Escape all special characters (i.e. everything except for a-z, A-Z, 0-9, '-', '.', '_' or '~') for use in URLs.
curl_escape(url)
curl_unescape(url)
# Escape strings
out <- curl_escape("foo = bar + 5")
curl_unescape(out)
#> [1] "foo = bar + 5"
# All non-ascii characters are encoded
mu <- "\u00b5"
curl_escape(mu)
#> [1] "%C2%B5"
curl_unescape(curl_escape(mu))
#> [1] "µ"