
\Sexpr\S:  Description

Syntax Summary:  expr expression1 operator expression2

         where:  expressions  are names of files, variable names,
                              regular expressions, or integers.
                 operator  is a logical or arithmetic operator.

Description:
     \Sexpr\S stands for "expression." Use \Sexpr\S to evaluate expressions
     that are composed of two strings and an operator. \Sexpr\S sends the
     value of the expression to standard output.  The primary use for \Sexpr\S
     is in shell programs.  In programs, \Sexpr\S changes the value of shell
     variables through addition, subtraction, multiplication, or division of an
     integer.  \Sexpr\S can also compare strings to a regular expression to
     check for matches, and evaluate expressions with logical operators.  The
     operators are listed on the manual page for \Sexpr\S.
