Re^4: how to use perl variable in system command to run on unix

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Re^5: how to use perl variable in system command to run on unix by Laurent_R (Canon) on Sep 03, 2013 at 17:53 UTC
Because $9 is a variable in Perl, the ninth capture in a regular expression. Since you don't have a regex before, it is an undefined variable in your case, so il will be omitted altogether from your command line. If you escape the $ sign, you say that you want a $ sign, not a variable called $9. Then it is not interpolated and passed to awk correctly.	[reply]
Re^6: how to use perl variable in system command to run on unix by tousifp (Novice) on Sep 04, 2013 at 11:57 UTC
Thanks buddy.	[reply]
Re^5: how to use perl variable in system command to run on unix by Arunbear (Prior) on Sep 04, 2013 at 09:50 UTC
Because in this case you want a literal "$9", you don't want it to be expanded by Perl. An example that you can experiment with: % date Wed Sep 4 10:41:55 BST 2013 % date \| awk '{ print $2 }' Sep % perl -de0 Loading DB routines from perl5db.pl version 1.32 Editor support available. Enter h or `h h' for help, or `man perldebug' for more help. main::(-e:1): 0 DB<1> $cmd = qq[date \| awk '{ print $2 }'] DB<2> p $cmd date \| awk '{ print }' DB<3> p qx/$cmd/ Wed Sep 4 10:47:41 BST 2013 DB<4> $cmd = qq[date \| awk '{ print \$2 }'] DB<5> p $cmd date \| awk '{ print $2 }' DB<6> p qx/$cmd/ Sep DB<7> q % [download]	[reply] [d/l]
Re^6: how to use perl variable in system command to run on unix by tousifp (Novice) on Sep 04, 2013 at 11:59 UTC
Thanks. I got it. Will try your code later surely.	[reply]