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#include <stdlib.h>
#include <string.h>
#include "../include/libstream.h"
int get_flags(const char *mode)
{
int flags;
if (strcmp(mode, "r") == 0)
{
flags = O_RDONLY;
}
else if (strcmp(mode, "r+") == 0)
{
flags = O_RDWR;
}
else if (strcmp(mode, "w") == 0)
{
flags = O_WRONLY | O_TRUNC | O_CREAT;
}
else
{
flags = O_RDWR | O_TRUNC | O_CREAT;
}
return flags;
}
struct stream *lbs_fopen(const char *path, const char *mode)
{
int fd = open(path, get_flags(mode));
return lbs_fdopen(fd, mode);
}
struct stream *lbs_fdopen(int fd, const char *mode)
{
if (fd == -1)
{
return NULL;
}
struct stream *s = malloc(sizeof(struct stream));
if (s == NULL)
{
return NULL;
}
s->flags = get_flags(mode);
s->error = 0;
s->fd = fd;
if (isatty(fd))
{
s->buffering_mode = STREAM_LINE_BUFFERED;
}
else
{
s->buffering_mode = STREAM_BUFFERED;
}
s->buffered_size = 0;
s->already_read = 0;
return s;
}
int lbs_fflush(struct stream *stream)
{
if (stream == NULL || stream->buffered_size == 0)
{
return 0;
}
if (stream->io_operation == STREAM_READING)
{
if (!stream_readable(stream))
{
stream->error = 1;
return LBS_EOF;
}
if (stream_remaining_buffered(stream) != 0
&& lseek(stream->fd, -stream_remaining_buffered(stream), SEEK_CUR)
== -1)
{
stream->error = 1;
return LBS_EOF;
}
stream->buffered_size = 0;
stream->already_read = 0;
}
else
{
if (!stream_writable(stream))
{
stream->error = 1;
return LBS_EOF;
}
ssize_t w;
if ((w = write(stream->fd, stream->buffer, stream->buffered_size))
== -1)
{
stream->error = 1;
return LBS_EOF;
}
stream->buffered_size = 0;
stream->already_read = 0;
}
return 0;
}
int lbs_fclose(struct stream *stream)
{
if (stream == NULL)
{
return 1;
}
lbs_fflush(stream);
if (close(stream->fd) == -1)
{
return 1;
}
free(stream);
return 0;
}
int lbs_fputc(int c, struct stream *stream)
{
if (!stream_writable(stream))
{
stream->error = 1;
return -1;
}
if (stream->io_operation == STREAM_READING)
{
if (lbs_fflush(stream) != 0)
{
return -1;
}
stream->buffered_size = 0;
stream->already_read = 0;
}
stream->io_operation = STREAM_WRITING;
if (stream_unused_buffer_space(stream) == 0
|| stream->buffering_mode == STREAM_UNBUFFERED)
{
if (lbs_fflush(stream) != 0)
{
return -1;
}
}
stream->buffer[stream->buffered_size] = c;
stream->buffered_size++;
if (stream_unused_buffer_space(stream) == 0
|| stream->buffering_mode == STREAM_UNBUFFERED
|| (stream->buffering_mode == STREAM_LINE_BUFFERED && c == '\n'))
{
if (lbs_fflush(stream) != 0)
{
return -1;
}
}
return c;
}
int refill_buffer(struct stream *stream)
{
stream->already_read = 0;
ssize_t r;
if ((r = read(stream->fd, stream->buffer, LBS_BUFFER_SIZE)) == -1)
{
stream->error = 1;
return -1;
}
if (r == 0)
{
return -1;
}
stream->buffered_size = r;
return r;
}
int lbs_fgetc(struct stream *stream)
{
if (!stream_readable(stream))
{
stream->error = 1;
return -1;
}
if (stream->io_operation == STREAM_WRITING)
{
if (lbs_fflush(stream) != 0)
{
stream->error = 1;
return -1;
}
stream->already_read = 0;
}
stream->io_operation = STREAM_READING;
if (stream_remaining_buffered(stream) == 0)
{
int r;
if ((r = refill_buffer(stream)) == -1)
{
stream->error = 1;
return -1;
}
}
int res = stream->buffer[stream->already_read++];
unsigned char c = res;
return c;
}
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