diff options
| -rw-r--r-- | Libraries/LibC/stdio.cpp | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/Libraries/LibC/stdio.cpp b/Libraries/LibC/stdio.cpp index e59fe96891..0bd0f0e679 100644 --- a/Libraries/LibC/stdio.cpp +++ b/Libraries/LibC/stdio.cpp @@ -92,6 +92,7 @@ private: bool may_use() const { return m_ungotten || m_mode != _IONBF; } bool is_not_empty() const { return m_ungotten || !m_empty; } + size_t buffered_size() const; const u8* begin_dequeue(size_t& available_size) const; void did_dequeue(size_t actual_size); @@ -172,7 +173,20 @@ bool FILE::flush() } if (m_mode & O_RDONLY) { // When open for reading, just drop the buffered data. + size_t had_buffered = m_buffer.buffered_size(); m_buffer.drop(); + // Attempt to reset the underlying file position to what the user + // expects. + int rc = lseek(m_fd, -had_buffered, SEEK_CUR); + if (rc < 0) { + if (errno == ESPIPE) { + // We can't set offset on this file; oh well, the user will just + // have to cope. + errno = 0; + } else { + return false; + } + } } return true; @@ -440,6 +454,19 @@ void FILE::Buffer::drop() m_ungotten = false; } +size_t FILE::Buffer::buffered_size() const +{ + // Note: does not include the ungetc() buffer. + + if (m_empty) + return 0; + + if (m_begin < m_end) + return m_end - m_begin; + else + return m_capacity - (m_begin - m_end); +} + const u8* FILE::Buffer::begin_dequeue(size_t& available_size) const { if (m_ungotten) { |