FreeBSD Manual Pages
open_nonblock(3) Arcan Lua API open_nonblock(3) NAME open_nonblock - Open a file in read or write mode for non-blocking I/O. SYNOPSIS blocktbl open_nonblock( vid:res ) open_nonblock( vid:res, bool:write ) open_nonblock( vid:res, bool:write, string:identifier=stream ) open_nonblock( vid:res, bool:write, string:identifier=stream, userdata:nbi- oud ) open_nonblock( vid:res, table:opts, string:identifier=stream ) open_nonblock( vid:res, table:opts, string:identifier=stream, userdata:nbi- oud ) open_nonblock( string:res ) open_nonblock( string:res, bool:write ) DESCRIPTION Create or open the resource indicated by res in (default) read-mode or (if mode is provided, write mode) If res is a vid connected to a frameserver, either a streaming fifo ses- sion will be set up over the connection along with the corresponding _BCHUNK events or an pre-existing nonblock-io stream, nbioud , will be redirected to said client and the backing descriptor closed locally. The identifier argument can then be used to specify some client announced type identifier, or one of the reserved "stdin", "stdout", "stderr". If res is a string, the initial character determines if it creates a FIFO (<) or a SOCKET (=). Unless a namespace is explicitly set and the name- space is marked as valid for IPC , FIFO s and SOCKET s will be created in the RESOURCE_APPL_TEMP namespace. For sockets, the write argument deter- mines if the connection should be outbound (=true) or listening (=false). If the identifier starts with a valid namespace identifier and separator (alphanum:/) the identifier will first be matched to a user defined name- space (see list_namespaces ). If the res is connected to a frameserver, the namespace identifier is fixed and only defined for connections coming from net_open . The default is to target the private store of the authenticated client. To let the server side controller script decide, prefix the identifier with appl:/ If successful, FIFO s and normal resources return a table wih a close oper- ation (which is activated on garbage collection unless called in before- hand) and a read or write function depending on the mode that the resource was opened in. The socket table is special in that it allows multiple connections. the initial table for a socket only has a close and an accept function. The ac- cept function takes no arguments and returns a table in both read and write mode when there is a client waiting. The opts table argument form is used to tune transfer parameters. NOTES 1 Do note that input processing has soft realtime constraints, and care should be taken to avoid processing large chunks of data in one go as it may affect application responsiveness. 2 FIFO s and sockets that were created will be unlinked when the close method is called or when the table reference is garbage collected. 3 When a nonblocking userdata is handed over to a frameserver, the write argument will be ignored and the corresponding BCHUNK event will match the userdata. This was a bug in a previous version where the write argument was respected and the argument had to be kept to avoid breaking compatibility. EXAMPLE function open_nonblock0() a = open_nonblock("test.txt") if (a == nil) then return shutdown("couldn't open test.txt"); end end function main_clock_pulse() local line = a:read(); if (line ~= nil) then print(line); end end EXAMPLE function open_nonblock1() a = open_nonblock("=test", false) b = open_nonblock("=test", true) -- our reader, note the scoping and the closure here local counter = 20 local dh dh = function() local res, alive = a:read() if res then print("read:", res) counter = counter - 1 if alive and counter > 0 then a:data_handler(dh) return end end a:close() -- will close on error or if counter reaches 0 end a:data_handler(dh) end function main_clock_pulse() if CLOCK % 100 == 0 then local _, alive = b:write("sent at " .. tostring(CLOCK)) if not alive then return shutdown() end end end SEE ALSO: resource August 2026 open_nonblock(3)
NAME | SYNOPSIS | DESCRIPTION | NOTES | EXAMPLE | EXAMPLE | SEE ALSO:
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=open_nonblock&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>