calc(1) calc(1)
CALC
calc - BASIC-style expression evaluator
SYNOPSIS
calc [-?] [-h] [-s] [-v] [expression[,expression]]
DESCRIPTION
calc is an interactive or command-line expression evaluator using
algebraic notation similar to most BASIC languages. If an expression
is omitted on the command- line then an interactive mode is entered.
During normal command-line use, you may wish to delimit the expression
with single quotes (e.g. '~(2*2+$F4)/4') to avoid shell problems. The
interactive mode has no such problems.
USING ENVIRONMENTAL VARIABLES IN EXPRESSIONS
It is possible to read and write environmental variables from within
calc, using the syntax 'symbol=expression' to write to a variable and
just 'symbol' to read from it. For example, 'A=2,B=3,A*B' will result
in 6 being displayed and it makes calc extremely useful for floating
point calculations in shell scripts of course. However, a limitation
of UNIX is that you cannot change a parent's environment, so an
expression like answer=`calc 'A=2,B=3,A*B'` would have to be used in a
script. As you may have noticed, you can comma-separate expressions on
one line too.
OPTIONS
There are only four options with calc:
-? Display a syntax usage message.
-h Display the interactive help, explaining about expression
syntax.
-s Read from standard input, but don't enter the interactive
mode. Useful for feeding in large files via stdin (either
manually or in a shell script).
-v Display the version number of calc.
BUGS
Need to trap overflow errors better (e.g. try 1000^1000).
SEE ALSO (I WOULDN'T BOTHER)
bc(1), bs(1), dc(1)
AUTHOR
Richard K. Lloyd <richard.lloyd@connectinternetsolutions.com>
- 1 - Formatted: October 26, 2025
