обновление: вы сказали, что на Windows
<?php
$file = "somefile.txt";
$lines = count(file($file));
echo "There are $lines lines in $file";
?>
<?php
$text = "This is some text.";
$count = count(explode(" ", $text));
echo "$text contains $count words";
?>
В системе posix вы могли бы сделать это по-другому
<?php
$lines_command = 'cat FILE_NAME | wc -l';
$words_command = 'cat FILE_NAME | wc -w';
$lines = system($lines_command);
$words = system($words_command);
?>
Подробнее на
$ man wc
WC(1) User Commands WC(1)
NAME
wc - print newline, word, and byte counts for each file
SYNOPSIS
wc [OPTION]... [FILE]...
wc [OPTION]... --files0-from=F
DESCRIPTION
Print newline, word, and byte counts for each FILE, and a total line if more than one FILE is
specified. With no FILE, or when FILE is -, read standard input.
-c, --bytes
print the byte counts
-m, --chars
print the character counts
-l, --lines
print the newline counts
--files0-from=F
read input from the files specified by NUL-terminated names in file F; If F is - then
read names from standard input
-L, --max-line-length
print the length of the longest line
-w, --words
print the word counts
--help display this help and exit
--version
output version information and exit