<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
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--></style></head><body lang=EN-IN link=blue vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'>Hello!<o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'>I am taking a short-cut to inquire this, by posting to you all (than going through relevant documentation).<o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'>Is gen_udp:recv() to be invoked per datagram, or can it return a binary of multiple datagrams concatenated?<o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'>I am asking this because there is Length to recv(), and I don’t understand why it is there. Should it specify the length of expected datagram? What if the datagrams of variable length? Should it, then, specify the maximum length?<o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'>The default receive buffer size is 8K bytes. If Length argument to recv() is specified to this value, will it still return one datagram or multiple?<o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'>In contrast, in gen_tcp:recv(), the Length argument could be specified to zero, in which case, all the arrived bytes are returned as the binary (as per documentation). Does gen_udp:recv() do similar – return all the datagrams arrived (if Length is specified to be zero)?<o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'>My need for the socket is {active, false}. I had tried with {active, true} in the past, and got the datagrams as individual messages in the inbox of my process. So, I assume that there will be one call to recv() per datagram. I do not have the setup to test {active, false}; hence, I am not sure about the behaviour of (and, rationale for) Length argument to recv().<o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'>Please!<o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'>Thanks<o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'>Avinash<o:p></o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span style='font-size:14.0pt'><o:p> </o:p></span></span></p></div></body></html>