[Feature Request] Add json based output API to make output friendly to frontends

[mhogomchungu]

wget2 seems to always expect to be run from the terminal and it always send control terminal control characters even when its output is directed to a file or when its output is connected to a pipe.

The feature request is the addition of json based output to make it easy for frontends to parse wget2 output regardless of how many simultaneous downloads are taking place.

[rockdaboot]

Control characters are part of progress output, you can suppress that with --progress=none.

Not sure which information you want to have exactly.

Did you look at --stats-site? It's CSV output.

--stats-site=[FORMAT:]FILE

Save Site stats in format FORMAT, in file FILE.

FORMAT can be human or csv. - is shorthand for stdout and h is shorthand for human.

The CSV output format is

ID,ParentID,URL,Status,Link,Method,Size,SizeDecompressed,TransferTime,ResponseTime,Encoding,Verification

`ID` unique ID for a stats record.

`ParentID` ID of the parent document, relevant for `--recursive` mode.

`URL` URL of the document.

`Status` HTTP response code or 0 if not applicable.

`Link` 1 means 'direkt link', 0 means 'redirection link'.

`Method` 1,2,3 mean GET, HEAD, POST request type.

`Size` size of downloaded body (theoretical value for HEAD requests).

`SizeDecompressed` size of decompressed body (0 for HEAD requests).

`TransferTime` ms between start of request and completed download.

`ResponseTime` ms between start of request and first response packet.

`Encoding` 0,1,2,3,4,5 mean server side compression was 'identity', 'gzip', 'deflate', 'lzma/xz', 'bzip2', 'brotli', 'zstd', 'lzip'

`Verification` PGP verification status. 0,1,2,3 mean 'none',  'valid', 'invalid', 'bad', 'missing'.