.TH substdio_copy 3
.SH NAME
substdio_copy \- copy an entire input to an output
.SH SYNTAX
.B #include <substdio.h>

int \fBsubstdio_copy\fP(&\fIsout\fR,&\fIsin\fR);

substdio \fIsout\fR;
.br
substdio \fIsin\fR;
.SH DESCRIPTION
.B substdio_copy
reads characters from
.I sin
until end of file,
writing each character to
.IR sout .
It then returns 0.
It does not flush
.IR sout .

Upon a
.I sin
error,
.B substdio_copy
returns -2,
leaving
.B errno
set appropriately.

Upon a
.I sout
error,
.B substdio_copy
returns -3,
leaving
.B errno
set appropriately.
.SH "SEE ALSO"
substdio(3)