1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . O S _ L I B --
9 -- Copyright (C) 1995-2007, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 -- Operating system interface facilities
36 -- This package contains types and procedures for interfacing to the
37 -- underlying OS. It is used by the GNAT compiler and by tools associated
38 -- with the GNAT compiler, and therefore works for the various operating
39 -- systems to which GNAT has been ported. This package will undoubtedly grow
40 -- as new services are needed by various tools.
42 -- This package tends to use fairly low-level Ada in order to not bring in
43 -- large portions of the RTL. For example, functions return access to string
44 -- as part of avoiding functions returning unconstrained types.
46 -- Except where specifically noted, these routines are portable across all
47 -- GNAT implementations on all supported operating systems.
49 -- Note: this package is in the System hierarchy so that it can be directly
50 -- be used by other predefined packages. User access to this package is via
51 -- a renaming of this package in GNAT.OS_Lib (file g-os_lib.ads).
56 package System.OS_Lib is
57 pragma Elaborate_Body (OS_Lib);
59 -----------------------
60 -- String Operations --
61 -----------------------
63 -- These are reexported from package Strings (which was introduced to
64 -- avoid different packages declarting different types unnecessarily).
65 -- See package System.Strings for details.
67 subtype String_Access is Strings.String_Access;
69 function "=" (Left, Right : String_Access) return Boolean
72 procedure Free (X : in out String_Access) renames Strings.Free;
74 subtype String_List is Strings.String_List;
76 function "=" (Left, Right : String_List) return Boolean
79 function "&" (Left : String_Access; Right : String_Access)
80 return String_List renames Strings."&";
81 function "&" (Left : String_Access; Right : String_List)
82 return String_List renames Strings."&";
83 function "&" (Left : String_List; Right : String_Access)
84 return String_List renames Strings."&";
85 function "&" (Left : String_List; Right : String_List)
86 return String_List renames Strings."&";
88 subtype String_List_Access is Strings.String_List_Access;
90 function "=" (Left, Right : String_List_Access) return Boolean
93 procedure Free (Arg : in out String_List_Access)
100 type OS_Time is private;
101 -- The OS's notion of time is represented by the private type OS_Time.
102 -- This is the type returned by the File_Time_Stamp functions to obtain
103 -- the time stamp of a specified file. Functions and a procedure (modeled
104 -- after the similar subprograms in package Calendar) are provided for
105 -- extracting information from a value of this type. Although these are
106 -- called GM, the intention is not that they provide GMT times in all
107 -- cases but rather the actual (time-zone independent) time stamp of the
108 -- file (of course in Unix systems, this *is* in GMT form).
110 Invalid_Time : constant OS_Time;
111 -- A special unique value used to flag an invalid time stamp value
113 subtype Year_Type is Integer range 1900 .. 2099;
114 subtype Month_Type is Integer range 1 .. 12;
115 subtype Day_Type is Integer range 1 .. 31;
116 subtype Hour_Type is Integer range 0 .. 23;
117 subtype Minute_Type is Integer range 0 .. 59;
118 subtype Second_Type is Integer range 0 .. 59;
119 -- Declarations similar to those in Calendar, breaking down the time
121 function Current_Time return OS_Time;
122 -- Return the system clock value as OS_Time
124 function GM_Year (Date : OS_Time) return Year_Type;
125 function GM_Month (Date : OS_Time) return Month_Type;
126 function GM_Day (Date : OS_Time) return Day_Type;
127 function GM_Hour (Date : OS_Time) return Hour_Type;
128 function GM_Minute (Date : OS_Time) return Minute_Type;
129 function GM_Second (Date : OS_Time) return Second_Type;
130 -- Functions to extract information from OS_Time value
132 function "<" (X, Y : OS_Time) return Boolean;
133 function ">" (X, Y : OS_Time) return Boolean;
134 function ">=" (X, Y : OS_Time) return Boolean;
135 function "<=" (X, Y : OS_Time) return Boolean;
136 -- Basic comparison operators on OS_Time with obvious meanings. Note that
137 -- these have Intrinsic convention, so for example it is not permissible
138 -- to create accesses to any of these functions.
142 Year : out Year_Type;
143 Month : out Month_Type;
145 Hour : out Hour_Type;
146 Minute : out Minute_Type;
147 Second : out Second_Type);
148 -- Analogous to the Split routine in Ada.Calendar, takes an OS_Time
149 -- and provides a representation of it as a set of component parts,
150 -- to be interpreted as a date point in UTC.
156 -- These routines give access to the open/creat/close/read/write level of
157 -- I/O routines in the typical C library (these functions are not part of
158 -- the ANSI C standard, but are typically available in all systems). See
159 -- also package Interfaces.C_Streams for access to the stream level
162 -- Note on file names. If a file name is passed as type String in any of
163 -- the following specifications, then the name is a normal Ada string and
164 -- need not be NUL-terminated. However, a trailing NUL character is
165 -- permitted, and will be ignored (more accurately, the NUL and any
166 -- characters that follow it will be ignored).
168 type File_Descriptor is new Integer;
169 -- Corresponds to the int file handle values used in the C routines
171 Standin : constant File_Descriptor := 0;
172 Standout : constant File_Descriptor := 1;
173 Standerr : constant File_Descriptor := 2;
174 -- File descriptors for standard input output files
176 Invalid_FD : constant File_Descriptor := -1;
177 -- File descriptor returned when error in opening/creating file;
179 type Mode is (Binary, Text);
180 for Mode'Size use Integer'Size;
181 for Mode use (Binary => 0, Text => 1);
182 -- Used in all the Open and Create calls to specify if the file is to be
183 -- opened in binary mode or text mode. In systems like Unix, this has no
184 -- effect, but in systems capable of text mode translation, the use of
185 -- Text as the mode parameter causes the system to do CR/LF translation
186 -- and also to recognize the DOS end of file character on input. The use
187 -- of Text where appropriate allows programs to take a portable Unix view
188 -- of DOS-format files and process them appropriately.
192 Fmode : Mode) return File_Descriptor;
193 -- Open file Name for reading, returning file descriptor File descriptor
194 -- returned is Invalid_FD if file cannot be opened.
196 function Open_Read_Write
198 Fmode : Mode) return File_Descriptor;
199 -- Open file Name for both reading and writing, returning file descriptor.
200 -- File descriptor returned is Invalid_FD if file cannot be opened.
204 Fmode : Mode) return File_Descriptor;
205 -- Creates new file with given name for writing, returning file descriptor
206 -- for subsequent use in Write calls. File descriptor returned is
207 -- Invalid_FD if file cannot be successfully created.
209 function Create_Output_Text_File (Name : String) return File_Descriptor;
210 -- Creates new text file with given name suitable to redirect standard
211 -- output, returning file descriptor. File descriptor returned is
212 -- Invalid_FD if file cannot be successfully created.
214 function Create_New_File
216 Fmode : Mode) return File_Descriptor;
217 -- Create new file with given name for writing, returning file descriptor
218 -- for subsequent use in Write calls. This differs from Create_File in
219 -- that it fails if the file already exists. File descriptor returned is
220 -- Invalid_FD if the file exists or cannot be created.
222 Temp_File_Len : constant Integer := 12;
223 -- Length of name returned by Create_Temp_File call (GNAT-XXXXXX & NUL)
225 subtype Temp_File_Name is String (1 .. Temp_File_Len);
226 -- String subtype set by Create_Temp_File
228 procedure Create_Temp_File
229 (FD : out File_Descriptor;
230 Name : out Temp_File_Name);
231 -- Create and open for writing a temporary file in the current working
232 -- directory. The name of the file and the File Descriptor are returned.
233 -- The File Descriptor returned is Invalid_FD in the case of failure. No
234 -- mode parameter is provided. Since this is a temporary file, there is no
235 -- point in doing text translation on it.
237 -- On some OSes, the maximum number of temp files that can be created with
238 -- this procedure may be limited. When the maximum is reached, this
239 -- procedure returns Invalid_FD. On some OSes, there may be a race
240 -- condition between processes trying to create temp files at the same
241 -- time in the same directory using this procedure.
243 procedure Create_Temp_File
244 (FD : out File_Descriptor;
245 Name : out String_Access);
246 -- Create and open for writing a temporary file in the current working
247 -- directory. The name of the file and the File Descriptor are returned.
248 -- No mode parameter is provided. Since this is a temporary file, there is
249 -- no point in doing text translation on it. It is the responsibility of
250 -- the caller to deallocate the access value returned in Name.
252 -- This procedure will always succeed if the current working directory is
253 -- writable. If the current working directory is not writable, then
254 -- Invalid_FD is returned for the file descriptor and null for the Name.
255 -- There is no race condition problem between processes trying to create
256 -- temp files at the same time in the same directory.
258 procedure Close (FD : File_Descriptor; Status : out Boolean);
259 -- Close file referenced by FD. Status is False if the underlying service
260 -- failed. Reasons for failure include: disk full, disk quotas exceeded
261 -- and invalid file descriptor (the file may have been closed twice).
263 procedure Close (FD : File_Descriptor);
264 -- Close file referenced by FD. This form is used when the caller wants to
265 -- ignore any possible error (see above for error cases).
267 procedure Set_Close_On_Exec
268 (FD : File_Descriptor;
269 Close_On_Exec : Boolean;
270 Status : out Boolean);
271 -- When Close_On_Exec is True, mark FD to be closed automatically when new
272 -- program is executed by the calling process (i.e. prevent FD from being
273 -- inherited by child processes). When Close_On_Exec is False, mark FD to
274 -- not be closed on exec (i.e. allow it to be inherited). Status is False
275 -- if the operation could not be performed.
277 procedure Delete_File (Name : String; Success : out Boolean);
278 -- Deletes file. Success is set True or False indicating if the delete is
281 procedure Rename_File
284 Success : out Boolean);
285 -- Rename a file. Success is set True or False indicating if the rename is
286 -- successful or not.
288 -- The following defines the mode for the Copy_File procedure below. Note
289 -- that "time stamps and other file attributes" in the descriptions below
290 -- refers to the creation and last modification times, and also the file
291 -- access (read/write/execute) status flags.
295 -- Copy the file. It is an error if the target file already exists. The
296 -- time stamps and other file attributes are preserved in the copy.
299 -- If the target file exists, the file is replaced otherwise the file
300 -- is just copied. The time stamps and other file attributes are
301 -- preserved in the copy.
304 -- If the target file exists, the contents of the source file is
305 -- appended at the end. Otherwise the source file is just copied. The
306 -- time stamps and other file attributes are are preserved if the
307 -- destination file does not exist.
311 -- Copy time stamps from source file to target file. All other
312 -- attributes are set to normal default values for file creation.
315 -- All attributes are copied from the source file to the target file.
316 -- This includes the timestamps, and for example also includes
317 -- read/write/execute attributes in Unix systems.
320 -- No attributes are copied. All attributes including the time stamp
321 -- values are set to normal default values for file creation.
323 -- Note: The default is Time_Stamps, which corresponds to the normal
324 -- default on Windows style systems. Full corresponds to the typical
325 -- effect of "cp -p" on Unix systems, and None corresponds to the typical
326 -- effect of "cp" on Unix systems.
328 -- Note: Time_Stamps and Full are not supported on VMS and VxWorks
333 Success : out Boolean;
334 Mode : Copy_Mode := Copy;
335 Preserve : Attribute := Time_Stamps);
336 -- Copy a file. Name must designate a single file (no wild cards allowed).
337 -- Pathname can be a filename or directory name. In the latter case Name
338 -- is copied into the directory preserving the same file name. Mode
339 -- defines the kind of copy, see above with the default being a normal
340 -- copy in which the target file must not already exist. Success is set to
341 -- True or False indicating if the copy is successful (depending on the
344 -- Note: this procedure is only supported to a very limited extent on VMS.
345 -- The only supported mode is Overwrite, and the only supported value for
346 -- Preserve is None, resulting in the default action which for Overwrite
347 -- is to leave attributes unchanged. Furthermore, the copy only works for
348 -- simple text files.
350 procedure Copy_Time_Stamps (Source, Dest : String; Success : out Boolean);
351 -- Copy Source file time stamps (last modification and last access time
352 -- stamps) to Dest file. Source and Dest must be valid filenames,
353 -- furthermore Dest must be writable. Success will be set to True if the
354 -- operation was successful and False otherwise.
356 -- Note: this procedure is not supported on VMS and VxWorks. On these
357 -- platforms, Success is always set to False.
360 (FD : File_Descriptor;
362 N : Integer) return Integer;
363 -- Read N bytes to address A from file referenced by FD. Returned value is
364 -- count of bytes actually read, which can be less than N at EOF.
367 (FD : File_Descriptor;
369 N : Integer) return Integer;
370 -- Write N bytes from address A to file referenced by FD. The returned
371 -- value is the number of bytes written, which can be less than N if a
372 -- disk full condition was detected.
374 Seek_Cur : constant := 1;
375 Seek_End : constant := 2;
376 Seek_Set : constant := 0;
377 -- Used to indicate origin for Lseek call
380 (FD : File_Descriptor;
381 offset : Long_Integer;
383 pragma Import (C, Lseek, "__gnat_lseek");
384 -- Sets the current file pointer to the indicated offset value, relative
385 -- to the current position (origin = SEEK_CUR), end of file (origin =
386 -- SEEK_END), or start of file (origin = SEEK_SET).
388 function File_Length (FD : File_Descriptor) return Long_Integer;
389 pragma Import (C, File_Length, "__gnat_file_length");
390 -- Get length of file from file descriptor FD
392 function File_Time_Stamp (Name : String) return OS_Time;
393 -- Given the name of a file or directory, Name, obtains and returns the
394 -- time stamp. This function can be used for an unopened file. Returns
395 -- Invalid_Time is Name doesn't correspond to an existing file.
397 function File_Time_Stamp (FD : File_Descriptor) return OS_Time;
398 -- Get time stamp of file from file descriptor FD Returns Invalid_Time is
399 -- FD doesn't correspond to an existing file.
401 function Normalize_Pathname
403 Directory : String := "";
404 Resolve_Links : Boolean := True;
405 Case_Sensitive : Boolean := True) return String;
406 -- Returns a file name as an absolute path name, resolving all relative
407 -- directories, and symbolic links. The parameter Directory is a fully
408 -- resolved path name for a directory, or the empty string (the default).
409 -- Name is the name of a file, which is either relative to the given
410 -- directory name, if Directory is non-null, or to the current working
411 -- directory if Directory is null. The result returned is the normalized
412 -- name of the file. For most cases, if two file names designate the same
413 -- file through different paths, Normalize_Pathname will return the same
414 -- canonical name in both cases. However, there are cases when this is not
415 -- true; for example, this is not true in Unix for two hard links
416 -- designating the same file.
418 -- On Windows, the returned path will start with a drive letter except
419 -- when Directory is not empty and does not include a drive letter. If
420 -- Directory is empty (the default) and Name is a relative path or an
421 -- absolute path without drive letter, the letter of the current drive
422 -- will start the returned path. If Case_Sensitive is True (the default),
423 -- then this drive letter will be forced to upper case ("C:\...").
425 -- If Resolve_Links is set to True, then the symbolic links, on systems
426 -- that support them, will be fully converted to the name of the file or
427 -- directory pointed to. This is slightly less efficient, since it
428 -- requires system calls.
430 -- If Name cannot be resolved or is null on entry (for example if there is
431 -- symbolic link circularity, e.g. A is a symbolic link for B, and B is a
432 -- symbolic link for A), then Normalize_Pathname returns an empty string.
434 -- In VMS, if Name follows the VMS syntax file specification, it is first
435 -- converted into Unix syntax. If the conversion fails, Normalize_Pathname
436 -- returns an empty string.
438 -- For case-sensitive file systems, the value of Case_Sensitive parameter
439 -- is ignored. For file systems that are not case-sensitive, such as
440 -- Windows and OpenVMS, if this parameter is set to False, then the file
441 -- and directory names are folded to lower case. This allows checking
442 -- whether two files are the same by applying this function to their names
443 -- and comparing the results. If Case_Sensitive is set to True, this
444 -- function does not change the casing of file and directory names.
446 function Is_Absolute_Path (Name : String) return Boolean;
447 -- Returns True if Name is an absolute path name, i.e. it designates a
448 -- file or directory absolutely rather than relative to another directory.
450 function Is_Regular_File (Name : String) return Boolean;
451 -- Determines if the given string, Name, is the name of an existing
452 -- regular file. Returns True if so, False otherwise. Name may be an
453 -- absolute path name or a relative path name, including a simple file
454 -- name. If it is a relative path name, it is relative to the current
455 -- working directory.
457 function Is_Directory (Name : String) return Boolean;
458 -- Determines if the given string, Name, is the name of a directory.
459 -- Returns True if so, False otherwise. Name may be an absolute path
460 -- name or a relative path name, including a simple file name. If it is
461 -- a relative path name, it is relative to the current working directory.
463 function Is_Readable_File (Name : String) return Boolean;
464 -- Determines if the given string, Name, is the name of an existing file
465 -- that is readable. Returns True if so, False otherwise. Note that this
466 -- function simply interrogates the file attributes (e.g. using the C
467 -- function stat), so it does not indicate a situation in which a file may
468 -- not actually be readable due to some other process having exclusive
471 function Is_Writable_File (Name : String) return Boolean;
472 -- Determines if the given string, Name, is the name of an existing file
473 -- that is writable. Returns True if so, False otherwise. Note that this
474 -- function simply interrogates the file attributes (e.g. using the C
475 -- function stat), so it does not indicate a situation in which a file may
476 -- not actually be writeable due to some other process having exclusive
479 function Is_Symbolic_Link (Name : String) return Boolean;
480 -- Determines if the given string, Name, is the path of a symbolic link on
481 -- systems that support it. Returns True if so, False if the path is not a
482 -- symbolic link or if the system does not support symbolic links.
484 -- A symbolic link is an indirect pointer to a file; its directory entry
485 -- contains the name of the file to which it is linked. Symbolic links may
486 -- span file systems and may refer to directories.
488 procedure Set_Writable (Name : String);
489 -- Change the permissions on the named file to make it writable
492 procedure Set_Read_Only (Name : String);
493 -- Change the permissions on the named file to make it non-writable
496 procedure Set_Executable (Name : String);
497 -- Change the permissions on the named file to make it executable
500 function Locate_Exec_On_Path
501 (Exec_Name : String) return String_Access;
502 -- Try to locate an executable whose name is given by Exec_Name in the
503 -- directories listed in the environment Path. If the Exec_Name doesn't
504 -- have the executable suffix, it will be appended before the search.
505 -- Otherwise works like Locate_Regular_File below.
507 -- Note that this function allocates some memory for the returned value.
508 -- This memory needs to be deallocated after use.
510 function Locate_Regular_File
512 Path : String) return String_Access;
513 -- Try to locate a regular file whose name is given by File_Name in the
514 -- directories listed in Path. If a file is found, its full pathname is
515 -- returned; otherwise, a null pointer is returned. If the File_Name given
516 -- is an absolute pathname, then Locate_Regular_File just checks that the
517 -- file exists and is a regular file. Otherwise, if the File_Name given
518 -- includes directory information, Locate_Regular_File first checks if the
519 -- file exists relative to the current directory. If it does not, or if
520 -- the File_Name given is a simple file name, the Path argument is parsed
521 -- according to OS conventions, and for each directory in the Path a check
522 -- is made if File_Name is a relative pathname of a regular file from that
525 -- Note that this function allocates some memory for the returned value.
526 -- This memory needs to be deallocated after use.
528 function Get_Debuggable_Suffix return String_Access;
529 -- Return the debuggable suffix convention. Usually this is the same as
530 -- the convention for Get_Executable_Suffix. The result is allocated on
531 -- the heap and should be freed after use to avoid storage leaks.
533 function Get_Target_Debuggable_Suffix return String_Access;
534 -- Return the target debuggable suffix convention. Usually this is the
535 -- same as the convention for Get_Executable_Suffix. The result is
536 -- allocated on the heap and should be freed after use to avoid storage
539 function Get_Executable_Suffix return String_Access;
540 -- Return the executable suffix convention. The result is allocated on the
541 -- heap and should be freed after use to avoid storage leaks.
543 function Get_Object_Suffix return String_Access;
544 -- Return the object suffix convention. The result is allocated on the heap
545 -- and should be freed after use to avoid storage leaks.
547 function Get_Target_Executable_Suffix return String_Access;
548 -- Return the target executable suffix convention. The result is allocated
549 -- on the heap and should be freed after use to avoid storage leaks.
551 function Get_Target_Object_Suffix return String_Access;
552 -- Return the target object suffix convention. The result is allocated on
553 -- the heap and should be freed after use to avoid storage leaks.
555 -- The following section contains low-level routines using addresses to
556 -- pass file name and executable name. In each routine the name must be
557 -- Nul-Terminated. For complete documentation refer to the equivalent
558 -- routine (using String in place of C_File_Name) defined above.
560 subtype C_File_Name is System.Address;
561 -- This subtype is used to document that a parameter is the address of a
562 -- null-terminated string containing the name of a file.
564 -- All the following functions need comments ???
568 Fmode : Mode) return File_Descriptor;
570 function Open_Read_Write
572 Fmode : Mode) return File_Descriptor;
576 Fmode : Mode) return File_Descriptor;
578 function Create_New_File
580 Fmode : Mode) return File_Descriptor;
582 procedure Delete_File (Name : C_File_Name; Success : out Boolean);
584 procedure Rename_File
585 (Old_Name : C_File_Name;
586 New_Name : C_File_Name;
587 Success : out Boolean);
591 Pathname : C_File_Name;
592 Success : out Boolean;
593 Mode : Copy_Mode := Copy;
594 Preserve : Attribute := Time_Stamps);
596 procedure Copy_Time_Stamps
597 (Source, Dest : C_File_Name;
598 Success : out Boolean);
600 function File_Time_Stamp (Name : C_File_Name) return OS_Time;
601 -- Returns Invalid_Time is Name doesn't correspond to an existing file
603 function Is_Regular_File (Name : C_File_Name) return Boolean;
604 function Is_Directory (Name : C_File_Name) return Boolean;
605 function Is_Readable_File (Name : C_File_Name) return Boolean;
606 function Is_Writable_File (Name : C_File_Name) return Boolean;
607 function Is_Symbolic_Link (Name : C_File_Name) return Boolean;
609 function Locate_Regular_File
610 (File_Name : C_File_Name;
611 Path : C_File_Name) return String_Access;
617 subtype Argument_List is String_List;
618 -- Type used for argument list in call to Spawn. The lower bound of the
619 -- array should be 1, and the length of the array indicates the number of
622 subtype Argument_List_Access is String_List_Access;
623 -- Type used to return Argument_List without dragging in secondary stack.
624 -- Note that there is a Free procedure declared for this subtype which
625 -- frees the array and all referenced strings.
627 procedure Normalize_Arguments (Args : in out Argument_List);
628 -- Normalize all arguments in the list. This ensure that the argument list
629 -- is compatible with the running OS and will works fine with Spawn and
630 -- Non_Blocking_Spawn for example. If Normalize_Arguments is called twice
631 -- on the same list it will do nothing the second time. Note that Spawn
632 -- and Non_Blocking_Spawn call Normalize_Arguments automatically, but
633 -- since there is a guarantee that a second call does nothing, this
634 -- internal call will have no effect if Normalize_Arguments is called
635 -- before calling Spawn. The call to Normalize_Arguments assumes that the
636 -- individual referenced arguments in Argument_List are on the heap, and
637 -- may free them and reallocate if they are modified.
640 (Program_Name : String;
641 Args : Argument_List;
642 Success : out Boolean);
643 -- This procedure spawns a program with a given list of arguments. The
644 -- first parameter of is the name of the executable. The second parameter
645 -- contains the arguments to be passed to this program. Success is False
646 -- if the named program could not be spawned or its execution completed
647 -- unsuccessfully. Note that the caller will be blocked until the
648 -- execution of the spawned program is complete. For maximum portability,
649 -- use a full path name for the Program_Name argument. On some systems
650 -- (notably Unix systems) a simple file name may also work (if the
651 -- executable can be located in the path).
653 -- "Spawn" should not be used in tasking applications. Why not??? More
654 -- documentation would be helpful here ??? Is it really tasking programs,
655 -- or tasking activity that cause trouble ???
657 -- Note: Arguments in Args that contain spaces and/or quotes such as
658 -- "--GCC=gcc -v" or "--GCC=""gcc -v""" are not portable across all
659 -- operating systems, and would not have the desired effect if they were
660 -- passed directly to the operating system. To avoid this problem, Spawn
661 -- makes an internal call to Normalize_Arguments, which ensures that such
662 -- arguments are modified in a manner that ensures that the desired effect
663 -- is obtained on all operating systems. The caller may call
664 -- Normalize_Arguments explicitly before the call (e.g. to print out the
665 -- exact form of arguments passed to the operating system). In this case
666 -- the guarantee a second call to Normalize_Arguments has no effect
667 -- ensures that the internal call will not affect the result. Note that
668 -- the implicit call to Normalize_Arguments may free and reallocate some
669 -- of the individual arguments.
671 -- This function will always set Success to False under VxWorks and other
672 -- similar operating systems which have no notion of the concept of
673 -- dynamically executable file.
676 (Program_Name : String;
677 Args : Argument_List) return Integer;
678 -- Similar to the above procedure, but returns the actual status returned
679 -- by the operating system, or -1 under VxWorks and any other similar
680 -- operating systems which have no notion of separately spawnable programs.
682 -- "Spawn" should not be used in tasking applications.
685 (Program_Name : String;
686 Args : Argument_List;
687 Output_File_Descriptor : File_Descriptor;
688 Return_Code : out Integer;
689 Err_To_Out : Boolean := True);
690 -- Similar to the procedure above, but redirects the output to the file
691 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the
692 -- Standard Error output is also redirected.
693 -- Return_Code is set to the status code returned by the operating system
695 -- "Spawn" should not be used in tasking applications.
698 (Program_Name : String;
699 Args : Argument_List;
700 Output_File : String;
701 Success : out Boolean;
702 Return_Code : out Integer;
703 Err_To_Out : Boolean := True);
704 -- Similar to the procedure above, but saves the output of the command to
705 -- a file with the name Output_File.
707 -- Success is set to True if the command is executed and its output
708 -- successfully written to the file. If Success is True, then Return_Code
709 -- will be set to the status code returned by the operating system.
710 -- Otherwise, Return_Code is undefined.
712 -- "Spawn" should not be used in tasking applications.
714 type Process_Id is private;
715 -- A private type used to identify a process activated by the following
716 -- non-blocking calls. The only meaningful operation on this type is a
717 -- comparison for equality.
719 Invalid_Pid : constant Process_Id;
720 -- A special value used to indicate errors, as described below
722 function Pid_To_Integer (Pid : Process_Id) return Integer;
723 -- Convert a process id to an Integer. Useful for writing hash functions
724 -- for type Process_Id or to compare two Process_Id (e.g. for sorting).
726 function Non_Blocking_Spawn
727 (Program_Name : String;
728 Args : Argument_List) return Process_Id;
729 -- This is a non blocking call. The Process_Id of the spawned process is
730 -- returned. Parameters are to be used as in Spawn. If Invalid_Pid is
731 -- returned the program could not be spawned.
733 -- "Non_Blocking_Spawn" should not be used in tasking applications.
735 -- This function will always return Invalid_Pid under VxWorks, since there
736 -- is no notion of executables under this OS.
738 function Non_Blocking_Spawn
739 (Program_Name : String;
740 Args : Argument_List;
741 Output_File_Descriptor : File_Descriptor;
742 Err_To_Out : Boolean := True) return Process_Id;
743 -- Similar to the procedure above, but redirects the output to the file
744 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the
745 -- Standard Error output is also redirected. Invalid_Pid is returned
746 -- if the program could not be spawned successfully.
748 -- "Non_Blocking_Spawn" should not be used in tasking applications.
750 -- This function will always return Invalid_Pid under VxWorks, since there
751 -- is no notion of executables under this OS.
753 function Non_Blocking_Spawn
754 (Program_Name : String;
755 Args : Argument_List;
756 Output_File : String;
757 Err_To_Out : Boolean := True) return Process_Id;
758 -- Similar to the procedure above, but saves the output of the command to
759 -- a file with the name Output_File.
761 -- Success is set to True if the command is executed and its output
762 -- successfully written to the file. Invalid_Pid is returned if the output
763 -- file could not be created or if the program could not be spawned
766 -- "Non_Blocking_Spawn" should not be used in tasking applications.
768 -- This function will always return Invalid_Pid under VxWorks, since there
769 -- is no notion of executables under this OS.
771 procedure Wait_Process (Pid : out Process_Id; Success : out Boolean);
772 -- Wait for the completion of any of the processes created by previous
773 -- calls to Non_Blocking_Spawn. The caller will be suspended until one of
774 -- these processes terminates (normally or abnormally). If any of these
775 -- subprocesses terminates prior to the call to Wait_Process (and has not
776 -- been returned by a previous call to Wait_Process), then the call to
777 -- Wait_Process is immediate. Pid identifies the process that has
778 -- terminated (matching the value returned from Non_Blocking_Spawn).
779 -- Success is set to True if this sub-process terminated successfully. If
780 -- Pid = Invalid_Pid, there were no subprocesses left to wait on.
782 -- This function will always set success to False under VxWorks, since
783 -- there is no notion of executables under this OS.
785 function Argument_String_To_List
786 (Arg_String : String) return Argument_List_Access;
787 -- Take a string that is a program and its arguments and parse it into an
788 -- Argument_List. Note that the result is allocated on the heap, and must
789 -- be freed by the programmer (when it is no longer needed) to avoid
796 function Getenv (Name : String) return String_Access;
797 -- Get the value of the environment variable. Returns an access to the
798 -- empty string if the environment variable does not exist or has an
799 -- explicit null value (in some operating systems these are distinct
800 -- cases, in others they are not; this interface abstracts away that
801 -- difference. The argument is allocated on the heap (even in the null
802 -- case), and needs to be freed explicitly when no longer needed to avoid
805 procedure Setenv (Name : String; Value : String);
806 -- Set the value of the environment variable Name to Value. This call
807 -- modifies the current environment, but does not modify the parent
808 -- process environment. After a call to Setenv, Getenv (Name) will always
809 -- return a String_Access referencing the same String as Value. This is
810 -- true also for the null string case (the actual effect may be to either
811 -- set an explicit null as the value, or to remove the entry, this is
812 -- operating system dependent). Note that any following calls to Spawn
813 -- will pass an environment to the spawned process that includes the
814 -- changes made by Setenv calls. This procedure is not available on VMS.
816 procedure OS_Exit (Status : Integer);
817 pragma Import (C, OS_Exit, "__gnat_os_exit");
818 pragma No_Return (OS_Exit);
819 -- Exit to OS with given status code (program is terminated). Note that
820 -- this is abrupt termination. All tasks are immediately terminated. There
821 -- are no finalization or other Ada-specific cleanup actions performed. On
822 -- systems with atexit handlers (such as Unix and Windows) are performed.
825 pragma Import (C, OS_Abort, "abort");
826 pragma No_Return (OS_Abort);
827 -- Exit to OS signalling an abort (traceback or other appropriate
828 -- diagnostic information should be given if possible, or entry made to
829 -- the debugger if that is possible).
831 function Errno return Integer;
832 pragma Import (C, Errno, "__get_errno");
833 -- Return the task-safe last error number
835 procedure Set_Errno (Errno : Integer);
836 pragma Import (C, Set_Errno, "__set_errno");
837 -- Set the task-safe error number
839 Directory_Separator : constant Character;
840 -- The character that is used to separate parts of a pathname
842 Path_Separator : constant Character;
843 -- The character to separate paths in an environment variable value
846 pragma Import (C, Path_Separator, "__gnat_path_separator");
847 pragma Import (C, Directory_Separator, "__gnat_dir_separator");
848 pragma Import (C, Current_Time, "__gnat_current_time");
850 type OS_Time is new Long_Integer;
851 -- Type used for timestamps in the compiler. This type is used to hold
852 -- time stamps, but may have a different representation than C's time_t.
853 -- This type needs to match the declaration of OS_Time in adaint.h.
855 -- Add pragma Inline statements for comparison operations on OS_Time. It
856 -- would actually be nice to use pragma Import (Intrinsic) here, but this
857 -- was not properly supported till GNAT 3.15a, so that would cause
858 -- bootstrap path problems. To be changed later ???
860 Invalid_Time : constant OS_Time := -1;
861 -- This value should match the return valud by __gnat_file_time_*
865 pragma Inline ("<=");
866 pragma Inline (">=");
868 type Process_Id is new Integer;
869 Invalid_Pid : constant Process_Id := -1;
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