This wiki has been migrated to https://gitlab.com/wireshark/wireshark/-/wikis/home and is now deprecated. Please use that site instead.
Differences between revisions 215 and 216
Revision 215 as of 2012-05-18 00:16:55
Size: 2187
Editor: GuyHarris
Comment: Not even close to the right place to ask; here are the right places to ask, and also a stab at an answer.
Revision 216 as of 2012-05-18 20:30:23
Size: 2264
Comment:
Deletions are marked like this. Additions are marked like this.
Line 3: Line 3:
Is there a repository/collection/library of [[Lua]] scripts beyond [[Lua/Examples]] to learn from ?
Specifically, it seems os.clock() has only timer tick resolution (15 ms on windows and 10 ms on linux), but I need sub-millisecond precision.
Is there a repository/collection/library of [[Lua]] scripts beyond [[Lua/Examples]] to learn from ? Specifically, it seems os.clock() has only timer tick resolution (15 ms on windows and 10 ms on linux), but I need sub-millisecond precision.
Line 6: Line 5:
Background:
I'm willing to write a Lua script to accumulate the timestamps of tens of thousands of sniffed packets and to account wall clock time to my client application once a packet is received on the client pc and to account wall clock time to the network or the other end of the socket (the server) once a packet is sent and do it vice versa on the server pc to get an exact measure of client, network and server times for a performance analysis, but don't know where to start from.
Background: I'm willing to write a Lua script to accumulate the timestamps of tens of thousands of sniffed packets and to account wall clock time to my client application once a packet is received on the client pc and to account wall clock time to the network or the other end of the socket (the server) once a packet is sent and do it vice versa on the server pc to get an exact measure of client, network and server times for a performance analysis, but don't know where to start from.
Line 15: Line 13:
However, [[http://www.lua.org/manual/5.1/manual.html#pdf-os.clock|the Lua 5.1 manual item on os.clock()]] seems to indicate that it's not what you want - it says it "returns an approximation of the amount in seconds of CPU time used by the program", but it sounds as if you want ''real'' time, not ''CPU'' time. I don't know whether [[http://www.lua.org/manual/5.1/manual.html#pdf-os.time|os.time()]] returns a value with a fractional part, or what the resolution is, but, if the OS call atop which os.time() is implemented - probably gettimeofday() or something such as that on most if not all UN*Xes - returns a higher-precision time value, that might give you what you want. However, [[http://www.lua.org/manual/5.1/manual.html#pdf-os.clock|the Lua 5.1 manual item on os.clock()]] seems to indicate that it's not what you want - it says it "returns an approximation of the amount in seconds of CPU time used by the program", but it sounds as if you want ''real'' time, not ''CPU'' time. I don't know whether [[http://www.lua.org/manual/5.1/manual.html#pdf-os.time|os.time()]] returns a value with a fractional part, or what the resolution is, but, if the OS call atop which os.time() is implemented - probably [[http://pubs.opengroup.org/onlinepubs/009604599/functions/gettimeofday.html|gettimeofday]]() or something such as that on most if not all UN*Xes - returns a higher-precision time value, that might give you what you want.

Seems editing this page is not peeing in the pool, so I try to ask here because I did't find the right place to ask questions:

Is there a repository/collection/library of Lua scripts beyond Lua/Examples to learn from ? Specifically, it seems os.clock() has only timer tick resolution (15 ms on windows and 10 ms on linux), but I need sub-millisecond precision.

Background: I'm willing to write a Lua script to accumulate the timestamps of tens of thousands of sniffed packets and to account wall clock time to my client application once a packet is received on the client pc and to account wall clock time to the network or the other end of the socket (the server) once a packet is sent and do it vice versa on the server pc to get an exact measure of client, network and server times for a performance analysis, but don't know where to start from.

Perhaps someone can point me to the right place to search or to the right method to use ? Thanks, Juergen.

It's not peeing in the pool, but it's also not the best place to ask, as not everybody will see it, and, if somebody sees it and replies, you won't necessarily get notified of it.

You could ask that question on, for example, http://ask.wireshark.org/ or on the wireshark-dev mailing list, but as it's really a Lua question, it might be better to ask on the lua-l mailing list or on http://stackoverflow.com (I don't know of any Lua-specific Q&A site).

However, the Lua 5.1 manual item on os.clock() seems to indicate that it's not what you want - it says it "returns an approximation of the amount in seconds of CPU time used by the program", but it sounds as if you want real time, not CPU time. I don't know whether os.time() returns a value with a fractional part, or what the resolution is, but, if the OS call atop which os.time() is implemented - probably gettimeofday() or something such as that on most if not all UN*Xes - returns a higher-precision time value, that might give you what you want.

WikiSandBox (last edited 2020-08-14 16:23:22 by 2601:200:c001:d44:81f6:197c:58b:2580)