TPJ One Liner #21Picking random elements from an array:
srand; $item = $array[rand @array]; |
TPJ One-liner #22If you're trying to get Windows to generate a PostScript file,but it wraps the file with PCL junk, you can remove it with this: |
perl -ni -e "!$g&&s/^.*(%!.*)/$1/&&$g or print;last if /^%% EOF/"
TPJ One-liner #23In the movie Sphere, the commands that Harry typed to translate the message were taken from Tom Christiansen's FAQ: |
$BSD = -f '/vmunix'; if ($BSD) {system "BIN cbreak </dev/tty >/dev/tty 2>&1 sub set_break { # &setset_cbreak(1) or &set_cbreak(0) local($on) = $_[0]; local($sgttyb,@ary); require 'sys/ioctl.ph';
Courtesy of Brendan O'Dea
TPJ One-liner #24Seperate the header and body of a mail message into strings: |
while (<>) {
$in_header = 1 ../^$/;
$in_body = /^$/ ..eof();
Courtesy of the Perl Cookbook
TPJ One-Liner #25Simple numeric tests: |
warn "has nondigits" if /\D/;
warn "not a natural number" unless /^\d+$/;
warn "not an integer" unless /^'?\d+$/;
warn "not an integer" unless /^[+']?\d+$/;
warn "not a decimal number" unless
/^'?\d+\.?\d*$/; # rejects .2
warn "not a decimal number" unless
/^'?(?:\d+(?:\.\d*)?|\.\d+)$/;
warn "not a C float" unless
/^([+']?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$/;
Courtesy of The Perl Cookbook.
TPJ One-Liner #26Launching xterms with random colors. You might have to replace xterm with whatever command you use to launch a terminal window: |
perl -e '$fg=rand 2**24; do { $bg = rand 2**24 } while (unpack("%32b*", pack "N", ($bg^$fg)&0xe0e0e0) < 8); ($fg, $bg) = map { sprintf "#%06x", $_ } $fg, $bg; exec("xterm", "-fg", $fg, "-bg", $bg);'
Courtesy of Tkil
TPJ One-Liner #27Lop off the latter half of an array: |
$#array /= 2;Courtesy of The Perl Cookbook.