Replacing a string with a memory variable

rsriram has asked for the wisdom of the Perl Monks concerning the following question:

hi, I am writing a perl script to code a text file to XML. A line which replaces a particular tag goes like,

$_ =~ s/<CT>/<section id=\"ch$acnofm\" label=\"\" xreflabel=\"\" role=\"fm\">/g;

I have stored the chapter number in $acno, the output should look like

<section id="ch01fm" label="" xreflabel="" role="fm">

Because the static text 'fm' immediately follows a variable $acno, perl considers $acnofm as a single variable and because $acnofm does not have any value assigned to it, the replacement is made as:

<section id="ch" label="" xreflabel="" role="fm">

Could anyone help me with the syntax for this replace?

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Re: Replacing a string with a memory variable by BrowserUk (Patriarch) on Jun 28, 2006 at 11:34 UTC
Use {} to delimit the variable name `$_ =~ s/<CT>/<section id=\"ch${acno}fm\" label=\"\" xreflabel=\"\" rol +e=\"fm\">/g;` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]
Re: Replacing a string with a memory variable by mickeyn (Priest) on Jun 28, 2006 at 12:11 UTC
use ${acno} instead of $acno Enjoy, Mickey	[reply]
Re: Replacing a string with a memory variable by VSarkiss (Monsignor) on Jun 28, 2006 at 14:08 UTC
Another WTDI would be to use sprintf, if only to make the code more readable: `my $fmt = '<section id="ch%02dfm" label="" xreflabel="" role="fm">'; # ..later.. $_ =~ s/<CT>/sprintf $fmt, $acno/ge;` [download] I guessed at the `%02d` in the format string based on your sample. BTW, the default target for the substitution is `$_` so you could actually shorten the assignment to just `s/<CT>/sprintf $fmt, $acno/ge;` [download] Do not rebuke them with harsh words ... but rather lead them gently - with URLs - so that they may learn wisdom.	[reply] [d/l] [select]