.TH fmt_copybytes_sizeof_minus1 3
.SH NAME
fmt_copybytes_sizeof_minus1 \- write binary data
.SH SYNTAX
.B #include <libowfat/fmt.h>

size_t \fBfmt_copybytes_sizeof_minus1\fP(char *\fIdest\fR,const char *\fIsource\fR);
.SH DESCRIPTION
This macro will copy sizeof(\fIsource\fP)-1 bytes from \fIsource\fP to \fIdest\fP.

This is a convenience wrapper interface around
\fIfmt_copybytes\fP for the situation where you construct a binary
message by concatenating hex constant strings like this:

  fmt_copybytes_sizeof_minus1(dest, "\\x01\\x02\\x03\\x04");

Since the source is technically a string, the compiler will add a 0 byte
and sizeof() will return the size including that 0 byte. That is why we
have a minus 1 in this function, so we do not copy or count that 0 byte.

.SH NOTE
Caution: \fIsource\fP must not have side effects or those will be
evaluated twice.

.SH "SEE ALSO"
fmt_copybytes(3)