ref: 82a3f55c5fb7b9f7a82449e4eb943c535ec3e491
dir: /man/1/fc/
.TH FC 1 .SH NAME fc \- command-line floating point calculator .SH SYNOPSIS .B fc [ .I base ] .I expression .br .SH DESCRIPTION .B Fc calculates the result of its argument .I expression and prints the result in the format indicated by the optional base argument. .I Base can be one of: .TP .B -d Decimal, as produced by the .B %g format of .IR sys-print (2). .br .TP .B -x Hexadecimal, prefixed with .BR 0x . .TP .B -o Octal, prefixed with .BR 0 . .TP .B -b Binary, prefixed with .BR 0b . .TP .B -B As .BR -b , but with extra lines to help bit-counting. .TP .BI -r\ radix In base .IR radix , prefixed with .IB \fR``\fPradix r\fR'',\fP as understood by Limbo (e.g. .BR 16r3fff ). .TP .B -c As a unicode character, prefixed with .BR @ . .RE .PP .I Expression is in reverse polish notation: each command line argument is either an operand (number) or an operator. Operands are pushed on a stack; operators pop items from the stack (the number of items depends on the operator) and push their result. All operands are converted to double precision floating point numbers before being pushed. Integer operations convert their operands to big (64-bit) integers. When all arguments are exhausted, all the values currently on the stack are printed, first-pushed first, in the specified output format. .PP Operands can be given in any of the formats that .I fc can print, as detailed above. .PP When an operation is not commutative, the argument values will be taken from the stack first-pushed first. Most functions from from .IR math-elem (2), .IR math-fp(2) are provided. In addition, other provided operators include: .TP .B + - / x Representing the four rules. Note the use of .B x rather than .BR * , to avoid clashes with shell metacharacters. .br .TP .B xx To the power. (equivelant to 'pow') .br .TP .B rad deg Convert value to or from radians. .br .TP ! Factorial. .br .TP .B _ Unary minus. .br .TP .B and or xor not Bitwise operations. .br .TP .B shl shr Bitwise shift left/right. .TP .B p Print the current top value on the stack. .br .TP .B sum Sum all the values currently pushed on the stack. .br .TP .B swap Swap the top two stack items. .br .TP .B dup Duplicate the top item on the stack. .br .TP .B rep Repeatedly execute the last operator until there is only only one item left on the stack. This is only valid for operators that take exactly two arguments. .RE .PP A few symbolic names for operands are recognised, including .B pi (or .BR π ), .BR e , and .BR macheps . .SH EXAMPLES .PP fc 22 7 / .PP .nf gives 3.1428571429 .fi .PP fc -b 1 2 3 4 sum .PP .nf gives 0b00001010 .fi .PP fc 10 0b10 010 0x10 x rep 0xa00 swap - .PP .nf gives 0 .fi .PP fc -help .PP .nf gives a usage summary, including a list of the names of all the operators. .fi .ne 5 .SH SEE ALSO .IR calc (1), .IR math-fp (2), .IR math-elem (2), .IR sh-expr (1) .SH DIAGNOSTICS An error message is displayed if an operator is called on a stack with too few elements. This also causes .I fc to yield a non-null exit status. .SH BUGS The .B -B option will only work for fixed-width fonts.