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#include <bdls_filesystemutil_uniximputil.h>
Public Types | |
| typedef int | FileDescriptor |
| typedef UNIX_INTERFACE::off_t | Offset |
Static Public Member Functions | |
| static Offset | getFileSize (FileDescriptor descriptor) |
| static int | getLastModificationTime (bdlt::Datetime *time, FileDescriptor descriptor) |
This component-private utility struct provides a namespace for a suite of functions that FilesystemUtil uses as implementation details. These functions have a UNIX_INTERFACE template parameter, which provides access to the entities that large-file environment Unix systems declare, and that the function implementations need.
Note that, on some Unix platforms and some build configurations, the stat struct does not have an st_mtime field, and st_mtime is a macro that emulates the access of the field. Similarly, on some Unix platforms and some build configurations, the stat structure does not have an st_mtim field or the st_mtim struct does not have a tv_nsec (or, for some versions of Solaris, __tv_nsec) field, in which case the get_st_mtim_nsec function returns zero. For more information, please see the specification of the sys/stat.h header from IEEE Std 1003.1-2017, which provides information about the evolution of the stat struct in the POSIX specification (https://pubs.opengroup.org/onlinepubs/9699919799.2018edition/).
The program is ill-formed unless the specified UNIX_INTERFACE is a class type that meets the following requirements:
UNIX_INTERFACE::off_t is a type alias to the off_t type provided by the sys/types.h header. UNIX_INTERFACE::stat is a type alias to the stat type provided by the sys/stat.h header. UNIX_INTERFACE::time_t is a type alias to the time_t type provided by the sys/types.h header. UNIX_INTERFACE::get_st_mtim_nsec is a public, static member function that has long (const stat& stat) type and whose contract is to return the value of the st_mtim.tv_nsec field of the specified stat struct. UNIX_INTERFACE::get_st_mtime is a public, static member function that has time_t (const stat& stat) type and whose contract is to return the value of the st_mtime field of the specified stat struct. UNIX_INTERFACE::get_st_size is a public, static member function that has off_t (const stat& stat) type and whose contract is to return the value of the st_size field of the specified stat struct. Note that this function is required in order to access the data members of a stat struct in a manner consistent with the requirements of get_st_mtime. UNIX_INTERFACE::fstat is a public, static member function that has int (int fildes, stat *buf) type and whose contract is to return the result of ::fstat(fildes, buf), where ::fstat is the function provided by the sys/stat.h header. See Component bdls_filesystemutil_uniximputil
| typedef int bdls::FilesystemUtil_UnixImpUtil< UNIX_INTERFACE >::FileDescriptor |
| typedef UNIX_INTERFACE::off_t bdls::FilesystemUtil_UnixImpUtil< UNIX_INTERFACE >::Offset |
| static Offset bdls::FilesystemUtil_UnixImpUtil< UNIX_INTERFACE >::getFileSize | ( | FileDescriptor | descriptor | ) | [static] |
Return the size, in bytes, of the file with the specified descriptor, or a negative value if an error occurs.
| static int bdls::FilesystemUtil_UnixImpUtil< UNIX_INTERFACE >::getLastModificationTime | ( | bdlt::Datetime * | time, | |
| FileDescriptor | descriptor | |||
| ) | [static] |
Load into the specified time the last modification time of the file with the specified descriptor, as reported by the filesystem. Return 0 on success, and a non-zero value otherwise. Note that the time is reported in UTC.
1.7.1