cl_hp_get_field - Execute header parser

       Michael Baeuerle

       Note:  Consider  the  function  cl_hp_unfold_field() if the header field was already extracted by another
       header parser (but may still contain folding).

       The cl_hp_get_field() function executes the header parser to extract and unfold a single header field.
       This implementation executes the canlock-mhp utility in a separate process.

       The parameter data should point to the beginning of the input data.
       Specify the length of the input data with the data_len parameter.
       The name of a single header field must be specified with the field parameter.

       The input data must be a message in canonical format (with US-ASCII encoded CRLF  line  breaks).  If  the
       message  is  in  some  local format (e.g. EBCDIC encoded or with LF line breaks), it must be converted to
       canonical format before it can be used as input.

       The input data may be a naked header without message body, but the empty line separator after the  header
       must always be present.  The syntax of the extracted header field is not checked beyond the folding.  The
       rest  of the message need not be fully RFC 5536 conformant too, as long as all header fields start on new
       lines (and are correctly folded, so that there  is  no  ambiguity).  Common  syntax  errors  (like  8-bit
       characters in the header) are ignored.

       cl_hp_get_field - Execute header parser

       Report bugs to <mailto:michael.baeuerle@gmx.net>.

       If  the  parser reports success, a pointer to the NUL-terminated output data is returned. Otherwise, NULL
       is returned.

       On success, the caller is responsible to free() the memory block allocated for the output data.

free(3), cl_hp_parse_field(3), cl_hp_unfold_field(3), canlock-hfp(1), canlock-mhp(1), canlock(1)

Unix                                               2024-05-11                                 cl_hp_get_field(3)

cl_hp_get_field() tries to comply with the following standards:

       RFC 5322, RFC 5536

#include<libcanlock-3/canlock-hp.h>char*cl_hp_get_field(constchar*data,size_tdata_len,constchar*field);