Changing an array in Perl
I am trying to use Perl to parse output from a (C-based) program.
Every output line is a (1D) Perl array, which I sometimes want to store (based on certain conditions).
I now wish to (deep) copy an array when its first element has a certain keyword,
and print that same copied array if another keyword matches in a later line-array.
So far, I have attempted the following:
#!/usr/bin/env perl
use strict; # recommended
use Storable qw(dclone);
...
while(1) # loop over the lines
{
# subsequent calls to tbse_line contain
# (references to) arrays of data
my $la = $population->tbse_line();
my @copy;
my $header = shift @$la;
# break out of the loop:
last if ($header eq 'fin');
if($header eq 'keyword')
{
@copy = @{ dclone @$la };
}
if($header eq 'other_keyword')
{
print "second condition met, print first line:n"
print "@copyn";
}
}
However, this prints an empty line to the screen, instead of the contents of the copied array. I don't have a lot of Perl experience, and I can't figure out what I am doing wrong.
Any idea on how to go about this?
arrays perl parsing
asked Nov 19 '18 at 17:43
Final_SunFinal_Sun
32
add a comment |
I am trying to use Perl to parse output from a (C-based) program.
Every output line is a (1D) Perl array, which I sometimes want to store (based on certain conditions).
I now wish to (deep) copy an array when its first element has a certain keyword,
and print that same copied array if another keyword matches in a later line-array.
So far, I have attempted the following:
#!/usr/bin/env perl
use strict; # recommended
use Storable qw(dclone);
...
while(1) # loop over the lines
{
# subsequent calls to tbse_line contain
# (references to) arrays of data
my $la = $population->tbse_line();
my @copy;
my $header = shift @$la;
# break out of the loop:
last if ($header eq 'fin');
if($header eq 'keyword')
{
@copy = @{ dclone @$la };
}
if($header eq 'other_keyword')
{
print "second condition met, print first line:n"
print "@copyn";
}
}
However, this prints an empty line to the screen, instead of the contents of the copied array. I don't have a lot of Perl experience, and I can't figure out what I am doing wrong.
Any idea on how to go about this?
arrays perl parsing
asked Nov 19 '18 at 17:43
Final_SunFinal_Sun
32
3
We don't know what ->tbse_line() returns.
– choroba
Nov 19 '18 at 17:46
add a comment |
I am trying to use Perl to parse output from a (C-based) program.
Every output line is a (1D) Perl array, which I sometimes want to store (based on certain conditions).
I now wish to (deep) copy an array when its first element has a certain keyword,
and print that same copied array if another keyword matches in a later line-array.
So far, I have attempted the following:
#!/usr/bin/env perl
use strict; # recommended
use Storable qw(dclone);
...
while(1) # loop over the lines
{
# subsequent calls to tbse_line contain
# (references to) arrays of data
my $la = $population->tbse_line();
my @copy;
my $header = shift @$la;
# break out of the loop:
last if ($header eq 'fin');
if($header eq 'keyword')
{
@copy = @{ dclone @$la };
}
if($header eq 'other_keyword')
{
print "second condition met, print first line:n"
print "@copyn";
}
}
However, this prints an empty line to the screen, instead of the contents of the copied array. I don't have a lot of Perl experience, and I can't figure out what I am doing wrong.
Any idea on how to go about this?
arrays perl parsing
asked Nov 19 '18 at 17:43
Final_SunFinal_Sun
32
I am trying to use Perl to parse output from a (C-based) program.
Every output line is a (1D) Perl array, which I sometimes want to store (based on certain conditions).
I now wish to (deep) copy an array when its first element has a certain keyword,
and print that same copied array if another keyword matches in a later line-array.
So far, I have attempted the following:
#!/usr/bin/env perl
use strict; # recommended
use Storable qw(dclone);
...
while(1) # loop over the lines
{
# subsequent calls to tbse_line contain
# (references to) arrays of data
my $la = $population->tbse_line();
my @copy;
my $header = shift @$la;
# break out of the loop:
last if ($header eq 'fin');
if($header eq 'keyword')
{
@copy = @{ dclone @$la };
}
if($header eq 'other_keyword')
{
print "second condition met, print first line:n"
print "@copyn";
}
}
However, this prints an empty line to the screen, instead of the contents of the copied array. I don't have a lot of Perl experience, and I can't figure out what I am doing wrong.
Any idea on how to go about this?
arrays perl parsing
arrays perl parsing
asked Nov 19 '18 at 17:43
Final_SunFinal_Sun
32
asked Nov 19 '18 at 17:43
Final_SunFinal_Sun
32
asked Nov 19 '18 at 17:43
Final_SunFinal_Sun
32
asked Nov 19 '18 at 17:43
Final_SunFinal_Sun
32
asked Nov 19 '18 at 17:43
Final_SunFinal_Sun
32
32
3
We don't know what ->tbse_line() returns.
– choroba
Nov 19 '18 at 17:46
add a comment |
3
We don't know what ->tbse_line() returns.
– choroba
Nov 19 '18 at 17:46
3
3
We don't know what ->tbse_line() returns.
– choroba
Nov 19 '18 at 17:46
We don't know what ->tbse_line() returns.
– choroba
Nov 19 '18 at 17:46
add a comment |
1 Answer
1
active
oldest
votes
my @copy allocates a new Perl array named @copy in the current scope. It looks like you want to set @copy during one iteration of your while loop and print it in a different iteration. In order for your array not to be erased each time a new while loop iteration starts, you should move the my @copy declaration outside of the loop.
my @copy;
while (1) { ... }
answered Nov 19 '18 at 17:48
mobmob
97.2k14130251
Thanks, that fixed the issue! The code above is just a small part of a very large code that I did not write myself, but am trying to adapt to my current processing needs. I must have overlooked the positioning of the array declaration.
– Final_Sun
Nov 19 '18 at 17:52
You should accept the answer if it's solved your problem :)
– Grinnz
Nov 19 '18 at 18:18
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
my @copy allocates a new Perl array named @copy in the current scope. It looks like you want to set @copy during one iteration of your while loop and print it in a different iteration. In order for your array not to be erased each time a new while loop iteration starts, you should move the my @copy declaration outside of the loop.
my @copy;
while (1) { ... }
answered Nov 19 '18 at 17:48
mobmob
97.2k14130251
Thanks, that fixed the issue! The code above is just a small part of a very large code that I did not write myself, but am trying to adapt to my current processing needs. I must have overlooked the positioning of the array declaration.
– Final_Sun
Nov 19 '18 at 17:52
You should accept the answer if it's solved your problem :)
– Grinnz
Nov 19 '18 at 18:18
add a comment |
my @copy allocates a new Perl array named @copy in the current scope. It looks like you want to set @copy during one iteration of your while loop and print it in a different iteration. In order for your array not to be erased each time a new while loop iteration starts, you should move the my @copy declaration outside of the loop.
my @copy;
while (1) { ... }
answered Nov 19 '18 at 17:48
mobmob
97.2k14130251
Thanks, that fixed the issue! The code above is just a small part of a very large code that I did not write myself, but am trying to adapt to my current processing needs. I must have overlooked the positioning of the array declaration.
– Final_Sun
Nov 19 '18 at 17:52
You should accept the answer if it's solved your problem :)
– Grinnz
Nov 19 '18 at 18:18
add a comment |
my @copy allocates a new Perl array named @copy in the current scope. It looks like you want to set @copy during one iteration of your while loop and print it in a different iteration. In order for your array not to be erased each time a new while loop iteration starts, you should move the my @copy declaration outside of the loop.
my @copy;
while (1) { ... }
answered Nov 19 '18 at 17:48
mobmob
97.2k14130251
my @copy allocates a new Perl array named @copy in the current scope. It looks like you want to set @copy during one iteration of your while loop and print it in a different iteration. In order for your array not to be erased each time a new while loop iteration starts, you should move the my @copy declaration outside of the loop.
my @copy;
while (1) { ... }
answered Nov 19 '18 at 17:48
mobmob
97.2k14130251
answered Nov 19 '18 at 17:48
mobmob
97.2k14130251
answered Nov 19 '18 at 17:48
mobmob
97.2k14130251
answered Nov 19 '18 at 17:48
mobmob
97.2k14130251
97.2k14130251
Thanks, that fixed the issue! The code above is just a small part of a very large code that I did not write myself, but am trying to adapt to my current processing needs. I must have overlooked the positioning of the array declaration.
– Final_Sun
Nov 19 '18 at 17:52
You should accept the answer if it's solved your problem :)
– Grinnz
Nov 19 '18 at 18:18
add a comment |
Thanks, that fixed the issue! The code above is just a small part of a very large code that I did not write myself, but am trying to adapt to my current processing needs. I must have overlooked the positioning of the array declaration.
– Final_Sun
Nov 19 '18 at 17:52
You should accept the answer if it's solved your problem :)
– Grinnz
Nov 19 '18 at 18:18
Thanks, that fixed the issue! The code above is just a small part of a very large code that I did not write myself, but am trying to adapt to my current processing needs. I must have overlooked the positioning of the array declaration.
– Final_Sun
Nov 19 '18 at 17:52
Thanks, that fixed the issue! The code above is just a small part of a very large code that I did not write myself, but am trying to adapt to my current processing needs. I must have overlooked the positioning of the array declaration.
– Final_Sun
Nov 19 '18 at 17:52
You should accept the answer if it's solved your problem :)
– Grinnz
Nov 19 '18 at 18:18
You should accept the answer if it's solved your problem :)
– Grinnz
Nov 19 '18 at 18:18
add a comment |
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3
We don't know what ->tbse_line() returns.
– choroba
Nov 19 '18 at 17:46