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Php escape string with GET function issue with apostrophe
mac_gyver replied to PNewCode's topic in PHP Coding Help
you need to use a prepared query in order to prevent any sql special characters in a value from being able to break the sql query syntax, which is how sql injection is accomplished. if it seems like the mysqli extension is overly complicated and inconsistent, especially when dealing with prepared queries, it is. this would be a good time to switch to the much simpler and better designed PDO extension. converting an old query that puts the data values directly into the sql query statement into a prepared query using the PDO extension is straightforward - remove, and keep for later, any php variables that are inside the sql query statement. note: any wild-card characters in a LIKE comparison are supplied as part of the data value remove any quotes or {} around the value and any concatenation dots/extra quotes that were used to get the php variable into the sql query statement put a simple ? prepared query place-holder into the sql query statement for each value call the PDO prepare method for the sql query statement call the PDOStatement execute method with an array of the variables you removed in step #1. for a query that returns a result set, fetch the data from the query. see the fetch() method when fetching a single row of data. the fetchAll() method when fetching all the rows of data at once. and occasionally the fetchColum() method when fetching a single column from a single row of data. forget about any num rows function. just fetch then test if/how many rows of data there are. here is typical PDO connection code - $DB_HOST = ''; // database host name or ip address $DB_USER = ''; // database username $DB_PASS = ''; // database password $DB_NAME = ''; // database name $DB_ENCODING = 'utf8mb4'; // db character encoding. set to match your database table's character set. note: utf8 is an alias of utf8mb3/utf8mb4 $options = [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, // set the error mode to exceptions. this is the default setting now in php8+ PDO::ATTR_EMULATE_PREPARES => false, // run real prepared queries PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC // set default fetch mode to assoc, so that you don't need to specify it in each fetch statement ]; $pdo = new pdo("mysql:host=$DB_HOST;dbname=$DB_NAME;charset=$DB_ENCODING",$DB_USER,$DB_PASS,$options); -
without knowing what symptom you are getting and what debugging steps you have already performed, it is not possible to help you. there's no point in echoing a static string in the php code (2 places). just put the string as the value in the markup. don't use PHP_SELF. to cause the form to submit to the same page it is on, leave out the entire action attribute.
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how to hide data behind the = (page.php?id=xx) for the user
mac_gyver replied to wildware's topic in PHP Coding Help
your code should be as general-purpose as possible, so that you don't need to keep redoing it as requirements change. the URL should uniquely determine what information will be displayed on a page, so, yes you should put the user id as a get parameter in the URL. the code for any page must enforce access permission for that page. for what you are seemingly asking, you would compare the logged in session user id with the get parameter id and only query for and display the requested user's data, using the get parameter id, if they match. if at some point you have a site administrator or a list of permitted 'friended' users, you would query for and display the requested user's data, using the get parameter id, depending on the current user's access permission for the requested user's data. -
without some examples, the uncommented, wall of markup and your statement doesn't make sense. are you adding these sub questions dynamically? are the number of choices per sub question dynamic? do you mean that all the choices for a sub question will be either text or they will be files? if so, you would have a radio field to show just the text fields or the file fields for that sub question. i would hope you are dynamically producing this markup? you should not use a series of name-numbered things. use an array instead. the labels are invalid (ids must be unique.) you would either generate unique ids, or more simply put the closing </label> tag after the form field it corresponds to.
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had you initially posted the error message (someone did ask), you could have gotten help earlier. that error (most likely) means that the query failed with an sql error and the code does not have error handling for database errors. to add error handling for database errors, add the following line of code before the point where the database connection is made, then report back with the database error (this is the default setting now in php8+, so you need to also update to using php8) - mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT); once you solve the current problem, to do what you have asked, which requires knowing first if the email/password is correct, then what the authorized value is, will require actual programming changes to be made to the query and to the program logic. programing is not about finding something that does what you want and repeat it in your code. programming is a creative writing (and reading) activity. you must actually learn the meaning of the words and syntax you are using so that what you write makes sense when it is executed by the computer. lastly, because the current query is putting the values directly into the sql query statement, sql injection is possible. someone can submit an email address for an administrator, to match his row of data, and bypass the need for the password and become logged in as an administrator. since i doubt you want this to be possible, you will need to convert this query to be a prepared query.
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what error? if you want to do something based on the authorized value, you would not include it in the WHERE term in the query. you would SELECT it, then test its value in the program logic. also - use 'require' for things your code must have. include/require are not functions. leave the () around the path/file out. don't attempt to detect if the submit button is set. there are cases where it wont be. instead, test if a post method form was submitted. you need to trim, mainly so that you can detect if all white-space characters were entered, then validate all inputs before using them. don't copy variables to other variables for nothing. don't put dynamic values directly into sql query statements. use a prepared query. if it seems like using the mysqli extension is overly complicated and inconsistent, it is. this would be a good time to switch to the much simpler and better designed PDO extension. you should be hashing the passwords. see php's password_hash() and password_verify(). you would not include the password in the WHERE term. you would SELECT the password, then after you have determined if a row of data was matched, use password_verify() in your program logic to test the password hash. the fetch instruction returns either an array, a null, or a false value, not a number. is this where you are getting an error? the only user value you should store in a session variable is the user id. you should query on each page request to get any other user data. the redirect you perform upon successful completion of the post method form processing code needs to be to the exact same URL of the current page to cause a get request. every redirect needs an exit/die statement to stop php code execution. if you want to display a one-time success message, store it in a session variable, then test, display, and clear that session variable at the appropriate location in the html document.
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check the browser's developer tools, console tab for errors.
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unset() not working within foreach loop
mac_gyver replied to nlomb_hydrogeo's topic in PHP Coding Help
the query is SELECTing the column_name, which is why you are echoing column_name to produce the output - $row['column_name'] will be 'well_no' or 'geom'. you would create an array with the two values you want to exclude, then because you cannot directly loop over the result set from a query a second time, fetch all the rows of data into a php variable (see the fetchAll() method), then as you are looping over this array of data, use a conditional test if( !in_array($row['column_name'],['well_no','geom']) ) { produce the output here... } to exclude those two column_name values. and as was written in one of your previous threads, there no good reason to catch and handle an exception from a SELECT query in your code. just let php catch and handle it. remove the try/catch logic from this query, simplifying the code. also, where this catch logic is at, you won't see the output from it unless you look in the 'view source' in the browser. -
Upgrading PHP to current
mac_gyver replied to AdmiralQ's topic in PHP Installation and Configuration
if/when you update your code, here is a list of practices, based on a review of the login code in your other thread, that will help make the code more secure, provide a better user experience, eliminate unnecessary code, and though having usable validation logic and error handling will get your code to tell you when and why it doesn't work - always use a full opening php tag - <?php don't use $_REQUEST. use the correct $_GET, $_POST, or $_COOKIE variable that you expect data to be in don't use extract() as this allows hackers to inject their data values into your code, which is what register_globals allowed, which is why they were removed from php use 'require' for things your code must have post method form processing code needs to detect if a post method form was submitted before referencing any of the form data you need to trim, mainly so that you can detect if a value was all white-space characters, then validate all input data before using it you should list out the columns you are SELECTing in a query as already written, you would use prepared queries you need to hash the stored passwords. see php's password_hash() and password_verify() as already written, you would use exceptions for database error handling, and remove any existing error handling logic you would fetch and test if there is fetched data, meaning that the username was matched, then verify the password hash the only user related data that you should store in a session variable upon successful authentication is the user id (autoincrement primary index). you would query on each page request to get any other user data, permissions, ... this will insure that any changes made to this other user data will take effect on the very next page request, without requiring the user to log out and back in again you should only create and store data in the session variable(s) if authentication was successful. by unconditionally creating it/them, you now have session variables that exist, even if they are empty/null the first redirect implies that the form and form processing code are on separate pages. they should be on the same page. the code for any page should be laid out in this general order - 1. initialization, 2. post method form processing, 3. get method business logic - get/produce data needed to display the page, 4. html document by redirecting around on your site and using values from the url to control what the form page reports, your site is open to phishing attacks, where someone could trick your users to enter their username/password on the phishing site, then redirect them to your site and make it look like they just entered an incorrect username/password the only redirect you should have in your code is upon successful completion of post method form processing and it should be to the exact same URL of the current page to cause a get request for that page. this will prevent the browser from trying to resubmit the form data should that page get browsed back to or reloaded if you want to allow the user to go to a different page, provide navigation links, or more simply, just integrate the login operation on any page that needs it every redirect needs an exit/die statement to stop php code execution. while you have the remainder of the code inside an else {...} conditional branch, if you had stopped the php code after the redirect, you could just put the remainder of the code w/o the else the inno_login_track_staff INSERT query is part of the successful authentication code. after the logic is changed to use password_verify() and only store data to session variable(s) upon successful authentication, there will be a specific place in the php logic to put this query inno_school_staff - this indicates you have separate 'user' tables for students and staff. you should have one user/authentication table. the user data that you query for on each page request would control what the current user can see or do on any page don't copy variables to other variables for nothing and don't use intermediate variables when you only reference a value once as an advanced programming practice, if you have more than 2-3 form fields, you should dynamically validate and process the form data, and dynamically produce the form, rather than writing out bespoke code for every field every time you do something different -
it sounds like the session data files are being read and locked. the permission issue isn't due to the permission settings, but that some other instance/process is reading the file at the same time. this would be either due to session garbage collection (you can temporarily configure it to not run as a test or perhaps it is configured to run on each session start?), some code that's reading/scanning the session data files (do you have some code that's trying to read and manage the session data, such as logging users out after a time?) , or multiple concurrent instances of your script accessing the same session data (this can occur when ajax requests are used.) as to why this worked before and has now changed, I don't have any suggestions. it would take knowing everything your code is capable of doing, session related, uploaded file related, ... are there currently a bunch of unusual requests being made to the site or just your requests for troubleshooting this problem?
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while this isn't the cause of the session data file open/permission error, it indicates there's something going on on the server. i'm going to guess something like the allocated disk space is full, causing the FTP service error and the session data file error. searching for - 'php session Permission denied (13)' gives a number of results, most of them having to do with the actual permissions. you haven't answered @requinix's question about - What's the hosting setup? If this is shared web hosting, you would typically have a session data folder within your account's directory tree for 'your' session data files. the 2nd warning message about headers already sent has nothing to due with the problem. this warning is due to the 1st warning message being output. once the problem with the session data file open()/permissions is solved, both of these errors messages will go away.
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Upgrading PHP to current
mac_gyver replied to AdmiralQ's topic in PHP Installation and Configuration
there are migration appendices in the php documentation that list the removed and backward incompatible changes in each php version. the mysql_ database extension was removed, so, that code won't run at all and will need to be updated. if your code is organized so that the database specific code is grouped together and located before the start of the html document on any page, updating the database 'layer' would be straightforward. you just need to produce the same query result that the rest of the code needs. if your code is not organized like this, doing so will make it easier to test and debug the database code. if you do update any of the database specific code, forget about the mysqli extension. it is overly complicated and inconsistent when dealing with non-prepared and prepared queries, requiring you to essentially learn two different sets of statements. instead, learn and use the much simpler and better designed PDO extension. instead of putting dynamic values directly into sql query statements, you should use prepared queries. if code is currently using any ...escape_string() or addslashes() functions, these are removed. converting an old query to a prepared one is straightforward - remove, and keep for later, any php variables that are inside the sql query statement. note: any wild-card characters in a LIKE comparison are supplied as part of the data value remove any quotes or {} around the value and any concatenation dots/extra quotes that were used to get the php variable into the sql query statement put a simple ? prepared query place-holder into the sql query statement for each value call the PDO prepare() method for the sql query statement call the PDOStatement execute() method with an array of the variables you removed in step #1 for a query that returns a result set, fetch the data from the query. see the fetch() method when fetching a single row of data. the fetchAll() method when fetching all the rows of data at once. and occasionally the fetchColum() method when fetching a single column from a single row of data. forget about any num_rows method or property. just fetch then test if/how many rows of data there are. php8+ uses exceptions by default for database statements that can fail - connection, query, exec, prepare, and execute. when using exceptions no discrete error checking logic will get executed upon an error and should be removed. your main code will only see error-free execution. if execution continues past a statement that can throw an exception, you know there was no error, without needing any program logic. the only database exceptions you should catch and handle in your code are for user recoverable errors, such as when inserting/updating duplicate user submitted data. the exception catch block would test for a duplicate index error number and setup a message for the user letting them know what was wrong with the data that they submitted. for all other error numbers, just rethrow the exception and let php handle it and for all other type of queries do nothing in your code and let php catch and handle any database exception, where php will use its error related settings to control what happens with the actual error information, via an uncaught exception error (database errors will get displayed or logged the same as php errors.) two other major things that old code likely used that have been removed are register_globals and magic_quotes. for register_globals, you will need to use the correct super-global variable that data is in - $_POST, $_FILES, $_GET, $_COOKIE, and $_SESSION. for magic_quotes, any conditional logic testing for them and applying stripslashes() can be removed. old code found on the web is also filled with unnecessary things, such as trying to strip tags from data, copying variables to other variables for nothing, and missed out on applying htmlentities() to dynamic values being output in a html context, right before outputting it. if you want to post examples of your existing code, i/we can show what it would look like using current practices. -
Urgent help needed in php image validation
mac_gyver replied to Dealmightyera's topic in PHP Coding Help
as already stated - -
the attached code doesn't produce a php syntax error. there are only 270 lines. any chance you made a change and didn't save the file before trying to execute it? btw - addslashes() should never have been used with database code.
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Urgent help needed in php image validation
mac_gyver replied to Dealmightyera's topic in PHP Coding Help
no matter how large you set the max_post_size setting, someone can upload a file that is larger. the size of the file someone tries to upload is out of your control. your code must test for this condition and handle it. also, by increasing the setting beyond a reasonable size, it will allow hackers to flood your server with huge uploaded files, consuming all the available processing and memory on the server, allowing a denial of service (DoS) attack.