Input and Output

As a supplement to the I/O functions described above two dot commands are available to manipulate files

         
.REWIND <channel>
.CLOSE  <channel>

The channel number can be an expression to be evaluated. The simplest dot command is used as an output function

. <expression>

This evaluates the expression and then writes the resulting character string to the users terminal. This command is therefore a shorthand way of performing

#(6)=<expression>         

since channel 6 is assigned to the system output. The use of assignment commands and this output command provides the user with a powerful interactive calculator. The symbolic names % and %N are assigned to the result of the last expression evaluated and the name last assigned respectively. They are therefore useful when carrying out various stages of a calculation.

qcl>. 10+4
 14.00000
qcl>. %/7
 2.00000