Join server directly after launching the game

[MkSui]

i want to join server automatically
but
launch 1.19 -commands "--server 1.1.1.1"
launch 1.19 -commands "--server" "1.1.1.1"
launch 1.19 -commands "server 1.1.1.1"
Not working at all

[3arthqu4ke]

Sorry but that's not possible and I'm not sure where you got the idea from that it is. In order to support this I would have to write specific code for every single Minecraft version.

You could however install fabric/forge for 1.19 and use the HMC-Specifics. Then, after launching the game, you can execute the following commands:

• gui (dumps the gui in text form, will probably look like this:

Screen: net.minecraft.client.gui.screens.TitleScreen
Buttons:
0    Multiplayer                               113   132   200   20   1    Button
1    Singleplayer                              113   108   200   20   1    Button
2    Minecraft Realms                          215   156   98    20   1    Button
3    Mods                                      113   156   98    20   1    Button
4    Language                                  89    192   20    20   1    ImageButton
5    Options...                                113   192   98    20   1    Button
6    Quit Game                                 215   192   98    20   1    Button
7    Accessibility                             317   192   20    20   1    ImageButton
8    Copyright Mojang AB. Do not distribute!   229   230   196   10   1    PlainTextButton
TextFields:
id   text   x   y   w   h   type
-    -      -   -   -   -   -

• click 0 (clicks the Multiplayer button)
• gui (again, dump the Multiplayer gui)
• If it's you first time launching the game Minecraft might display the "Caution Third party, .." screen. In order to skip use
  click 2 to check the "Don't show again" checkbox, then click 1 to proceed.
• gui (always do gui after you clicked something)
• You should be on the Multiplayer screen, click 0 for "Direct Connection"
• gui (you get the idea)
• text 2 <ip of the server>
• gui (of course)
• click 1 on older versions the "Join" button might disabled still, in that case add the -enable flag.
• You should now be connecting to the server.

Another option would be to get 1.19 mappings and do it programmatically using the -commands flag and its reflection commands without the HMC-Specifics but that's even worse.

[MkSui]

A custom minecraft launcher named HMCL could join server automatically(sad it didn't support command start), by add '--server' 'x.x.x.x' '--port' '25565' args or edit in config gui
https://sm.ms/image/iCQUq1KVpJHuSjN
This is the minecrft start script HMCL generated

Set-Location -Path 'C:\Users\mikus\AppData\Roaming\.minecraft'
& 'C:\Program Files\Microsoft\jdk-17.0.3.7-hotspot\bin\java.exe' '-Dfile.encoding=GB18030' '-Dminecraft.client.jar=C:\Users\mikus\AppData\Roaming\.minecraft\versions\1.19\1.19.jar' '-XX:+UnlockExperimentalVMOptions' '-XX:+UseG1GC' '-XX:G1NewSizePercent=20' '-XX:G1ReservePercent=20' '-XX:MaxGCPauseMillis=50' '-XX:G1HeapRegionSize=16m' '-XX:-UseAdaptiveSizePolicy' '-XX:-OmitStackTraceInFastThrow' '-XX:-DontCompileHugeMethods' '-Xmn128m' '-Xmx9551m' '-Dfml.ignoreInvalidMinecraftCertificates=true' '-Dfml.ignorePatchDiscrepancies=true' '-Djava.rmi.server.useCodebaseOnly=true' '-Dcom.sun.jndi.rmi.object.trustURLCodebase=false' '-Dcom.sun.jndi.cosnaming.object.trustURLCodebase=false' '-Dlog4j2.formatMsgNoLookups=true' '-Dlog4j.configurationFile=C:\Users\mikus\AppData\Roaming\.minecraft\versions\1.19\log4j2.xml' '-XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump' '-Djava.library.path=C:\Users\mikus\AppData\Roaming\.minecraft\versions\1.19\natives-windows-x86_64' '-Dminecraft.launcher.brand=HMCL' '-Dminecraft.launcher.version=3.5.3' '-cp' 'C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\mojang\logging\1.0.0\logging-1.0.0.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\mojang\blocklist\1.0.10\blocklist-1.0.10.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\mojang\patchy\2.2.10\patchy-2.2.10.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\github\oshi\oshi-core\5.8.5\oshi-core-5.8.5.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\net\java\dev\jna\jna\5.10.0\jna-5.10.0.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\net\java\dev\jna\jna-platform\5.10.0\jna-platform-5.10.0.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\slf4j\slf4j-api\1.8.0-beta4\slf4j-api-1.8.0-beta4.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\apache\logging\log4j\log4j-slf4j18-impl\2.17.0\log4j-slf4j18-impl-2.17.0.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\ibm\icu\icu4j\70.1\icu4j-70.1.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\mojang\javabridge\1.2.24\javabridge-1.2.24.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\net\sf\jopt-simple\jopt-simple\5.0.4\jopt-simple-5.0.4.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\io\netty\netty-common\4.1.77.Final\netty-common-4.1.77.Final.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\io\netty\netty-buffer\4.1.77.Final\netty-buffer-4.1.77.Final.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\io\netty\netty-codec\4.1.77.Final\netty-codec-4.1.77.Final.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\io\netty\netty-handler\4.1.77.Final\netty-handler-4.1.77.Final.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\io\netty\netty-resolver\4.1.77.Final\netty-resolver-4.1.77.Final.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\io\netty\netty-transport\4.1.77.Final\netty-transport-4.1.77.Final.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\io\netty\netty-transport-native-unix-common\4.1.77.Final\netty-transport-native-unix-common-4.1.77.Final.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\io\netty\netty-transport-classes-epoll\4.1.77.Final\netty-transport-classes-epoll-4.1.77.Final.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\google\guava\failureaccess\1.0.1\failureaccess-1.0.1.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\google\guava\guava\31.0.1-jre\guava-31.0.1-jre.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\apache\commons\commons-lang3\3.12.0\commons-lang3-3.12.0.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\commons-io\commons-io\2.11.0\commons-io-2.11.0.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\commons-codec\commons-codec\1.15\commons-codec-1.15.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\mojang\brigadier\1.0.18\brigadier-1.0.18.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\mojang\datafixerupper\5.0.28\datafixerupper-5.0.28.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\google\code\gson\gson\2.8.9\gson-2.8.9.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\mojang\authlib\3.5.41\authlib-3.5.41.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\apache\commons\commons-compress\1.21\commons-compress-1.21.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\apache\httpcomponents\httpclient\4.5.13\httpclient-4.5.13.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\commons-logging\commons-logging\1.2\commons-logging-1.2.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\apache\httpcomponents\httpcore\4.4.14\httpcore-4.4.14.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\it\unimi\dsi\fastutil\8.5.6\fastutil-8.5.6.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\apache\logging\log4j\log4j-api\2.17.0\log4j-api-2.17.0.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\apache\logging\log4j\log4j-core\2.17.0\log4j-core-2.17.0.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\3.3.1\lwjgl-3.3.1.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\3.3.1\lwjgl-3.3.1-natives-windows.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl\3.3.1\lwjgl-3.3.1-natives-windows-x86.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-jemalloc\3.3.1\lwjgl-jemalloc-3.3.1.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-jemalloc\3.3.1\lwjgl-jemalloc-3.3.1-natives-windows.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-jemalloc\3.3.1\lwjgl-jemalloc-3.3.1-natives-windows-x86.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-openal\3.3.1\lwjgl-openal-3.3.1.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-openal\3.3.1\lwjgl-openal-3.3.1-natives-windows.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-openal\3.3.1\lwjgl-openal-3.3.1-natives-windows-x86.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-opengl\3.3.1\lwjgl-opengl-3.3.1.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-opengl\3.3.1\lwjgl-opengl-3.3.1-natives-windows.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-opengl\3.3.1\lwjgl-opengl-3.3.1-natives-windows-x86.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-glfw\3.3.1\lwjgl-glfw-3.3.1.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-glfw\3.3.1\lwjgl-glfw-3.3.1-natives-windows.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-glfw\3.3.1\lwjgl-glfw-3.3.1-natives-windows-x86.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-stb\3.3.1\lwjgl-stb-3.3.1.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-stb\3.3.1\lwjgl-stb-3.3.1-natives-windows.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-stb\3.3.1\lwjgl-stb-3.3.1-natives-windows-x86.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-tinyfd\3.3.1\lwjgl-tinyfd-3.3.1.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-tinyfd\3.3.1\lwjgl-tinyfd-3.3.1-natives-windows.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\org\lwjgl\lwjgl-tinyfd\3.3.1\lwjgl-tinyfd-3.3.1-natives-windows-x86.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\mojang\text2speech\1.13.9\text2speech-1.13.9.jar;C:\Users\mikus\AppData\Roaming\.minecraft\libraries\com\mojang\text2speech\1.13.9\text2speech-1.13.9-natives-windows.jar;C:\Users\mikus\AppData\Roaming\.minecraft\versions\1.19\1.19.jar' 'net.minecraft.client.main.Main' '--username' '' '--version' '1.19' '--gameDir' 'C:\Users\mikus\AppData\Roaming\.minecraft' '--assetsDir' 'C:\Users\mikus\AppData\Roaming\.minecraft\assets' '--assetIndex' '1.19' '--uuid' '' '--accessToken' '' '--clientId' '${clientid}' '--xuid' '${auth_xuid}' '--userType' 'mojang' '--versionType' 'HMCL 3.5.3' '--width' '854' '--height' '480' '--server' 'x.x.x.x' '--port' '25565'

Sorry for the length, I have no idea to cut short:(

[3arthqu4ke]

Ohhh, I didn't realize this was a Minecraft feature.
Add the following to your config.properties file:

hmc.gameargs=--server x.x.x.x --port 25565

[dolphin-cat]

i believe it is --server ip:port, not --server ip --port port

[3arthqu4ke]

Minecrafts code says no, its --server ip --port port.

[nothub]

The behavior seems to vary depending on version.

Passing flags via hmc.gameargs works for me in 1.12.2 but stopped working in 1.20.4.

The 1.20.4 client just prints this line to logs on startup:
[main/INFO]: Completely ignored arguments: [--server, 172.17.0.1, --port, 25565]

[3arthqu4ke]

True, on 1.20.4 it seems to be a single argument: --quickPlayMultiplayer and then something like 127.0.0.1:25565.