How to read file into keyed array?

[deko]

I have a text file ("eighty.txt ") that looks like this:

83|84|85|86

I can read the file into an array like this:

$numbers= file("eighty.tx t");

But how do I key the array? I'd like to use strings as keys: three, four, five,
six - do I add the key names in the file?

The reason I need keys is because I will need to open the file and change one or
more of the key elements every so often. So, I assume I would read the file
into an array, reference the key, and change the value for that key?

suggestions/examples welcome...

Thanks!

[Erik Dähne]

"deko" <dj****@hotmail .com> schrieb im Newsbeitrag news:ru******** ***********@new ssvr25.news.pro digy.com... I have a text file ("eighty.txt ") that looks like this:

83|84|85|86

I can read the file into an array like this:

$numbers= file("eighty.tx t");

But how do I key the array? I'd like to use strings as keys: three, four, five, six - do I add the key names in the file?

The reason I need keys is because I will need to open the file and change one or more of the key elements every so often. So, I assume I would read the file into an array, reference the key, and change the value for that key?

suggestions/examples welcome...

Thanks!

Hi!

Look at the following code:

$lines=file('ei ghty.txt');
$numbers=explod e('|',$lines[0]);
$numbers[0]=11; //change any number
$output=implode ('|',$numbers); //create a string (numbers seperated by | )
$fhandler=fopen ('eighty.txt',' w');
fwrite($fhandle r,$output);
fclose($fhandle r);

1. First, the file is read into the array $lines.
2. Your numbers are in line no 1, seperated by '|'. -> use explode to read
the numbers into an array
3. now you can change the numbers, e.g. $numbers[0] (the first number).
4. finally, you create a string containing all numbers seperated by '|' and
write them into your file.
Erik

[Chung Leong]

Uzytkownik "deko" <dj****@hotmail .com> napisal w wiadomosci
news:ru******** ***********@new ssvr25.news.pro digy.com...

The reason I need keys is because I will need to open the file and change one or more of the key elements every so often. So, I assume I would read the file into an array, reference the key, and change the value for that key?

If the actual format of the file doesn't matter, the easiest thing to do is
to serialize the array and save it to file.

$data = file_get_conten ts("array.dat") ;
$a = unserialize($da ta);

..... modify aray ...

$data = serialize($a);
file_put_conten ts("array.dat" , $data);

[deko]

> contents of eighty.txt:

83|84|85|86

code:

1 $lines=file('ei ghty.txt');
2 $numbers=explod e('|',$lines[0]);
3 $numbers[0]=11; //change any number
4 $output=implode ('|',$numbers); //create a string (numbers seperated by | )
5 $fhandler=fopen ('eighty.txt',' w');
6 fwrite($fhandle r,$output);
7 fclose($fhandle r);

Fantastic! This is exactly what I was looking for - thanks.

A couple of questions:

Let's say I just want to get the value of the second element in the array (84).
Do I still need the ",$lines[0]" bit at the end of line 2? Is this optional, or
necessary, to begin the key index at 0? If it's optional, then my code might
look like this:

$lines=file('ei ghty.txt');
$numbers=explod e('|');
$my_second_numb er = $numbers[1];
echo "my second number = ".$my_second_nu mber[value]

This assumes the array will be automatically indexed starting at 0. Is this
correct? Also, I'm not opening the file with fopen - I don't need to, if all I
want is the value of $numbers[1], correct? I will not be adding or removing
anything from the file, so I will not have to worry about the the index getting
out of order - is this correct? Again, if ",$lines[0]" is optional in the above
example, then do I really need it when writing to the file?

[Erik Dähne]

"deko" <dj****@hotmail .com> schrieb im Newsbeitrag
news:xc******** *********@newss vr27.news.prodi gy.com...

contents of eighty.txt:

83|84|85|86

code:

1 $lines=file('ei ghty.txt');
2 $numbers=explod e('|',$lines[0]);
3 $numbers[0]=11; //change any number
4 $output=implode ('|',$numbers); //create a string (numbers seperated by | ) 5 $fhandler=fopen ('eighty.txt',' w');
6 fwrite($fhandle r,$output);
7 fclose($fhandle r);
Fantastic! This is exactly what I was looking for - thanks.

A couple of questions:

Let's say I just want to get the value of the second element in the array

(84). Do I still need the ",$lines[0]" bit at the end of line 2? Is this optional, or necessary, to begin the key index at 0? If it's optional, then my code might look like this:

$lines=file('ei ghty.txt');
$numbers=explod e('|');
$my_second_numb er = $numbers[1];
echo "my second number = ".$my_second_nu mber[value] explode needs two arguments: the seperator ( in your case '|', and the
string that should be read into an array; in your case, this is the first
row of the textfile ($lines[0] ), so you shouldn't change the first two
rows.

if you want to get the value of the second element, you simply use
$numbers[1], the third $numbers[2] and so on.
your example should look like this:

$lines=file('ei ghty.txt');
$numbers=explod e('|',$lines[0]);
$my_second_numb er = $numbers[1];
echo "my second number = ".$my_second_nu mber;

This assumes the array will be automatically indexed starting at 0. Is this correct? yes, the index of arrays usually starts at 0. Also, I'm not opening the file with fopen - I don't need to, if all I
want is the value of $numbers[1], correct? you could also use fopen(), fread(), ... to get the content of the text
file, but in your case as the file has only one line its the easiest way to
use
$lines=file('ei ghty.txt');
to read the content.
I will not be adding or removing
anything from the file, so I will not have to worry about the the index getting out of order - is this correct? Again, if ",$lines[0]" is optional in the above example, then do I really need it when writing to the file?

$lines[0] is not optional. it is required to read your data.

[deko]

Okay - it seems to be working as you've described - thanks.

I have another issue with this script I'm wondering if you can help me with. I
want to update certain values in the file based on a time interval. For
example:

$lines=file('ei ghty.txt');
$numbers=explod e('|',$lines[0]);

//pseudo code
$startdate = "03/19/2004"
if today's date is more than one day ahead of $startdate, then:

$numbers[0]=11; //change any number
$output=implode ('|',$numbers); //create a string (numbers seperated by | )
$fhandler=fopen ('eighty.txt',' w');
fwrite($fhandle r,$output);
fclose($fhandle r);

Basically, I want a conditional clause that prevents $numbers[0] from being
updated until 24 hours after the $startdate. How would I code this? Is
"03/19/2004" proper format for specifying a date?