Scan file contents

Is it possible to scan for a string within a file without reading the file into a variable?

Short answer, no.

You can read 'chunks' of a file into memory at a time, and search within the chunk. If for some reason a match is split between chunks though, you may not get correct results.

what about fgets?

What happens if the search term includes a line-break?

Or if the term is two words, and they happen to reside at the end of one line, and the start of the other?

Line breaks are fine, I am compressing the data before I put it into the file, so line breaks are then removed (when saved). So then when I search, I search compressed data against compressed data. I then uncompress matches.

Line breaks are fine, I am compressing the data before I put it into the file, so line breaks are then removed (when saved). So then when I search, I search compressed data against compressed data. I then uncompress matches.

Then how would you expect fgets() to help you? Per the manual it gets 1 line of data. If you have no line breaks then it would, by default, get the entire file content since there are no line breaks. You can specify a length parameter to read the line/file in chunks, but then you're back to the problem of the scenario where the text you are searching for could be split between chunks. I can think of some elaborate means to overcome that, but I'm sure there is a more efficient method.

if you were to describe the format of the file (and why you must compress the data) and what the search value would typically look like we might be able to provide some actual help. As of right now this is all hypothetical.

So I am doing this:

Insert the data

$values = array("one", "two", "dog", "mouse", "one", "cat", "mouse");
$handle = fopen("some/file", "ab");
foreach($values as $value){
    $value = "\n".gzcompress($value, 9);
    fwrite($handle, $value);
}
fclose($handle);

Search the data

$handle = fopen("some/file", "rb");
$search = gzcompress("mouse", 9);
$results = array();
while (($buffer = fgets($handle)) !== false) {
    $i = 0;
    if($search == ($saved = trim($buffer, "\n"))){
        $results[$i] = gzuncompress($saved);
    }
}
print_r($results);

Just an FYI, I am attempting to make a NoSQL database in php (because I was bored).

Sure, provided you have a *nix based server. shell_exec

for reading websites

echo shell_exec(curl -s 'http://forums.phpfreaks.com/index.php?topic=364198.0' | grep 'description' | awk -F 'content="' '{print $2}' | awk -F '"' '{print $1}');

for reading files

echo shell_exec(grep 'description' /path/to/file | awk -F 'content="' '{print $2}' | awk -F '"' '{print $1}');

@Mahngiel, have you ever tried to execute the scripts?

@jazzman1, by "execute the scripts" i'm assuming you're asking if I've ever used what i described?  The answer is of course, else I would not have posted it.  I didn't test the command in PHP, but through CLI. So it might be broken - but the concept remains

B/s I've created a bash file and put the script inside it, but I cannot execute the script from php command line.

See what I've done:

#!/usr/bin/php5
echo shell_exec(curl -s 'http://forums.phpfreaks.com/index.php?topic=364198.0' | grep 'description' | awk -F 'content="' '{print $2}' | awk -F '"' '{print $1}');

// php command line

php -f shell_exec.php // echo shell_exec(curl -s 'http://forums.phpfreaks.com/index.php?topic=364198.0' | grep 'description' | awk -F 'content="' '{print $2}' | awk -F '"' '{print $1}')

PS. There is something wrong

code used for screenshot: echo shell_exec("curl -s 'http://forums.phpfreaks.com/index.php?topic=364198.0' | grep 'description' | awk -F 'content=\"' '{print $2}' | awk -F '\"' '{print $1}'");

Ok, I'm doing something wrong.

I am going to post a result later 

Kill me with something heavy. I was forget to put the php open tags in my bash file 

Everything is fine, I got a result.

Nice response.