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2600AS-901-01 Rev. B / September 2008
Section 19: Remote Commands
Series 2600A System SourceMeter® Instruments Reference Manual
Table 19-1
Base library functions
String library functions
This library provides generic functions for string manipulation, such as finding and extracting
substrings. When indexing a string in TSL, the first character is at position 1 (not 0 as in ANSI C).
Indices may be negative and are interpreted as indexing backwards, from the end of the string.
Thus, the last character is at position 1, and so on.
print(x)
Prints the argument x to the active host interface, using the
tostring()
function to convert x to a string (note that numbers are
converted to scientific notation using
format.asciiprecision
).
collectgarbage([limit])
Sets the garbage-collection threshold to the given limit (in Kbytes)
and checks it against the byte counter. If the new threshold is smaller
than the byte counter, then TSL immediately runs the garbage
collector. If the limit parameter is absent, it defaults to 0 (thus forcing a
garbage-collection cycle). See
Note
for more information.
gcinfo()
Returns the number of Kbytes of dynamic memory that TSP is using.
tonumber(x [,base])
Returns x converted to a number. If x is already a number, or a
convertible string, then the number is returned; otherwise, it returns
nil.
An optional argument specifies the base to interpret the numeral. The
base may be any integer between 2 and 36, inclusive. In bases above
10, the letter ‘A’ (in either upper or lower case) represents 10, ‘B’
represents 11, and so forth, with ‘Z’ representing 35. In base 10, the
default, the number may have a decimal part, as well as an optional
exponent. In other bases, only unsigned integers are accepted.
tostring(x)
Receives an argument of any type and converts it to a string in a
reasonable format.
type(v)
Returns the type of its only argument, coded as a string. The possible
results of this function are: nil, number, Boolean, table, or function.
NOTE
: TSL does automatic memory management. That means that you do not have to worry about
allocating memory for new objects and freeing it when the objects are no longer needed. TSL manages mem-
ory automatically by running a garbage collector from time to time to collect all dead objects (that is, those
objects that are no longer accessible from TSL). All objects in TSL are subject to automatic management:
tables, variables, functions, threads, and strings. TSL uses two numbers to control its garbage-collection
cycles. One number counts how many bytes of dynamic memory TSL is using; the other is a threshold. When
the number of bytes crosses the threshold, TSL runs the garbage collector, which reclaims the memory of all
dead objects. The byte counter is adjusted, and then the threshold is reset to twice the new value of the byte
counter.
string.byte(s [,i])
Returns the internal numerical code of the i-th character of string
s, or nil if the index is out of range.
string.char(i1, i1, …)
Receives 0 or more integers. Returns a string with length equal
to the number of arguments, in which each character has the
internal numerical code equal to its corresponding argument.
string.format(fs, e1,
e2, …)
Returns a formatted version of its variable number of arguments
following the description given in its first argument, which must
be a string. The format string follows the same rules as the print
family of ANSI C functions. The only differences are that the
options/modifiers *, l, L, n, p, and h are not supported. The
options c, d, E, e, f, g, G, I, o, u, X, and x all expect a numeric
argument, where s expects a string argument. String values to
be formatted with %s cannot contain embedded zeros.
string.len(s)
Returns the length of the strings.
string.lower(s)
Returns a copy of the string s with all uppercase letters changed
to lowercase.
string.rep(s, n)
Returns a string that is the concatenation of n copies of the
string s.