in reply to Re: Conditional question
in thread Conditional question

  • use strict
  • use warnings
  • use my before first variable use
  • it is STDIN not stdin
  • chomp input to remove new line
  • use $ in front of variables
  • use eq to compare, = is assignment not comparison
  • Put quotes around strings

    Are those your 8?


    ___________
    Eric Hodges

    • Replies are listed 'Best First'.
    Re^3: Conditional question
    by Corion (Patriarch) on Oct 19, 2007 at 14:04 UTC 
      #!usr/bin/perl -w #1
use strict; #2

print "type hw to print hello world script!\n"; #3, newline(s) missing

my $cmd = <STDIN>; #4 STDIN

if ( $cmd eq "hw" ) #5,6,7 $cmd, "=" should be "==" or "eq", "hw" must
+ be quoted
{
print "Hello, world\n"; #3, newline(s) missing
}

else {

print "sorry I didn't understand the command.\n"; #8,3 "Print" -> "pri
+nt", newline(s) missing
}

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      I didn't count the missing my as an error, that could have been intended as a global variable instead of a lexical with global scope. I missed the chomp, and I had the \n after the print statements so the buffers get flushed. I'm not sure if Perl autoflushes buffers when alternating between printing to STDOUT and reading from STDIN.

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        I now use warnings; instead of perl -w since Windows seems to ignore the she-bang line.

        I humbly seek wisdom.
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          But Perl does not:

          C:\Projekte>type tmp.pl
#!/usr/bin/perl -w
use strict;

my $foo;
print $foo
__END__
C:\Projekte>perl tmp.pl
Use of uninitialized value in print at tmp.pl line 5.

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