SPAR(1)SPAR(1)NAMEspar - a modular console calculator
SYNOPSISspar [options] [--] expression
DESCRIPTION
Spar is a console calculator, primarily intended for problem solving in
arbitrary precision. It supports also modules (aka code that can be
loaded dynamically) and a number of other features, such as: user vari‐
ables, functions, and constants.
OPTIONS
-d, --decimals
Set the decimal precision (number of digits printed after
the point).
-i, --integers
Set the integer precision (number of digits printed before
the point).
-c, --config
Use a user-defined modules configuration file.
-q, --quiet
Don't display the welcome message.
-h, --help
Display usage information and exit.
-v, --version
Print version information and exit.
-- Terminate option list: now all arguments is interpreted as
an expression to evaluate.
NUMBERS
The most basic element in spar is the number. Numbers are dou‐
ble precision numbers. All numbers are represented internally as
a standard C double variable. There are no attributes of num‐
bers, but the precision can affect the number output. This pre‐
cision is both in the integer part and the decimal part.
For example: The number 0.123456789 is represented internally as
a double precision variable, but if we change the precision, the
output will change: 0.123456789 = 0.123457
VARIABLES
Numbers can be stored in named variables. Variable names begin
with a letter followed by any number of letters, digits and
underscores. The variable names are case sensitive. Variables
may have values assigned to them as well as used in expressions
and it contains a special data member that stores the "previous"
value".
To declare a variable you must supply both a name and a value.
Any undeclared variable generate an error. For example, to
declare the variable i of value 5 enter:
i = 5
CONSTANTS
Constants are special variables that is read-only. This means
that you can read a constant value but you can modify. There is
a number of "preloaded" variables such as "e", "pi" ecc.
FUNCTIONSspar support a number of often used scientific functions
(directly from The Spar Library). For example, to get the value
of the natural logarithm in 0 enter:
log(0)
Trig Functions
These are the familiar `sin', `cos', and `tan' functions. The
arguments to all of these functions are in units of radians;
recall that pi radians equals 180 degrees.
Inverse Trig Functions
These are the usual arc sine, arc cosine and arc tangent func‐
tions, which are the inverses of the sine, cosine and tangent
functions respectively.
Exponents and Logarithms
These are the 'exp' group, 'log' group, 'pow' group and 'sqrt'
group.
Hyperbolic Functions
sinh, cosh, tanh. The functions in this section are related to
the exponential functions.
Inverse Hyperbolic Functions
asinh, acosh, atanh. The functions in this section are related
to the Hyperbolicfunctions.
Infinite Functions
isnan, finite, isinf.
Special Functions
Factorial, sum, and other specific spar functions.
EXPRESSIONS
The numbers are manipulated by expressions and statements.
Since the math parser was implemented to be interactive, state‐
ments and expressions are executed as soon as possible.
A simple expression is just a constant. spar displays constants
using the current precision (see OPTIONS). Full expressions are
similar to many other high level languages. Since there is only
one kind of number, there are no rules for mixing types.
In the following descriptions of legal expressions, "expr"
refers to a complete expression and "var" refers to a simple
variable.
- expr The result is the negation of the expression.
expr + expr
The result of the expression is the sum of the two
expressions.
expr - expr
The result of the expression is the difference of the two
expressions.
expr * expr
The result of the expression is the product of the two
expressions.
expr / expr
The result of the expression is the quotient of the two
expressions.
expr % expr
The result of the expression is the "remainder" and it is
computed in the following way.
expr ^ expr
The result of the expression is the value of the first
raised to the second.
( expr )
This alters the standard precedence to force the evalua‐
tion of the expression.
var = expr
The variable is assigned the value of the expression.
var This prints variable value's: note that "var" could be
also a constant.
COMMANDS
help Print a brief commands notice. If a command name is sup‐
plied print a detailed command report.
warranty
Print a longer warranty notice. No arguments.
comment
Add a comment to a variable. At least two arguments.
consts Print the built-in constants table. No arguments.
funcs Print the built-in functions table. No arguments.
modules
Print the all loaded modules. No arguments.
old Swap the current variable value with the old one. One
argument.
quit Program termination.
run Run a module. Note that you must supply a valid module
name otherwise, the list of the loaded modules is
printed.
vars Print all user variables.
FEATURES
Spar supports terminal features (termios) to allow the program
to be more user-friendly and also more robust.
READLINE OPTION
Spar can be compiled (via configure script) to use the GNU read‐
line input editor library. This allows the user to do more
editing of lines before sending them to spar.
It also allows for a history of previous lines typed: the his‐
tory can be viewed by '´ key, whereas the readline auto-comple‐
tion was implemented by the TAB key. For more information, read
the user manuals for the GNU readline and history libraries.
Instead the key '!' run the last command and, finally the key
':' can be used to display a specific history item. For example:
':1' shows the first history item.
SIGNALS SUPPORT
During a session, the SIGINT signal (usually generated by the
control-C character from the terminal), SIGSTP signal (usually
generated by the control-Z character from the terminal) and
SIGTERM signal will cause execution to be interrupted. After all
run-time structures have been cleaned up, a message will be
printed to notify the user that spar is aborted. All variables
and modules are removed during the clean up process.
TERMCAP SUPPORT
The control key EOF is inhibited. spar restore this setting on
exit.
BUGS
The best way to submit a bug report for Spar is to use the file
BUG-REPORT, that will enable me to fix the problem. Please visit
the Spar homepages at:
http://spar.sourceforge.net/index.html (main site)
http://web.tiscalinet.it/Davide18/index.html
for the latest version, patches and documentation.
FILES
/usr/local/bin/spar Spar
/usr/local/lib/libspar.so Spar Library
/usr/local/include/spar/* Spar Headers
/usr/local/lib/spar/* Spar modules
/usr/local/share/spar/modules_config Spar modules config
AUTHOR
Davide Angelocola davide178@inwind.it
ACKNOWLEDGMENTS
The author would like to thank Sebastian Ritterbusch (Ras‐
cal@Ritterbusch.de) for his extensive help in testing the pro‐
gram and the documentation. Many great suggestions were given.
Please visit his website http://rascal.sourceforge.net or the
sourceforge project at http://sourceforge.net/projects/rascal.
SEE ALSObc(1) An arbitrary precision calculator language
Spar can be used also as library, a API reference can be founded
via web at http://sourceforge.net/projects/spar. Please help me
to extend and correct it.
26 Jun 2001 SPAR(1)
