core-lightning/doc/lightning-waitinvoice.7.md
Vasil Dimov 55173a56b7 Use dedicated type for error codes
Before this patch we used `int` for error codes. The problem with
`int` is that we try to pass it to/from wire and the size of `int` is
not defined by the standard. So a sender with 4-byte `int` would write
4 bytes to the wire and a receiver with 2-byte `int` (for example) would
read just 2 bytes from the wire.

To resolve this:

* Introduce an error code type with a known size:
  `typedef s32 errcode_t`.

* Change all error code macros to constants of type `errcode_t`.
  Constants also play better with gdb - it would visualize the name of
  the constant instead of the numeric value.

* Change all functions that take error codes to take the new type
  `errcode_t` instead of `int`.

* Introduce towire / fromwire functions to send / receive the newly added
  type `errcode_t` and use it instead of `towire_int()`.

In addition:

* Remove the now unneeded `towire_int()`.

* Replace a hardcoded error code `-2` with a new constant
  `INVOICE_EXPIRED_DURING_WAIT` (903).

Changelog-Changed: The waitinvoice command would now return error code 903 to designate that the invoice expired during wait, instead of the previous -2
2020-01-31 06:02:47 +00:00

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lightning-waitinvoice -- Command for waiting for specific payment
=================================================================
SYNOPSIS
--------
**waitinvoice** *label*
DESCRIPTION
-----------
The **waitinvoice** RPC command waits until a specific invoice is paid,
then returns that single entry as per **listinvoice**.
RETURN VALUE
------------
On success, an invoice description will be returned as per
lightning-listinvoice(7). The *status* field will be *paid*.
On error the returned object will contain `code` and `message` properties,
with `code` being one of the following:
- -32602: If the given parameters are wrong.
- -1: If the invoice is deleted while unpaid, or the invoice does not exist.
- 903: If the invoice expires before being paid, or is already expired.
AUTHOR
------
Christian Decker <<decker.christian@gmail.com>> is mainly
responsible.
SEE ALSO
--------
lightning-waitanyinvoice(7), lightning-listinvoice(7),
lightning-delinvoice(7), lightning-invoice(7)
RESOURCES
---------
Main web site: <https://github.com/ElementsProject/lightning>