[Please don't top-post]
Rich Busse wrote: > > From: John W. Krahn [mailto:[EMAIL PROTECTED]] > > > > Here is one way to do it: > > > > $_ = q[P=IcwRcsm D=D: SL=20 ST=d:\icw\rcsm\StartSv.bat Parm1 Parm2 > > U=http://uslv...]; > > > > my ( $Proc, $Start, $Url, $Sleep, $Drive ); > > my %keys; > > > > @keys{ qw/P ST U SL D/ } = \( $Proc, $Start, $Url, $Sleep, $Drive ); > > > > while ( /(\S+)=(.+?)(?=\s+\S+=|\z)/g ) { > > ${$keys{uc $1}} = $2; > > } > > > > print "Proc: $Proc\nStart: $Start\nUrl: $Url\nSleep: $Sleep\nDrive: > > $Drive\n"; > > Thank you, John. This code does exactly what I want. Problem is, I > only understand about 30% of what's going on. I can figure out > the use of the hash, some of the pattern matching & $1/$2. But can > someone elaborate on: > > @keys{ qw/P ST U SL D/ } = \( $Proc, $Start, $Url, $Sleep, $Drive ); This populates the hash %keys with the letters to search for as the keys and references to the variables declared earlier as the values. It is equivalent to: my %keys = ( P => \$Proc, ST => \$Start, U => \$Url, SL => \$Sleep, D => \$Drive, ); > /(\S+)=(.+?)(?=\s+\S+=|\z)/g This searches for one or more non-whitespace characters (\S+ captured in $1) followed by an equal sign (=) followed by one or more non-newline characters (.+? captured in $2). This pattern must be followed by a whitespace, non-whitespace, equal-sign (\s+\S+=) pattern or the end of the string (\z) but the pattern enclosed in (?=pattern) does not affect where the search looks for the second and subsequent matches. > ${$keys{uc $1}} = $2; Since the values of %keys are references to scalar variables we have to dereference them to store the content. This is equivalent to: ${ \$Drive } = $2 if uc $1 eq 'D'; N.B. After I posted I thought of this change to make it more robust: while ( /(\S+)=(.+?)(?=\s+\S+=|\z)/g ) { ${$keys{uc $1}} = $2 if exists $keys{uc $1}; } HTH John -- use Perl; program fulfillment -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
