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#include "__stdio.h"
#include <atomic.h>
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
extern void __libc_init_io(void);
void *__libc_force_io_init = (void *)__libc_init_io;
size_t fwrite_unlocked(const void *restrict ptr, size_t size, size_t nitems, FILE *restrict stream)
{
size_t total_bytes;
size_t written = 0;
const char *data = (const char *)ptr;
if (ptr == NULL || stream == NULL || size == 0) {
if (size == 0) {
return nitems;
}
errno = EINVAL;
return 0;
}
if (__builtin_mul_overflow(size, nitems, &total_bytes)) {
errno = EOVERFLOW;
return 0;
}
if ((stream->flags & O_ACCMODE) == O_RDONLY) {
errno = EBADF;
return 0;
}
if (stream->flags & _IO_ERR) {
errno = EIO;
return 0;
}
/* Handle in-memory buffer case (e.g., string streams) */
if (stream->fd == -1 && stream->buf != NULL) {
size_t space_left = (stream->buf_size > stream->buf_len) ?
stream->buf_size - stream->buf_len - 1 /* Reserve for '\0' */
:
0;
if (space_left == 0) {
return 0;
}
size_t to_copy = (total_bytes < space_left) ? total_bytes : space_left;
if (to_copy > 0) {
memcpy(stream->buf + stream->buf_len, data, to_copy);
stream->buf_len += to_copy;
}
return (to_copy == total_bytes) ? nitems : to_copy / size;
}
if (stream->type != _IONBF && stream->buf == NULL) {
errno = EIO;
return 0;
}
/* Unbuffered mode: direct write */
if (stream->type == _IONBF) {
ssize_t result = write(stream->fd, data, total_bytes);
if (result < 0) {
stream->flags |= _IO_ERR;
return 0;
}
return (result == (ssize_t)total_bytes) ? nitems : result / size;
}
size_t remaining = total_bytes;
while (remaining > 0) {
size_t space_available = stream->buf_size - stream->buf_len;
if (space_available == 0) {
if (fflush_unlocked(stream) != 0) {
return written / size;
}
space_available = stream->buf_size;
}
size_t to_copy = (remaining < space_available) ? remaining : space_available;
memcpy(stream->buf + stream->buf_len, data + written, to_copy);
stream->buf_len += to_copy;
written += to_copy;
remaining -= to_copy;
/* Line-buffered: flush on newline in the copied chunk */
if (stream->type == _IOLBF) {
char *newline_pos = memchr(stream->buf + stream->buf_len - to_copy, '\n', to_copy);
if (newline_pos != NULL) {
if (fflush_unlocked(stream) != 0) {
return written / size;
}
}
} else if (stream->type == _IOFBF && stream->buf_len == stream->buf_size) {
/* Full-buffered: flush when buffer is full */
if (fflush_unlocked(stream) != 0) {
return written / size;
}
}
}
return (written == total_bytes) ? nitems : written / size;
}
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