netreport(1) -- Linux man page
NAMEnetreport - request notification of network interface changes
DESCRIPTIONnetreport tells the network management scripts to send a SIGIO signal to the process which called netreport when any network interface status changes occur.
- Remove the current request (if any) for the calling process.
NOTESIf a program does not call netreport with the -r option before it exits, and another process is created with the same PID before any changes take place in interface status, it is possible that the new process will receive a spurious SIGIO.