replacing "\L" character in strings

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

Hi,

I have a program which takes in server name as a parameter, forms a connection string and calls a DBI->connect with that server name. The problem is if the server name has backslash inside it "\", it escapes it and as a result, the connection fails. Ex: $server = "SERVER05\LDEV" is converted to "SERVER05dev", the characters coming after the "\L" is changed to lower case.

I tried to find and replace \L to \\L or to space, but it does not seem to work. Is there a way to treat the string as 'raw', i.e., without escape chars? Kindly advise.

Comment on replacing "\L" character in strings

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Re: replacing "\L" character in strings by ww (Archbishop) on Jul 25, 2010 at 17:55 UTC
Put the `path\filename` inside single quotes (which do not interpolate)... or, possibly, use `path/filename` which your script will (very high probability) use gracefully.	[reply] [d/l] [select]
Re: replacing "\L" character in strings by Marshall (Canon) on Jul 25, 2010 at 18:06 UTC
Try "forward slash": /. Perl is amazingly smart about path names under Windows and without any exceptions that I can think of, / works better than \ for paths that Perl knows about.	[reply]
Re^2: replacing "\L" character in strings by ikegami (Patriarch) on Jul 26, 2010 at 16:12 UTC
Actually, Perl is incredibly dumb about path names, passing the path unchanged to Windows. Windows accepts both "/" and "\" as path separators.	[reply]
Re^2: replacing "\L" character in strings by ananthbv (Initiate) on Jul 25, 2010 at 18:16 UTC
Thanks ww and Marshall, sorry if I was not clear, but what is passed here is not path names but database server names and the server names have a backslash inside it. and if the letter coming after the backslash is a recognised escape character, it escapes it. Ex: if someone passes the server name as "SERVER05\LDEV", it is changed to "SERVER05dev" because \L is taken as 'convert all characters to lower case till a \E is found. Since the server name is different, the connection fails is there a way to ignore escape characters in strings or some other way?	[reply]
Re^3: replacing "\L" character in strings by Corion (Patriarch) on Jul 25, 2010 at 18:25 UTC
As you don't show any code, it's hard to tell you what you really mean. Maybe you want to use quotemeta respectively `\Q` in your regular expression, to prevent interpolation of regex-meta-characters? See perlre and/or perlop.	[reply] [d/l]
Re^4: replacing "\L" character in strings by ananthbv (Initiate) on Jul 25, 2010 at 22:09 UTC
Re^3: replacing "\L" character in strings by Marshall (Canon) on Jul 25, 2010 at 18:33 UTC
The normal way to put a "backslash" in a character stream is to "back slash" the "backslash", i.e. with '\\', the first back slash means that the next char (which is a backslash) should be taken literally. In other words, convert single '\' to '\\'.	[reply]
Re^3: replacing "\L" character in strings by ww (Archbishop) on Jul 25, 2010 at 20:03 UTC
Lacking any hint of how you've code the script, it's hard to be confident that my first suggestion -- that you use NON-INTERPOLATING SINGLE QUOTES (') -- will solve your problem... but it might, as might Corion's re quotemeta.	[reply]
Re: replacing "\L" character in strings by ikegami (Patriarch) on Jul 26, 2010 at 16:15 UTC
"`\`" is special in string literals. You need to escape it. `$server = "SERVER05\\LDEV"; # Produces SERVER05\LDEV $server = 'SERVER05\\LDEV'; # Produces SERVER05\LDEV $server = 'SERVER05\LDEV'; # Produces SERVER05\LDEV` [download] The third works since "`\`" only needs to be escaped when it's followed by another "`\`" or the string delimiter (`'`) in single quoted strings.	[reply] [d/l] [select]