I'm probably missing something obvious... Why do many C fprintf statements take around 1 second (wallclock) and the equivalent perl printf statements take 4 seconds? Consider (ignoring for now some of my perhaps idiomatic failings):

#!/usr/bin/perl -w

use strict;

my $outf = "/tmp/outf.p.out";

open OUTF, ">$outf" or die "ERROR: could not open file $outf - $!\n";

foreach my $i ( 1..1000 )
{
    foreach my $j ( 0..255 )
    {
        printf( OUTF "host DAAA%02X { blah blah XX:XX:XX:%02X; }\n", $
+j, $j );
        printf( OUTF "host DAAA%02X { blah blah XX:XX:XX:%02X; }\n", $
+j, $j );
        printf( OUTF "host DAAA%02X { blah blah XX:XX:XX:%02X; }\n", $
+j, $j );
        printf( OUTF "host DAAA%02X { blah blah XX:XX:XX:%02X; }\n", $
+j, $j );
    }
}

close OUTF;

exit 0;

__DATA__

/*  C (somewhat?) equivalent of the perl script above  */
#include <stdio.h>

int main ()
{
    char *outf = "/tmp/outf.c.out";
    FILE *fd;
    int i,j;

    if ( !( fd = fopen( outf, "w" ) ) )
    {
        printf( "ERROR: could not open file %s\n", outf );
        exit(1);
    }

    for ( i=1;i<=1000;i++ )
    {
        for ( j=0;j<=255;j++ )
        {
            fprintf( fd, "   host DAAA%02X { blah blah XX:XX:XX:%02X; 
+}\n", j, j );
            fprintf( fd, "   host DAAA%02X { blah blah XX:XX:XX:%02X; 
+}\n", j, j );
            fprintf( fd, "   host DAAA%02X { blah blah XX:XX:XX:%02X; 
+}\n", j, j );
            fprintf( fd, "   host DAAA%02X { blah blah XX:XX:XX:%02X; 
+}\n", j, j );
        }
    }

    fclose( fd );

    exit(0);
}
[download]

My configuration is as follows:

hostname% uname -a
SunOS hostname 5.9 Generic_117171-07 sun4u sparc SUNW,Sun-Fire-V440
hostname% perl -v

This is perl, v5.6.1 built for sun4-solaris-64int

Timed results are:

hostname% time ../bin/ftest
1.0u 0.0s 0:01 85% 0+0k 0+0io 0pf+0w
hostname% time ./ftest.pl
4.0u 0.0s 0:04 86% 0+0k 0+0io 0pf+0w

(... for the curious, I have ported a C program which generates our DHCP table to perl, thus the pseudo formatting of the string...)

Taking out the hex formatting results in a faster run time (duh!), but still slower than equivalent C fprintf().

Thanks in advance for any info...

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