Question

I would like to check if csv file contain a header and ignore the header.

I have to do a check if the first column is not a character

csv file has format : avgTemperature, minTemperature, maxTemperature

$f = fopen("./uploads/" .$filename, "r");
$string = "avgTemperature";
if (fgetcsv($f)==$string){  
    // read the first line and ignore it
    fgets($f);
}

Answer 1

Going from your comment, and from the idea that the actual data is temperatures (i.e. numeric data), if you do have headers, then they will be text strings and not numbers. Therefore you can do something like this:

$f = fopen("./uploads/" .$filename, "r");

if(!($data = fgetcsv($f))) {
    return;    //most likely empty file
}

if(!is_numeric($data[0])) {
    //this is your header line - skip it - and read the next line
    $data = fgetcsv($f);
}

while($data) {
    //process a line of data
    ...
    //and read the next line
    $data = fgetcsv($f);
}

EDIT: An alternative version of the last loop would look like this:

do {
    //process a line of data
    ...
}
while ($data = fgetcsv($f));