heyy,
I want to run the code found in the string below
$str=" $row["AccountID"].$row["CurrencyID"] ";
like this:
while($row = $result2->fetch_assoc()) {
echo $str;
}
but the output is shown like this:
$row["AccountID"].$row["CurrencyID"]
That's not what i need ,
how can i make it run the code inside the string and allowing it to read the "$row" word as a variable not as a string?
Programming languages, like PHP, will not evaluate strings, for good reason. You'd have huge security holes in your application if PHP tried to evaluate everything it found in strings.
The reason why $str = "$row"; works is because PHP is evaluating "$row" before the string is even assigned. The variable $row doesn't live in $str, the value does.
A common use case is storing a template syntax and replacing the placeholders in your view. Possible placeholders are %AccountID% or {{AccountID}}. Whatever you prefer, and then using string replacements on those placeholders with the $row values inside the loop:
$template = "The account ID is %AccountID%.";
...
while($row = $result2->fetch_assoc()) {
echo str_replace('%AccountID%', $row['AccountID'], $template);
}
I'd urge you not to rely on eval() here because it'd leave you open to dangerous injections when you don't have full control over the input.
this is a way:
sprintf('%d%d', $row["AccountID"], $row["CurrencyID"]);
%d is integer format
You can find and replace the values within the string using this implode/explode method.
$str = '$row["AccountID"].$row["CurrencyID"]';
//first remove the '.'
$str = implode('', explode('.', $str));
while($row = $result2->fetch_assoc()) {
$row_str = $str;
foreach($row as $field=>$value){
$row_str = implode($value, explode('$row["'.$field.'"]', $row_str ));
}
echo $row_str;
}
Related
With code something like this
$tk = intval($_GET['tk']);
$vosa = $_GET['vosa'];
echo $tk*100*$vosa;
Where $vosa is a string of something like 0.0425/1920*60*8. I'd need it replaced, without being calculated first, into the echo and then echo the entire thing $tk*100*0.0425/1920*60*8 result. How could I achieve this?
Ok another version. Replace the values in your string with sprintf.
echo sprintf("%s*100*%s", (string)$tk, (string)$vosa);
if %d for digit don't match your case then you can use %s. You use in your case directly $_GET variables. So sprintf is a good choice. I have tested it with:
php -r 'echo sprintf("%s*100*%s", "123", "4.000");'
output:
123*100*4.000
To output, just echo the string:
echo "{$vosa} = {$result}";
Your problem is how to calculate $result from $vosa.
A very risky way would be to use eval() - or as someone sometimes calls it, evil().
The risk is that I could send you a vosa value of system('FORMAT C: /AUTOTEST') (which would not work, but you get my meaning).
// vosa='/bin/dd if=/dev/zero of=etc etc'
// This will return zero. It will return a whole lot of zeroes
// all over your hard disk.
$result = eval("return {$tk}*100*{$vosa};");
Possibly, validating $vosa with a regular expression could help, at least as long as you use simple expressions.
Alternately, you must implement an expression parser.
This is another ready made. You would use it like this:
include('./some/where/mathparser.php');
$parser = new MathParser();
$parser->setExpression("{$tk}*100*{$vosa}");
$result = $parser->getValue();
echo "The result of {$tk}*100*{$vosa} is {$result}.";
You can use string and then use eval to execute it as a php code:
<?php
$tk = intval($_GET['tk']);
$vosa = $_GET['vosa'];
echo eval("return $tk*100*$vosa;");
Caution
The eval() language construct is very dangerous because it allows execution of arbitrary PHP code. Its use thus is discouraged. If you have carefully verified that there is no other option than to use this construct, pay special attention not to pass any user provided data into it without properly validating it beforehand.
$tk = intval($_GET['tk']);
$vosa = $_GET['vosa']; // "0.0425/1920*60*8"
$ans = eval('return '.$vosa.';');
echo $ans;
echo "<br>";
echo $tk*100*$ans;
Example : https://eval.in/819834
Got it myself
<?php
$tk = $_GET['tk'];
$aeg = $_GET['aeg'];
$kfc = $_GET['kfc'];
$vosa = $_GET['vosa'];
$final = $tk.'*'.$aeg.'*'.$kfc.'*'.$vosa;
$ans = eval('return '.$final.';');
echo round($ans,2);
I am getting an "Array to string conversion error on PHP";
I am using the "variable" (that should be a string) as the third parameter to str_replace. So in summary (very simplified version of whats going on):
$str = "very long string";
str_replace("tag", $some_other_array, $str);
$str is throwing the error, and I have been trying to fix it all day, the thing I have tried is:
if(is_array($str)) die("its somehow an array");
serialize($str); //inserted this before str_replace call.
I have spent all day on it, and no its not something stupid like variables around the wrong way - it is something bizarre. I have even dumped it to a file and its a string.
My hypothesis:
The string is too long and php can't deal with it, turns into an array.
The $str value in this case is nested and called recursively, the general flow could be explained like this:
--code
//pass by reference
function the_function ($something, &$OFFENDING_VAR, $something_else) {
while(preg_match($something, $OFFENDING_VAR)) {
$OFFENDING_VAR = str_replace($x, y, $OFFENDING_VAR); // this is the error
}
}
So it may be something strange due to str_replace, but that would mean that at some point str_replace would have to return an array.
Please help me work this out, its very confusing and I have wasted a day on it.
---- ORIGINAL FUNCTION CODE -----
//This function gets called with multiple different "Target Variables" Target is the subject
//line, from and body of the email filled with << tags >> so the str_replace function knows
//where to replace them
function perform_replacements($replacements, &$target, $clean = TRUE,
$start_tag = '<<', $end_tag = '>>', $max_substitutions = 5) {
# Construct separate tag and replacement value arrays for use in the substitution loop.
$tags = array();
$replacement_values = array();
foreach ($replacements as $tag_text => $replacement_value) {
$tags[] = $start_tag . $tag_text . $end_tag;
$replacement_values[] = $replacement_value;
}
# TODO: this badly needs refactoring
# TODO: auto upgrade <<foo>> to <<foo_html>> if foo_html exists and acting on html template
# Construct a regular expression for use in scanning for tags.
$tag_match = '/' . preg_quote($start_tag) . '\w+' . preg_quote($end_tag) . '/';
# Perform the substitution until all valid tags are replaced, or the maximum substitutions
# limit is reached.
$substitution_count = 0;
while (preg_match ($tag_match, $target) && ($substitution_count++ < $max_substitutions)) {
$target = serialize($target);
$temp = str_replace($tags,
$replacement_values,
$target); //This is the line that is failing.
unset($target);
$target = $temp;
}
if ($clean) {
# Clean up any unused search values.
$target = preg_replace($tag_match, '', $target);
}
}
How do you know $str is the problem and not $some_other_array?
From the manual:
If search and replace are arrays, then str_replace() takes a value
from each array and uses them to search and replace on subject. If
replace has fewer values than search, then an empty string is used for
the rest of replacement values. If search is an array and replace is a
string, then this replacement string is used for every value of
search. The converse would not make sense, though.
The second parameter can only be an array if the first one is as well.
I'm localizing a website that I've built. I'm doing this by having a .lang file read and each line (syntax: key=string) is placed in a variable depending on the chosen language.
This array is then used to place the strings in the correct places.
The problem I'm having is that certain strings need to have hyperlinks in the middle of them for example someplace I've put my name that links to my contact page. Or a lot of the readouts of the website need to be in the strings.
To solve this I've defined a variable that holds the html + Forecaster + html,
and the localization file contains the $Forecaster variable in the string.
The problem with this as I promptly discovered is that it stubbornly refuses to parse the inline variables in the strings from the file.
Instead it prints the string and variable name as it looks in the file.
And I have yet to find a way to make it parse the variables.
For example "Heating up took $str_time" would be printed on the page exactly like that, instead of inputting the previously defined value of $str_time.
I currently use fopen() and fgets() to open and read the lines. I then explode them to separate the key and the string and then place these into the array.
Is there a way to make it parse the variables, or alternatively is there another way of reading the lines that allows for parsing the inline variables?
The code that gets the line and converts it to the array looks like this:
(It obviously loops through the lines)
#list($key, $string) = explode('=', $line);
$key = strtok($line, '=');
$string = strtok('=');
$local[$key] = $string;
$counter++;
echo $local[$key] . "<br>";
The counter is unused and the echo is for testing.
A line from the .lang file looks like this:
fuel.results.heatup.timeused=Heating up took $str_time
I would call the array where I want the string like this:
$local['fuel.results.heatup.timeused']
As you can see I've tried both explode and strtok but it hasn't made a difference.
Personally I'd write your text file in JSON format to make it easier to pull data out.
Here is a solution directly from the php manual: http://nz2.php.net/manual/en/function.eval.php
$string = 'cup';
$name = 'coffee';
$str = 'This is a $string with my $name in it.';
echo $str. "\n";
eval("\$str = \"$str\";");
echo $str. "\n";
It is worth noting that eval() can be very dangerous used in the wrong way so make sure you're code is very secure E.g. if someone altered your txt file with real PHP code they could execute it directly on the server.
Another approach would require you to know all your variable names and could then do something like:
$str = 'Heating up took $str_time';
echo 'str=' . str_replace('$str_time', $str_time, $str);
Or do this via an array:
$str = 'Heating up took $str_time as well as $other_value';
$vars = Array('str_time', 'other_value');
foreach($vars as $varName) {
$str = str_replace('$' . $varName, $$varName, $str);
}
echo 'str=' . $str;
If you not know all the variable name, you can use this example, without eval(). It is indicatred to avoid eval().
$str = 'fuel.results.heatup.timeused=Heating up took $str_time';
$str_time = 'value';
if(preg_match('/\$([a-z0-9_]+)/i', $str, $v)) {
$vname = $v[1];
$str = str_replace('$'.$vname, $$vname, $str);
}
echo $str; // fuel.results.heatup.timeused=Heating up took value
I am trying to use a License PHP System…
I will like to show the status of their license to the users.
The license Server gives me this:
name=Service_Name;nextduedate=2013-02-25;status=Active
I need to have separated the data like this:
$name = “Service_Name”;
$nextduedate = “2013-02-25”;
$status = “Active”;
I have 2 days tring to resolve this problem with preg_match_all but i cant :(
This is basically a query string if you replace ; with &. You can try parse_str() like this:
$string = 'name=Service_Name;nextduedate=2013-02-25;status=Active';
parse_str(str_replace(';', '&', $string));
echo $name; // Service_Name
echo $nextduedate; // 2013-02-25
echo $status; // Active
This can rather simply be solved without regex. The use of explode() will help you.
$str = "name=Service_Name;nextduedate=2013-02-25;status=Active";
$split = explode(";", $str);
$structure = array();
foreach ($split as $element) {
$element = explode("=", $element);
$$element[0] = $element[1];
}
var_dump($name);
Though I urge you to use an array instead. Far more readable than inventing variables that didn't exist and are not explicitly declared.
It sounds like you just want to break the text down into separate lines along the semicolons, add a dollar sign at the front and then add spaces and quotes. I'm not sure you can do that in one step with a regular expression (or at least I don't want to think about what that regular expression would look like), but you can do it over multiple steps.
Use preg_split() to split the string into an array along the
semicolons.
Loop over the array.
Use str_replace to replace each '=' with ' = "'.
Use string concatenation to add a $ to the front and a "; to the end of each string.
That should work, assuming your data doesn't include quotes, equal signs, semicolons, etc. within the data. If it does, you'll have to figure out the parsing rules for that.
i have a string with double quote like this
$count = 5;
$str = "result: $count";
echo $str; //result: 5
variable parsing work well, and my problem is $count var must be define later than $str
$str = "result: $count";
$count = 5;
echo $str; //result:
So i will use single quote and ask a question here to finding a way to parse var whenever i want
$str = 'result: $count';
$count = 5;
//TODO: parse var process
echo $str; //result: 5
I'm will not using regex replace.
For this type of thing, I'd probably use string formatting. In PHP, that'd be printf.
?php
$str="result: %d"
....dostuff.....define $count.....
printf($str,$count)
?
edit:
although, the best way to do this probably depends partly on why you have to define $string before $count.
If it's a string that's repeated a lot, and you wanted to put it in a global variable or something, printf would be my choice, or putting it in a function as other answers have suggested.
If the string is only used once or twice, are you sure you can't refactor the code to make $count be defined before $string?
finally, a bit of bland theory:
when you write '$string = "result: $count"',
PHP immediately takes the value of $count and puts it into the string. after that, it isn't worried about $count anymore, for purposes of $string, and even if $count changes, $string won't, because it contains a literal copy of the value.
There isn't, as far as I'm aware, a way of binding a position in a string to a yet-to-be-defined variable. The 'printf' method leaves placeholders in the string, which the function printf replaces with values when you decide what should go in the placeholders.
So, if you wanted to only write
$string = "result: $count"
$count=5
$echo string
(and not have to call another function)
and get
"result: 5",
there's no way to do that. The closest method would be using placeholders and printf, but that requires an explicit call to a function, not an implicit substitution.
Why don't you use a function?
function result_str($count) { return "result: $count"; }
preg_replace is the simplest method. Something like this:
$str = preg_replace("/\\$([a-z0-9_]+)/ie", "$\\1", $str);
But if you really don't want to use a regex, then you'll have to parse the string manually, extract the variable name, and replace it.