.TH fmt_asn1dertag 3
.SH NAME
fmt_asn1dertag \- encode unsigned integer like ASN.1 DER tag
.SH SYNTAX
.B #include <fmt.h>

size_t \fBfmt_asn1dertag\fP(char *\fIdest\fR,unsigned long long \fIsource\fR);
.SH DESCRIPTION
fmt_asn1dertag encodes an unsigned integer using the ASN.1 DER for
encoding tag.  This takes one byte for every 7 bits in the number.

If \fIdest\fR equals FMT_LEN (i.e. is NULL), fmt_asn1dertag returns the
number of bytes it would have written.

For convenience, fmt.h defines the integer FMT_ASN1TAG to be big
enough to contain every possible fmt_asn1dertag output.
.SH "SEE ALSO"
scan_asn1dertag(3)