Chapters:
1: Introduction
2: Simple example
3: Invocation
4: Finer Control
5: X-Y Plots
6: Contour Plots
7: Image Plots
8: Examples
9: Gri Commands
10: Programming
11: Environment
12: Emacs Mode
13: History
14: Installation
15: Gri Bugs
16: Test Suite
17: Gri in Press
18: Acknowledgments
19: License
Indices:
Concepts
Commands
Variables

### 9.3.31: ``query`'

    `query \synonym|.variable. \
      ["\prompt" ["\default"|.default.]]'

Ask the user for the value of a variable (number) or synonym (text string). Gri recognizes the type of the item being asked for, either a variable or synonym, by the presence of a dot or backslash in the second word of the command line. If a prompt string is given (in quotes), then this string is shown to the user. If a default is given (in parentheses), then it will be displayed also, and if the user types carriage-return, then that item will be assigned to the variable or synonym. If the default has more than one item, then Gri considers this a restrictive list of possibilities, and will demand that the answer be in that list, going into an infinite query loop until an item from the list (or carriage-return, meaning take first item) is found. The items in the list are to be separated by spaces, not commas or any other non-whitespace characters.

NOTE: The ``-y`' command-line option bypasses all query commands, fooling Gri into thinking that the user typed a carriage-return to all questions. Thus the defaults, if they exist, are selected.