Performs one of several string operations, depending on
option. The legal options (which may
be abbreviated) are:
string comparestring1 string2
Performs a character-by-character comparison of strings
string1 and string2 in the same way as
the C strcmp procedure. It returns -1, 0, or 1,
depending on whether string1 is lexicographically
less than, equal to, or greater than string2.
string firststring1 string2
Searches string2 for a sequence of characters
that exactly match the characters in string1. If
found, it returns the index of the first character in the
first such match within string2. If not found,
it returns -1.
string indexstring charIndex
Returns the charIndex'th character of the
string argument. A charIndex of 0
corresponds to the first character of the string. If
charIndex is less than 0 or greater than or equal
to the length of the string then an empty string is
returned.
string laststring1 string2
Searches string2 for a sequence of characters
that exactly match the characters in string1. If
found, it returns the index of the first character in the
last such match within string2. If there is no
match, then it returns -1.
string lengthstring
Returns a decimal string giving the number of characters in
string.
string matchpatternstring
Checks if pattern matches string;
returns 1 if it does, 0 if it doesn't. Matching is done in
a fashion similar to that used by the C-shell. For the two
strings to match, their contents must be identical except
that the following special sequences may appear in
pattern:
Matches any sequence of characters in string,
including a null string.
?
Matches any single character in string.
[chars]
Matches any character in the set given by chars.
If a sequence of the form
x-y appears in
chars, then any character between x and
y, inclusive, will match.
\x
Matches the single character x. This provides a
way of avoiding the special interpretation of the
characters ?[]\ in pattern.
string rangestring first last
Returns a range of consecutive characters from
string, starting with the character whose index
is first and ending with the character whose
index is last. An index of 0 refers to the first
character of the string. last may be
end (or any abbreviation of it) to refer to the
last character of the string. If first is less
than zero then it is treated as if it were zero, and if
last is greater than or equal to the length of
the string then it is treated as if it were end.
If first is greater than last then an
empty string is returned.
string tolowerstring
Returns a value equal to string except that all
upper case letters have been converted to lower case.
string toupperstring
Returns a value equal to string except that all
lower case letters have been converted to upper case.
string trimstring [chars]
Returns a value equal to string except that any
leading or trailing characters from the set given by
chars are removed. If chars is not
specified then white space is removed (spaces, tabs,
newlines, and carriage returns).
string trimleftstring [chars]
Returns a value equal to string except that any
leading characters from the set given by chars
are removed. If chars is not specified then
white space is removed (spaces, tabs, newlines, and
carriage returns).
string trimrightstring [chars]
Returns a value equal to string except that any
trailing characters from the set given by chars are
removed.
If chars is not specified then white space is removed
(spaces, tabs, newlines, and carriage returns).