diff options
Diffstat (limited to 'butl/fdstream')
| -rw-r--r-- | butl/fdstream | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/butl/fdstream b/butl/fdstream index 21df3f8..23cc58c 100644 --- a/butl/fdstream +++ b/butl/fdstream @@ -7,6 +7,10 @@ #include <istream> #include <ostream> +#include <cstdint> // uint16_t + +#include <butl/path> +#include <butl/filesystem> // permissions namespace butl { @@ -73,7 +77,7 @@ namespace butl private: int fd_ = -1; - char buf_[2048]; + char buf_[4096]; }; // File descriptor translation mode. It has the same semantics as the @@ -129,6 +133,49 @@ namespace butl bool is_open () const {return buf_.is_open ();} }; + // File open flags. + // + enum class fdopen_mode: std::uint16_t + { + in = 0x01, // Open for reading. + out = 0x02, // Open for writing. + append = 0x04, // Seek to the end of file before each write. + truncate = 0x08, // Discard the file contents on open. + create = 0x10, // Create a file if not exists. + exclusive = 0x20, // Fail if the file exists and the create flag is set. + binary = 0x40, // Set binary translation mode. + + none = 0 // Usefull when build the mode incrementally. + }; + + fdopen_mode operator& (fdopen_mode, fdopen_mode); + fdopen_mode operator| (fdopen_mode, fdopen_mode); + fdopen_mode operator&= (fdopen_mode&, fdopen_mode); + fdopen_mode operator|= (fdopen_mode&, fdopen_mode); + + // Open a file returning the file descriptor on success and throwing + // std::system_error otherwise. + // + // The mode argument should have at least one of the in or out flags set. + // The append and truncate flags are meaningless in the absense of the out + // flag and are ignored without it. The exclusive flag is meaningless in the + // absense of the create flag and is ignored without it. Note also that if + // the exclusive flag is specified then a dangling symbolic link is treated + // as an existing file. + // + // The permissions argument is taken into account only if the file is + // created. Note also that permissions can be adjusted while being set in a + // way specific for the OS. On POSIX systems they are modified with the + // process' umask, so effective permissions are permissions & ~umask. On + // Windows permissions other than ru and wu are unlikelly to have effect. + // + int + fdopen (const path&, + fdopen_mode, + permissions = permissions::ru | permissions::wu | + permissions::rg | permissions::wg | + permissions::ro | permissions::wo); + // Set the translation mode for the file descriptor. Return the previous // mode on success, throw std::system_error otherwise. // @@ -161,4 +208,6 @@ namespace butl fdnull () noexcept; } +#include <butl/fdstream.ixx> + #endif // BUTL_FDSTREAM |