NAME

       TSMimeHdrFieldValueStringGet - get HTTP MIME header values

SYNOPSIS

       #include <ts/ts.h>

       const   char   *  TSMimeHdrFieldValueStringGet(TSMBuffer bufp,  TSMLoc hdr,  TSMLoc field,  int idx,  int
       * value_len_ptr)

       int TSMimeHdrFieldValueIntGet(TSMBuffer bufp, TSMLoc hdr, TSMLoc field, int idx)

       int64_t TSMimeHdrFieldValueInt64Get(TSMBuffer bufp, TSMLoc hdr, TSMLoc field, int idx)

       unsigned int TSMimeHdrFieldValueUintGet(TSMBuffer bufp, TSMLoc hdr, TSMLoc field, int idx)

       time_t TSMimeHdrFieldValueDateGet(TSMBuffer bufp, TSMLoc hdr, TSMLoc field)

DESCRIPTION

       MIME headers and fields can be components of request headers, response  headers,  or  standalone  headers
       created  within  a  Traffic  Server  plugin.  The  functions here are all used to access header values of
       specific types, but it is up to the caller to know if a header has  appropriate  semantics  for  the  API
       used.  For all but TSMimeHdrFieldValueStringGet(), an appropriate data conversion algorithm is applied to
       the header field string.

       All the APIs take a TSMBuffer marshal buffer argument bufp, and a  TSMLoc  argument  hdr  indicating  the
       location  of  the HTTP headers. The required field argument is the locator of a specific header value, as
       returned by an accessor function such as TSMimeHdrFieldFind().

       Within the header field, comma-separated values can be retrieved with an index idx ranging from 0 to  the
       maximum  number of fields for this value; this maximum is retrieved using TSMimeHdrFieldValuesCount(). An
       idx value of -1 has the semantics  of  retrieving  the  entire  header  value,  regardless  of  how  many
       comma-separated values there are. If a header is not comma-separated, an idx of 0 or -1 are the same, but
       the latter is preferred.

       TSMimeHdrFieldValueStringGet() returns a pointer to the header value, and  populated  value_len_ptr  with
       the length of the value in bytes. The returned header value is not NUL-terminated.

RETURN VALUES

       All  functions  returns  the  header  value  with  a  type  matching  the respective function name. Using
       TSMimeHdrFieldValueDateGet() on a header which does not have date-time semantics always returns 0.

EXAMPLES

       This examples show how to retrieve and copy a specific header.

          #include <string.h>
          #include <ts/ts.h>

          int
          get_content_type(TSHttpTxn txnp, char* buf, size_t buf_size)
          {
            TSMBuffer bufp;
            TSMLoc hdrs;
            TSMLoc ctype_field;
            int len = -1;

            if (TS_SUCCESS == TSHttpTxnServerRespGet(txnp, &bufp, &hdrs)) {
              ctype_field = TSMimeHdrFieldFind(bufp, hdrs, TS_MIME_FIELD_CONTENT_TYPE, TS_MIME_LEN_CONTENT_TYPE);

              if (TS_NULL_MLOC != ctype_field) {
                const char* str = TSMimeHdrFieldValueStringGet(bufp, hdrs, ctype_field, -1, &len);

                if (len > buf_size)
                  len = buf_size;
                memcpy(buf, str, len);
                TSHandleMLocRelease(bufp, hdrs, ctype_field);
              }
              TSHandleMLocRelease(bufp, TS_NULL_MLOC, hdrs);
            }

            return len;
          }

SEE SLSO

       TSAPI(3ts), TSMBufferCreate(3ts), TSMimeHdrFieldValuesCount(3ts)

COPYRIGHT

       2018, dev@trafficserver.apache.org