I'm not sure how to really word this. I've been getting into PHP CLI lately, and I wanted to make like a dynamic counter. For example, it starts with echoing Count: 0 and then as the count increases (or decreases) the number changes as the program advances.
I hope you can understand what I mean. If you do, any idea on if its possible, and if so, how to do it?
As I understand you question, you don't wan't to repeatedly echo "Count: N", but you want it to remain on the screen and that only the number changes.
For this you must use the PHP extension Ncurses - http://si2.php.net/ncurses
It's basically a wrapper for the Ncurses terminal control library. It's quite powerful but not so easy to learn.
One way is to create a file somewhere in a directory like:
/files/counter.txt
Start it with a single number 0,
then every time you want to change it, read the file in
and update it. Since the only content in the file
is a number, just increment it.
Related
I am trying to make it so users can enter text files and a short message near it and it will be visible for everyone. I am using PHP and SQL (MariaDB/MySQL for the database) and I want it so every like ten for example inputs it will make a new page. So for example if there is ten files up on the page then if someone puts another one in it will automatically make a page two and have the oldest file submitted be there. How can I do this. I have seen other sites use a GET method and have it be something like ?page=2 . How can I do this myself?
What you're looking for is "Pagination".
Pagination using MySQL LIMIT, OFFSET
Though that can look a bit scary at first. However, if you use a framework such as Laravel it can easily be done, see:
https://laravel.com/docs/8.x/pagination#introduction
I have a node script that fetches all the peers. Can I filter that output using php?
I mean I dont need all the peers fetched by that script, so can i just get some specific peers using functions like strcmp? Currently my node script outputs the result in an html page. But I want it to be printed on php page with filter applied to it.
You can check lines of output one-by-one and use strpos or regexp searching functions(pref_match etc)
You also can list only some peers using construction
sip show peers like something
Technically speaking, you can do that. I would assume that your script is using the Asterisk "-rx" parameter to achieve this. Personally, that is a none reliable solution, I've seen situations in the past where running a command while "-rx", while within a script will yield no result.
My suggestion to you is to use something like PHPAGI and connect directly to the Asterisk Manager (AMI) and obtain the information from there. The solution will include less moving parts and will most surely be more reliable.
There are quite a few different threads about this similar topic, yet I have not been able to fully comprehend a solution to my problem.
What I'd like to do is quite simple, I have a flat-file db, with data stored like this -
$username:$worldLocation:$resources
The issue is I would like to have a submit data html page that would update this line based upon a search of the term using php
search db for - $worldLocation
if $worldLocation found
replace entire line with $username:$worldLocation:$updatedResources
I know there should be a fairly easy way to get this done but I am unable to figure it out at the moment, I will keep trying as this post is up but if you know a way that I could use I would greatly appreciate the help.
Thank you
I always loved c, and functions that came into php from c.
Check out fscanf and fprintf.
These will make your life easier while reading writing in a format. Like say:
$filehandle = fopen("file.txt", "c");
while($values = fscanf($filehandle, "%s\t%s\t%s\n")){
list($a, $b, $c) = $values;
// do something with a,b,c
}
Also, there is no performance workaround for avoiding reading the entire file into memory -> changing one line -> writing the entire file. You have to do it.
This is as efficient as you can get. Because you most probably using native c code since I read some where that php just wraps c's functions in these cases.
You like the hard way so be it....
Make each line the same length. Add space, tab, capital X etc to fill in the blanks
When you want to replace the line, find it and as each line is of a fixed length you can replace it.
For speed and less hassle use a database (even SQLLite)
If you're committed to the flat file, the simplest thing is iterating through each line, writing a new file & changing the one that matches.
Yeah, it sucks.
I'd strongly recommend switching over to a 'proper' database. If you're concerned about resources or the complexity of running a server, you can look into SQLite or Berkeley DB. Both of these use a database that is 'just a file', removing the issue of installing and maintaining a DB server, but still you the ability to quickly & easily search, replace and delete individual records. If you still need the flat file for some other reason, you can easily write some import/export routines.
Another interesting possibility, if you want to be creative, would be to look at your filesystem as a database. Give each user a directory. In each directory, have a file for locations. In each file, update the resources. This means that, to insert a row, you just write to a new file. To update a file, you just rewrite a single file. Deleting a user is just nuking a directory. Sure, there's a bit more overhead in slurping the whole thing into memory.
Other ways of solving the problem might be to make your flat-file write-only, since appending to the end of a file is a trivial operation. You then create a second file that lists "dead" line numbers that should be ignored when reading the flat file. Similarly, you could easily "X" out the existing lines (which, again, is far easier than trying to update lines in a file that might not be the same length) and append your new data to the end.
Those second two ideas aren't really meant to be practical solutions as much as they are to show you that there's always more than one way to solve a problem.
ok.... after a few hours work..this example woorked fine for me...
I intended to code an editing tool...and use it for password update..and it did the
trick!
Not only does this page send and email to user (sorry...address harcoded to avoid
posting aditional code) with new password...but it also edits entry for thew user
and re-writes all file info in new file...
when done, it obviously swaps filenames, storing old file as usuarios_old.txt.
grab the code here (sorry stackoverflow got VERY picky about code posting)
https://www.iot-argentina.xyz/edit_flat_databse.txt
Is that what you are location for :
update `field` from `table` set `field to replace` = '$username:$worldlocation:$updatesResources' where `field` = '$worldLocation';
I have a function to write a text file based on the form settings, a rather large form.
Shortly, I want to compare the output of a function to a single file, and only do execution (rewriting the file) if the destination file is different from the output. As you guess, it is a performance concern.
Is it doable, BTW?
The process is, I fill up some forms:
A single file is written to contain some "specific" selected options
Some "non-specific" options do not necessarily write anything to the file.
The form is updateable anytime, so the content of the file may grow or shrink based on different options.
It only needs a rewrite to the file if I am at point #1.
When at point #2, nothing should be written.
This is what I tried:
if ($output != file_get_contents($filepath)) {
// save the data
}
But I felt so much delay of execution in this.
I found a almost similar issue here: Can I use file_get_contents() to compare two files?, but my issue is different. Mine is comparing the result of the process to an already existing file which simply the result of the process previously. And only rewrite the file if they are different.
No sensitive data on the form, btw.
Any hint is very much appreciated.
Thanks
To compare a whole file with a string (I suppose it's a string, isn't it?) the only way is to read whole file and do comparison. To improve performance you can read file line by line and stop at first different line, as Explosion Pills said before me.
If your file is really big, and you want to improve performance further, you can do some hashing stuff:
Generate the output, let's say $output.
Calculate md5($output) and store in $output_md5.
Compare $output_md5 with a stored one, let's say in file output.md5.
Are they equal?
If yes, do nothing.
If not, save $output into output.txt and $output_md5 in output.md5.
Rather than load the entire file into memory, it may be faster to read it line-by-line (fgets) and compare it to the input string also line-by-line. You could even go as small as character-by-character, but I think that's overkill.
You could always try a combination of what was in the other post, the sha1_file($file) function, with the sha1($string) function, and check the equality of that.
I have files I need to convert into a database. These files (I have over 100k) are from an old system (generated from a COBOL script). I am now part of the team that migrate data from this system to the new system.
Now, because we have a lot of files to parse (each files is from 50mb to 100mb) I want to make sure I use the right methods in order to convert them to sql statement.
Most of the files have these following format:
#id<tab>name<tab>address1<tab>address2<tab>city<tab>state<tab>zip<tab>country<tab>#\n
the address2 is optional and can be empty
or
#id<tab>client<tab>taxid<tab>tagid<tab>address1<tab>address2<tab>city<tab>state<tab>zip<tab>country<tab>#\n
these are the 2 most common lines (I'll say around 50%), other than these, all the line looks the same but with different information.
Now, my question is what should I do to open them to be as efficient as possible and parse them correctly?
Honestly, I wouldn't use PHP for this. I'd use awk. With input that's as predictably formatted as this, it'll run faster, and you can output into SQL commands which you can also insert via a command line.
If you have other reasons why you need to use PHP, you probably want to investigate the fgetcsv() function. Output is an array which you can parse into your insert. One of the first user-provided examples takes CSV and inserts it into MySQL. And this function does let you specify your own delimiter, so tab will be fine.
If the id# in the first column is unique in your input data, then you should definitely insert this into a primary key in mysql, to save you from duplicating data if you have to restart your batch.
When I worked on a project where it was necessary to parse huge and complex log files (Apache, firewall, sql), we had a big gain in performance using the function preg_match_all(less than 10% of the time required using explode / trims / formatting).
Huge files (>100Mb) are parsed in 2 or 3 minutes in a core 2 duo (the drawback is that memory consumption is very high since it creates a giant array with all the information ready to be synthesized).
Regular expressions allow you to identify the content of line if you have variations within the same file.
But if your files are simple, try ghoti suggestion (fgetscv), will work fine.
If you're already familiar with PHP then using it is a perfectly fine tool.
If records do not span multiple lines, the best way to do this to guarantee that you won't run out of memory will be to process one line at a time.
I'd also suggest looking at the Standard PHP Library. It has nice directory iterators and file objects that make working with files and directories a bit nicer (in my opinion) than it used to be.
If you can use the CSV features and you use the SPL, make sure to set your options correctly for the tab characters.
You can use trim to remove the # from the first and last fields easily enough after the call to fgetcsv
Just sit and parse.
It's one-time operation and looking for the most efficient way makes no sense.
Just more or less sane way would be enough.
As a matter of fact, most likely you'll waste more overall time looking for the super-extra-best solution. Say, your code will run for a hour. You will spend another hour to find a solution that runs 30% faster. You'll spend 1,7 hours vs. 1.