okamoto@hpcc01.HP.COM (Jeff Okamoto) (05/04/91)
I'm trying to get the .. construct to work when it is passed in as a command line argument. What I am having trouble with is getting the .. to properly expand. I've tried a bunch of ways to force the result into an array context, but I'm obviously doing something wrong. I've tried a number of variations on the following, to no avail: $a = "'A0'..'A9'"; # Eventually will be shift(@ARGV); eval "\@b = (\$a)"; Can anyone offer any suggestions? -- \ oo The New Number Who, \____|\mm Jeff Okamoto //_//\ \_\ HP Corporate Computing & Services /K-9/ \/_/ okamoto@ranma.corp.hp.com /___/_____\ ----------- (415) 857-6236
tchrist@convex.COM (Tom Christiansen) (05/08/91)
From the keyboard of okamoto@hpcc01.HP.COM (Jeff Okamoto):
:I'm trying to get the .. construct to work when it is passed in as a command
:line argument. What I am having trouble with is getting the .. to properly
:expand. I've tried a bunch of ways to force the result into an array context,
:but I'm obviously doing something wrong.
:
:I've tried a number of variations on the following, to no avail:
:
: $a = "'A0'..'A9'"; # Eventually will be shift(@ARGV);
:
: eval "\@b = (\$a)";
:
:Can anyone offer any suggestions?
I'm not sure why you're going through the eval. I would just use:
@b = 'A0' .. 'A9';
and be done with it. If for some reason you must use the eval
way, remove the 2nd backslash:
: eval "\@b = ($a)";
--tom
--
Tom Christiansen tchrist@convex.com convex!tchrist
"So much mail, so little time." niklas@appli.se (Niklas Hallqvist) (05/10/91)
okamoto@hpcc01.HP.COM (Jeff Okamoto) writes: >I'm trying to get the .. construct to work when it is passed in as a command >line argument. What I am having trouble with is getting the .. to properly >expand. I've tried a bunch of ways to force the result into an array context, >but I'm obviously doing something wrong. >I've tried a number of variations on the following, to no avail: > $a = "'A0'..'A9'"; # Eventually will be shift(@ARGV); > eval "\@b = (\$a)"; >Can anyone offer any suggestions? What version of perl are you running? On my 4.003 the following perl-script works allright: #!/local/bin/perl $range = shift; eval "@array = $range"; print "@array\n"; When invoked as: foo "'A1'..'A9'" it prints: A1 A2 A3 A4 A5 A6 A7 A8 A9 That's what you wanted, wasn't it? Niklas
lwall@jpl-devvax.jpl.nasa.gov (Larry Wall) (05/10/91)
In article <1362@appli.se> niklas@appli.se (Niklas Hallqvist) writes: : okamoto@hpcc01.HP.COM (Jeff Okamoto) writes: : : >I'm trying to get the .. construct to work when it is passed in as a command : >line argument. What I am having trouble with is getting the .. to properly : >expand. I've tried a bunch of ways to force the result into an array context, : >but I'm obviously doing something wrong. : : >I've tried a number of variations on the following, to no avail: : : > $a = "'A0'..'A9'"; # Eventually will be shift(@ARGV); : : > eval "\@b = (\$a)"; : : >Can anyone offer any suggestions? : : What version of perl are you running? On my 4.003 the following : perl-script works allright: : : #!/local/bin/perl : $range = shift; : eval "@array = $range"; : print "@array\n"; : : When invoked as: : foo "'A1'..'A9'" : : it prints: : A1 A2 A3 A4 A5 A6 A7 A8 A9 : : That's what you wanted, wasn't it? This just happens to work because @array inside double quotes is grandfathered not to work unless @array is referenced outside of double quotes, to protect ancient scripts in which @array was never interpolated. You can prove this to yourself by adding @array; at the end of your script--it stops working. It's better to backwhack the @array reference in the eval: eval "\@array = ($range)"; die $@ if $@; If you put the parens around $range like that, you can also invoke it as foo "A1..A9,A13" And checking $@ after evaluating user supplied strings will save a lot of aggravation in the long run. Larry