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NGHOOK(8) System Manager's Manual NGHOOK(8) NAME nghook -- connect to a netgraph(4) node SYNOPSIS nghook [-adlnSs] [-m msg] path [hookname] nghook -e [-n] [-m msg] path hookname program [args ...] DESCRIPTION The nghook utility creates a ng_socket(4) socket type node and connects it to hook hookname of the node found at path. If hookname is omitted, "debug" is assumed. If the -e option is given, the third argument is interpreted as the path to a program, and this program is executed with the remaining ar- guments as its arguments. Before executing, the program Netgraph mes- sages (specified by the -m option) are sent to the node. The program is executed with its standard input (unless closed by -n) and output connected to the hook. If the -e option is not given, all data written to standard input is sent to the node, and all data received from the node is relayed to standard output. Messages specified with -m are sent to the node be- fore the loop is entered. The nghook utility exits when EOF is de- tected on standard input in this case. The options are as follows: -a Output each packet read in human-readable decoded ASCII form instead of raw binary. -d Increase the debugging verbosity level. -e Execute the program specified by the third argument. -l Loops all received data back to the hook in addition to writing it to standard output. -m msg Before executing the program (in -e mode) send the given ASCII control message to the node. This option may be given more than once. -n Do not attempt to read any data from standard input. The nghook utility will continue reading from the node until stopped by a signal. -S Use file descriptor 0 for output instead of the default 1. -s Use file descriptor 1 for input instead of the default 0. SEE ALSO netgraph(3), netgraph(4), ngctl(8) HISTORY The netgraph system was designed and first implemented at Whistle Com- munications, Inc. in a version of FreeBSD 2.2 customized for the Whis- tle InterJet. AUTHORS Archie Cobbs <archie@whistle.com> BUGS Although all input is read in unbuffered mode, there is no way to con- trol the packetization of the input. If the node sends a response to a message (specified by -m), this re- sponse is lost. FreeBSD 14.3 October 24, 2003 NGHOOK(8)
NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | HISTORY | AUTHORS | BUGS
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