static int
stdin_open(gx_io_device * iodev, const char *access, stream ** ps,
gs_memory_t * mem)
{
i_ctx_t *i_ctx_p = (i_ctx_t *)iodev->state; /* see above */
stream *s;
if (!streq1(access, 'r'))
return_error(e_invalidfileaccess);
if (file_is_invalid(s, &ref_stdin)) {
/****** stdin SHOULD NOT LINE-BUFFER ******/
gs_memory_t *mem = imemory_system;
byte *buf;
s = file_alloc_stream(mem, "stdin_open(stream)");
/* We want stdin to read only one character at a time, */
/* but it must have a substantial buffer, in case it is used */
/* by a stream that requires more than one input byte */
/* to make progress. */
buf = gs_alloc_bytes(mem, STDIN_BUF_SIZE, "stdin_open(buffer)");
if (s == 0 || buf == 0)
return_error(e_VMerror);
sread_file(s, gs_stdin, buf, STDIN_BUF_SIZE);
s->procs.process = s_stdin_read_process;
s->save_close = s_std_null;
s->procs.close = file_close_file;
make_file(&ref_stdin, a_readonly | avm_system, s->read_id, s);
*ps = s;
return 1;
}
*ps = s;
return 0;
}
/*
* Set up a file stream on an OS file. The caller has allocated the
* stream and buffer.
*/
void
file_init_stream(stream *s, FILE *file, const char *fmode, byte *buffer,
uint buffer_size)
{
switch (fmode[0]) {
case 'a':
sappend_file(s, file, buffer, buffer_size);
break;
case 'r':
/* Defeat buffering for terminals. */
{
struct stat rstat;
fstat(fileno(file), &rstat);
sread_file(s, file, buffer,
(S_ISCHR(rstat.st_mode) ? 1 : buffer_size));
}
break;
case 'w':
swrite_file(s, file, buffer, buffer_size);
}
if (fmode[1] == '+')
s->file_modes |= s_mode_read | s_mode_write;
s->save_close = s->procs.close;
s->procs.close = file_close_file;
}
/* Switch a file stream to reading or writing. */
static int
s_fileno_switch(stream * s, bool writing)
{
uint modes = s->file_modes;
int fd = sfileno(s);
long pos;
if (writing) {
if (!(s->file_modes & s_mode_write))
return ERRC;
pos = stell(s);
if_debug2('s', "[s]switch 0x%lx to write at %ld\n",
(ulong) s, pos);
lseek(fd, pos, SEEK_SET); /* pacify OS */
if (modes & s_mode_append) {
sappend_file(s, s->file, s->cbuf, s->cbsize); /* sets position */
} else {
swrite_file(s, s->file, s->cbuf, s->cbsize);
s->position = pos;
}
s->modes = modes;
} else {
if (!(s->file_modes & s_mode_read))
return ERRC;
pos = stell(s);
if_debug2('s', "[s]switch 0x%lx to read at %ld\n",
(ulong) s, pos);
if (sflush(s) < 0)
return ERRC;
lseek(fd, 0L, SEEK_CUR); /* pacify OS */
sread_file(s, s->file, s->cbuf, s->cbsize);
s->modes |= modes & s_mode_append; /* don't lose append info */
s->position = pos;
}
s->file_modes = modes;
return 0;
}
