[RESOLVED] Display Lines from Flatfile DB based on Keyword

DaleRobbins

I need a script that will display all lines from a flatfile DB that contain a keyword or value in a specific field, such as field 2. Do you have any ideas?

Here's the code I'm now using... which currently looks through all the fields... but I need it to pull only from a specified field.


echo "All occurances of line based on keyword in field 0";
echo "<br>";

$user = 'billybob'; //get this value from wherever it is you get it

//get datafile as an array of lines
$lines = file('info2.txt');

// Loop through the lines
foreach ($lines as $line_num => $line)
{
if (strpos($line,$user) === 0) //string found at start of line
echo "$line<br>";
}

sneakyimp

You could explode the line at each pipe char, creating an array for each line:

foreach ($lines as $line_num => $line)
{
    $fields = explode('|', $line);
    if (strpos($field[0], $user) === 0) //string found at start of line
      echo "$field<br>";     

}

DaleRobbins

Thanks so much for your reply, however I'm sorry I didn't explain my need very well.

Basically, I want to "search" on one specific field. For instance, I want to display all the lines which contain "smith" in field 1, or pehaps all the lines which contain the value "subscriber" in the last field.

sneakyimp

i would recommend trying me code. $field[0] will search the data in each line before the first | char. Using $field[1] would search the data between the 1st and 2nd | chars. etc.

If you want to search the whole field rather than just checking to see if the field starts with your string, you might consider [man]preg_match[/man].

laserlight

A little off topic, but do you really need to use a flatfile database? SQLite might be a good option if you want a database consisting of a single file, with no need to install database server software.

DaleRobbins

Thanks for taking your time to help... I really appreciate it. I think Preg_match would probably be better... however, I'm still unable to make the current code work. I must be missing something simple. Here's what I have (based on your help and the sample DB line):

$user = 'billybob';

//get datafile as an array of lines
$lines = file('info2.txt');

// Loop through the lines
foreach ($lines as $line_num => $line)
{
$fields = explode('|', $line);
if (strpos($field[2], $user) === 0) //string found at start of line
echo "$field<br>";

}

DaleRobbins

Thank you... yes, I would like to try this. What are the advantages over a flatfile?

laserlight

DaleRobbins wrote:
What are the advantages over a flatfile?

You would be able to make use of SQL and the database handling algorithms that have already been implemented instead of implementing them yourself. For example, you might simply run the query: SELECT * FROM users WHERE username LIKE '%billybob%';

sneakyimp

SQLLite, if you take the time to learn it, will bring you enormous power over your data. You'll have to get accustomed to using SQL, but that's a good thing.

In the meantime:

$user = 'billybob';

//get datafile as an array of lines
$lines = file('info2.txt');

// Loop through the lines
foreach ($lines as $line_num => $line)
{
  $fields = explode('|', $line);
  if (preg_match('/' . preg_quote($user,'/') . '/', $field[2]))
    echo "$field<br>";
}

DaleRobbins

I apologize, but I am unable to get either version of the script to work. Strange. I'm sure that I'm doing something stupid on my end... but can't seem to locate the issue. I'm using PHP 5.2.8 on Linux. Would it be too much to ask for your help in debugging the first script? That will meet my need best. The flatfile data is exactly as shown above... and below is is exactly how my script reads:

<?php
$user = 'billybob';

//get datafile as an array of lines
$lines = file('info2.txt');

// Loop through the lines
foreach ($lines as $line_num => $line)
{
$fields = explode('|', $line);
if (strpos($field[2], $user) === 0) //string found at start of line
echo "$field<br>";
}
?>

sneakyimp

Dale, can you please use the code formatting tags? put [/code] after your code and

 before it.

What exactly is it doing?

DaleRobbins

Thanks for the reply... and sorry, I'll add the tags next time.

The script isn't doing anything... nothing prints to screen. But my original code still works fine...

sneakyimp

That last code you posted shouldn't work either.

I had a mistake in my code. Make sure all occurrences of $field are changed to $fields (plural).

That last one needs to echo $fields[2] and not $field or $fields.

DaleRobbins

Ahh... THANK YOU! It's working fine now!

If I could ask one last question. The strpos looks for a match starting at the beginning of the field string... so how would I look for a match starting from the end of the string? For instance, if I wanted to look for a match for the pattern "bob" starting from the last position in the field string?

I can't thank you enough for taking your time to assist a stumbling newbie like me! Your kindness has been a real encouragement.

sneakyimp

The code I posted using preg_match should report a match if the string matches any part of the line.

I'm posting it again here hopefully with all the errors corrected:

<?php
$user = 'billybob';

//get datafile as an array of lines
$lines = file('info2.txt');

// Loop through the lines
foreach ($lines as $line_num => $line)
{
  $fields = explode('|', $line);
  if (preg_match('/' . preg_quote($user,'/') . '/', $fields[2]))
    echo "line #" . ($line_num+1)  . " matches: $fields[2]<br>";
}
?>

martyndix

Dear All,
This is my first post, so please forgive me if there is anything not quite right.

I am using the above code with much success, but I need to be able to search multiple .txt files. I have a cron job that runs a script to make a new text file every day so things don't get too big and are filed nicely, but as the script only searches one file at a time it is not much use.

Is it possible to modify this line:
$lines = file('info2.txt');

to make it search an entire FOLDER of text files, not just one specified text file?

I hope this makes sense.

Many thanks in advance,
Martyn.