in reply to Re: regular expression across lines?
in thread regular expression across lines?

Thanks for your suggestion. I have a print statement in my code following the regular expression: 
print "'$tablename'\n";
and the interpreter scolds me with Use of uninitialized value in concatenation (.) or string when I try your regular expression which focuses on only the line comprising the FROM clause.

I'm still baffled...

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Re: Re: Re: regular expression across lines?
by Roger (Parson) on Dec 03, 2003 at 00:22 UTC
    Drop the g switch. And then modify your regex to capture table names with \w+ instead of \S+.
    use strict;
use warnings;

my $stmt0 = "SELECT table.field0, table.field1\nFROM table0;\n";
my $stmt1 = "SELECT table.field0, table.field1\nFROM table1\nWHERE fie
+ld0 = 'foo';\n";

my $nameA = $1 if $stmt0 =~ m/^FROM\s+(\S+)$/ms;
my $nameB = $1 if $stmt1 =~ m/^FROM\s+(\S+)$/ms;

my $name0 = do { $stmt0 =~ m/^FROM\s+(\w+)(;*?)$/ms; $1 };
my $name1 = do { $stmt1 =~ m/^FROM\s+(\w+)(;*?)$/ms; $1 };

print "table name A ='$nameA'\n";
print "table name B ='$nameB'\n";
print "table name 0 ='$name0'\n";
print "table name 1 ='$name1'\n";

    [download]
    And the output is -
    table name A ='table0;'
table name B ='table1'
table name 0 ='table0'
table name 1 ='table1'

    [download]
    Notice that in table name A, there is a ';' because of the ; character. The new regex is capable of filtering it out.

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Re: Re: Re: regular expression across lines?
by Anonymous Monk on Dec 03, 2003 at 00:14 UTC
    My bad. I tried the following: 
    $tablename = $1 if $stmt =~ m/^FROM\s+(\S+)/mgs;
#$tablename =~ s/;//g;
print "'$tablename'\n";
    but I am back to table; as to what is assigned to $tablename. I guess I need to resort to refining the character class I want to save. Thanks again.
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