[EMAIL PROTECTED] wrote:
> Hi,
> With regards to the script below, inside the foreach loop, can
> someone explain to me why the expression $_=~ s/\nfred\n/nancy/;
> did not change the default variable $_ from fred (enclosed by \n) to nancy.
>
> Thanks
>
> ######### start of script ###################
> use strict;
Always
use warnings;
> open (MYDATA, ">BACCARATDATA.TXT") || DIE $!;
Perl is case sensitive. DIE is a filehandle and you mean the function
'die'.
It is much safer to use the three-argument version of open and indirect
file handles:
open my $mydata, '>', 'BACCARATDATA.TXT' or die $!;
> print MYDATA "hello how are you\nfred\n";
> close MYDATA;
>
> open (MYDATA, "<BACCARATDATA.TXT") || DIE $!;
> my @newdata = <MYDATA>;
> close MYDATA;
Here you are reading back the contents of the file you just wrote, with
the default record separator of "\n". So @newdata consists of two
elements:
0: "hello how are you\n"
1: "fred\n"
> open (MYDATA, ">>BACCARATDATA.TXT") || DIE $!;
> foreach (@newdata){
> $_=~ s/\nfred\n/nancy/;
There is no need to mention $_ here - as you mentioned at the top of
your post it is the default if you don't specify an object variable.
But none of the lines contain "\nfred\n" as I showed above, so this
substitute will never succeed.
s/^fred$/nancy/;
will do what you intended.
> print MYDATA "$_";
> print "$_";
> }
> close MYDATA;
HTH,
Rob
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