Perl performance?

[Kevin Horton]

I'm a perl newbie, with next to no programming experience (I did a bunch
of Fortran 25 years ago, but nothing since).

I have a problem I need to solve, and I'm wondering whether perl is the
best tool. I need to log a fairly fast data stream to a file, after
adding a time stamp to the end of each line. The data is ASCII text, and
will be coming into a serial port on a laptop. The data stream is at
115,200 baud, with 64 lines per second, each line being 40 to 45
characters long. I'm not sure yet what format the line ends are.

I've successfully logged the data using a Windows terminal program, but I
really need to add a time stamp to each line, so I can sync the data up
with another data stream when I do the post processing. I think I could
use the Win32::SerialPort module to get the data into perl, have it parse
the data looking for line ends, add a time stamp to the end of each line
and log the line to a file.

Win32::SerialPort info:

http://members.aol.com/Bbirthisel/SerialPort.html

I realize that the time stamps will only have a resolution of one second,
but I figure that when I do the post processing I could look for the
records where the time stamp changed seconds, and then count records to
infer the time for each one. I don't need super high accuracy. Plus or
minus a half second will be more than good enough.

The only laptop I currently have available that has a serial port is a
Dell PIII 500 running Win 98. I can't put Linux on it, as it belongs to
my wife, and she needs Win 98 for some business applications. Is it
likely that a perl program would have enough performance to deal with data
at 115,200 baud, with 64 records per second?

I'm tempted to try perl as it seems to be general purpose enough that I
could use my new perl skills for all kinds of other things. But, if perl
likely won't be up to the task I'll look into using a compiled language.

Thanks for your advice,

 

[Isaac Mushinsky]

I'm a perl newbie, with next to no programming experience (I did a bunch
of Fortran 25 years ago, but nothing since).

I have a problem I need to solve, and I'm wondering whether perl is the
best tool. I need to log a fairly fast data stream to a file, after
adding a time stamp to the end of each line. The data is ASCII text, and
will be coming into a serial port on a laptop. The data stream is at
115,200 baud, with 64 lines per second, each line being 40 to 45
characters long. I'm not sure yet what format the line ends are.

I've successfully logged the data using a Windows terminal program, but I
really need to add a time stamp to each line, so I can sync the data up
with another data stream when I do the post processing. I think I could
use the Win32::SerialPort module to get the data into perl, have it parse
the data looking for line ends, add a time stamp to the end of each line
and log the line to a file.

Win32::SerialPort info:

http://members.aol.com/Bbirthisel/SerialPort.html

I realize that the time stamps will only have a resolution of one second,
but I figure that when I do the post processing I could look for the
records where the time stamp changed seconds, and then count records to
infer the time for each one. I don't need super high accuracy. Plus or
minus a half second will be more than good enough.

The only laptop I currently have available that has a serial port is a
Dell PIII 500 running Win 98. I can't put Linux on it, as it belongs to
my wife, and she needs Win 98 for some business applications. Is it
likely that a perl program would have enough performance to deal with data
at 115,200 baud, with 64 records per second?

I'm tempted to try perl as it seems to be general purpose enough that I
could use my new perl skills for all kinds of other things. But, if perl
likely won't be up to the task I'll look into using a compiled language.

Thanks for your advice,

If it's a serial port, the stream cannot be that fast by modern standards.
Any language will do fine, perl is probably easier to start with than, say,
C. You can have timestamps of any precision with Time::HiRes module (look
at CPAN), or you may call gettimeofday() via syscall (I am not sure if
Windows has this function but most probably it does).

 

[Kevin Horton]

If it's a serial port, the stream cannot be that fast by modern standards.
Any language will do fine, perl is probably easier to start with than,
say, C. You can have timestamps of any precision with Time::HiRes module
(look at CPAN), or you may call gettimeofday() via syscall (I am not sure
if Windows has this function but most probably it does).

Yeah, 115,200 is way faster than needed, but that is what this box puts
out, so I am stuck with it unless the vendor will heed my requests that he
ratchet the speed down a bit. I have successfully captured coherent data
using HyperTerminal PE on this laptop, so I know the serial port is up to
the task.

Thanks for the pointer to the Time::HiRes module. I'll install perl on
the laptop and start playing around with it. I suspect I'll be back for
more help once I get into this.