diff options
Diffstat (limited to 'butl/fdstream')
| -rw-r--r-- | butl/fdstream | 51 |
1 files changed, 43 insertions, 8 deletions
diff --git a/butl/fdstream b/butl/fdstream index 3fb52f7..3ed104f 100644 --- a/butl/fdstream +++ b/butl/fdstream @@ -30,7 +30,7 @@ namespace butl class LIBBUTL_EXPORT auto_fd { public: - auto_fd (nullfd_t = nullfd): fd_ (-1) {} + auto_fd (nullfd_t = nullfd) noexcept: fd_ (-1) {} explicit auto_fd (int fd) noexcept: fd_ (fd) {} @@ -41,17 +41,22 @@ namespace butl auto_fd (const auto_fd&) = delete; auto_fd& operator= (const auto_fd&) = delete; - ~auto_fd () noexcept {reset ();} + ~auto_fd () noexcept; int get () const noexcept {return fd_;} - int - release () noexcept; - void reset (int fd = -1) noexcept; + int + release () noexcept + { + int r (fd_); + fd_ = -1; + return r; + } + // Close an open file descriptor. Throw ios::failure on the underlying OS // error. Reset the descriptor to -1 whether the exception is thrown or // not. @@ -151,7 +156,10 @@ namespace butl // // The text/binary flags have the same semantics as those in std::fstream. // Specifically, this is a noop for POSIX systems where the two modes are - // the same. + // the same. On Windows, when reading in the text mode the sequence of 0xD, + // 0xA characters is translated into the single OxA character and 0x1A is + // interpreted as EOF. When writing in the text mode the OxA character is + // translated into the 0xD, 0xA sequence. // // The skip flag instructs the stream to skip to the end before closing the // file descriptor. This is primarily useful when working with pipes where @@ -505,8 +513,17 @@ namespace butl LIBBUTL_EXPORT auto_fd fddup (int fd); - // Set the translation mode for the file descriptor. Return the previous - // mode on success, throw ios::failure otherwise. + // Set the translation mode for the file descriptor. Throw invalid_argument + // for an invalid combination of flags. Return the previous mode on success, + // throw ios::failure otherwise. + // + // The text and binary flags are mutually exclusive on Windows. Due to + // implementation details at least one of them should be specified. On POSIX + // system the two modes are the same and so no check is performed. + // + // The blocking and non-blocking flags are mutually exclusive on POSIX + // system. Non-blocking mode is not supported on Windows and so the blocking + // mode is assumed regardless of the flags. // LIBBUTL_EXPORT fdstream_mode fdmode (int, fdstream_mode); @@ -558,6 +575,24 @@ namespace butl LIBBUTL_EXPORT int fdnull (bool temp = false) noexcept; #endif + + struct fdpipe + { + auto_fd in; + auto_fd out; + }; + + // Create a pipe. Throw ios::failure on the underlying OS error. By default + // both ends of the pipe are opened in the text mode. Pass the binary flag + // to instead open them in the binary mode. Passing a mode other than none + // or binary is illegal. + // + // Note that on Windows both ends of the created pipe are not inheritable. + // In particular, the process class that uses fdpipe underneath makes the + // appropriate end of pipe (the one being passed to the child) inheritable. + // + LIBBUTL_EXPORT fdpipe + fdopen_pipe (fdopen_mode = fdopen_mode::none); } #include <butl/fdstream.ixx> |