@param plugin in Restricts schemes to only those from 'plugin.
@param sc_list out Filled out with the scheme names
@param nschemes [in/out] Size of sc_list (in) and number returned (out)
Plugin may be passed in as NULL in which case all schemes are returned.
Use plugin "built-in" to list the built in schemes.
The size of sc_list is determined by the input value of *nschemes.
This is updated to return the output size. It is up to the caller to
determine whether to call again with a larger number if this is too small.
The return value represents the total number found matching plugin, which
may be larger than *nschemes if too small a value was specified.
@return the number of schemes found on success.
-1 on failure
@param plugin in Restricts schemes to only those from 'plugin. @param sc_list out Filled out with the scheme names @param nschemes [in/out] Size of sc_list (in) and number returned (out)
Plugin may be passed in as NULL in which case all schemes are returned. Use plugin "built-in" to list the built in schemes. The size of sc_list is determined by the input value of *nschemes. This is updated to return the output size. It is up to the caller to determine whether to call again with a larger number if this is too small.
The return value represents the total number found matching plugin, which may be larger than *nschemes if too small a value was specified.
@return the number of schemes found on success. -1 on failure