TACL Reference Manual

Lexical Elements

HP NonStop TACL Reference Manual—429513-018

2-6

Question Mark (?)

TACL uses the question mark character for two purposes:

•

Displaying previous command lines

•

Specifying the start of a TACL directive

To start a line with a question mark for any other purpose, use two question marks.

TACL then discards the first question mark and any adjacent spaces and treats the

remainder of the line as text.

Ampersand (&)

An ampersand (&) at the end of a line of TACL commands or function calls signals that

the line continues on the next physical line. This continuation applies to executable

statements and comments, with two exceptions:

•

TACL does not interpret data transmitted by a process or file opened using

#REQUESTER or #SERVER; any special characters are treated as text. If you

receive a line that contains an ampersand, TACL does not view the ampersand as

a continuation character.

•

You cannot use the continuation character with a TACL directive (a line beginning

with a question mark).

Template Characters

Templates are special constructs that allow you to perform simple pattern-matching

operations. For example, the command

FILENAMES c?t

displays all three-letter file names in the default volume and subvolume that begin with

C and end with T, such as CAT or CUT. The command

FILENAMES cat*

displays all file names that begin with CAT, regardless of name length, such as CAT,

CATALOG, or CATERERS. You can use templates to specify several entities with

similar names in a single request. TACL supports templates for file names and

DEFINEs.

Note. TACL strips off comments when converting text from external format to internal format,

so any ampersand that appears before a comment appears to be at the end of the line. This

behavior can cause TACL to treat the next line as a continuation of the previous line.

The maximum line length is 239 characters; if a line is longer than 239 characters, TACL

truncates the line to 239 characters.