Beefy Boxes and Bandwidth Generously Provided by pair Networks
Welcome to the Monastery

Re: foreach type of deal?

by toolic (Bishop)
on Mar 15, 2017 at 18:07 UTC ( #1184741=note: print w/replies, xml ) Need Help??

in reply to foreach type of deal?

One way to get rid of the g is to use the substitution operator (s///). This deletes the g if it is the 1st character on a line:
while (<>) { s/^g//; }

  • Show a few lines of your input (in "code" tags), if you need more help.
  • perlintro

Replies are listed 'Best First'.
Re^2: foreach type of deal?
by kennethk (Abbot) on Mar 15, 2017 at 18:32 UTC
    Since 500k+ is a big number and the spec says "They all start out with a g", I would rather use substr since there is no need for a test.
    while (<>) { my $word = substr($_,1); # Start with the second letter }

    As a note for the OP, while is a nicer option than Foreach Loops in this scenario since, in general, foreach constructs the entire list before incrementing over it, whereas while will just hit your file-handle once per loop -- normally, that means while has a much smaller memory footprint than foreach does for large sets. I don't recall if in the particular case of foreach(<$fh>) { there is an optimization in perl to avoid this pitfall.

    #11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

      Do we ever have perfect data? I prefer to use a test to warn about invalid data. The following code (untested) makes use of runtime switches (ref: perldoc perlrun). Use -p for the I/O and -i for backup.
      #!perl -p -ibak if (!s/^g(Ord_\d{4}\.png)\s*$/$1/) { warn "Invalid line: $_\n"; $_ = <>; redo; }

Log In?

What's my password?
Create A New User
Domain Nodelet?
Node Status?
node history
Node Type: note [id://1184741]
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others having an uproarious good time at the Monastery: (8)
As of 2022-01-24 13:23 GMT
Find Nodes?
    Voting Booth?
    In 2022, my preferred method to securely store passwords is:

    Results (64 votes). Check out past polls.