split efficiency needed

[Anonymous Monk]

I want to parse this line and just print the date and Time.

Out of this:

-rwxr-xr-x  1 svcn-3  ymn-3  7618486 Jan 20 21:42 20040120-299-x49.exe

I want this:

Updated on Jan 20 at 21:42 hours

I would put this in a variable:

my $var = '-rwxr-xr-x  1 svcn-3  ymn-3  7618486 Jan 20 21:42 20040120-
+299-x49.exe';
my @newvar = split ' ', $var;
print "Update at $newvar[5] $newvar[6] at $newvar[7]";

Any better way to do this??

[markov]

I do not know you exact environment, but apparently you are processing ls output on a Unix/Linux system. If so, would it be possible to avoid using ls in the first place... The reason for this, is that the date format in the ls output depends on the locale settings and may therefore change. In my settings, it is 2004-01-21!

Maybe you can rewrite the code to this:

  my $mtime = (stat $file)[9];

  use POSIX 'strftime';
  print strftime "any format you like", localtime $mtime;

[Roger]

Split is quite efficient on short and simple strings. The following is what I normally do, with a one-liner, not necessarily better, but less typing.


my $var = '-rwxr-xr-x  1 svcn-3  ymn-3  7618486 Jan 20 21:42 20040120-
+299-x49.exe';
printf "Update at %s %s at %s hours\n", (split /\s+/, $var)[5,6,7];


Here's another method I can think of that might improve the efficiency a bit if the string is long and has plenty of spaces. This approach only remembers the required fields and throws away the rest.


printf "Update at %s %s at %s hours\n",
      ($var =~ /^(?:\S+\s+){5}(\S+)\s+(\S+)\s+(\S+)/);

[Anonymous Monk]

thanks