +.I E +means expression, +.I S +means statement. +.TF length(E) +.TP +Lexical +.RS +.HP +comments are enclosed in +.B /* */ +.HP +newlines end statements +.RE +.TP +Names +.IP +simple variables: +.I L +.br +array elements: +.IB L [ E ] +.br +The words +.BR ibase , +.BR obase , +and +.B scale +.TP +Other operands +.IP +arbitrarily long numbers with optional sign and decimal point. +.RS +.TP +.BI ( E ) +.TP +.BI sqrt( E ) +.TP +.BI length( E ) +number of significant decimal digits +.TP +.BI scale( E ) +number of digits right of decimal point +.TP +.IB L ( E , ... ,\fIE\fP) +function call +.RE +.TP +Operators +.RS +.HP +.B "+ - * / % ^\ " +.RB ( % +is remainder; +.B ^ +is power) +.HP +.B "++ --\ " +.TP +.B "== <= >= != < >" +.TP +.B "= += -= *= /= %= ^=" +.RE +.TP +Statements +.RS +.br +.I E +.br +.B { +.I S +.B ; +\&... +.B ; +.I S +.B } +.br +.B "print" +.I E +.br +.B "if (" +.I E +.B ) +.I S +.br +.B "while (" +.I E +.B ) +.I S +.br +.B "for (" +.I E +.B ; +.I E +.B ; +.I E +.B ")" +.I S +.br +null statement +.br +.B break +.br +.B quit +.br +\fL"\fRtext\fL"\fR +.RE +.TP +Function definitions +.RS +.br +.B define +.I L +.B ( +.I L +.B , +\&... +.B , +.I L +.B ){ +.PD0 +.br +.B auto +.I L +.B , +\&... +.B , +.I L +.br +.I S +.B ; +\&... +.B ; +.I S +.br +.B return +.I E +.LP +.B } +.RE +.TP +Functions in +.B -l +math library +.RS +.TP +.BI s( x ) +sine +.TP +.BI c( x ) +cosine +.TP +.BI e( x ) +exponential +.TP +.BI l( x ) +log +.TP +.BI a( x ) +arctangent +.TP +.BI j( "n, x" ) +Bessel function +.RE +.PP +.DT +All function arguments are passed by value. +.PD +.PP +The value of an expression at the top level is printed +unless the main operator is an assignment or the +.B -s +command line argument is given. +Text in quotes, which may include newlines, is always printed. +Either semicolons or newlines may separate statements. +Assignment to +.B scale +influences the number of digits to be retained on arithmetic +operations in the manner of +.IR dc (1). +Assignments to +.B ibase +or +.B obase +set the input and output number radix respectively. +.PP +The same letter may be used as an array, a function, +and a simple variable simultaneously. +All variables are global to the program. +Automatic variables are pushed down during function calls. +In a declaration of an array as a function argument +or automatic variable +empty square brackets must follow the array name. +.PP +.I Bc +is actually a preprocessor for +.IR dc (1), +which it invokes automatically, unless the +.B -c +(compile only) +option is present. +In this case the +.I dc +input is sent to the standard output instead. +.SH EXAMPLE +Define a function to compute an approximate value of +the exponential. +Use it to print 10 values. +(The exponential function in the library gives better answers.) +.PP +.EX +scale = 20 +define e(x) { + auto a, b, c, i, s + a = 1 + b = 1 + s = 1 + for(i=1; 1; i++) { + a *= x + b *= i + c = a/b + if(c == 0) return s + s += c + } +} +for(i=1; i<=10; i++) print e(i) +.EE +.SH FILES +.B /sys/lib/bclib +mathematical library +.SH SOURCE +.B /usr/local/plan9/src/cmd/bc.y +.SH "SEE ALSO" +.IR dc (1), +.IR hoc (1) +.SH BUGS +No +.LR && , +.LR || , +or +.L ! +operators. +.br +A +.L for +statement must have all three +.LR E s. +.br +A +.L quit +is interpreted when read, not when executed. -- cgit v1.2.3