Description
string 
sha1 ( string str [, bool raw_output] )
     Calculates the sha1 hash of str using the
     US Secure Hash Algorithm 1,
     and returns that hash. The hash is a 40-character hexadecimal number.
     If the optional raw_output is set to TRUE,
     then the sha1 digest is instead returned in raw binary format with a
     length of 20. 
    
Note: 
      The optional raw_output parameter was added in
      PHP 5.0.0 and defaults to FALSE
     
     
| Example 1. A sha1() example | 
<?php$str = 'apple';
 
 if (sha1($str) === 'd0be2dc421be4fcd0172e5afceea3970e2f3d940') {
 echo "Would you like a green or red apple?";
 exit;
 }
 ?>
 | 
 | 
    
     See also sha1_file(),
     crc32(), and
     md5()