.TH buffer_get_token_sa_pred 3
.SH NAME
buffer_get_token_sa_pred \- read token from buffer
.SH SYNTAX
.nf
.B #include <libowfat/stralloc.h>
.B #include <libowfat/buffer.h>

int \fBbuffer_get_token_sa_pred\fP(buffer* \fIb\fR,stralloc* \fIsa\fR,
                 int (*\fIpredicate\fR)(stralloc* * \fIsa\fR));
.SH DESCRIPTION
buffer_get_token_sa_pred appends data from \fIb\fR to \fIsa\fR until
\fIpredicate\fR(\fIsa\fR) returns 1 or -1.

If \fIpredicate\fR returns 1 once a '\\n' was read, that new-line
character is still appended to \fIsa\fR -- use stralloc_chop or
stralloc_chomp to get rid of it.  \fIpredicate\fR can also return 0
(indicating further input is required to complete the token) or -1
(abort and return -1; use this if \fIpredicate\fR wants to enfore a
maximum message size or does timeout handling or detects a malformed
message).

If reading from the buffer or allocating memory fails,
buffer_get_token_sa_pred returns -1 and sets \fIerrno\fR appropriately.  At
that point \fIsa\fR may already contain a partial token.

On success, buffer_get_token_sa_pred returns 0.
.SH RATIONALE
buffer_get_token_sa_pred appends instead of overwriting so it can be
used on non-blocking sockets (these signal error and set \fIerrno\fR to
EAGAIN; in this case you can simply call buffer_get_token_sa again when
\fBselect\fR or \fBpoll\fR indicate more data is available).
.SH "SEE ALSO"
buffer_getline_sa(3), buffer_get_token(3), buffer(3)