src/src/lookups/lf_quote.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2018 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 #include "../exim.h"
  10 #include "lf_functions.h"
  11
  12
  13 /*************************************************
  14 *   Add string to result, quoting if necessary   *
  15 *************************************************/
  16
  17 /* This function is called by some lookups that create name=value result
  18 strings, to handle the quoting of the data. It adds "name=" to the result,
  19 followed by appropriately quoted data, followed by a single space.
  20
  21 Arguments:
  22   name           the field name
  23   value          the data value
  24   vlength        the data length
  25   result         the result expanding-string
  26
  27 Returns:         the result pointer (possibly updated)
  28 */
  29
  30 gstring *
  31 lf_quote(uschar *name, uschar *value, int vlength, gstring * result)
  32 {
  33 result = string_append(result, 2, name, US"=");
  34
  35 /* NULL is handled as an empty string */
  36
  37 if (!value)
  38   {
  39   value = US"";
  40   vlength = 0;
  41   }
  42
  43 /* Quote the value if it is empty, contains white space, or starts with a quote
  44 character. */
  45
  46 if (value[0] == 0 || Ustrpbrk(value, " \t\n\r") != NULL || value[0] == '\"')
  47   {
  48   result = string_catn(result, US"\"", 1);
  49   for (int j = 0; j < vlength; j++)
  50     {
  51     if (value[j] == '\"' || value[j] == '\\')
  52       result = string_catn(result, US"\\", 1);
  53     result = string_catn(result, US value+j, 1);
  54     }
  55   result = string_catn(result, US"\"", 1);
  56   }
  57 else
  58   result = string_catn(result, US value, vlength);
  59
  60 return string_catn(result, US" ", 1);
  61 }
  62
  63 /* End of lf_quote.c */