LaTeX fails for dollar sign - mathjax

I am trying to create a latex expression
She owes me \$200 and I owe her $y^2$
But when it is executed, '\$' is converted to '$' but '$y^2$' is not evaluated properly.
Any help is appreciated!
It appears as

Related

Sublime Text 3 Literal Dollar Sign with Stata

I started using Sublime Text 3 for Stata with Improved Stata Editor for MacOS. I need to use $ (literal dollar sign) to call global variables, but whenever I try to type in $ (shift+4) ${} with a line break between two parentheses.
I found some posts about snippets, but I am not sure how to go about this. May I get some help on this?

Is it possible to change the way Maxima generates LaTeX code?

I would like to be able to change the way Maxima generates the LaTeX code (in general). For example, I have the following code in Maxima:
I then exported the code to LaTeX, and I immediately get an error saying:
! Package inputenc Error: Unicode char \u8:− not set up for use with LaTeX.
See the inputenc package documentation for explanation.
Type H <return> for immediate help.
You can check out the LaTeX code generated through this gist on GitHub.
I would like at least not only to not get any errors, but also to change a little bit the style of the LaTeX code generation to adapt it to certain circumstances. For example, I would like to be able to insert a break line (or more) after the outputs...
Is it possible to do? Are there any alternatives?
You can put the following line in the preamble of the LaTeX output:
\DeclareUnicodeCharacter{2212}{-}
which tells LaTeX what to do with the Unicode hyphen (character 2212 according to this table).
WxMaxima should generate this declaration itself -- it is a bug that it does not.
Most likely something happened when you exported the code. To fix the existing file you can follow the accepted answer to this question.
https://tex.stackexchange.com/questions/83440/inputenc-error-unicode-char-u8-not-set-up-for-use-with-latex
But try exporting again and see if the error was accidental.
Update:
Add
\DeclareUnicodeCharacter{00A0}{ }
to your preamble.
Well, the gistfile1.txt at line 54 contains − characters instead of -. I wonder how those characters were generated. What commands did you enter in wxMaxima to generate gistfile1.txt?
Anyway, I find that if I replace those characters with ordinary hyphens, it avoids the error you reported. So perhaps the problem is to avoid generating those characters in the first place.
EDIT: This answer is off the mark. See my other answer for a real solution.

In Vim, how to substitute text with combining characters?

In Vim, for text é,e (\x65 \u0301 \x2c \x65):
If I use :s/\Ze/x/g, I get x,x. How to get x́,x?
If I use :s/́/̂/g (substitue \u0301 with \u0302), I get ̂,e. How to get ê,e?
If you have vim compiled with perl support, you can try this:
:perldo s/e/x/g
:perldo s/́/̂/g
This works for me in case that the ́ sign should have been above the , sign which is what I got when used the sequence you provided. Similarly, I get the ̂ sign above the , sign in the result of second command. But I still guess this is what you want as I was getting same copy-paste errors when compiling the answer.

Decrypt obfuscated perl script

Had some spam issues on my server and, after finding out and removing some Perl and PHP scripts I'm down to checking what they really do, although I'm a senior PHP programmer I have little experience with Perl, can anyone give me a hand with the script here:
http://pastebin.com/MKiN8ifp
(It was one long line of code, script was called list.pl)
The start of the script is:
$??s:;s:s;;$?::s;(.*); ]="&\%[=.*.,-))'-,-#-*.).<.'.+-<-~-#,~-.-,.+,~-{-,.<'`.{'`'<-<--):)++,+#,-.{).+,,~+{+,,<)..})<.{.)-,.+.,.)-#):)++,+#,-.{).+,,~+{+,,<)..})<*{.}'`'<-<--):)++,+#,-.{).+:,+,+,',~+*+~+~+{+<+,)..})<'`'<.{'`'<'<-}.<)'+'.:*}.*.'-|-<.+):)~*{)~)|)++,+#,-.{).+:,+,+,',~+*+~+~+{+<+,)..})
It continues with precious few non-punctuation characters until the very end:
0-9\;\\_rs}&a-h;;s;(.*);$_;see;
Replace the s;(.*);$_;see; with print to get this. Replace s;(.*);$_;see; again with print in the first half of the payload to get this, which is the decryption code. The second half of the payload is the code to decrypt, but I can't go any further with it, because as you see, the decryption code is looking for a key in an envvar or a cookie (so that only the script's creator can control it or decode it, presumably), and I don't have that key. This is actually reasonably cleverly done.
For those interested in the nitty gritty... The first part, when de-tangled looks like this:
$? ? s/;s/s;;$?/ :
s/(.*)/...lots of punctuation.../;
The $? at the beginning of the line is the pre-defined variable containing the child error, which no doubt serves only as obfuscation. It will be undefined, as there can be no child error at this point.
The questionmark following it is the start of a ternary operator
CONDITION ? IF_TRUE : IF_FALSE
Which is also added simply to obfuscate. The expression returned for true is a substitution regex, where the / slash delimiter has been replaced with colon s:pattern:replacement:. Above, I have put back slashes. The other expression, which is the one that will be executed is also a substitution regex, albeit an incredibly long one. The delimiter is semi-colon.
This substitution replaces .* in $_ - the default input and pattern-searching space - with a rather large amount of punctuation characters, which represents the bulk of the code. Since .* matches any string, even the empty string, it will simply get inserted into $_, and is for all intents and purposes identical to simply assigning the string to $_, which is what I did:
$_ = q;]="&\%[=.*.,-))'-,-# .......;;
The following lines are a transliteration and another substitution. (I inserted comments to point out the delimiters)
y; -"[%-.:<-#]-`{-}#~\$\\;{\$()*.0-9\;\\_rs}&a-h;;
#^ ^ ^ ^
#1 2 3
(1,2,3 are delimiters, the semi-colon between 2 and 3 is escaped)
The basic gist of it is that various characters and ranges -" (space to double quote), and something that looks like character classes (with ranges) [%-.:<-#], but isn't, get transliterated into more legible characters e.g. curly braces, dollar sign, parentheses,0-9, etc.
s;(.*);$_;see;
The next substitution is where the magic happens. It is also a substitution with obfuscated delimiters, but with three modifers: see. s does nothing in this case, as it only allows the wildcard character . to match newline. ee means to evaluate the expression twice, however.
In order to see what I was evaluating, I performed the transliteration and printed the result. I suspect that I somewhere along the line got some characters corrupted, because there were subtle errors, but here's the short (cleaned up) version:
s;(.*);73756220656e6372797074696f6e5f6 .....;; # very long line of alphanumerics
s;(..);chr(hex($1));eg;
s;(.*);$_;see;
s;(.*);704b652318371910023c761a3618265 .....;; # another long line
s;(..);chr(hex($1));eg;
&e_echr(\$_);
s;(.*);$_;see;
The long regexes are once again the data containers, and insert data into $_ to be evaluated as code.
The s/(..)/chr(hex($1))/eg; is starting to look rather legible. It is basically reading two characters at the time from $_ and converting it from hex to corresponding character.
The next to last line &e_echr(\$_); stumped me for a while, but it is a subroutine that is defined somewhere in this evaluated code, as hobbs so aptly was able to decode. The dollar sign is prefixed by backslash, meaning it is a reference to $_: I.e. that the subroutine can change the global variable.
After quite a few evaluations, $_ is run through this subroutine, after which whatever is contained in $_ is evaluated a last time. Presumably this time executing the code. As hobbs said, a key is required, which is taken from the environment %ENV of the machine where the script runs. Which we do not have.
Ask the B::Deparse module to make it (a little more) readable.

PHP heredoc parse error [closed]

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Closed 9 years ago.
This produces output page OK
$mystring = "<<<EOT";
Replacing it with the following produces
Parse error: syntax error, unexpected $end in file.php on line 737
$mystring = <<<EOT
This is some PHP text.
It is completely free
I can use "double quotes"
and 'single quotes',
plus $variables too, which will
be properly converted to their values,
you can even type EOT, as long as it
is not alone on a line, like this:
EOT;
Any ideas as to what is causing the parser to choke?
I'm using PHP 4.4.7.
It is only on one file that this behaviour happens all others follow the PHP defined functionality.
What I am trying to recitify is what could be possibly wrong in the proceding lines so that the PHP parser shows in this failure.
John
changed file contents to :-
<?php
$mystring = <<<WHATEVER
This is some PHP text.
WHATEVER;
?>
result =
Parse error: syntax error, unexpected $end in file.php on line 5
Any clues
EDIT
original error was to do with T_ENCAPSED_AND_WHITESPACE this can be caused with jQuery for example "if(x == y){$('#my_image').hide():}" is within the heredoc the bigram "{$ will start the parser looking for php variable for substitution.
EDIT
2 good responses.
1) Ch4m3l3on - "<?php" vs "<?" handling.
2) The Disintegrator - <q>had a similar problem with a stupid program that insisted in putting the BOM in a utf-8 file (ignoring preferences)</q>.
EDIT
1) Replacing all content with a single block didn't fix the problem or give any other pointers.
2) No BOM (Byte Order Mark), pity as this or similar majic characters would have explained all symptoms perfectly.
you have to place your ending heredoc at the beginning of line. if you use some IDE that have indentation, remove them! your ending heredoc must be vertically in the same line as your ending php tag(
Make sure that there is nothing after the 'WHATEVER;'. Even a space will give a parse error.
I would delete the line and retype it, hitting <enter> immediately after typing the semi-colon.
make sure that EOT; is really at the begin of the line.
if ($muh="kuh") {
$foo = <<<EOT
some text text text
EOT;
}
What if you try:
$mystring = <<<'EOT'
...
EOT;
(Notice the single quotes around the first EOT)
I just copy/pasted that into a file and it ran without errors. (PHP 5.2.8 (cli) (built: Feb 6 2009 12:33:08))
So the problem is likely something near that code, but not something you included in the question.
Either that, or a change in PHP since your version was built.
You probably should check if you have any unclosed curly bracket (or brace, can't remember).
For example:
<?php
while(true) {
echo "Something\n";
?>
Will produce that error.
I don't have the rep for an uptic, but Ch4m3l3on and Pedro Cunhna are right... an incorrect heredoc probably won't cause that unexpected $end error, but an unclosed curly brace definitely would.

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