Sprint
Sprint is a quake-c engine function that prints text to a specific entity. Most often it is used by the default game code to print text to the player or to players connected to a multiplayer game. In contrast to centerprint, sprint prints text in the upper left-hand corner of the screen.
In the 2021 release the output of sprint is mirrored in the console log file
Defs.qc Declaration
void(entity client, string s) sprint = #24;
Notes
On a locally hosted game sprint seems to be able to react to 4 calls per 'frame' per entity(?) - meaning that if you call sprint more than 4 times in a row some of the text will probably disappear or otherwise not make it to the screen. Note that this has nothing to do how much text is shown, only the number of function calls. Increasing the cvar scr_maxlines (defaults to 4, max of 20) seems to increase this limit.
'sprint' will fail if it is called with a string parameter of longer than 2047 characters.
Writebyte equivalent
msg_entity = self.owner;
WriteByte( MSG_ONE, SVC_PRINT );
WriteShort( MSG_ONE, 1 );
WriteString( MSG_ONE, "hello world!\n" );