 |  |
| |
Read in each line with fgets( ), separate the line into words, and process each word:
$fh = fopen('great-american-novel.txt','r') or die($php_errormsg);
while (! feof($fh)) {
if ($s = fgets($fh,1048576)) {
$words = preg_split('/\s+/',$s,-1,PREG_SPLIT_NO_EMPTY);
// process words
}
}
fclose($fh) or die($php_errormsg);Here's how to calculate average word length in a file:
$word_count = $word_length = 0;
if ($fh = fopen('great-american-novel.txt','r')) {
while (! feof($fh)) {
if ($s = fgets($fh,1048576)) {
$words = preg_split('/\s+/',$s,-1,PREG_SPLIT_NO_EMPTY);
foreach ($words as $word) {
$word_count++;
$word_length += strlen($word);
}
}
}
}
print sprintf("The average word length over %d words is %.02f characters.",
$word_count,
$word_length/$word_count);Processing every word proceeds differently depending on how "word" is defined. The code in this recipe uses the Perl-compatible regular-expression engine's \s whitespace metacharacter, which includes space, tab, newline, carriage return, and formfeed. Section 2.6 breaks apart a line into words by splitting on a space, which is useful in that recipe because the words have to be rejoined with spaces. The Perl-compatible engine also has a word-boundary assertion (\b) that matches between a word character (alphanumeric) and a nonword character (anything else). Using \b instead of \s to delimit words most noticeably treats differently words with embedded punctuation. The term 6 o'clock is two words when split by whitespace (6 and o'clock); it's four words when split by word boundaries (6, o, ', and clock).
Section 13.3 discusses regular expressions to match words; Section 1.5 for breaking apart a line by words; documentation on fgets( ) at http://www.php.net/fgets, on preg_split( ) at http://www.php.net/preg-split, and on the Perl-compatible regular expression extension at http://www.php.net/pcre.
|  | |
| 18.7. Counting Lines, Paragraphs, or Records in a File |  | 18.9. Reading a Particular Line in a File |
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