Form parameter - ytomino/drake GitHub Wiki

The format is "keyword1=value1,keyword2=value2,...". All characters are lower case.

When In_File,

Form (when In_File)	Which locking flag does Create/Open try
"shared=allow", "shared=yes" or "shared=no"	0, FILE_SHARE_READ or FILE_SHARE_WRITE
"shared=read" or default	O_SHLOCK, FILE_SHARE_READ
"shared=deny"	O_EXLOCK, 0

When Out_File or Append_File (or Inout_File of Ada.Direct_IO),

Form (when Out_File or Append_File)	Which locking flag does Create/Open try
"shared=allow", "shared=yes" or "shared=no"	0, FILE_SHARE_READ or FILE_SHARE_WRITE
"shared=read"	O_SHLOCK, FILE_SHARE_READ
"shared=deny" or default	O_EXLOCK, 0

In POSIX, the locking flags are 0 (does not care, allows others to read/write), O_SHLOCK (allows others only to read) or O_EXLOCK (disallows others from reading/writing).

In Windows, the locking flags are the combinations of FILE_SHARE_READ (allows others to read) and FILE_SHARE_WRITE (allows others to write).

Form	What does Create/Open do in that case
"wait=false" or default	raises Task_Error immediately
"wait=true"	waits until the lock has been acquired

Form	What does Create do
"overwrite=false"	fails if the file has existed
"overwrite=true" or default	always create new empty file

Same as shared of Ada.Streams.Stream_IO.

Same as wait of Ada.Streams.Stream_IO.

Same as overwrite of Ada.Streams.Stream_IO.

Same as shared of Ada.Streams.Stream_IO.

Same as wait of Ada.Streams.Stream_IO.

Same as overwrite of Ada.Streams.Stream_IO.

Same as shared of Ada.Streams.Stream_IO.

Same as wait of Ada.Streams.Stream_IO.

Same as overwrite of Ada.Streams.Stream_IO.

Form	What happens on writing
"private=false" or default	the change is shared and saved to the file
"private=true"	the change is local and not visible to others

Same as shared of Ada.Streams.Stream_IO.

Same as wait of Ada.Streams.Stream_IO.

Same as overwrite of Ada.Streams.Stream_IO.

In POSIX, it assumes file contents are encoded as UTF-8.

Form (in POSIX)	Text_IO	Wide_Text_IO	Wide_Wide_Text_IO	In external file
default	UTF-8	UTF-16	UTF-32	UTF-8

In Windows,

Form (in Windows)	Text_IO	Wide_Text_IO	Wide_Wide_Text_IO	In external file
"external=dbcs" or default	UTF-8	UTF-16	UTF-32	Active Code Page
"external=utf-8" or "wcem=8"	UTF-8	UTF-16	UTF-32	UTF-8

In POSIX,

Form (in POSIX)	What does New_Line put
"nl=lf" or default	LF
"nl=cr"	CR
"nl=m"	CR & LF

In Windows,

Form (in Windows)	What does New_Line put
"nl=lf"	LF
"nl=cr"	CR
"nl=m" or default	CR & LF

Form parameter has no effect for other subprograms except Copy_File.

Form	What does Copy_File do
"overwrite=false" or "mode=copy"	fails if the file has existed
"overwrite=true", "mode=overwrite" or default	overwrites the existing file