substitution op. (s///) won't work

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

hello, I am trying to replace variables in a string (indicated by /\$\w+/), but am for some reason unsucessfull. This will probbably illustrate the problem best:

  DB<7> x $sql
0  'This string represents a SQL statement $replaceme'
  DB<8> x $what
0  '$replaceme'
  DB<9> x $with
0  'value'
  DB<10> $sql=~s/$what/$with/
  DB<11> x $sql
0  'This string represents a SQL statement $replaceme'
[download]

What i am trying to achieve is

$sql eq 'This string represents a SQL statement value'
[download]

Any suggestions what i am doing wrong here?

Comment on substitution op. (s///) won't work Select or Download Code

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Re: substitution op. (s///) won't work by Abigail-II (Bishop) on Sep 30, 2003 at 08:45 UTC
The problem is the content of the variable $what. It contains $replaceme, and for the regular expression engine, this means you want to replace a string 'replaceme' that follows the end of the string, because that's what $ means. Of course, there is no such string. You might want to use something like: `$sql =~ s/\Q$what/$with/;` [download] Abigail	[reply] [d/l]