Info Catalog elisp: Network Options elisp: Low-Level Network

elisp: Network Feature Testing

 
 36.17.3 Testing Availability of Network Features
 ------------------------------------------------
 
 To test for the availability of a given network feature, use ‘featurep’
 like this:
 
      (featurep 'make-network-process '(KEYWORD VALUE))
 
 The result of this form is ‘t’ if it works to specify KEYWORD with value
 VALUE in ‘make-network-process’.  Here are some of the KEYWORD—VALUE
 pairs you can test in this way.
 
 ‘(:nowait t)’
      Non-‘nil’ if non-blocking connect is supported.
 ‘(:type datagram)’
      Non-‘nil’ if datagrams are supported.
 ‘(:family local)’
      Non-‘nil’ if local (a.k.a. “UNIX domain”) sockets are supported.
 ‘(:family ipv6)’
      Non-‘nil’ if IPv6 is supported.
 ‘(:service t)’
      Non-‘nil’ if the system can select the port for a server.
 
    To test for the availability of a given network option, use
 ‘featurep’ like this:
 
      (featurep 'make-network-process 'KEYWORD)
 
 The accepted KEYWORD values are ‘:bindtodevice’, etc.  For the complete
 list, Network Options.  This form returns non-‘nil’ if that
 particular network option is supported by ‘make-network-process’ (or
 ‘set-network-process-option’).
 

Info Catalog elisp: Network Options elisp: Low-Level Network