Read and write file

[karol29]

Hi
I have a file like this:

name
city
435

I want to increase only the last row (example: 435 +1) and leave the others rows.

How can I do this?

Thanks

[wilku]

• use [man]file[/man] to read your file to the table
• change third element of that table (this will be with index 2, as indexes are 0 based)
• join the table to string using [man]implode[/man] - first parameter= empty string, second parameter your table
• open your file for writing ([man]fopen[/man] with proper mode to truncate file to 0)
• [man]fwrite[/man] new string to opened file

[NogDog]

$fileName = "file.txt";
$lines = file($fileName);
if(is_array($lines) and count($lines)) // we got something
{
   $lines[count($lines) - 1] += 1;
   if(($fh = fopen($fileName, 'w')) !== FALSE)
   {
      fwrite($fh, implode("\n", $lines));
   }
   else
   {
      // handle error for inability to read file
   }
}
else
{
   // handle no-data error
}

[karol29]

wilku wrote:

- use [man]file[/man] to read your file to the table
- change third element of that table (this will be with index 2, as indexes are 0 based)
- join the table to string using [man]implode[/man] - first parameter= empty string, second parameter your table
- open your file for writing ([man]fopen[/man] with proper mode to truncate file to 0)
- [man]fwrite[/man] new string to opened file

I'm sorry but how can I write this?
I uso this code

$thefile= "myfile.txt";
$lines = file('myfile.txt');
foreach($lines as $line) {
}
	$file = fopen($thefile,"a+");
	$countplus = ($lines[2] + 1);
  	fclose($file);

but it it does not increase the third value ($lines[2]): where it is wrong?

@:
your code doesn't works because it adds more lines between the three values every time that page is viewed

[Weedpacket]

Read what your code is doing (everything about what your code is doing is in the code):

1. Set a variable called $thefile to equal "myfile.txt".

2. Read the contents of a file called "myfile.txt" into a variable called $lines as an array of lines.

3. Loop through the $lines array, putting each element into an array called $line.

4. Don't do anything with $line.

5. Don't do anything else in the loop either.

6. Open the file with its name stored in $thefile in order to add stuff to the end. Use a variable called $file to hold on to this open file.

7. Take the value contained in $lines[2], add one to it, and put the result in a variable called $countplus.

8. Don't do anything with $countplus.

9. Don't do anything with the file.

10. Don't change any of the values in $lines.

11. Close the file held open by $file.

[scross]

Yeah, that code is pretty crazy, especially that empty loop 😛
NogDog's code is nearly there, you just need to change:

fwrite($fh, implode("\n", $lines));

to:

fwrite($fh, implode('', $lines));

since file() does not remove the newline characters and they remain attached (as is said here: http://www.php.net/manual/en/function.file.php

[NogDog]

Scross is correct, I forgot that file() keeps the newlines with each array element.

[karol29]

thank you!

If I want to include only the first row of a text file, how can I do?

[scross]

This is how you get the first line:

$filename = 'yourfile.txt';
$lines = file($filename);
$first_line = $lines[0]; //the first line

is this what you want??

[karol29]

yes, thank you very much!

[bradgrafelman]

Don't forget to mark this thread resolved (if it is).