* Related to the contents of the buffer
+`strbuf_trim`::
+
+ Strip whitespace from the beginning and end of a string.
+ Equivalent to performing `strbuf_rtrim()` followed by `strbuf_ltrim()`.
+
`strbuf_rtrim`::
Strip whitespace from the end of a string.
+`strbuf_ltrim`::
+
+ Strip whitespace from the beginning of a string.
+
`strbuf_tolower`::
Lowercase each character in the buffer using `tolower`.