{
    "mode": "man",
    "parameter": "systemd.socket",
    "section": "5",
    "url": "https://www.chedong.com/phpMan.php/man/systemd.socket/5/json",
    "generated": "2026-06-02T18:06:31Z",
    "synopsis": "socket.socket",
    "sections": {
        "NAME": {
            "content": "systemd.socket - Socket unit configuration\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "socket.socket\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "A unit configuration file whose name ends in \".socket\" encodes information about an IPC or\nnetwork socket or a file system FIFO controlled and supervised by systemd, for socket-based\nactivation.\n\nThis man page lists the configuration options specific to this unit type. See systemd.unit(5)\nfor the common options of all unit configuration files. The common configuration items are\nconfigured in the generic [Unit] and [Install] sections. The socket specific configuration\noptions are configured in the [Socket] section.\n\nAdditional options are listed in systemd.exec(5), which define the execution environment the\nExecStartPre=, ExecStartPost=, ExecStopPre= and ExecStopPost= commands are executed in, and\nin systemd.kill(5), which define the way the processes are terminated, and in\nsystemd.resource-control(5), which configure resource control settings for the processes of\nthe socket.\n\nFor each socket unit, a matching service unit must exist, describing the service to start on\nincoming traffic on the socket (see systemd.service(5) for more information about .service\nunits). The name of the .service unit is by default the same as the name of the .socket unit,\nbut can be altered with the Service= option described below. Depending on the setting of the\nAccept= option described below, this .service unit must either be named like the .socket\nunit, but with the suffix replaced, unless overridden with Service=; or it must be a template\nunit named the same way. Example: a socket file foo.socket needs a matching service\nfoo.service if Accept=no is set. If Accept=yes is set, a service template foo@.service must\nexist from which services are instantiated for each incoming connection.\n\nNo implicit WantedBy= or RequiredBy= dependency from the socket to the service is added. This\nmeans that the service may be started without the socket, in which case it must be able to\nopen sockets by itself. To prevent this, an explicit Requires= dependency may be added.\n\nSocket units may be used to implement on-demand starting of services, as well as parallelized\nstarting of services. See the blog stories linked at the end for an introduction.\n\nNote that the daemon software configured for socket activation with socket units needs to be\nable to accept sockets from systemd, either via systemd's native socket passing interface\n(see sdlistenfds(3) for details about the precise protocol used and the order in which the\nfile descriptors are passed) or via traditional inetd(8)-style socket passing (i.e. sockets\npassed in via standard input and output, using StandardInput=socket in the service file).\n\nAll network sockets allocated through .socket units are allocated in the host's network\nnamespace (see networknamespaces(7)). This does not mean however that the service activated\nby a configured socket unit has to be part of the host's network namespace as well. It is\nsupported and even good practice to run services in their own network namespace (for example\nthrough PrivateNetwork=, see systemd.exec(5)), receiving only the sockets configured through\nsocket-activation from the host's namespace. In such a set-up communication within the host's\nnetwork namespace is only permitted through the activation sockets passed in while all\nsockets allocated from the service code itself will be associated with the service's own\nnamespace, and thus possibly subject to a restrictive configuration.\n",
            "subsections": []
        },
        "AUTOMATIC DEPENDENCIES": {
            "content": "",
            "subsections": [
                {
                    "name": "Implicit Dependencies",
                    "content": "The following dependencies are implicitly added:\n\n•   Socket units automatically gain a Before= dependency on the service units they activate.\n\n•   Socket units referring to file system paths (such as AFUNIX sockets or FIFOs) implicitly\ngain Requires= and After= dependencies on all mount units necessary to access those\npaths.\n\n•   Socket units using the BindToDevice= setting automatically gain a BindsTo= and After=\ndependency on the device unit encapsulating the specified network interface.\n\nAdditional implicit dependencies may be added as result of execution and resource control\nparameters as documented in systemd.exec(5) and systemd.resource-control(5).\n"
                },
                {
                    "name": "Default Dependencies",
                    "content": "The following dependencies are added unless DefaultDependencies=no is set:\n\n•   Socket units automatically gain a Before= dependency on sockets.target.\n\n•   Socket units automatically gain a pair of After= and Requires= dependency on\nsysinit.target, and a pair of Before= and Conflicts= dependencies on shutdown.target.\nThese dependencies ensure that the socket unit is started before normal services at boot,\nand is stopped on shutdown. Only sockets involved with early boot or late system shutdown\nshould disable DefaultDependencies= option.\n"
                }
            ]
        },
        "OPTIONS": {
            "content": "Socket files must include a [Socket] section, which carries information about the socket or\nFIFO it supervises. A number of options that may be used in this section are shared with\nother unit types. These options are documented in systemd.exec(5) and systemd.kill(5). The\noptions specific to the [Socket] section of socket units are the following:\n\nListenStream=, ListenDatagram=, ListenSequentialPacket=\nSpecifies an address to listen on for a stream (SOCKSTREAM), datagram (SOCKDGRAM), or\nsequential packet (SOCKSEQPACKET) socket, respectively. The address can be written in\nvarious formats:\n\nIf the address starts with a slash (\"/\"), it is read as file system socket in the AFUNIX\nsocket family.\n\nIf the address starts with an at symbol (\"@\"), it is read as abstract namespace socket in\nthe AFUNIX family. The \"@\" is replaced with a NUL character before binding. For details,\nsee unix(7).\n\nIf the address string is a single number, it is read as port number to listen on via\nIPv6. Depending on the value of BindIPv6Only= (see below) this might result in the\nservice being available via both IPv6 and IPv4 (default) or just via IPv6.\n\nIf the address string is a string in the format \"v.w.x.y:z\", it is interpreted as IPv4\naddress v.w.x.y and port z.\n\nIf the address string is a string in the format \"[x]:y\", it is interpreted as IPv6\naddress x and port y. An optional interface scope (interface name or number) may be\nspecified after a \"%\" symbol: \"[x]:y%dev\". Interface scopes are only useful with\nlink-local addresses, because the kernel ignores them in other cases. Note that if an\naddress is specified as IPv6, it might still make the service available via IPv4 too,\ndepending on the BindIPv6Only= setting (see below).\n\nIf the address string is a string in the format \"vsock:x:y\", it is read as CID x on a\nport y address in the AFVSOCK family. The CID is a unique 32-bit integer identifier in\nAFVSOCK analogous to an IP address. Specifying the CID is optional, and may be set to\nthe empty string.\n\nNote that SOCKSEQPACKET (i.e.  ListenSequentialPacket=) is only available for AFUNIX\nsockets.  SOCKSTREAM (i.e.  ListenStream=) when used for IP sockets refers to TCP\nsockets, SOCKDGRAM (i.e.  ListenDatagram=) to UDP.\n\nThese options may be specified more than once, in which case incoming traffic on any of\nthe sockets will trigger service activation, and all listed sockets will be passed to the\nservice, regardless of whether there is incoming traffic on them or not. If the empty\nstring is assigned to any of these options, the list of addresses to listen on is reset,\nall prior uses of any of these options will have no effect.\n\nIt is also possible to have more than one socket unit for the same service when using\nService=, and the service will receive all the sockets configured in all the socket\nunits. Sockets configured in one unit are passed in the order of configuration, but no\nordering between socket units is specified.\n\nIf an IP address is used here, it is often desirable to listen on it before the interface\nit is configured on is up and running, and even regardless of whether it will be up and\nrunning at any point. To deal with this, it is recommended to set the FreeBind= option\ndescribed below.\n\nListenFIFO=\nSpecifies a file system FIFO (see fifo(7) for details) to listen on. This expects an\nabsolute file system path as argument. Behavior otherwise is very similar to the\nListenDatagram= directive above.\n\nListenSpecial=\nSpecifies a special file in the file system to listen on. This expects an absolute file\nsystem path as argument. Behavior otherwise is very similar to the ListenFIFO= directive\nabove. Use this to open character device nodes as well as special files in /proc/ and\n/sys/.\n\nListenNetlink=\nSpecifies a Netlink family to create a socket for to listen on. This expects a short\nstring referring to the AFNETLINK family name (such as audit or kobject-uevent) as\nargument, optionally suffixed by a whitespace followed by a multicast group integer.\nBehavior otherwise is very similar to the ListenDatagram= directive above.\n\nListenMessageQueue=\nSpecifies a POSIX message queue name to listen on (see mqoverview(7) for details). This\nexpects a valid message queue name (i.e. beginning with \"/\"). Behavior otherwise is very\nsimilar to the ListenFIFO= directive above. On Linux message queue descriptors are\nactually file descriptors and can be inherited between processes.\n\nListenUSBFunction=\nSpecifies a USB FunctionFS[1] endpoints location to listen on, for implementation of USB\ngadget functions. This expects an absolute file system path of a FunctionFS mount point\nas the argument. Behavior otherwise is very similar to the ListenFIFO= directive above.\nUse this to open the FunctionFS endpoint ep0. When using this option, the activated\nservice has to have the USBFunctionDescriptors= and USBFunctionStrings= options set.\n\nSocketProtocol=\nTakes one of udplite or sctp. The socket will use the UDP-Lite (IPPROTOUDPLITE) or SCTP\n(IPPROTOSCTP) protocol, respectively.\n\nBindIPv6Only=\nTakes one of default, both or ipv6-only. Controls the IPV6V6ONLY socket option (see\nipv6(7) for details). If both, IPv6 sockets bound will be accessible via both IPv4 and\nIPv6. If ipv6-only, they will be accessible via IPv6 only. If default (which is the\ndefault, surprise!), the system wide default setting is used, as controlled by\n/proc/sys/net/ipv6/bindv6only, which in turn defaults to the equivalent of both.\n\nBacklog=\nTakes an unsigned integer argument. Specifies the number of connections to queue that\nhave not been accepted yet. This setting matters only for stream and sequential packet\nsockets. See listen(2) for details. Defaults to SOMAXCONN (128).\n\nBindToDevice=\nSpecifies a network interface name to bind this socket to. If set, traffic will only be\naccepted from the specified network interfaces. This controls the SOBINDTODEVICE socket\noption (see socket(7) for details). If this option is used, an implicit dependency from\nthis socket unit on the network interface device unit is created (see systemd.device(5)).\nNote that setting this parameter might result in additional dependencies to be added to\nthe unit (see above).\n\nSocketUser=, SocketGroup=\nTakes a UNIX user/group name. When specified, all AFUNIX sockets and FIFO nodes in the\nfile system are owned by the specified user and group. If unset (the default), the nodes\nare owned by the root user/group (if run in system context) or the invoking user/group\n(if run in user context). If only a user is specified but no group, then the group is\nderived from the user's default group.\n\nSocketMode=\nIf listening on a file system socket or FIFO, this option specifies the file system\naccess mode used when creating the file node. Takes an access mode in octal notation.\nDefaults to 0666.\n\nDirectoryMode=\nIf listening on a file system socket or FIFO, the parent directories are automatically\ncreated if needed. This option specifies the file system access mode used when creating\nthese directories. Takes an access mode in octal notation. Defaults to 0755.\n\nAccept=\nTakes a boolean argument. If yes, a service instance is spawned for each incoming\nconnection and only the connection socket is passed to it. If no, all listening sockets\nthemselves are passed to the started service unit, and only one service unit is spawned\nfor all connections (also see above). This value is ignored for datagram sockets and\nFIFOs where a single service unit unconditionally handles all incoming traffic. Defaults\nto no. For performance reasons, it is recommended to write new daemons only in a way that\nis suitable for Accept=no. A daemon listening on an AFUNIX socket may, but does not need\nto, call close(2) on the received socket before exiting. However, it must not unlink the\nsocket from a file system. It should not invoke shutdown(2) on sockets it got with\nAccept=no, but it may do so for sockets it got with Accept=yes set. Setting Accept=yes is\nmostly useful to allow daemons designed for usage with inetd(8) to work unmodified with\nsystemd socket activation.\n\nFor IPv4 and IPv6 connections, the REMOTEADDR environment variable will contain the\nremote IP address, and REMOTEPORT will contain the remote port. This is the same as the\nformat used by CGI. For SOCKRAW, the port is the IP protocol.\n\nWritable=\nTakes a boolean argument. May only be used in conjunction with ListenSpecial=. If true,\nthe specified special file is opened in read-write mode, if false, in read-only mode.\nDefaults to false.\n\nFlushPending=\nTakes a boolean argument. May only be used when Accept=no. If yes, the socket's buffers\nare cleared after the triggered service exited. This causes any pending data to be\nflushed and any pending incoming connections to be rejected. If no, the socket's buffers\nwon't be cleared, permitting the service to handle any pending connections after restart,\nwhich is the usually expected behaviour. Defaults to no.\n\nMaxConnections=\nThe maximum number of connections to simultaneously run services instances for, when\nAccept=yes is set. If more concurrent connections are coming in, they will be refused\nuntil at least one existing connection is terminated. This setting has no effect on\nsockets configured with Accept=no or datagram sockets. Defaults to 64.\n\nMaxConnectionsPerSource=\nThe maximum number of connections for a service per source IP address. This is very\nsimilar to the MaxConnections= directive above. Disabled by default.\n\nKeepAlive=\nTakes a boolean argument. If true, the TCP/IP stack will send a keep alive message after\n2h (depending on the configuration of /proc/sys/net/ipv4/tcpkeepalivetime) for all TCP\nstreams accepted on this socket. This controls the SOKEEPALIVE socket option (see\nsocket(7) and the TCP Keepalive HOWTO[2] for details.) Defaults to false.\n\nKeepAliveTimeSec=\nTakes time (in seconds) as argument. The connection needs to remain idle before TCP\nstarts sending keepalive probes. This controls the TCPKEEPIDLE socket option (see\nsocket(7) and the TCP Keepalive HOWTO[2] for details.) Defaults value is 7200 seconds (2\nhours).\n\nKeepAliveIntervalSec=\nTakes time (in seconds) as argument between individual keepalive probes, if the socket\noption SOKEEPALIVE has been set on this socket. This controls the TCPKEEPINTVL socket\noption (see socket(7) and the TCP Keepalive HOWTO[2] for details.) Defaults value is 75\nseconds.\n\nKeepAliveProbes=\nTakes an integer as argument. It is the number of unacknowledged probes to send before\nconsidering the connection dead and notifying the application layer. This controls the\nTCPKEEPCNT socket option (see socket(7) and the TCP Keepalive HOWTO[2] for details.)\nDefaults value is 9.\n\nNoDelay=\nTakes a boolean argument. TCP Nagle's algorithm works by combining a number of small\noutgoing messages, and sending them all at once. This controls the TCPNODELAY socket\noption (see tcp(7)). Defaults to false.\n\nPriority=\nTakes an integer argument controlling the priority for all traffic sent from this socket.\nThis controls the SOPRIORITY socket option (see socket(7) for details.).\n\nDeferAcceptSec=\nTakes time (in seconds) as argument. If set, the listening process will be awakened only\nwhen data arrives on the socket, and not immediately when connection is established. When\nthis option is set, the TCPDEFERACCEPT socket option will be used (see tcp(7)), and the\nkernel will ignore initial ACK packets without any data. The argument specifies the\napproximate amount of time the kernel should wait for incoming data before falling back\nto the normal behavior of honoring empty ACK packets. This option is beneficial for\nprotocols where the client sends the data first (e.g. HTTP, in contrast to SMTP), because\nthe server process will not be woken up unnecessarily before it can take any action.\n\nIf the client also uses the TCPDEFERACCEPT option, the latency of the initial\nconnection may be reduced, because the kernel will send data in the final packet\nestablishing the connection (the third packet in the \"three-way handshake\").\n\nDisabled by default.\n\nReceiveBuffer=, SendBuffer=\nTakes an integer argument controlling the receive or send buffer sizes of this socket,\nrespectively. This controls the SORCVBUF and SOSNDBUF socket options (see socket(7) for\ndetails.). The usual suffixes K, M, G are supported and are understood to the base of\n1024.\n\nIPTOS=\nTakes an integer argument controlling the IP Type-Of-Service field for packets generated\nfrom this socket. This controls the IPTOS socket option (see ip(7) for details.). Either\na numeric string or one of low-delay, throughput, reliability or low-cost may be\nspecified.\n\nIPTTL=\nTakes an integer argument controlling the IPv4 Time-To-Live/IPv6 Hop-Count field for\npackets generated from this socket. This sets the IPTTL/IPV6UNICASTHOPS socket options\n(see ip(7) and ipv6(7) for details.)\n\nMark=\nTakes an integer value. Controls the firewall mark of packets generated by this socket.\nThis can be used in the firewall logic to filter packets from this socket. This sets the\nSOMARK socket option. See iptables(8) for details.\n\nReusePort=\nTakes a boolean value. If true, allows multiple bind(2)s to this TCP or UDP port. This\ncontrols the SOREUSEPORT socket option. See socket(7) for details.\n\nSmackLabel=, SmackLabelIPIn=, SmackLabelIPOut=\nTakes a string value. Controls the extended attributes \"security.SMACK64\",\n\"security.SMACK64IPIN\" and \"security.SMACK64IPOUT\", respectively, i.e. the security label\nof the FIFO, or the security label for the incoming or outgoing connections of the\nsocket, respectively. See Smack.txt[3] for details.\n\nSELinuxContextFromNet=\nTakes a boolean argument. When true, systemd will attempt to figure out the SELinux label\nused for the instantiated service from the information handed by the peer over the\nnetwork. Note that only the security level is used from the information provided by the\npeer. Other parts of the resulting SELinux context originate from either the target\nbinary that is effectively triggered by socket unit or from the value of the\nSELinuxContext= option. This configuration option applies only when activated service is\npassed in single socket file descriptor, i.e. service instances that have standard input\nconnected to a socket or services triggered by exactly one socket unit. Also note that\nthis option is useful only when MLS/MCS SELinux policy is deployed. Defaults to \"false\".\n\nPipeSize=\nTakes a size in bytes. Controls the pipe buffer size of FIFOs configured in this socket\nunit. See fcntl(2) for details. The usual suffixes K, M, G are supported and are\nunderstood to the base of 1024.\n\nMessageQueueMaxMessages=, MessageQueueMessageSize=\nThese two settings take integer values and control the mqmaxmsg field or the mqmsgsize\nfield, respectively, when creating the message queue. Note that either none or both of\nthese variables need to be set. See mqsetattr(3) for details.\n\nFreeBind=\nTakes a boolean value. Controls whether the socket can be bound to non-local IP\naddresses. This is useful to configure sockets listening on specific IP addresses before\nthose IP addresses are successfully configured on a network interface. This sets the\nIPFREEBIND/IPV6FREEBIND socket option. For robustness reasons it is recommended to use\nthis option whenever you bind a socket to a specific IP address. Defaults to false.\n\nTransparent=\nTakes a boolean value. Controls the IPTRANSPARENT/IPV6TRANSPARENT socket option.\nDefaults to false.\n\nBroadcast=\nTakes a boolean value. This controls the SOBROADCAST socket option, which allows\nbroadcast datagrams to be sent from this socket. Defaults to false.\n\nPassCredentials=\nTakes a boolean value. This controls the SOPASSCRED socket option, which allows AFUNIX\nsockets to receive the credentials of the sending process in an ancillary message.\nDefaults to false.\n\nPassSecurity=\nTakes a boolean value. This controls the SOPASSSEC socket option, which allows AFUNIX\nsockets to receive the security context of the sending process in an ancillary message.\nDefaults to false.\n\nPassPacketInfo=\nTakes a boolean value. This controls the IPPKTINFO, IPV6RECVPKTINFO, NETLINKPKTINFO or\nPACKETAUXDATA socket options, which enable reception of additional per-packet metadata\nas ancillary message, on AFINET, AFINET6, AFUNIX and AFPACKET sockets. Defaults to\nfalse.\n\nTimestamping=\nTakes one of \"off\", \"us\" (alias: \"usec\", \"µs\") or \"ns\" (alias: \"nsec\"). This controls the\nSOTIMESTAMP or SOTIMESTAMPNS socket options, and enables whether ingress network\ntraffic shall carry timestamping metadata. Defaults to off.\n\nTCPCongestion=\nTakes a string value. Controls the TCP congestion algorithm used by this socket. Should\nbe one of \"westwood\", \"veno\", \"cubic\", \"lp\" or any other available algorithm supported by\nthe IP stack. This setting applies only to stream sockets.\n\nExecStartPre=, ExecStartPost=\nTakes one or more command lines, which are executed before or after the listening\nsockets/FIFOs are created and bound, respectively. The first token of the command line\nmust be an absolute filename, then followed by arguments for the process. Multiple\ncommand lines may be specified following the same scheme as used for ExecStartPre= of\nservice unit files.\n\nExecStopPre=, ExecStopPost=\nAdditional commands that are executed before or after the listening sockets/FIFOs are\nclosed and removed, respectively. Multiple command lines may be specified following the\nsame scheme as used for ExecStartPre= of service unit files.\n\nTimeoutSec=\nConfigures the time to wait for the commands specified in ExecStartPre=, ExecStartPost=,\nExecStopPre= and ExecStopPost= to finish. If a command does not exit within the\nconfigured time, the socket will be considered failed and be shut down again. All\ncommands still running will be terminated forcibly via SIGTERM, and after another delay\nof this time with SIGKILL. (See KillMode= in systemd.kill(5).) Takes a unit-less value in\nseconds, or a time span value such as \"5min 20s\". Pass \"0\" to disable the timeout logic.\nDefaults to DefaultTimeoutStartSec= from the manager configuration file (see systemd-\nsystem.conf(5)).\n\nService=\nSpecifies the service unit name to activate on incoming traffic. This setting is only\nallowed for sockets with Accept=no. It defaults to the service that bears the same name\nas the socket (with the suffix replaced). In most cases, it should not be necessary to\nuse this option. Note that setting this parameter might result in additional dependencies\nto be added to the unit (see above).\n\nRemoveOnStop=\nTakes a boolean argument. If enabled, any file nodes created by this socket unit are\nremoved when it is stopped. This applies to AFUNIX sockets in the file system, POSIX\nmessage queues, FIFOs, as well as any symlinks to them configured with Symlinks=.\nNormally, it should not be necessary to use this option, and is not recommended as\nservices might continue to run after the socket unit has been terminated and it should\nstill be possible to communicate with them via their file system node. Defaults to off.\n\nSymlinks=\nTakes a list of file system paths. The specified paths will be created as symlinks to the\nAFUNIX socket path or FIFO path of this socket unit. If this setting is used, only one\nAFUNIX socket in the file system or one FIFO may be configured for the socket unit. Use\nthis option to manage one or more symlinked alias names for a socket, binding their\nlifecycle together. Note that if creation of a symlink fails this is not considered fatal\nfor the socket unit, and the socket unit may still start. If an empty string is assigned,\nthe list of paths is reset. Defaults to an empty list.\n\nFileDescriptorName=\nAssigns a name to all file descriptors this socket unit encapsulates. This is useful to\nhelp activated services identify specific file descriptors, if multiple fds are passed.\nServices may use the sdlistenfdswithnames(3) call to acquire the names configured for\nthe received file descriptors. Names may contain any ASCII character, but must exclude\ncontrol characters and \":\", and must be at most 255 characters in length. If this setting\nis not used, the file descriptor name defaults to the name of the socket unit, including\nits .socket suffix.\n\nTriggerLimitIntervalSec=, TriggerLimitBurst=\nConfigures a limit on how often this socket unit my be activated within a specific time\ninterval. The TriggerLimitIntervalSec= may be used to configure the length of the time\ninterval in the usual time units \"us\", \"ms\", \"s\", \"min\", \"h\", ... and defaults to 2s (See\nsystemd.time(7) for details on the various time units understood). The TriggerLimitBurst=\nsetting takes a positive integer value and specifies the number of permitted activations\nper time interval, and defaults to 200 for Accept=yes sockets (thus by default permitting\n200 activations per 2s), and 20 otherwise (20 activations per 2s). Set either to 0 to\ndisable any form of trigger rate limiting. If the limit is hit, the socket unit is placed\ninto a failure mode, and will not be connectible anymore until restarted. Note that this\nlimit is enforced before the service activation is enqueued.\n\nCheck systemd.exec(5) and systemd.kill(5) for more settings.\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "systemd(1), systemctl(1), systemd-system.conf(5), systemd.unit(5), systemd.exec(5),\nsystemd.kill(5), systemd.resource-control(5), systemd.service(5), systemd.directives(7),\nsdlistenfds(3), sdlistenfdswithnames(3)\n\nFor more extensive descriptions see the \"systemd for Developers\" series: Socket\nActivation[4], Socket Activation, part II[5], Converting inetd Services[6], Socket Activated\nInternet Services and OS Containers[7].\n",
            "subsections": []
        },
        "NOTES": {
            "content": "1. USB FunctionFS\nhttps://www.kernel.org/doc/Documentation/usb/functionfs.txt\n\n2. TCP Keepalive HOWTO\nhttp://www.tldp.org/HOWTO/htmlsingle/TCP-Keepalive-HOWTO/\n\n3. Smack.txt\nhttps://www.kernel.org/doc/Documentation/security/Smack.txt\n\n4. Socket Activation\nhttp://0pointer.de/blog/projects/socket-activation.html\n\n5. Socket Activation, part II\nhttp://0pointer.de/blog/projects/socket-activation2.html\n\n6. Converting inetd Services\nhttp://0pointer.de/blog/projects/inetd.html\n\n7. Socket Activated Internet Services and OS Containers\nhttp://0pointer.de/blog/projects/socket-activated-containers.html\n\n\n\nsystemd 249                                                                        SYSTEMD.SOCKET(5)",
            "subsections": []
        }
    },
    "summary": "systemd.socket - Socket unit configuration",
    "flags": [],
    "examples": [],
    "see_also": [
        {
            "name": "systemd",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/systemd/1/json"
        },
        {
            "name": "systemctl",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/systemctl/1/json"
        },
        {
            "name": "systemd-system.conf",
            "section": "5",
            "url": "https://www.chedong.com/phpMan.php/man/systemd-system.conf/5/json"
        },
        {
            "name": "systemd.unit",
            "section": "5",
            "url": "https://www.chedong.com/phpMan.php/man/systemd.unit/5/json"
        },
        {
            "name": "systemd.exec",
            "section": "5",
            "url": "https://www.chedong.com/phpMan.php/man/systemd.exec/5/json"
        },
        {
            "name": "systemd.kill",
            "section": "5",
            "url": "https://www.chedong.com/phpMan.php/man/systemd.kill/5/json"
        },
        {
            "name": "systemd.resource-control",
            "section": "5",
            "url": "https://www.chedong.com/phpMan.php/man/systemd.resource-control/5/json"
        },
        {
            "name": "systemd.service",
            "section": "5",
            "url": "https://www.chedong.com/phpMan.php/man/systemd.service/5/json"
        },
        {
            "name": "systemd.directives",
            "section": "7",
            "url": "https://www.chedong.com/phpMan.php/man/systemd.directives/7/json"
        },
        {
            "name": "sdlistenfds",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/sdlistenfds/3/json"
        },
        {
            "name": "sdlistenfdswithnames",
            "section": "3",
            "url": "https://www.chedong.com/phpMan.php/man/sdlistenfdswithnames/3/json"
        }
    ]
}