Printing status displays in Perl scripts
While developing a Perl script this weekend to summarize Solaris zone usage, I wanted to display some type of status while my script did it’s thing. My friend Clay came up with a cool way to do this, and I thought I would share it here in case others needed to do something similar. Here is the code:
#!/usr/bin/perl -w
# Initialize the index.
my $index=0;
# The characters to use as spinners.
my @spinners = ("-", "\\", "|", "/");
my $totalspinners = $#spinners + 1;
# Turn on autoflush.
$| = 1;
print "Factoring primes: ";
while (1) {
print "\\b$spinners[$index++ % $totalspinners]";
sleep 1;
}
# If you were to exit the loop, turn off autoflush.
$| = 0;
There may be a better way to do this (adding an additional module isn’t an option), but I have yet to find it. Niiiiiice!
Clayton Scott on November 10th, 2007
You can get rid of your $totalspinners variable altogether since an array in scalar context will give up the number of elements. Also autoflush is not controlling the loop, so your last comment is incorrect.
#!/usr/bin/perl -w
# Initialize the index.
my $index=0;
# The characters to use as spinners.
my @spinners = ("-", "\\", "|", "/");
# Turn on autoflush.
$| = 1;
print "Factoring primes: ";
while (1) {
print "\\b$spinners[$index++ % @spinners]";
sleep 1;
}
# If you were to exit the loop, turn off autoflush.
$| = 0;