Convert to a valid environment variable name
See also
Other string functions:
as_chr()
,
as_comment_str()
,
as_line_feed_chr()
,
as_str()
,
capitalize_first()
,
dsv_colnames()
,
enum_str()
,
escape_lf()
,
fuse_regex()
,
phrase_nr()
,
sentenceify()
,
wrap_chr()