Is it possible to create Switch statements that use variables in the case condition, in Maya Mel Script language?
Something along the lines (stupid example for the sake of explanation):
$val1 = "foo";
$val2 = "bar";
// imagine $input as an argument of some proc
switch ($input)
{
case $val1:
print "Input is 'foo'";
break;
case $val2:
print "Input is 'bar'";
break;
}
P.s. I tried that and it didn't work, but you might know of another option.
Thanks a lot
You can't use variables as case values directly, but you can build a string containing the code that you want to execute, with variables replaced with their values, and pass that string to the eval function:
$val1 = "foo";
$val2 = "bar";
// imagine $input as an argument of some proc
string $cmd;
$cmd = "switch (\"" + $input + "\")";
$cmd += "{";
$cmd += "case \"" + $val1 + "\":";
$cmd += " print \"Input is 'foo'\";";
$cmd += " break;";
$cmd += "case \"" + $val2 + "\":";
$cmd += " print \"Input is 'bar'\";";
$cmd += " break;";
$cmd += "}";
eval $cmd;
Related
for (my $j = 0; $j <100000; $j++){
my $outcome = rand();
for (my $k = 0; $k < #cum_sum; $k++){
if ($cum_sum[$k] >= $outcome){
if ($keys[$k] =~ m/\"|\/|\<|\>|\\|\`|\~|\#|\#|\$|\%|\^|\*|[0-9]/) {
print $out "";
}
if ($keys[$k] =~ m/\s/){
print $out " ";
}
elsif ($keys[$k] =~ m/\&/){
print $out " and ";
}
elsif ($keys[$k] =~ m/\!/){
print $out "! ";
}
elsif ($keys[$k] =~ m/\:/){
print $out ": ";
}
elsif ($keys[$k] =~ m/\'/){
print $out "' ";
}
elsif ($keys[$k] =~ m/\./){
print $out ". ";
}
elsif ($keys[$k] =~ m/\;/){
print $out "; ";
}
elsif ($keys[$k] =~ m/\?/){
print $out "? ";
}
elsif ($keys[$k] =~ m/\,/){
print $out ", ";
}
else {
print $out "$keys[$k]";
}
last;
}
}
# print "$outcome\n";
}
I mostly need help with simplifying the long chain of elsif statements I have.
The logic in the outer for loops works.
#keys is an array of two character (digrams) strings.
I am trying to make the elsif statements more efficient by comparing the digrams from #key to an array of the punctuation marks #punctuation = qw(! : " ' ; ? , .)
Then, if the digram does contain one of the punctuation marks in the punctuation array, the digram gets changed to "punctuation_mark " e.g. "a!" -> "! "
The end result would be that I do not use regexes for any of #punctuation.
However, I am not sure on how to implement this change.
Thank you!
In order to simplify your code, it may have sense to use the Tie::RegexpHash CPAN module. The main idea is build a hash with regexpr as keys, so you easily find the related values by matching:
use Tie::RegexpHash;
my $rehash = Tie::RegexpHash->new();
$rehash->add( qr/\s/, " " );
$rehash->add( qr/\&/, " and " );
#...
my $value = $rehash->match( "&" ); # $value <-- " and "
Use alternation, just like in the first regex, but capture the match and use $1 to replace the word
my $re_punct = join '|', map { quotemeta } qw(& ! : ' . ; ? ,); #'
for my $j (0..99_999) {
my $outcome = rand();
for my $k (0..$#cum_sum) {
...
if ($keys[$k] =~ /($re_punct)/) {
if ($1 eq '&') { $keys[$k] = " and " }
else { $keys[$k] = "$1 " }
}
...
}
}
Comments
quotemeta escapes by \ all "ASCII non-"word" characters"
syntax: $#ary is the index of the last element in #ary, just right for looping over array index
for my $i ($beg .. $end) is much clearer than the equivalent C-style for loop†
The presented logic leaves a question: what if both characters are punctuation?
Note on your idea to do it "By Comparing With Array"
You could use List::MoreUtils::first_value, for instance. It would go like
use List::MoreUtils qw(first_value);
my #punc = map { quotemeta } qw(& ! : ' . ; ? ,); #'
foreach my $word (#words) {
if (my $match = first_value { $word =~ /$_/ } #punct) {
$word = $match;
}
}
The first_value (or firstval) returns the first element of #punct for which the block returns true, and undef if none do. The $word aliases the currently processed element of #words and changing it changes the array element; so you get your replacement.
However, you still have to deal with regex and escape (at least some of) punctuation. Thus I see no advantage in going to this trouble; the "straight-up" regex is far clearer in this case.
† Even compiled languages evolve this way. The C++11 introduced the range-based for loop
for (auto var: container) ... // (really, const auto&), or auto&, or auto&&
and a standard reference linked above says
Used as a more readable equivalent to the traditional for loop [...]
In Perl this is how things are done; just use it.
So, looking at it you have two cases:
One where you replace a set of values, with 'the value and a space'. And another where you replace with something different.
So how about creating a lookup table for each, and processing just two regexes:
#!/usr/bin/env perl.
use strict;
use warnings;
use Data::Dumper;
my %replace = (
'"' => "",
'/' => "",
'&' => " and ",
);
my #add_space = ( ',', '?', ';', '.', "'", ':', '!' );
my $search = join ( "|", map { quotemeta } keys %replace );
$search = qr/($search)/;
my $add_space_after = join "|", map {quotemeta} #add_space;
$add_space_after = qr/($add_space_after)/;
while ( <DATA> ) {
s/\s/ /g;
s/$search/$replace{$1}/;
s/$add_space_after/$1 /;
print;
}
__DATA__
Work:Work
cookies&milk;wordhere
why?are;you/so "sad"
This gives us what you want I think, and - hopefully - keeps the code pretty conscise.
Of importance is the quotemeta function here, because it ensures your metachars are escaped before regexing them.
Note - the only one of your examples this doesn't handle is the \s to " ". But that's IMO probably best to write separately for clarity, as obviously youc can't quotemeta it.
I am new to PowerShell, but not scripting.
Why does this script:
$usr = "john.doe"
$usrname = $usr -split ".", 0, "simplematch"
$fullname = upperInitial($usrname[0]) + upperInitial($usrname[1])
write-host "Hello $fullname"
function upperInitial($upperInitialString) {
return $upperInitialString.substring(0, 1).toupper() + $upperInitialString.substring(1).tolower()
}
return me just 'Hello John' and not 'Hello John Doe'?
It's not treating the second call of the upperInitial function as a function, it's treating it as a paramter of the first call to the function I think.
Either of these work:
$fullname = "$(upperInitial($usrname[0])) $(upperInitial($usrname[1]))"
write-host "Hello $fullname"
The above uses the subexpression operator $() to execute the functions within a double quoted string.
$fullname = (upperInitial($usrname[0])) + ' ' + (upperInitial($usrname[1]))
write-host "Hello $fullname"
This one combines the result of the two functions as you had intended, although I also added a space character because otherwise it was JohnDoe.
I'm trying to get the following Perl program to print a default value, if no result is returned from a query. I am not sure how to do that.
When I run the script, I get the error: Can't call method "country_name" on an undefined value. Are there Any ideas on how I can change the program to print a default value, if no results are returned?
#!/usr/bin/perl update IP addresses with country
use strict;
use warnings;
use Net::IPInfoDB;
my $psql = "/usr/local/pgsql/current/bin/psql";
my $db = 'cpi';
my $args = "-U postgres -qc";
my $date = `/bin/date +\%y\%m\%d%H`;
my $reportfile = "/tmp/multiiplogins-$date";
my $sendmail = "/usr/sbin/sendmail -t -fcpi\#user.com";
my $mailsubject = "Login Report";
my $mailto = 'email#user.com';
my $query = "SELECT userid, login, email, logins, ips FROM (SELECT userid,login,email, count(userid) AS logins, count(ipaddr) AS ips FROM (SELECT l.userid, u.login, u.email, l.ipaddr FROM synloginaccess l, synusers u$
my $query2 = "SELECT l.userid, login, email, ipaddr FROM synloginaccess l, synusers u where l.accesstime > (now() - interval '24 hours') and l.type=2 and l.userid=u.userid ORDER BY l.userid;";
open (REPORT, ">$reportfile");
my $command = qq/$psql $db $args "$query"/;
my $command2 = qq/$psql $db $args "$query2"/;
my $result = `$command`;
my $result2 = `$command2`;
my $g = Net::IPInfoDB->new;
$g->key("api_key");
#we split $login into an array, line-by-line
my #lines = split("\n", $result2);
for my $line (#lines) {
#now we iterate through every line one-by-one
if ($line =~ /(?<ip>\d+\.\d+\.\d+\.\d+)/) {
my $city = $g->get_city("$1");
my $addr = $g->get_country("$1");
print "$line " . "| " . "\t" . $city->city_name . ", " . $addr->country_name ."\n";
print REPORT "$line " . "| " . "\t" . $city->city_name . ", ". $addr->country_name ."\n";
}
else {
print "$line \n ";
}
}
close REPORT;
mailReport();
sub mailReport{
#mail it
open(MAIL, "|$sendmail");
print MAIL "To: $mailto\n";
print MAIL "Subject: $mailsubject\n";
print MAIL "\n";
open (INFILE, "$reportfile");
my #contents = <INFILE>;
my $line;`
$addr ? $addr->country_name : "default"
I have a simple section in a PowerShell script that goes through each array in a list and grabs the data (found at [3] of the current array), using it to determine if another part of the array (found at [0]) should be added to the end of a string.
$String = "There is"
$Objects | Foreach-Object{
if ($_[3] -match "YES")
{$String += ", a " + $_[0]}
}
This works fine and dandy, resulting in a $String of something like
"There is, a car, a airplane, a truck"
But unfortunately this doesn't really make sense grammatically for what I want. I'm aware that I could either fix the string after it's been created, or include lines in the foreach/if statement that determine which characters to add. This would need to be:
$String += " a " + $_[0] - for the first match.
$String += ", a " + $_[0] - for following matches.
$String += " and a " + $_[0] + " here." - for the last match.
Furthermore I need to determine whether to use " a " if $_[0] starts with a consonant, or " an " if $_[0] starts with a vowel. All in all, I'd like the output to be
"There is a car, an airplane and a truck here."
Thanks!
Try something like this:
$vehicles = $Objects | ? { $_[3] -match 'yes' } | % { $_[0] }
$String = 'There is'
for ($i = 0; $i -lt $vehicles.Length; $i++) {
switch ($i) {
0 { $String += ' a' }
($vehicles.Length-1) { $String += ' and a' }
default { $String += ', a' }
}
if ($vehicles[$i] -match '^[aeiou]') { $String += 'n' }
$String += ' ' + $vehicles[$i]
}
$String += ' here.'
I cannot figure out how to do this. My current code is as follows:
[string]$strTest = Read-Host "Please input an IP host address in full dotted decimal.`n(Example: 192.168.004.214)"
[array]$arrTest = 0
$str = $strTest
$fs = "."
$index = $str.indexof($fs)
$count = 1
do{
$chunk = $str.substring(0,$index)
$arrTest += $chunk
$count++
$str = $str -replace ($chunk + ".", "")
}
until($count -eq 4)
$arrTest
I want this to give me an array that's populated with each octet of the IP address, but I'm getting a strange result. Running this in ISE gives me:
0
123
123
123
And I have no idea why.
If you want an array with the octets, just split the string:
$a = $str.Split('.')
You just messed up parenthesis
$str = $str -replace ($chunk + "."), ""