existence EXISTS first checks the User Scripts
folder and then Scripts folder. It sets
_$filerror to zero if the file exists and to a
nonzero value if the file does not exist.
The STN Express Script Language has few general syntax
requirements. However, each statement has its own syntax.
More than one statement may appear on the same line, or
each statement may be typed on its own line.
The keywords in the Script Language are not case-
sensitive. For example, the EXIT statement may be written
EXIT or exit.
Upper- and lowercase are significant in character strings.
For example, "Yes" is different from "yes".
Blank lines may appear anywhere.
Blanks and space characters may appear anywhere.
However, they are significant in strings (inside double
quotes). For example, "STNExpress" is different from "STN
A line in a script is limited to 80 characters, but a single
script statement can be 140 characters long. To continue a
statement on the next line, put a backslash, \, at the end of
each line that is continued on the next line.
Enclose strings in double quotes.
Comments are notes that describe or explain the script, and
they are ignored by the script processor. Comments begin
with \* and continue until the end of the line. Comments may
appear on lines of their own, or they may appear at the end
of any statement except the Prompt Statement.
STN commands can be up to 256 characters in length.
The Script Language is composed of "keywords" and "values."
Keywords are words that have special meaning in the Script Language.
Values are pieces of data in the form of variables, strings, numbers, or
file names. A "statement" has at least one keyword, and some
statements have parameters. A "parameter" is the object of the
statement and may be a keyword, a value, or a combination of
keywords and values. You can sometimes think of statements as having
verbs and objects. For example, in the statement GET _author, GET is
the verb and _author is the object (parameter).
The conventions used to describe the STN Express Script Language
1. Keywords are shown in uppercase letters, e.g., EXIT.