Re^3: Search and replace

[Bharath666]

Also if you don't mind can you please explain me how exactly this command works

$found =~ s/ENV{\"(.*?)\"}/\$ENV(\"$1\")/g;

Thanks!!

[Athanasius]

I thought I already had. :-) But OK, let’s add an /x modifier to the regex to make it easier to break apart:

$found =~ s/
              ENV{\"    # match the characters: ENV{"
              (.*?)     # followed by any characters -- this sequence 
+is the "value", and the parentheses capture it into the special varia
+ble $1
              \"}       # followed by: "}
           /
              \$ENV(    # and substitute a literal: $ENV("
              $1        # followed by the captured "value"
              \")       # followed by: ")
           /gx;         # and repeat the search & replacement to the e
+nd of $found

Notes:

• The double quotes are backslashed only because I was using a one-liner (and I’m on Windows). This is unnecessary in a .pl script. (But the $ must be backslashed to show that it is literal, not the special symbol for “match the end of a line” (in the search part) or a sigil denoting a scalar variable to be interpolated (in the replacement part). Update: Added the words from “(in the search part)” to the end of the sentence.)

• The ? in the capture group (.*?) makes the match non-greedy. So the regex engine looks for the fewest number of characters occurring between ENV{" and "}. Without the ?, the match would be greedy, and on the string:

  ENV{"VCINSTALLDIR"}\ATLMFC\LIB\amd64;ENV{"LIBPATH"}
  

  it would match

  VCINSTALLDIR"}\ATLMFC\LIB\amd64;ENV{"LIBPATH

which is not what we want!

Hope that helps,

[Bharath666]

Yeah!! I got it now :) Thanks a lot :)