Can't substitute Newline in text

[zzapper]

Hi
I am reading a text field from an XML feed. When I view that field in various ways eg with vi I can see the plain text is formatted in lines and paragraphs. So i want to substitute newlines for say 'fred'. I've tried the following with no success

$p_desc=~s/\n/fred/g;
$p_desc=~s/\n\r/fred/g;
$p_desc=~s/^$/fred/g;
$p_desc=~s/^ *$/fred/g;

Can you help? Should I be splitting?

 

[KevinADC]

try:

$p_desc =~ s/\n/fred/sg;

assumes you have multiple lines stored in the scalar.

------------------------------------------
- Kevin, perl coder unexceptional!

 

[feherke]

Hi

I would say the problem is with the order of substitutions :

$p_desc=~s/\n/fred/g;    # eliminate \n
$p_desc=~s/\n\r/fred/g;  # searching for more \n
$p_desc=~s/^$/fred/g;    # searching empty lines (?) but line delimiters were removed previously
$p_desc=~s/^ *$/fred/g;  # similarly

(?) - assuming you intended to use the [tt]m[/tt] modifier.

Feherke.

http://rootshell.be/~feherke/

 

[KevinADC]

I think those are examples of everything he has tried, but maybe not.

------------------------------------------
- Kevin, perl coder unexceptional!

 

[KevinADC]

this works for me:

foo = qq{this is a test
this is a test
this is a test
};
$foo =~ s/\n/fred/sg;
print $foo;

output:

this is a testfredthis is a testfredthis is a testfred

------------------------------------------
- Kevin, perl coder unexceptional!

 

[KevinADC]

should be $foo in the first line of code above.

------------------------------------------
- Kevin, perl coder unexceptional!

 

[feherke]

Hi

Oops. I supposed (s)he done all four substitutions one after another. Otherwise I do not understand the problem, as that substitution works for me without [tt]s[/tt] modifier too :

$foo =~ s/\n/fred/g;

Feherke.

http://rootshell.be/~feherke/

 

[KevinADC]

Yea, it does, it works with or without the "s". So I am also confused at this point. Seeing some of the actual data may help.

------------------------------------------
- Kevin, perl coder unexceptional!

 

[zzapper]

Hi
Thanks y'all it turns out my problem that in the xml feed the newlines were being transmitted as actual or literal \n (where \n is two ascii characters)
so I needed

$p_pdesc =~s/\\n/<br>/sg;

What I don't understand is how previously there were being translated into real \n newlines when I spat the result into mysql?

 

[Kirsle]

Without seeing your code we couldn't tell why MySQL would turn a literal \n (\\n) into a \n line break, but I run into something similar when outputting JavaScript from within Perl, like

print qq~
document.onLoad = function() {
   window.alert("hello\\nworld!");
}~;

which outputs JavaScript code

document.onLoad = function() {
   window.alert("hello\nworld!");
}

which pops up an alertbox saying

hello
world

In your case it might also be possible that MySQL understands the literal \n and translates it into a line break automatically (i.e. if you were typing commands at a SQL command prompt, you might type in a literal "\n" in one of the values and MySQL would have to know to turn it into a line feed).

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