Strings (str)

Description

vmod_str implements various helper function to manipulate strings.

API

`INT len(STRING S)`

Returns the number of ascii characters in S, or -1 if S is null.

`BOOL startswith(STRING S1, STRING S2)`

Returns true if S1 starts with S2.

`BOOL endswith(STRING S1, STRING S2)`

Returns true if S1 ends with S2.

`BOOL contains(STRING S1, STRING S2)`

Returns true if S1 contains S2.

`STRING substr(STRING S, INT N, INT OFFSET = 0)`

Returns a substring that is at most abs(N) characters long, from the character at the OFFSET position (negative OFFSET counts from the back of the string). If N is positive, the substring is extracted right of OFFSET, left otherwise.

Example:

substr(“0123456789abcdef”, 2, 5) -> “56”, 2 characters from the 5th one
substr(“0123456789abcdef”, 2, -5) -> “be”, 2 characters from the 5th to last one
substr(“0123456789abcdef”, -2, 5) -> “45”, 2 characters to the 5th one
substr(“0123456789abcdef”, -2, -5) -> “ab”, 2 characters to the 5th to last one
substr(“0123456789abcdef”, 10, 20) -> “abcdef”, truncated because the end of the string was reached.

If S in NULL, NULL is returned.

`STRING reverse(STRING S)`

Reverse S.

`STRING split(STRING S, INT N, STRING SEP = " \t")`

Split S and return the N-th token. Characters in SEP are separators. A negative N indicate “from the end of the string”.

`BOOL token_intersect(STRING S1, STRING S2, SEPARATORS = " ,")`

Checks if the set tokens in one string intersects the set of tokens in the other string. In other words, it returns true if there is a token which exists in both strings.

If the SEPARATORS argument is not supplied, the space and comma characters are the separators. Empty tokens are ignored in both strings.