Prompt Prefix (Units: A Unit Conversion Program and Scientific Calculator)

### 8.3 Prompt Prefix ¶

If a unit system is specified with the `--units` option, the selected system’s name is prepended to the ‘`You have:`’ prompt as a reminder, e.g.,

    (Gaussian) You have: stC
               You want:
            Definition: statcoulomb = sqrt(dyne) cm = 1 sqrt_cm^3 sqrt_g / s

You can suppressed the prefix by including a line

    !prompt

with no argument in a site or personal units data file. The prompt can be conditionally suppressed by including such a line within ‘`!var`’ ... ‘`!endvar`’ constructs, e.g.,

    !var UNITS_SYSTEM gaussian gauss
    !prompt
    !endvar

This might be appropriate if you normally use Gaussian units and find the prefix distracting but want to be reminded when you have selected a different CGS system.