View source for C-escape

The ''C-escape'' [[filter]] replaces C escape sequences with the corresponding control character and vice versa. 

In encode mode, recognized control characters are replaced with their C escapes.  For example, newline (ASCII 10) becomes ''\n'', horizontal tab (ASCII 9) becomes ''\t'', etc.

In decode mode, the reverse operation is performed, i.e. each C escape  is replaced with the corresponding character.  Unrecognized escape sequences are copied verbatim.

Only named escapes are supported, i.e.: ''\\'', ''\a'', ''\b'', ''\f'', ''\n'', ''\r'', ''\t'', ''\v''.

This filter does not take arguments. 

The following object, declared in mailutils/filter.h describes the ''C-escape'' filter:

<source lang="C">
extern mu_filter_record_t mu_c_escape_filter;
</source>

The example below shows how to create an instance of this filter in decode mode for reading:

<source lang="C">
  int rc;          /* Return code */
  mu_stream_t flt; /* Filter stream */
  mu_stream_t input; /* Input stream */
 
  initialize_input_stream (&stream);
  rc = mu_filter_create (&flt, input, "C-escape", MU_FILTER_DECODE, MU_STREAM_READ);
</source>

[[Category:Filters]]
[[Category:C API]]