User manual

Section 2: TSP Programming Fundamentals Series 3700 System Switch/Multimeter Reference Manual
2-44 3700S-901-01 Rev. C / July 2008
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 backward from the end of the string. Thus, the last character is at
position 1, and so on.
-- Returns the internal numerical code of the i-th
character of string s, or nil if the index is out of
range.
string.byte(s [,i])
-- 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.char(i1, i1, …)
-- 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.format(fs, e1, e2, …)
-- Returns the length of the strings.
string.len(s)
-- Returns a copy of the string s with all uppercase
letters changed to lowercase.
string.lower(s)
-- Returns a string that is the concatenation of n copies
of the string s.
string.rep(s, n)
-- Returns the substring of s that starts at i and continues
until j. i and j may be negative. If j is absent, then it
is assumed to be equal to –1, which is the same as the
string length. In particular, the call string.sub(s,1,j)
returns a prefix s with length j, and string.sub(s, -i)
returns a suffix s with length i.
string.sub(s, i [,j])
-- Returns a copy of the string s with all lowercase
letters changed to uppercase.
string.upper(s)