On 1/30/2009 12:59 AM, thebarn...@gmail.com wrote:
Hi
I run this command and pipe the output to a perl one liner. not quite
sure how it parses the data:
svmon -Pt3 | perl -e 'while(<>){print if($.==2 || $& && !$x++); $.=0 if
(/^--+$/)}'
i understand that it resets the line count every time it sees a line
of "----" and it then will print line 2 which is the summary line we
are looking for. not sure what this part does "($.==2 || $& && !$x+
+)"
Technically, $. is a line number in the input file. Since the oneliner
reset it for every line made of dashes ("---"), it becomes a sort of
counter. $& is "last match", and !$x++ is "$x is false and then
increment it. Since in Perl, undef and 0 are false statues, you can read
it as "if the line number is 2, or if there was no match and $x (which
will be incremented) is undefined or 0) this part is what gets you the
lines that were not printed due to the $.=2 part.
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