------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- G N A T . O S _ L I B -- -- -- -- S p e c -- -- -- -- Copyright (C) 1995-2004 Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 2, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- Operating system interface facilities -- This package contains types and procedures for interfacing to the -- underlying OS. It is used by the GNAT compiler and by tools associated -- with the GNAT compiler, and therefore works for the various operating -- systems to which GNAT has been ported. This package will undoubtedly -- grow as new services are needed by various tools. -- This package tends to use fairly low-level Ada in order to not bring -- in large portions of the RTL. For example, functions return access -- to string as part of avoiding functions returning unconstrained types. -- Except where specifically noted, these routines are portable across -- all GNAT implementations on all supported operating systems. with System; with GNAT.Strings; package GNAT.OS_Lib is pragma Elaborate_Body (OS_Lib); subtype String_Access is Strings.String_Access; -- General purpose string access type. Some of the functions in this -- package allocate string results on the heap, and return a value of -- this type. Note that the caller is responsible for freeing this -- String to avoid memory leaks. function "=" (Left, Right : in String_Access) return Boolean renames Strings."="; procedure Free (X : in out String_Access) renames Strings.Free; -- This procedure is provided for freeing returned values of type -- String_Access subtype String_List is Strings.String_List; function "=" (Left, Right : in String_List) return Boolean renames Strings."="; function "&" (Left : String_Access; Right : String_Access) return String_List renames Strings."&"; function "&" (Left : String_Access; Right : String_List) return String_List renames Strings."&"; function "&" (Left : String_List; Right : String_Access) return String_List renames Strings."&"; function "&" (Left : String_List; Right : String_List) return String_List renames Strings."&"; subtype String_List_Access is Strings.String_List_Access; -- General purpose array and pointer for list of string accesses function "=" (Left, Right : in String_List_Access) return Boolean renames Strings."="; procedure Free (Arg : in out String_List_Access) renames Strings.Free; -- Frees the given array and all strings that its elements reference, -- and then sets the argument to null. Provided for freeing returned -- values of this type (including Argument_List_Access). --------------------- -- Time/Date Stuff -- --------------------- type OS_Time is private; -- The OS's notion of time is represented by the private type OS_Time. -- This is the type returned by the File_Time_Stamp functions to obtain -- the time stamp of a specified file. Functions and a procedure (modeled -- after the similar subprograms in package Calendar) are provided for -- extracting information from a value of this type. Although these are -- called GM, the intention is not that they provide GMT times in all -- cases but rather the actual (time-zone independent) time stamp of the -- file (of course in Unix systems, this *is* in GMT form). Invalid_Time : constant OS_Time; -- A special unique value used to flag an invalid time stamp value subtype Year_Type is Integer range 1900 .. 2099; subtype Month_Type is Integer range 1 .. 12; subtype Day_Type is Integer range 1 .. 31; subtype Hour_Type is Integer range 0 .. 23; subtype Minute_Type is Integer range 0 .. 59; subtype Second_Type is Integer range 0 .. 59; -- Declarations similar to those in Calendar, breaking down the time function GM_Year (Date : OS_Time) return Year_Type; function GM_Month (Date : OS_Time) return Month_Type; function GM_Day (Date : OS_Time) return Day_Type; function GM_Hour (Date : OS_Time) return Hour_Type; function GM_Minute (Date : OS_Time) return Minute_Type; function GM_Second (Date : OS_Time) return Second_Type; -- Functions to extract information from OS_Time value function "<" (X, Y : OS_Time) return Boolean; function ">" (X, Y : OS_Time) return Boolean; function ">=" (X, Y : OS_Time) return Boolean; function "<=" (X, Y : OS_Time) return Boolean; -- Basic comparison operators on OS_Time with obvious meanings. Note -- that these have Intrinsic convention, so for example it is not -- permissible to create accesses to any of these functions. procedure GM_Split (Date : OS_Time; Year : out Year_Type; Month : out Month_Type; Day : out Day_Type; Hour : out Hour_Type; Minute : out Minute_Type; Second : out Second_Type); -- Analogous to the routine of similar name in Calendar, takes an OS_Time -- and splits it into its component parts with obvious meanings. ---------------- -- File Stuff -- ---------------- -- These routines give access to the open/creat/close/read/write level -- of I/O routines in the typical C library (these functions are not -- part of the ANSI C standard, but are typically available in all -- systems). See also package Interfaces.C_Streams for access to the -- stream level routines. -- Note on file names. If a file name is passed as type String in any -- of the following specifications, then the name is a normal Ada string -- and need not be NUL-terminated. However, a trailing NUL character is -- permitted, and will be ignored (more accurately, the NUL and any -- characters that follow it will be ignored). type File_Descriptor is new Integer; -- Corresponds to the int file handle values used in the C routines Standin : constant File_Descriptor := 0; Standout : constant File_Descriptor := 1; Standerr : constant File_Descriptor := 2; -- File descriptors for standard input output files Invalid_FD : constant File_Descriptor := -1; -- File descriptor returned when error in opening/creating file; type Mode is (Binary, Text); for Mode'Size use Integer'Size; for Mode use (Binary => 0, Text => 1); -- Used in all the Open and Create calls to specify if the file is to be -- opened in binary mode or text mode. In systems like Unix, this has no -- effect, but in systems capable of text mode translation, the use of -- Text as the mode parameter causes the system to do CR/LF translation -- and also to recognize the DOS end of file character on input. The use -- of Text where appropriate allows programs to take a portable Unix view -- of DOS-format files and process them appropriately. function Open_Read (Name : String; Fmode : Mode) return File_Descriptor; -- Open file Name for reading, returning file descriptor File descriptor -- returned is Invalid_FD if file cannot be opened. function Open_Read_Write (Name : String; Fmode : Mode) return File_Descriptor; -- Open file Name for both reading and writing, returning file -- descriptor. File descriptor returned is Invalid_FD if file cannot be -- opened. function Create_File (Name : String; Fmode : Mode) return File_Descriptor; -- Creates new file with given name for writing, returning file descriptor -- for subsequent use in Write calls. File descriptor returned is -- Invalid_FD if file cannot be successfully created. function Create_Output_Text_File (Name : String) return File_Descriptor; -- Creates new text file with given name suitable to redirect standard -- output, returning file descriptor. File descriptor returned is -- Invalid_FD if file cannot be successfully created. function Create_New_File (Name : String; Fmode : Mode) return File_Descriptor; -- Create new file with given name for writing, returning file descriptor -- for subsequent use in Write calls. This differs from Create_File in -- that it fails if the file already exists. File descriptor returned is -- Invalid_FD if the file exists or cannot be created. Temp_File_Len : constant Integer := 12; -- Length of name returned by Create_Temp_File call (GNAT-XXXXXX & NUL) subtype Temp_File_Name is String (1 .. Temp_File_Len); -- String subtype set by Create_Temp_File procedure Create_Temp_File (FD : out File_Descriptor; Name : out Temp_File_Name); -- Create and open for writing a temporary file in the current working -- directory. The name of the file and the File Descriptor are returned. -- The File Descriptor returned is Invalid_FD in the case of failure. -- No mode parameter is provided. Since this is a temporary file, -- there is no point in doing text translation on it. -- On some OSes, the maximum number of temp files that can be -- created with this procedure may be limited. When the maximum is -- reached, this procedure returns Invalid_FD. On some OSes, there may be -- a race condition between processes trying to create temp files -- at the same time in the same directory using this procedure. procedure Create_Temp_File (FD : out File_Descriptor; Name : out String_Access); -- Create and open for writing a temporary file in the current working -- directory. The name of the file and the File Descriptor are returned. -- No mode parameter is provided. Since this is a temporary file, -- there is no point in doing text translation on it. -- It is the responsibility of the caller to deallocate the access value -- returned in Name. -- This procedure will always succeed if the current working directory -- is writable. If the current working directory is not writable, then -- Invalid_FD is returned for the file descriptor and null for the Name. -- There is no race condition problem between processes trying to -- create temp files at the same time in the same directory. procedure Close (FD : File_Descriptor; Status : out Boolean); -- Close file referenced by FD. Status is False if the underlying service -- failed. Reasons for failure include: disk full, disk quotas exceeded -- and invalid file descriptor (the file may have been closed twice). procedure Close (FD : File_Descriptor); -- Close file referenced by FD. This form is used when the caller -- wants to ignore any possible error (see above for error cases). procedure Delete_File (Name : String; Success : out Boolean); -- Deletes file. Success is set True or False indicating if the delete is -- successful. procedure Rename_File (Old_Name : String; New_Name : String; Success : out Boolean); -- Rename a file. Success is set True or False indicating if the -- rename is successful or not. -- The following defines the mode for the Copy_File procedure below. -- Note that "time stamps and other file attributes" in the descriptions -- below refers to the creation and last modification times, and also -- the file access (read/write/execute) status flags. type Copy_Mode is (Copy, -- Copy the file. It is an error if the target file already exists. -- The time stamps and other file attributes are preserved in the copy. Overwrite, -- If the target file exists, the file is replaced otherwise -- the file is just copied. The time stamps and other file -- attributes are preserved in the copy. Append); -- If the target file exists, the contents of the source file -- is appended at the end. Otherwise the source file is just -- copied. The time stamps and other file attributes are -- are preserved if the destination file does not exist. type Attribute is (Time_Stamps, -- Copy time stamps from source file to target file. All other -- attributes are set to normal default values for file creation. Full, -- All attributes are copied from the source file to the target -- file. This includes the timestamps, and for example also includes -- read/write/execute attributes in Unix systems. None); -- No attributes are copied. All attributes including the time stamp -- values are set to normal default values for file creation. -- Note: The default is Time_Stamps, which corresponds to the normal -- default on Windows style systems. Full corresponds to the typical -- effect of "cp -p" on Unix systems, and None corresponds to the -- typical effect of "cp" on Unix systems. -- Note: Time_Stamps and Full are not supported on VMS and VxWorks procedure Copy_File (Name : String; Pathname : String; Success : out Boolean; Mode : Copy_Mode := Copy; Preserve : Attribute := Time_Stamps); -- Copy a file. Name must designate a single file (no wild cards allowed). -- Pathname can be a filename or directory name. In the latter case Name -- is copied into the directory preserving the same file name. Mode -- defines the kind of copy, see above with the default being a normal -- copy in which the target file must not already exist. Success is set -- to True or False indicating if the copy is successful (depending on -- the specified Mode). -- -- Note: this procedure is only supported to a very limited extent on -- VMS. The only supported mode is Overwrite, and the only supported -- value for Preserve is None, resulting in the default action which -- for Overwrite is to leave attributes unchanged. Furthermore, the -- copy only works for simple text files. procedure Copy_Time_Stamps (Source, Dest : String; Success : out Boolean); -- Copy Source file time stamps (last modification and last access time -- stamps) to Dest file. Source and Dest must be valid filenames, -- furthermore Dest must be writable. Success will be set to True if the -- operation was successful and False otherwise. -- -- Note: this procedure is not supported on VMS and VxWorks. On these -- platforms, Success is always set to False. function Read (FD : File_Descriptor; A : System.Address; N : Integer) return Integer; -- Read N bytes to address A from file referenced by FD. Returned value -- is count of bytes actually read, which can be less than N at EOF. function Write (FD : File_Descriptor; A : System.Address; N : Integer) return Integer; -- Write N bytes from address A to file referenced by FD. The returned -- value is the number of bytes written, which can be less than N if -- a disk full condition was detected. Seek_Cur : constant := 1; Seek_End : constant := 2; Seek_Set : constant := 0; -- Used to indicate origin for Lseek call procedure Lseek (FD : File_Descriptor; offset : Long_Integer; origin : Integer); pragma Import (C, Lseek, "__gnat_lseek"); -- Sets the current file pointer to the indicated offset value, -- relative to the current position (origin = SEEK_CUR), end of -- file (origin = SEEK_END), or start of file (origin = SEEK_SET). function File_Length (FD : File_Descriptor) return Long_Integer; pragma Import (C, File_Length, "__gnat_file_length"); -- Get length of file from file descriptor FD function File_Time_Stamp (Name : String) return OS_Time; -- Given the name of a file or directory, Name, obtains and returns the -- time stamp. This function can be used for an unopened file. -- Returns Invalid_Time is Name doesn't correspond to an existing file. function File_Time_Stamp (FD : File_Descriptor) return OS_Time; -- Get time stamp of file from file descriptor FD -- Returns Invalid_Time is FD doesn't correspond to an existing file. function Normalize_Pathname (Name : String; Directory : String := ""; Resolve_Links : Boolean := True; Case_Sensitive : Boolean := True) return String; -- Returns a file name as an absolute path name, resolving all relative -- directories, and symbolic links. The parameter Directory is a fully -- resolved path name for a directory, or the empty string (the default). -- Name is the name of a file, which is either relative to the given -- directory name, if Directory is non-null, or to the current working -- directory if Directory is null. The result returned is the normalized -- name of the file. For most cases, if two file names designate the same -- file through different paths, Normalize_Pathname will return the same -- canonical name in both cases. However, there are cases when this is -- not true; for example, this is not true in Unix for two hard links -- designating the same file. -- -- On Windows, the returned path will start with a drive letter except -- when Directory is not empty and does not include a drive letter. -- If Directory is empty (the default) and Name is a relative path -- or an absolute path without drive letter, the letter of the current -- drive will start the returned path. If Case_Sensitive is True -- (the default), then this drive letter will be forced to upper case -- ("C:\..."). -- -- If Resolve_Links is set to True, then the symbolic links, on systems -- that support them, will be fully converted to the name of the file -- or directory pointed to. This is slightly less efficient, since it -- requires system calls. -- -- If Name cannot be resolved or is null on entry (for example if there is -- a circularity in symbolic links: A is a symbolic link for B, while B is -- a symbolic link for A), then Normalize_Pathname returns an empty string. -- -- In VMS, if Name follows the VMS syntax file specification, it is first -- converted into Unix syntax. If the conversion fails, Normalize_Pathname -- returns an empty string. -- -- For case-sensitive file systems, the value of Case_Sensitive parameter -- is ignored. In systems that have a non case-sensitive file system like -- Windows and OpenVMS, if this parameter is set OFF, then the result -- is returned folded to lower case, this allows to checks if two files -- are the same by applying this function to their names and by comparing -- the results of these calls. If Case_Sensitive is ON, this function does -- not change the casing of file and directory names. function Is_Absolute_Path (Name : String) return Boolean; -- Returns True if Name is an absolute path name, i.e. it designates -- a file or a directory absolutely, rather than relative to another -- directory. function Is_Regular_File (Name : String) return Boolean; -- Determines if the given string, Name, is the name of an existing -- regular file. Returns True if so, False otherwise. Name may be an -- absolute path name or a relative path name, including a simple file -- name. If it is a relative path name, it is relative to the current -- working directory. function Is_Directory (Name : String) return Boolean; -- Determines if the given string, Name, is the name of a directory. -- Returns True if so, False otherwise. Name may be an absolute path -- name or a relative path name, including a simple file name. If it is -- a relative path name, it is relative to the current working directory. function Is_Readable_File (Name : String) return Boolean; -- Determines if the given string, Name, is the name of an existing -- file that is readable. Returns True if so, False otherwise. Note -- that this function simply interrogates the file attributes (e.g. -- using the C function stat), so it does not indicate a situation -- in which a file may not actually be readable due to some other -- process having exclusive access. function Is_Writable_File (Name : String) return Boolean; -- Determines if the given string, Name, is the name of an existing -- file that is writable. Returns True if so, False otherwise. Note -- that this function simply interrogates the file attributes (e.g. -- using the C function stat), so it does not indicate a situation -- in which a file may not actually be writeable due to some other -- process having exclusive access. function Is_Symbolic_Link (Name : String) return Boolean; -- Determines if the given string, Name, is the path of a symbolic link -- on systems that support it. Returns True if so, False if the path -- is not a symbolic link or if the system does not support symbolic links. -- -- A symbolic link is an indirect pointer to a file; its directory entry -- contains the name of the file to which it is linked. Symbolic links may -- span file systems and may refer to directories. function Locate_Exec_On_Path (Exec_Name : String) return String_Access; -- Try to locate an executable whose name is given by Exec_Name in the -- directories listed in the environment Path. If the Exec_Name doesn't -- have the executable suffix, it will be appended before the search. -- Otherwise works like Locate_Regular_File below. -- -- Note that this function allocates some memory for the returned value. -- This memory needs to be deallocated after use. function Locate_Regular_File (File_Name : String; Path : String) return String_Access; -- Try to locate a regular file whose name is given by File_Name in the -- directories listed in Path. If a file is found, its full pathname is -- returned; otherwise, a null pointer is returned. If the File_Name given -- is an absolute pathname, then Locate_Regular_File just checks that the -- file exists and is a regular file. Otherwise, if the File_Name given -- includes directory information, Locate_Regular_File first checks if -- the file exists relative to the current directory. If it does not, -- or if the File_Name given is a simple file name, the Path argument is -- parsed according to OS conventions, and for each directory in the Path -- a check is made if File_Name is a relative pathname of a regular file -- from that directory. -- -- Note that this function allocates some memory for the returned value. -- This memory needs to be deallocated after use. function Get_Debuggable_Suffix return String_Access; -- Return the debuggable suffix convention. Usually this is the same as -- the convention for Get_Executable_Suffix. The result is allocated on -- the heap and should be freed when no longer needed to avoid storage -- leaks. function Get_Executable_Suffix return String_Access; -- Return the executable suffix convention. The result is allocated on -- the heap and should be freed when no longer needed to avoid storage -- leaks. function Get_Object_Suffix return String_Access; -- Return the object suffix convention. The result is allocated on the -- heap and should be freed when no longer needed to avoid storage leaks. -- The following section contains low-level routines using addresses to -- pass file name and executable name. In each routine the name must be -- Nul-Terminated. For complete documentation refer to the equivalent -- routine (using String in place of C_File_Name) defined above. subtype C_File_Name is System.Address; -- This subtype is used to document that a parameter is the address -- of a null-terminated string containing the name of a file. -- All the following functions need comments ??? function Open_Read (Name : C_File_Name; Fmode : Mode) return File_Descriptor; function Open_Read_Write (Name : C_File_Name; Fmode : Mode) return File_Descriptor; function Create_File (Name : C_File_Name; Fmode : Mode) return File_Descriptor; function Create_New_File (Name : C_File_Name; Fmode : Mode) return File_Descriptor; procedure Delete_File (Name : C_File_Name; Success : out Boolean); procedure Rename_File (Old_Name : C_File_Name; New_Name : C_File_Name; Success : out Boolean); procedure Copy_File (Name : C_File_Name; Pathname : C_File_Name; Success : out Boolean; Mode : Copy_Mode := Copy; Preserve : Attribute := Time_Stamps); procedure Copy_Time_Stamps (Source, Dest : C_File_Name; Success : out Boolean); function File_Time_Stamp (Name : C_File_Name) return OS_Time; -- Returns Invalid_Time is Name doesn't correspond to an existing file. function Is_Regular_File (Name : C_File_Name) return Boolean; function Is_Directory (Name : C_File_Name) return Boolean; function Is_Readable_File (Name : C_File_Name) return Boolean; function Is_Writable_File (Name : C_File_Name) return Boolean; function Is_Symbolic_Link (Name : C_File_Name) return Boolean; function Locate_Regular_File (File_Name : C_File_Name; Path : C_File_Name) return String_Access; ------------------ -- Subprocesses -- ------------------ subtype Argument_List is String_List; -- Type used for argument list in call to Spawn. The lower bound -- of the array should be 1, and the length of the array indicates -- the number of arguments. subtype Argument_List_Access is String_List_Access; -- Type used to return Argument_List without dragging in secondary stack. -- Note that there is a Free procedure declared for this subtype which -- frees the array and all referenced strings. procedure Normalize_Arguments (Args : in out Argument_List); -- Normalize all arguments in the list. This ensure that the argument list -- is compatible with the running OS and will works fine with Spawn and -- Non_Blocking_Spawn for example. If Normalize_Arguments is called twice -- on the same list it will do nothing the second time. Note that Spawn -- and Non_Blocking_Spawn call Normalize_Arguments automatically, but -- since there is a guarantee that a second call does nothing, this -- internal call will have no effect if Normalize_Arguments is called -- before calling Spawn. The call to Normalize_Arguments assumes that -- the individual referenced arguments in Argument_List are on the heap, -- and may free them and reallocate if they are modified. procedure Spawn (Program_Name : String; Args : Argument_List; Success : out Boolean); -- The first parameter of function Spawn is the name of the executable. -- The second parameter contains the arguments to be passed to the -- program. Success is False if the named program could not be spawned -- or its execution completed unsuccessfully. Note that the caller will -- be blocked until the execution of the spawned program is complete. -- For maximum portability, use a full path name for the Program_Name -- argument. On some systems (notably Unix systems) a simple file -- name may also work (if the executable can be located in the path). -- -- "Spawn" should not be used in tasking applications. -- -- Note: Arguments in Args that contain spaces and/or quotes such as -- "--GCC=gcc -v" or "--GCC=""gcc -v""" are not portable across all -- operating systems, and would not have the desired effect if they -- were passed directly to the operating system. To avoid this problem, -- Spawn makes an internal call to Normalize_Arguments, which ensures -- that such arguments are modified in a manner that ensures that the -- desired effect is obtained on all operating systems. The caller may -- call Normalize_Arguments explicitly before the call (e.g. to print -- out the exact form of arguments passed to the operating system). In -- this case the guarantee a second call to Normalize_Arguments has no -- effect ensures that the internal call will not affect the result. -- Note that the implicit call to Normalize_Arguments may free and -- reallocate some of the individual arguments. -- -- This function will always set Success to False under VxWorks and -- other similar operating systems which have no notion of the concept -- of a dynamically executable file. function Spawn (Program_Name : String; Args : Argument_List) return Integer; -- Similar to the above procedure, but returns the actual status returned -- by the operating system, or -1 under VxWorks and any other similar -- operating systems which have no notion of separately spawnable programs. -- -- "Spawn" should not be used in tasking applications. -- type Process_Id is private; -- A private type used to identify a process activated by the following -- non-blocking call. The only meaningful operation on this type is a -- comparison for equality. Invalid_Pid : constant Process_Id; -- A special value used to indicate errors, as described below. function Non_Blocking_Spawn (Program_Name : String; Args : Argument_List) return Process_Id; -- This is a non blocking call. The Process_Id of the spawned process -- is returned. Parameters are to be used as in Spawn. If Invalid_Id -- is returned the program could not be spawned. -- -- "Non_Blocking_Spawn" should not be used in tasking applications. -- -- This function will always return Invalid_Id under VxWorks, since -- there is no notion of executables under this OS. procedure Wait_Process (Pid : out Process_Id; Success : out Boolean); -- Wait for the completion of any of the processes created by previous -- calls to Non_Blocking_Spawn. The caller will be suspended until one -- of these processes terminates (normally or abnormally). If any of -- these subprocesses terminates prior to the call to Wait_Process (and -- has not been returned by a previous call to Wait_Process), then the -- call to Wait_Process is immediate. Pid identifies the process that -- has terminated (matching the value returned from Non_Blocking_Spawn). -- Success is set to True if this sub-process terminated successfully. -- If Pid = Invalid_Id, there were no subprocesses left to wait on. -- -- This function will always set success to False under VxWorks, since -- there is no notion of executables under this OS. function Argument_String_To_List (Arg_String : String) return Argument_List_Access; -- Take a string that is a program and its arguments and parse it into -- an Argument_List. Note that the result is allocated on the heap, and -- must be freed by the programmer (when it is no longer needed) to avoid -- memory leaks. ------------------- -- Miscellaneous -- ------------------- function Getenv (Name : String) return String_Access; -- Get the value of the environment variable. Returns an access -- to the empty string if the environment variable does not exist -- or has an explicit null value (in some operating systems these -- are distinct cases, in others they are not; this interface -- abstracts away that difference. The argument is allocated on -- the heap (even in the null case), and needs to be freed explicitly -- when no longer needed to avoid memory leaks. procedure Setenv (Name : String; Value : String); -- Set the value of the environment variable Name to Value. This call -- modifies the current environment, but does not modify the parent -- process environment. After a call to Setenv, Getenv (Name) will -- always return a String_Access referencing the same String as Value. -- This is true also for the null string case (the actual effect may -- be to either set an explicit null as the value, or to remove the -- entry, this is operating system dependent). Note that any following -- calls to Spawn will pass an environment to the spawned process that -- includes the changes made by Setenv calls. This procedure is not -- available under VMS. procedure OS_Exit (Status : Integer); pragma Import (C, OS_Exit, "__gnat_os_exit"); pragma No_Return (OS_Exit); -- Exit to OS with given status code (program is terminated) procedure OS_Abort; pragma Import (C, OS_Abort, "abort"); pragma No_Return (OS_Abort); -- Exit to OS signalling an abort (traceback or other appropriate -- diagnostic information should be given if possible, or entry made -- to the debugger if that is possible). function Errno return Integer; pragma Import (C, Errno, "__get_errno"); -- Return the task-safe last error number. procedure Set_Errno (Errno : Integer); pragma Import (C, Set_Errno, "__set_errno"); -- Set the task-safe error number. Directory_Separator : constant Character; -- The character that is used to separate parts of a pathname. Path_Separator : constant Character; -- The character to separate paths in an environment variable value. private pragma Import (C, Path_Separator, "__gnat_path_separator"); pragma Import (C, Directory_Separator, "__gnat_dir_separator"); type OS_Time is new Long_Integer; -- Type used for timestamps in the compiler. This type is used to -- hold time stamps, but may have a different representation than -- C's time_t. This type needs to match the declaration of OS_Time -- in adaint.h. -- Add pragma Inline statements for comparison operations on OS_Time. -- It would actually be nice to use pragma Import (Intrinsic) here, -- but this was not properly supported till GNAT 3.15a, so that would -- cause bootstrap path problems. To be changed later ??? Invalid_Time : constant OS_Time := -1; -- This value should match the return valud by __gnat_file_time_* pragma Inline ("<"); pragma Inline (">"); pragma Inline ("<="); pragma Inline (">="); type Process_Id is new Integer; Invalid_Pid : constant Process_Id := -1; end GNAT.OS_Lib;