substdio_copy - copy an entire input to output

#include <substdio.h>

int substdio_copy(&sout, &sin);

substdio sout;
substdio sin;

substdio_copy reads characters from sin until end of file, writing each character to sout. It then returns 0. It does not flush sout.

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

Upon a sout error, substdio_copy returns -3, leaving errno set appropriately.

substdio(3)