diff options
Diffstat (limited to 'src/stdio/__stdio_read.c')
-rw-r--r-- | src/stdio/__stdio_read.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/stdio/__stdio_read.c b/src/stdio/__stdio_read.c new file mode 100644 index 0000000..ea675da --- /dev/null +++ b/src/stdio/__stdio_read.c @@ -0,0 +1,24 @@ +#include "stdio_impl.h" +#include <sys/uio.h> + +size_t __stdio_read(FILE *f, unsigned char *buf, size_t len) +{ + struct iovec iov[2] = { + { .iov_base = buf, .iov_len = len - !!f->buf_size }, + { .iov_base = f->buf, .iov_len = f->buf_size } + }; + ssize_t cnt; + + cnt = iov[0].iov_len ? syscall(SYS_readv, f->fd, iov, 2) + : syscall(SYS_read, f->fd, iov[1].iov_base, iov[1].iov_len); + if (cnt <= 0) { + f->flags |= cnt ? F_ERR : F_EOF; + return 0; + } + if (cnt <= iov[0].iov_len) return cnt; + cnt -= iov[0].iov_len; + f->rpos = f->buf; + f->rend = f->buf + cnt; + if (f->buf_size) buf[len-1] = *f->rpos++; + return len; +} |