shishi_asn1_read_optional(3)
NAME
shishi_asn1_read_optional - API function
SYNOPSIS
#include <shishi.h> int shishi_asn1_read_optional(Shishi * handle, Shishi_asn1 node, const char * field, char ** data, size_t * datalen);
ARGUMENTS
- Shishi * handle
- shishi handle as allocated by shishi_init().
- Shishi_asn1 node
- ASN.1 variable to read field from.
- const char * field
- name of field in node to read.
- char ** data
- newly allocated output buffer that will hold ASN.1 field data.
- size_t * datalen
- actual size of output buffer.
DESCRIPTION
Extract data stored in a ASN.1 field into a newly allocated buffer. If
the field does not exist (i.e., SHISHI_ASN1_NO_ELEMENT), this function
set datalen to 0 and succeeds. Can be useful to read ASN.1 fields
which are marked OPTIONAL in the grammar, if you want to avoid special
error handling in your code.
RETURN VALUE
Returns SHISHI_OK if successful, SHISHI_ASN1_NO_VALUE if the field has
no value, ot SHISHI_ASN1_ERROR otherwise.
REPORTING BUGS
Report bugs to <bug-shishi@josefsson.org>.
COPYRIGHT
Copyright © 2002-2008 Simon Josefsson.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
SEE ALSO
- The full documentation for shishi is maintained as a Texinfo manual.
If the info and shishi programs are properly installed at your site,
the command
- info shishi
- should give you access to the complete manual.