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Re^2: Syntax error

by graff (Chancellor)
on Feb 11, 2014 at 05:47 UTC ( #1074343=note: print w/replies, xml ) Need Help??

in reply to Re: Syntax error
in thread Syntax error

Just to give you an idea of how little effort it should take to do the thing that your script does, here's a version that:
  • allows the user to specify all inputs and options at the command line, so the script knows what to do based on command-line args;
  • uses a hash instead of a set of separate scalar variables;
  • uses loops for input and output.
#!/usr/bin/perl use strict; # enforce variable declarations use warnings; # enable warnings my $Usage = "Usage: $0 [sequence.file]\n (reads stdin if no file name + is given)\n"; die $Usage unless ( -p STDIN or ( @ARGV and -f $ARGV[0] )); my %counts; # tally of letter occurrences # read lines from named file(s) or from stdin: while (<>) { s/\s+$//; # remove white space (line termination) from end of lin +e for my $ltr ( split // ) { # split into individual characters $counts{$ltr}++; } } # print results: for my $ltr ( sort keys %counts ) { print " Number of $ltr nucleotides: $counts{$ltr}\n"; }
Note that this version will count any character inventory you give it; if the input happens to contain something other than ACGT, you'll get the quantity of occurrence for all the letters that occur in the data.

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