Re: Problem matching a backslash in a regular expression

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Re^2: Problem matching a backslash in a regular expression by sauoq (Abbot) on Sep 17, 2005 at 03:35 UTC
How do I append the line, I am able to identify \ and \n. The following is one way... `while ($line = <>) { while ($line =~ s/\\\n//) { $line .= <>; } # ... do useful stuff with $line here ... }` [download] The outside loop reads a line. The inside loop 1) checks to see if it ends with backwhack-newline, 2) lops off the backwhack-newline, 3) appends the next line from the file, and 4) repeats. Note that steps 1 and 2 are both done in the while's conditional with the substitution. (If the substitution is successful, then the line did end with backwhack-newline and it was removed.) Caveats include the assumption that a newline is your command terminator and the backwhack escapes it by immediately preceding it (as if with a shell script, for instance) and also that you won't have to worry about other escaped characters. An example of the latter might be a line that ends with `"\\\n"`, which will break this code if that should be interpreted as an escaped backwhack rather than an escaped newline. -sauoq "My two cents aren't worth a dime.";	[reply] [d/l] [select]

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Re^2: Problem matching a backslash in a regular expression
by sauoq (Abbot) on Sep 17, 2005 at 03:35 UTC

How do I append the line, I am able to identify \ and \n.

The following is one way...

while ($line = <>) {
  while ($line =~ s/\\\n//) {
    $line .= <>;
  }
  # ... do useful stuff with $line here ...
}
[download]

Note that steps 1 and 2 are both done in the while's conditional with the substitution. (If the substitution is successful, then the line did end with backwhack-newline and it was removed.)

Caveats include the assumption that a newline is your command terminator and the backwhack escapes it by immediately preceding it (as if with a shell script, for instance) and also that you won't have to worry about other escaped characters. An example of the latter might be a line that ends with "\\\n", which will break this code if that should be interpreted as an escaped backwhack rather than an escaped newline.

-sauoq
"My two cents aren't worth a dime.";

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