View source for Linelen

The <tt>linelen</tt> [[filter]] limits the length of the output lines to a certain number of octets.  It operates in [[MU_FILTER_ENCODE|encode]] mode only and requires a single parameter: the desired output length in octets.
This filter makes no attempt to analyze the lexical structure of the input: the newline caracters are inserted
when the length of the output line reaches a predefined maximum.  Any "\n" characters present in the input are
taken into account when computing the input line length.

The following code creates an instance of read-only <tt>linelen</tt> stream which breaks the input stream (<tt>mu_stream_t input</tt>, which is supposed to have been initialized previously) to lines of no more than 76 characters.

<syntaxhighlight lang="C">
  int rc;          /* Return code */
  mu_stream_t flt; /* Filter stream */
  char *argv[] = { "linelen", "76", NULL };

  rc = mu_filter_chain_create (&flt, input, MU_FILTER_ENCODE, MU_STREAM_READ, 2, argv);
</syntaxhighlight>

The object describing this filter is declared in <tt>mailutils/filter.h</tt> as follows:

<syntaxhighlight lang="C">
extern mu_filter_record_t mu_linelen_filter;
</syntaxhighlight>

== See also ==

* [[base64 (filter)|base64]]

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