Contributed by Buckaroo Buddha
on May 10, 2000 at 19:40 UTC
Q&A
> input and output
Description: I've tried:
$start = $ARGV[0];
if ($start eq '') {
$start = &get_start_level;
}
sub get_start_level {
print "Please Enter the Start-Level (0-7,?)[0]: ";
$input = <>;
# clear all but numbers or '?'
#if ($input ne '?') {
# $input =~ tr/!(0-9)//\d;
#}
if ($input eq '?') {
print " **** internally coded help information **** \n";
print " **** internally coded help information **** \n";
$input = &get_start_level;
} elsif (($input < 0) || ($input > 7)) {
print "please enter a number that is between Zero and Seven\n";
$input = &get_start_level;
}
return ($input);
}
=========================== end code ============
This seems to me like a pretty straight forward problem.
What am i doing wrong? ... I can't seem to figure this out. Answer: how do i work this
contributed by Russ Here's one way to do this:
my $start = $ARGV[0];
while (1){
print "Please Enter the Start-Level (0-7,?)[0]: ";
chomp($start = <>);
# Check for non-numeric characters
if ($start =~ /\D/){
print "\nPlease enter a number (0-7) or ? for help\n";
next;
}
last if 0 <= $start and $start <= 7;
# Check for a help request
if ($start eq '?') {
print " **** internally coded help information **** \n";
next;
}
print "\nPlease enter a number between Zero and Seven, inclusive\n";
}
print $start;
First, we check that the input is numeric (as you
started to do in your commented-out code) to
prevent errors if the user enters non-numeric
characters.
If the input is valid, we just exit the loop.
If not, check for a help request and, if not '?',
print a generic error message and redo the loop.
There are a million different ways to do this,
and this is only one of them...
Russ
| Answer: How can I validate user input?
contributed by ton while ($start !~ /^[0-7]$/) {
print "Please Enter the Start-Level (0-7,?)[0]: ";
$start = <STDIN>;
chomp $start;
if ($start eq '?') {
print "Some help info.\n";
}
}
|
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