I wonder if I can create a php file with php code (my project is to write a php based online poker game) and it would be nice if I could add/delete tables from php, but in order to do that I need some code to generate the php file which will be associated with that specific table. (code on every table would be the same, just need something that will allow me to create a .php file for the life time of a table). Also can you tell me how to php-delete it after wards? Thanks ahead.
You can do this simply by having the code written to a file with
file_put_contents($filename, $content).
This will create a new file if it doesn't exist. If it exists it will truncate the file and write the new content.
To read dynamic code you could use eval($codeString). This would interpret the $codeStringas code. NOT RECCOMENDED because if there is ANY user input involved in the $codeString, it would be a huge security risk! (Read the WARNING below!)
To get the contents from a file, you could use $fileContents=file_get_contents($filename)
If you want to write to files with appending text and so on, you need to get deeper in to the php filesystem. A nice place to start is w3 schools: http://www.w3schools.com/php/php_ref_filesystem.asp
You should look at three major functions of writing to files:
fopen();
fwrite();
fclose();
Warning!
Reading dynamic generated code, whether it is from files or just strings, can be really dangerous. Especially if it gets any kind of user- or dynamic input. This is because php-files are capable of editing, creating and deleting ALOT on your server. I would recommend you to find an alternate solution!
You can use file_put_contents Or touch.
file_put_contents() will create the file if not exists and will write provided data in to the file.
touch() will create the file.
Related
I'm going to be using a JSON file to contain a list of links to a few posts, and it can be updated at any time. However, I'm stumped with the mode to use with PHP's fopen() function. This will be a flat-file database and primarily is for me learning to work with files, PHP, and JSON before moving onto a proper relational database (that, and it's not a huge collection of pages that I'm worried about using SQL or something like that yet...)
The process I'm using is that once a blog post is typed up, it will create a directory, save a new index.php file to it with all of the stuff that lets me view the page, and then, where I'm currently stuck, update a JSON file with the Title, Author, Date, and link to the newly created page.
Based on the PHP Manual, there are three modes I might want to use. r+, w+, or a+.
The process I am looking to use is to take the JSON file and place the data into an array. Update the array, then save it back to the file.
a+ places the pointer at the end of the file and writes are always appended, so I'm assuming this is the worst choice for this situation since I wouldn't add a new JSON entry at the end of the file (I'm tempted to actually insert any new data at the beginning of the JSON object instead of at the end).
w+ mentions read and write, but also truncating the file - does this happen upon saving data to the file, or does this happen the moment the file is opened? If I used this mode on an existing JSON file, would I then be reading a blank file before I can even modify the array and re-save it to the object?
r+ mentions placing the pointer at the beginning of the file - does saving data overwrite what's there or will it insert the data BEFORE what's existing there? If it inserts, how would I manually clear the file and then save the newly-modified array to the JSON object?
Which of those modes are best suited for what I'm looking to do? Is there a better way of doing this, anyway?
If you're always reading or writing an entire file, you don't have to work with file handles at all - PHP provides a pair of functions file_get_contents($file_name) and file_put_contents($file_name, $content) which are much simpler to work with.
File handles with their various modes are most useful when you're working with parts of files. For instance, if you are using CSV, you can read or write one line at a time, without having the full set of data in memory at once. Or, with binary file formats, you might know the location in the file you want to read from, and can "seek" the file handle to that location.
You should probably read the entire file first (eg with file_get_contents(), and then open it with w+ to write the new data. (Edit: Or rather, as the other answer points out, use file_put_contents(), which is always simpler when you are only making one write operation.)
r+ will overwrite as much of the file as you are writing, but won't erase beyond that. If your data always increases in size, this should be the same as overwriting the file entirely, but even if it's true now, that's an assumption that will likely mess up your data in the future.
I'm trying to write a script that allows the upload of php files for parsing. Most of the tutorials and security information I can find on Google and here assume you're only allowing the upload of images (so use getimagesize, etc).
How do I confirm a file uploaded is really a PHP file without relying on the headers? Also -- I don't plan on storing the file in any way, I just want to grab the contents, parse it, and dump the info -- is there a very secure way to just grab the contents without actually saving the file to temp? If I do have to save it to temp, if I just grab the contents and then quickly delete it, am I still facing security threats and, if so, how do I dampen them?
What sort of sanitization do I need to do to PHP file contents to prevent misuse of the system? Basically, is there a way for a malicious user to 'inject' running code if I'm just parsing the contents as text?
If you just want to get the content of the file, use file_get_contents(), you get the contents of the file as a string.
http://us1.php.net/manual/en/function.file-get-contents.php
And then just use regular expression or w/e you use to parse with strings.
I'm creating a php based web application which allows the user to upload a PDF file. This file will then be read and checked for certain data (text).
The problem is I can't figure out how to even open a PDF file in PHP. There are some PDF libraries mainly for creating PDF's, but they don't seem to be very good at reading them.
An alternative solution would be to use an already available solution in Python or something else (as described in other threads on this site) but I'd really like to stay as much as possible in PHP as I intend to later export the data to mysql, etc.
Any input on how to read a PDF and extract data from it would be much appreciated.
I personally haven't tried this out, but it looks like this one works: http://www.pdfparser.org/documentation
It's just a matter of downloading and telling your code to include it, just like the documentation shows.
Or you could try the class.pdf2text.php found in http://www.phpclasses.org/browse/file/31030.html
I have a system set up where, when the user registers, it creates a custom directory for them and then inside that directory it creates a file called index.html. I would like to write an entire HTML page of 100+ lines to that file. I was using fopen() fwrite($filepath, 'content');, but there are escape characters like '' and "" that mess up the PHP function.
Is there a better way to write large content to these files, or should I just have the file saved somewhere on my webserver and then just transfer it to each new registered user?
If you already have the file on disk, and it will not change for each user, then you should copy the file.
It is a waste of resources to read and then write the file with PHP..
PHP Manual - copy
Have a look at htmlentities($var);
http://php.net/manual/en/function.htmlentities.php
Well that means that where you say 'content' you have a hard coded html file in your script itself. It would be easier to just save a standard html file somewhere on the webserver and to something like this:
file_put_contents('/path/to/user/file', file_get_contents('/path/to/standard/index.html'));
Easier to maintain (no html in your code, but just in a testable html file) and no worries about escaping characters. Easy does it :)
Edit
Someone smarter than me proposed to just copy the file. Which is ofcourse a lot more sensible to do than reading and writing contents...
I am working on a database program using PHP to keep track of the products we manage at my workplace.
For this project, I need to be able to select an .XLS file which contains new product data.
New data consists of the following fields:
Type CHAR(3),
Line CHAR(2),
Number INT,
Measure INT,
Comments VARCHAR(255),
Variation CHAR(1) i.e.('Y' || 'N')
These files are created in Excel, or Google Docs; I have found a wonderful excel_reader which allows me to extract the values from this file.
As this is an action which will happen routinely, as new products are created, so I do not want the file to be stored in my server directory (after a while there would be dozens!).
I would rather that the file simply be read, because the import script I'm writing transfers the file's data into an array.
What I really want to happen is to have the user select the file's location (on their local computer) through an HTML form, and then have the script save that file's contents to a MySQL database without ever sending the file to the Server.
I would greatly appreciate any advice you can offer me, I'm not even sure that my plan is a valid way to handle this situation.
It will have to be stored, at least temporarily. Delete the file after you have what you need from it (presumably after moving it out of the temp directory using move_uploaded_file, to the folder from which you will read it), then remove it using unlink.
As a last point, I would be a little worried about immediate deletion of uploaded files. What if something goes wrong with the script while the file is being parsed and data stored in the database? It would probably be a good idea to have a cron job that periodically deletes the files, to be on the safe side, instead of deleting them immediately.
Since your PHP script is running on the server, the Excel file will have to be saved to the server to be read. Once you've read the file and stored it in the database, just delete it.
I found the answer to my question here. It is a nice tutorial on uploading, moving, reading, and deleting files using PHP.
Thank you to all who contributed.
I was struggling to do the same (for xlsx though).
The solution is to use the $_FILES['file']['tmp_name'],
where file is the input name.
Regards :)