String Utilities¶

Since Lua’s string utilities can be a little over-complicated for some tasks, KatieLib provides helper functions which make simpler string operations easy.

knRemoveSuffix(str: string, suffix: string): string¶: If the given suffix occurs at the end of the string, return a string without the suffix. Otherwise, return the string as-is.

knRemovePrefix(str: string, prefix: string): string¶: If the given prefix occurs at the start of the string, return a string without the prefix. Otherwise, return the string as-is.

knSplit( str: string, separator: string, [removeEmpty: boolean], [maxSplit: integer] ): table[string]¶

Split a string by the given separator, returning the pieces in a table.

Setting removeEmpty to true will remove the empty strings that occur e.g. when the separator appears multiple times in a row or at the start and end of a string.

The maximum number of times to split the string before leaving the remaining part in the final element can also be set with maxSplit. This is useful when you only want to split by the first few instances of a separator and leave the rest of the string intact, such as with key=value pairs that allow = to appear in the value.

When using both maxSplit and removeEmpty, the empty strings are considered not to count towards the split total.

Here are some examples that demonstrate various behaviours:

knSplit("This will split by every space!", " ")
   = {"This", "will", "split", "by", "every", "space!"}

knSplit("property=value=thisIsAlsoPartOfTheValue", "=")
   = {"property", "value", "thisIsAlsoPartOfTheValue"}

knSplit("property=value=thisIsAlsoPartOfTheValue", "=", false, 1)
   = {"property", "value=thisIsAlsoPartOfTheValue"}

-- notice that there are two spaces between the first and second value
knSplit(" 0x1234  0x5678 0x9abc", " ")
   = {"", "0x1234", "", "0x5678", "0x9abc"}

knSplit(" 0x1234  0x5678 0x9abc", " ", true)
   = {"0x1234", "0x5678", "0x9abc"}

knSplit(" 0x1234  0x5678 0x9abc", " ", true, 1)
   = {"0x1234", " 0x5678 0x9abc"}

knSplit("Player::hitSomething", "::")
   = {"Player", "hitSomething"}

knSplit(" = = = = ", " = ")
   = {"", "=", "= "}

Example for parsing and applying a line of a patch:

local data = knSplit("0x71574  c0 03 5f d6", " ", true, 1)
local address = tonumber(data[1])
local bytes = knHexToBin(data[2])
knPatch(address, bytes)