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	hoc.1 - 9base - revived minimalist port of Plan 9 userland to Unix
	git clone git://git.suckless.org/9base
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	hoc.1 (2356B)
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	1 .TH HOC 1
	2 .SH NAME
	3 hoc \- interactive floating point language
	4 .SH SYNOPSIS
	5 .B hoc
	6 [
	7 .I file ...
	8 ]
	9 [
	10 .B -e
	11 .I expression
	12 ]
	13 .SH DESCRIPTION
	14 .I Hoc
	15 interprets a simple language for floating point arithmetic,
	16 at about the level of BASIC, with C-like syntax and
	17 functions.
	18 .PP
	19 The named
	20 .I files
	21 are read and interpreted in order.
	22 If no
	23 .I file
	24 is given or if
	25 .I file
	26 is
	27 .L -
	28 .I hoc
	29 interprets the standard input.
	30 The
	31 .B -e
	32 option allows input to
	33 .I hoc
	34 to be specified on the command line, to be treated as if it appeared in …
	35 .PP
	36 .I Hoc
	37 input consists of
	38 .I expressions
	39 and
	40 .IR statements .
	41 Expressions are evaluated and their results printed.
	42 Statements, typically assignments and function or procedure
	43 definitions, produce no output unless they explicitly call
	44 .IR print .
	45 .PP
	46 Variable names have the usual syntax, including
	47 .LR _ ;
	48 the name
	49 .L _
	50 by itself contains the value of the last expression evaluated.
	51 The variables
	52 .BR E ,
	53 .BR PI ,
	54 .BR PHI ,
	55 .BR GAMMA
	56 and
	57 .B DEG
	58 are predefined; the last is 59.25..., degrees per radian.
	59 .PP
	60 Expressions are formed with these C-like operators, listed by
	61 decreasing precedence.
	62 .TP
	63 .B ^
	64 exponentiation
	65 .TP
	66 .B ! - ++ --
	67 .TP
	68 .B * / %
	69 .TP
	70 .B + -
	71 .TP
	72 .B > >= < <= == !=
	73 .TP
	74 .B &&
	75 .TP
	76 .B \|\|
	77 .TP
	78 .B = += -= *= /= %=
	79 .PP
	80 Built in functions are
	81 .BR abs ,
	82 .BR acos ,
	83 .BR asin ,
	84 .B atan
	85 (one argument),
	86 .BR cos ,
	87 .BR cosh ,
	88 .BR exp ,
	89 .BR int ,
	90 .BR log ,
	91 .BR log10 ,
	92 .BR sin ,
	93 .BR sinh ,
	94 .BR sqrt ,
	95 .BR tan ,
	96 and
	97 .BR tanh .
	98 The function
	99 .B read(x)
	100 reads a value into the variable
	101 .B x
	102 and returns 0 at EOF;
	103 the statement
	104 .B print
	105 prints a list of expressions that may include
	106 string constants such as
	107 \fL"hello\en"\f1.\fP
	108 .PP
	109 Control flow statements are
	110 .BR if - else ,
	111 .BR while ,
	112 and
	113 .BR for ,
	114 with braces for grouping.
	115 Newline ends a statement.
	116 Backslash-newline is equivalent to a space.
	117 .PP
	118 Functions and procedures are introduced by the words
	119 .B func
	120 and
	121 .BR proc ;
	122 .B return
	123 is used to return with a value from a function.
	124 .SH EXAMPLES
	125 .EX
	126 func gcd(a, b) {
	127 temp = abs(a) % abs(b)
	128 if(temp == 0) return abs(b)
	129 return gcd(b, temp)
	130 }
	131 for(i=1; i<12; i++) print gcd(i,12)
	132 .EE
	133 .SH SOURCE
	134 .B \*9/src/cmd/hoc
	135 .SH "SEE ALSO"
	136 .IR bc (1),
	137 .IR dc (1)
	138 .br
	139 B. W. Kernighan and R. Pike,
	140 .I
	141 The Unix Programming Environment,
	142 Prentice-Hall, 1984
	143 .SH BUGS
	144 Error recovery is imperfect within function and procedure definitions.