Get Local IP Address

I was working on adding some online functionality to a side project I am working on. I wrote this function to get the Local IP Address of the computer it runs on. It works on Windows, Linux, and Mac.


Function LocalIP$()
Select Case OS
Case "WINDOWS"
s$ = ""
temp_file$ = Env("Temp") + "\\rc_tmp_ip.txt"
System("ipconfig | findstr /R /C:\qIPv4 Address\q > " + temp_file)
f=FreeFile
FileOpen(f, temp_file, TEXT_INPUT)
While Not EOF(f)
s = s + Trim(ReadLine(f))
Wend
FileClose(f)
n = InStr(s, ":")+1
s = Trim(Mid(s, n, Length(s)))
Return s
Case "LINUX"
s$ = ""
temp_file$ = "/tmp/rc_tmp_ip.txt"
System("hostname -I | awk '{print $1}' > " + temp_file)
f=FreeFile
FileOpen(f, temp_file, TEXT_INPUT)
While Not EOF(f)
s = s + Trim(ReadLine(f))
Wend
FileClose(f)
s = Trim(s)
Return s
Case "MAC"
s$ = ""
temp_file0$ = "/tmp/rc_tmp_en0.txt"
temp_file1$ = "/tmp/rc_tmp_en1.txt"
System("ipconfig getifaddr en0 > " + temp_file0)
System("ipconfig getifaddr en1 > " + temp_file1)
f=FreeFile
FileOpen(f, temp_file0, TEXT_INPUT)
s = Trim(Readline(f))
FileClose(f)
If s <> "" Then
Return s
End If
FileOpen(f, temp_file1, TEXT_INPUT)
s = Trim(Readline(f))
FileClose(f)
return s
End Select
Return ""
End Function