term% cat index.txt HOC(1) General Commands Manual HOC(1)
NAME
hoc - interactive floating point language
SYNOPSIS
hoc [ file ... ]
DESCRIPTION
Hoc interprets a simple language for floating point arithmetic, at
about the level of BASIC, with C-like syntax and functions.
The named files are read and interpreted in order. If no file is given
or if file is `-' hoc interprets the standard input.
Hoc input consists of expressions and statements. Expressions are
evaluated and their results printed. Statements, typically assignments
and function or procedure definitions, produce no output unless they
explicitly call print.
Variable names are the usual syntax, including `_'; the name `_' by it‐
self contains the value of the last expression evaluated. The vari‐
ables E, PI, PHI, GAMMA and DEG are predefined; the last is 59.25...,
degrees per radian.
Expressions are formed with these operators:
^ exponentiation
! - ++ -- unary logical and arithmetic negation, ...
* / % the obvious
+ - ditto
> >= < <= == !=
&&
||
= += -= ∗= /= %=
Built in functions include abs, atan (one argument), cos, exp, int,
log, log10, sin, and sqrt. The function read(x) reads a value into the
variable x; the statement print prints a list of expressions that may
include string constants such as "hello\n".
Control flow includes if-else, while, and for, with braces for group‐
ing. End of line marks end of statement, as does a semicolon.
Functions and procedures are introduced by the words func and proc; re‐
turn is used to return, with a value from a function. Within a func‐
tion or procedure, arguments are referred to as $1, $2, etc.; all other
variables are global.
SEE ALSO
The Unix Programming Environment by Brian Kernighan and Rob Pike.
bc(1), dc(1)
BUGS
Error recovery is imperfect within function and procedure definitions.
The treatment of newlines is not exactly user-friendly.
HOC(1)