[CLI] Command-line playlist creation

[Ezep]

Description

The current way to create/update playlists is by using GUI menu 'Import Content'. Some CLI parameters on Retroarch would do the creation/update of playlists a lot of easier, specially by using shell scripts or batch files.

Expected behavior

Examples of different scans:

--filescan=FILE Path for a file to be scanned. --dirscan=PATH Path for a folder to be scanned.
--manualscan=PATH Path for a folder to be scanned. (OMMITED if --scansystem or --scancustomsystem is not set).

Examples of manual scan modifications:

--scansystem=SYSTEM Retroarch's system (For example: --scansystem=nes). Default: empty. --scancustomsystem=STRING Custom playlist name. (For example: --scancustomsystem="Never play this again") --scancore=LIBRETRO_CORE Default core of playlist. (For example: --scancore=mesen). Default: empty. --scanext=EXT1[,EXT...] File extensions to be considered. (For example: --scanext=nes,zip). --scanrecursive Include subfolders on scan. --scaninsidearchives Search inside archive files (.zip, .7z, etc). --scandat=FILE Use DAT file to name content. --scandatonly Include content only if matches with information of DAT file. --scanoverwrite Delete existing playlist before scan.

Actual behavior

No way of creating playlists other than GUI.

Steps to reproduce the bug

1. Open terminal
2. Type 'retroarch -h'
3. Hit Enter

Final Notes

I should mention @jdgleaver as requested on Discord.

[jdgleaver]

This is a significant undertaking! I can't give you an ETA, but I shall put it on the TODO list.... :)

[Ezep]

Thanks to add this on the TODO list. I agree with you this is not critical to the near future of Retroarch.

I really hope this blueprint helps devs face the problem in an easier way.

[9p6]

Since 1.16 there is an option for automatic scan from command line:

--scan=PATH|FILE           Import content from path.

Sadly still no option for doing manual scan with DAT.