in reply to $x = `cat big_file` seg faults

I can confirm the behaviour. OS is Linux, Ubuntu 22.04.

With Perl 5.34.0:

$ time perl -wE 'my $x = `cat 2`'

real    0m4.558s
user    0m0.802s
sys    0m3.192s

$ time perl -wE 'my $x = `cat 1`'
Segmentation fault (core dumped)

real    1m28.649s
user    0m0.430s
sys    0m2.341s

[download]

With Perl 5.39.10: 

$ time blead -wE 'my $x = `cat 2`'

real    0m8.851s
user    0m0.980s
sys    0m3.795s

$ time blead -wE 'my $x = `cat 1`'
Segmentation fault      (core dumped)

real    0m5.694s
user    0m0.397s
sys    0m1.378s

[download]

So the newer perl still fails, but much faster :-)

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

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Re^2: $x = `cat big_file` seg faults
by cavac (Prior) on Sep 10, 2024 at 10:16 UTC

    So the newer perl still fails, but much faster :-)

    So much for "Perl is slow". We even optimize the performance of bugs ;-)

    But really, i rather suspect that after the first run with 5.34, the operating system cached parts of the file in memory.

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[reply]
      You are right. Repeated experiments show comparable times across Perl versions.

      map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]
[reply]
[d/l]

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