Re: quotemeta() question...

Jason Barnett wrote: > Richard Lynch wrote: >> Steve Kaufman wrote: >> >>>Why does >>> quotemeta("pat:1$WRW") >>>return >>> pat:1 >>>instead of >>> pat:1\$WRW >>> >>>What am I misunderstanding about quotemeta function? >> >> >> You usually would use quotemeta on data coming from the database, or the >> user, or externally, or, errr, basically things you haven't typed in to >> PHP, that you need to pass into Regular Expressions. >> >> In those cases, you've already got the $ (and other characters) >> successfully embedded in the string, but you want to escape them for >> whatever reason. >> >> A better example code would be: >> $string = >> >> 'period.backslash\\plus+star*question?lbracket[rbracket]carat^lparen(rparen)dollar$'; >> echo "<PRE>", quotemeta($string), "</PRE>"; >> > > Interesting aside... with the test string above, I noticed that > backslash\\ only resolved to two backslashes. I thought there would be > 4. It seems that quotemeta will resolve \ and \\ to \\, \\\ and \\\\ > resolve to \\\\, etc. No, no, no. FORGET quotemeta for a moment. *BEFORE* the string ever GETS to quotemeta, PHP takes the characters you typed and builds a string. For PHP, \\ inside of apostrophes turns into a single \. You Type: Internal PHP string '\\' \ '\'' ' '\\\\' \\ "\\" \ "\"" " It's absolutely crucial that you understand that PHP itself alters the \\ to \ lonnnnnnng before quotemeta enters the picture. If you use just '\' in what you type, PHP is kinda stuck with just assuming you meant '\\' and it runs with \ as its internal representation. This is documented behaviour, but I consider it Bad Style. So using \ or \\\ or any odd number of \ inside of apostrophes/quotes to get a backslash in the internal PHP string is just plain bogus, if you ask me. [shrug] At any rate, quotemeta is *NOT* the thing that converts \ and \\ into \\. PHP converts \ and \\ into a single \ quotemeta converts that single \ into \\ -- Like Music? http://l-i-e.com/artists.htm