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calc/help/command
2017-05-21 15:38:30 -07:00

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Command sequence
This is a sequence of any the following command formats, where
each command is terminated by a semicolon or newline. Long command
lines can be extended by using a back-slash followed by a newline
character. When this is done, the prompt shows a double angle
bracket to indicate that the line is still in progress. Certain
cases will automatically prompt for more input in a similar manner,
even without the back-slash. The most common case for this is when
a function is being defined, but is not yet completed.
Each command sequence terminates only on an end of file. In
addition, commands can consist of expression sequences, which are
described in the next section.
NOTE: Calc commands are in lower case. UPPER case is used below
for emphasis only, and should be considered in lower case.
DEFINE function(params) { body }
DEFINE function(params) = expression
This first form defines a full function which can consist
of declarations followed by many statements which implement
the function.
The second form defines a simple function which calculates
the specified expression value from the specified parameters.
The expression cannot be a statement. However, the comma
and question mark operators can be useful. Examples of
simple functions are:
define sumcubes(a, b) = a^3 + b^3;
define pimod(a) = a % pi();
HELP
This displays a general help message.
READ filename
This reads definitions from the specified filename.
The name can be quoted if desired. The calculator
uses the CALCPATH environment variable to search
through the specified directories for the filename,
similarly to the use of the PATH environment variable.
If CALCPATH is not defined, then a default path which is
usually ":/usr/local/lib/calc" is used (that is, the current
directory followed by a general calc library directory).
The ".cal" extension is defaulted for input files, so
that if "filename" is not found, then "filename.cal" is
then searched for. The contents of the filename are
command sequences which can consist of expressions to
evaluate or functions to define, just like at the top
level command level.
If the -m mode disallows opening of files for reading,
this command will be disabled.
READ -once filename
This command acts like the regular READ expect that it
will ignore filename if is has been previously read.
This command is particularly useful in a library that
needs to read a 2nd library. By using the READ -once
command, one will not reread that 2nd library, nor will
once risk entering into a infinite READ loop (where
that 2nd library directly or indirectly does a READ of
the first library).
If the -m mode disallows opening of files for reading,
this command will be disabled.
WRITE filename
This writes the values of all global variables to the
specified filename, in such a way that the file can be
later read in order to recreate the variable values.
For speed reasons, values are written as hex fractions.
This command currently only saves simple types, so that
matrices, lists, and objects are not saved. Function
definitions are also not saved.
If the -m mode disallows opening of files for writing,
this command will be disabled.
QUIT
This leaves the calculator, when given as a top-level
command.
ABORT
Forces an immediate quit regardless calc command line
flags and termina state.
CD
Change the current directory to the home directory, if $HOME
is set in the environment.
CD dir
Change the current directory to dir.
Also see the help topic:
statement flow control and declaration statements
usage for -m modes