(PHP 4 >= 4.2.0, PHP 5)
openssl_csr_export_to_file — Exports a CSR to a file
$csr
   , string $outfilename
   [, bool $notext = true
  ] )
   openssl_csr_export_to_file() takes the Certificate
   Signing Request represented by csr and saves it
   as ascii-armoured text into the file named by outfilename.
  
csr
     
outfilename
     Path to the output file.
notext
     
 可选参数 notext 影响输出的冗余度; 如果设为 FALSE, 
 输出内容将包含附加的人类可读信息. notext 的缺省值为 TRUE.
   成功时返回 TRUE, 或者在失败时返回 FALSE.