1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- G N A T . O S _ L I B --
9 -- Copyright (C) 1995-2006, 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.
52 package GNAT.OS_Lib is
53 pragma Elaborate_Body (OS_Lib);
55 -----------------------
56 -- String Operations --
57 -----------------------
59 -- These are reexported from package Strings (which was introduced to
60 -- avoid different packages declarting different types unnecessarily).
61 -- See package GNAT.Strings for details.
63 subtype String_Access is Strings.String_Access;
65 function "=" (Left, Right : String_Access) return Boolean
68 procedure Free (X : in out String_Access) renames Strings.Free;
70 subtype String_List is Strings.String_List;
72 function "=" (Left, Right : String_List) return Boolean
75 function "&" (Left : String_Access; Right : String_Access)
76 return String_List renames Strings."&";
77 function "&" (Left : String_Access; Right : String_List)
78 return String_List renames Strings."&";
79 function "&" (Left : String_List; Right : String_Access)
80 return String_List renames Strings."&";
81 function "&" (Left : String_List; Right : String_List)
82 return String_List renames Strings."&";
84 subtype String_List_Access is Strings.String_List_Access;
86 function "=" (Left, Right : String_List_Access) return Boolean
89 procedure Free (Arg : in out String_List_Access)
96 type OS_Time is private;
97 -- The OS's notion of time is represented by the private type OS_Time.
98 -- This is the type returned by the File_Time_Stamp functions to obtain
99 -- the time stamp of a specified file. Functions and a procedure (modeled
100 -- after the similar subprograms in package Calendar) are provided for
101 -- extracting information from a value of this type. Although these are
102 -- called GM, the intention is not that they provide GMT times in all
103 -- cases but rather the actual (time-zone independent) time stamp of the
104 -- file (of course in Unix systems, this *is* in GMT form).
106 Invalid_Time : constant OS_Time;
107 -- A special unique value used to flag an invalid time stamp value
109 subtype Year_Type is Integer range 1900 .. 2099;
110 subtype Month_Type is Integer range 1 .. 12;
111 subtype Day_Type is Integer range 1 .. 31;
112 subtype Hour_Type is Integer range 0 .. 23;
113 subtype Minute_Type is Integer range 0 .. 59;
114 subtype Second_Type is Integer range 0 .. 59;
115 -- Declarations similar to those in Calendar, breaking down the time
117 function Current_Time return OS_Time;
118 -- Return the system clock value as OS_Time
120 function GM_Year (Date : OS_Time) return Year_Type;
121 function GM_Month (Date : OS_Time) return Month_Type;
122 function GM_Day (Date : OS_Time) return Day_Type;
123 function GM_Hour (Date : OS_Time) return Hour_Type;
124 function GM_Minute (Date : OS_Time) return Minute_Type;
125 function GM_Second (Date : OS_Time) return Second_Type;
126 -- Functions to extract information from OS_Time value
128 function "<" (X, Y : OS_Time) return Boolean;
129 function ">" (X, Y : OS_Time) return Boolean;
130 function ">=" (X, Y : OS_Time) return Boolean;
131 function "<=" (X, Y : OS_Time) return Boolean;
132 -- Basic comparison operators on OS_Time with obvious meanings. Note that
133 -- these have Intrinsic convention, so for example it is not permissible
134 -- to create accesses to any of these functions.
138 Year : out Year_Type;
139 Month : out Month_Type;
141 Hour : out Hour_Type;
142 Minute : out Minute_Type;
143 Second : out Second_Type);
144 -- Analogous to the Split routine in Ada.Calendar, takes an OS_Time
145 -- and provides a representation of it as a set of component parts,
146 -- to be interpreted as a date point in UTC.
152 -- These routines give access to the open/creat/close/read/write level of
153 -- I/O routines in the typical C library (these functions are not part of
154 -- the ANSI C standard, but are typically available in all systems). See
155 -- also package Interfaces.C_Streams for access to the stream level
158 -- Note on file names. If a file name is passed as type String in any of
159 -- the following specifications, then the name is a normal Ada string and
160 -- need not be NUL-terminated. However, a trailing NUL character is
161 -- permitted, and will be ignored (more accurately, the NUL and any
162 -- characters that follow it will be ignored).
164 type File_Descriptor is new Integer;
165 -- Corresponds to the int file handle values used in the C routines
167 Standin : constant File_Descriptor := 0;
168 Standout : constant File_Descriptor := 1;
169 Standerr : constant File_Descriptor := 2;
170 -- File descriptors for standard input output files
172 Invalid_FD : constant File_Descriptor := -1;
173 -- File descriptor returned when error in opening/creating file;
175 type Mode is (Binary, Text);
176 for Mode'Size use Integer'Size;
177 for Mode use (Binary => 0, Text => 1);
178 -- Used in all the Open and Create calls to specify if the file is to be
179 -- opened in binary mode or text mode. In systems like Unix, this has no
180 -- effect, but in systems capable of text mode translation, the use of
181 -- Text as the mode parameter causes the system to do CR/LF translation
182 -- and also to recognize the DOS end of file character on input. The use
183 -- of Text where appropriate allows programs to take a portable Unix view
184 -- of DOS-format files and process them appropriately.
188 Fmode : Mode) return File_Descriptor;
189 -- Open file Name for reading, returning file descriptor File descriptor
190 -- returned is Invalid_FD if file cannot be opened.
192 function Open_Read_Write
194 Fmode : Mode) return File_Descriptor;
195 -- Open file Name for both reading and writing, returning file descriptor.
196 -- File descriptor returned is Invalid_FD if file cannot be opened.
200 Fmode : Mode) return File_Descriptor;
201 -- Creates new file with given name for writing, returning file descriptor
202 -- for subsequent use in Write calls. File descriptor returned is
203 -- Invalid_FD if file cannot be successfully created.
205 function Create_Output_Text_File (Name : String) return File_Descriptor;
206 -- Creates new text file with given name suitable to redirect standard
207 -- output, returning file descriptor. File descriptor returned is
208 -- Invalid_FD if file cannot be successfully created.
210 function Create_New_File
212 Fmode : Mode) return File_Descriptor;
213 -- Create new file with given name for writing, returning file descriptor
214 -- for subsequent use in Write calls. This differs from Create_File in
215 -- that it fails if the file already exists. File descriptor returned is
216 -- Invalid_FD if the file exists or cannot be created.
218 Temp_File_Len : constant Integer := 12;
219 -- Length of name returned by Create_Temp_File call (GNAT-XXXXXX & NUL)
221 subtype Temp_File_Name is String (1 .. Temp_File_Len);
222 -- String subtype set by Create_Temp_File
224 procedure Create_Temp_File
225 (FD : out File_Descriptor;
226 Name : out Temp_File_Name);
227 -- Create and open for writing a temporary file in the current working
228 -- directory. The name of the file and the File Descriptor are returned.
229 -- The File Descriptor returned is Invalid_FD in the case of failure. No
230 -- mode parameter is provided. Since this is a temporary file, there is no
231 -- point in doing text translation on it.
233 -- On some OSes, the maximum number of temp files that can be created with
234 -- this procedure may be limited. When the maximum is reached, this
235 -- procedure returns Invalid_FD. On some OSes, there may be a race
236 -- condition between processes trying to create temp files at the same
237 -- time in the same directory using this procedure.
239 procedure Create_Temp_File
240 (FD : out File_Descriptor;
241 Name : out String_Access);
242 -- Create and open for writing a temporary file in the current working
243 -- directory. The name of the file and the File Descriptor are returned.
244 -- No mode parameter is provided. Since this is a temporary file, there is
245 -- no point in doing text translation on it. It is the responsibility of
246 -- the caller to deallocate the access value returned in Name.
248 -- This procedure will always succeed if the current working directory is
249 -- writable. If the current working directory is not writable, then
250 -- Invalid_FD is returned for the file descriptor and null for the Name.
251 -- There is no race condition problem between processes trying to create
252 -- temp files at the same time in the same directory.
254 procedure Close (FD : File_Descriptor; Status : out Boolean);
255 -- Close file referenced by FD. Status is False if the underlying service
256 -- failed. Reasons for failure include: disk full, disk quotas exceeded
257 -- and invalid file descriptor (the file may have been closed twice).
259 procedure Close (FD : File_Descriptor);
260 -- Close file referenced by FD. This form is used when the caller wants to
261 -- ignore any possible error (see above for error cases).
263 procedure Set_Close_On_Exec
264 (FD : File_Descriptor;
265 Close_On_Exec : Boolean;
266 Status : out Boolean);
267 -- When Close_On_Exec is True, mark FD to be closed automatically when new
268 -- program is executed by the calling process (i.e. prevent FD from being
269 -- inherited by child processes). When Close_On_Exec is False, mark FD to
270 -- not be closed on exec (i.e. allow it to be inherited). Status is False
271 -- if the operation could not be performed.
273 procedure Delete_File (Name : String; Success : out Boolean);
274 -- Deletes file. Success is set True or False indicating if the delete is
277 procedure Rename_File
280 Success : out Boolean);
281 -- Rename a file. Success is set True or False indicating if the rename is
282 -- successful or not.
284 -- The following defines the mode for the Copy_File procedure below. Note
285 -- that "time stamps and other file attributes" in the descriptions below
286 -- refers to the creation and last modification times, and also the file
287 -- access (read/write/execute) status flags.
291 -- Copy the file. It is an error if the target file already exists. The
292 -- time stamps and other file attributes are preserved in the copy.
295 -- If the target file exists, the file is replaced otherwise the file
296 -- is just copied. The time stamps and other file attributes are
297 -- preserved in the copy.
300 -- If the target file exists, the contents of the source file is
301 -- appended at the end. Otherwise the source file is just copied. The
302 -- time stamps and other file attributes are are preserved if the
303 -- destination file does not exist.
307 -- Copy time stamps from source file to target file. All other
308 -- attributes are set to normal default values for file creation.
311 -- All attributes are copied from the source file to the target file.
312 -- This includes the timestamps, and for example also includes
313 -- read/write/execute attributes in Unix systems.
316 -- No attributes are copied. All attributes including the time stamp
317 -- values are set to normal default values for file creation.
319 -- Note: The default is Time_Stamps, which corresponds to the normal
320 -- default on Windows style systems. Full corresponds to the typical
321 -- effect of "cp -p" on Unix systems, and None corresponds to the typical
322 -- effect of "cp" on Unix systems.
324 -- Note: Time_Stamps and Full are not supported on VMS and VxWorks
329 Success : out Boolean;
330 Mode : Copy_Mode := Copy;
331 Preserve : Attribute := Time_Stamps);
332 -- Copy a file. Name must designate a single file (no wild cards allowed).
333 -- Pathname can be a filename or directory name. In the latter case Name
334 -- is copied into the directory preserving the same file name. Mode
335 -- defines the kind of copy, see above with the default being a normal
336 -- copy in which the target file must not already exist. Success is set to
337 -- True or False indicating if the copy is successful (depending on the
340 -- Note: this procedure is only supported to a very limited extent on VMS.
341 -- The only supported mode is Overwrite, and the only supported value for
342 -- Preserve is None, resulting in the default action which for Overwrite
343 -- is to leave attributes unchanged. Furthermore, the copy only works for
344 -- simple text files.
346 procedure Copy_Time_Stamps (Source, Dest : String; Success : out Boolean);
347 -- Copy Source file time stamps (last modification and last access time
348 -- stamps) to Dest file. Source and Dest must be valid filenames,
349 -- furthermore Dest must be writable. Success will be set to True if the
350 -- operation was successful and False otherwise.
352 -- Note: this procedure is not supported on VMS and VxWorks. On these
353 -- platforms, Success is always set to False.
356 (FD : File_Descriptor;
358 N : Integer) return Integer;
359 -- Read N bytes to address A from file referenced by FD. Returned value is
360 -- count of bytes actually read, which can be less than N at EOF.
363 (FD : File_Descriptor;
365 N : Integer) return Integer;
366 -- Write N bytes from address A to file referenced by FD. The returned
367 -- value is the number of bytes written, which can be less than N if a
368 -- disk full condition was detected.
370 Seek_Cur : constant := 1;
371 Seek_End : constant := 2;
372 Seek_Set : constant := 0;
373 -- Used to indicate origin for Lseek call
376 (FD : File_Descriptor;
377 offset : Long_Integer;
379 pragma Import (C, Lseek, "__gnat_lseek");
380 -- Sets the current file pointer to the indicated offset value, relative
381 -- to the current position (origin = SEEK_CUR), end of file (origin =
382 -- SEEK_END), or start of file (origin = SEEK_SET).
384 function File_Length (FD : File_Descriptor) return Long_Integer;
385 pragma Import (C, File_Length, "__gnat_file_length");
386 -- Get length of file from file descriptor FD
388 function File_Time_Stamp (Name : String) return OS_Time;
389 -- Given the name of a file or directory, Name, obtains and returns the
390 -- time stamp. This function can be used for an unopened file. Returns
391 -- Invalid_Time is Name doesn't correspond to an existing file.
393 function File_Time_Stamp (FD : File_Descriptor) return OS_Time;
394 -- Get time stamp of file from file descriptor FD Returns Invalid_Time is
395 -- FD doesn't correspond to an existing file.
397 function Normalize_Pathname
399 Directory : String := "";
400 Resolve_Links : Boolean := True;
401 Case_Sensitive : Boolean := True) return String;
402 -- Returns a file name as an absolute path name, resolving all relative
403 -- directories, and symbolic links. The parameter Directory is a fully
404 -- resolved path name for a directory, or the empty string (the default).
405 -- Name is the name of a file, which is either relative to the given
406 -- directory name, if Directory is non-null, or to the current working
407 -- directory if Directory is null. The result returned is the normalized
408 -- name of the file. For most cases, if two file names designate the same
409 -- file through different paths, Normalize_Pathname will return the same
410 -- canonical name in both cases. However, there are cases when this is not
411 -- true; for example, this is not true in Unix for two hard links
412 -- designating the same file.
414 -- On Windows, the returned path will start with a drive letter except
415 -- when Directory is not empty and does not include a drive letter. If
416 -- Directory is empty (the default) and Name is a relative path or an
417 -- absolute path without drive letter, the letter of the current drive
418 -- will start the returned path. If Case_Sensitive is True (the default),
419 -- then this drive letter will be forced to upper case ("C:\...").
421 -- If Resolve_Links is set to True, then the symbolic links, on systems
422 -- that support them, will be fully converted to the name of the file or
423 -- directory pointed to. This is slightly less efficient, since it
424 -- requires system calls.
426 -- If Name cannot be resolved or is null on entry (for example if there is
427 -- symbolic link circularity, e.g. A is a symbolic link for B, and B is a
428 -- symbolic link for A), then Normalize_Pathname returns an empty string.
430 -- In VMS, if Name follows the VMS syntax file specification, it is first
431 -- converted into Unix syntax. If the conversion fails, Normalize_Pathname
432 -- returns an empty string.
434 -- For case-sensitive file systems, the value of Case_Sensitive parameter
435 -- is ignored. For file systems that are not case-sensitive, such as
436 -- Windows and OpenVMS, if this parameter is set to False, then the file
437 -- and directory names are folded to lower case. This allows checking
438 -- whether two files are the same by applying this function to their names
439 -- and comparing the results. If Case_Sensitive is set to True, this
440 -- function does not change the casing of file and directory names.
442 function Is_Absolute_Path (Name : String) return Boolean;
443 -- Returns True if Name is an absolute path name, i.e. it designates a
444 -- file or directory absolutely rather than relative to another directory.
446 function Is_Regular_File (Name : String) return Boolean;
447 -- Determines if the given string, Name, is the name of an existing
448 -- regular file. Returns True if so, False otherwise. Name may be an
449 -- absolute path name or a relative path name, including a simple file
450 -- name. If it is a relative path name, it is relative to the current
451 -- working directory.
453 function Is_Directory (Name : String) return Boolean;
454 -- Determines if the given string, Name, is the name of a directory.
455 -- Returns True if so, False otherwise. Name may be an absolute path
456 -- name or a relative path name, including a simple file name. If it is
457 -- a relative path name, it is relative to the current working directory.
459 function Is_Readable_File (Name : String) return Boolean;
460 -- Determines if the given string, Name, is the name of an existing file
461 -- that is readable. Returns True if so, False otherwise. Note that this
462 -- function simply interrogates the file attributes (e.g. using the C
463 -- function stat), so it does not indicate a situation in which a file may
464 -- not actually be readable due to some other process having exclusive
467 function Is_Writable_File (Name : String) return Boolean;
468 -- Determines if the given string, Name, is the name of an existing file
469 -- that is writable. Returns True if so, False otherwise. Note that this
470 -- function simply interrogates the file attributes (e.g. using the C
471 -- function stat), so it does not indicate a situation in which a file may
472 -- not actually be writeable due to some other process having exclusive
475 function Is_Symbolic_Link (Name : String) return Boolean;
476 -- Determines if the given string, Name, is the path of a symbolic link on
477 -- systems that support it. Returns True if so, False if the path is not a
478 -- symbolic link or if the system does not support symbolic links.
480 -- A symbolic link is an indirect pointer to a file; its directory entry
481 -- contains the name of the file to which it is linked. Symbolic links may
482 -- span file systems and may refer to directories.
484 procedure Set_Writable (Name : String);
485 -- Change the permissions on the named file to make it writable
488 procedure Set_Read_Only (Name : String);
489 -- Change the permissions on the named file to make it non-writable
492 procedure Set_Executable (Name : String);
493 -- Change the permissions on the named file to make it executable
496 function Locate_Exec_On_Path
497 (Exec_Name : String) return String_Access;
498 -- Try to locate an executable whose name is given by Exec_Name in the
499 -- directories listed in the environment Path. If the Exec_Name doesn't
500 -- have the executable suffix, it will be appended before the search.
501 -- Otherwise works like Locate_Regular_File below.
503 -- Note that this function allocates some memory for the returned value.
504 -- This memory needs to be deallocated after use.
506 function Locate_Regular_File
508 Path : String) return String_Access;
509 -- Try to locate a regular file whose name is given by File_Name in the
510 -- directories listed in Path. If a file is found, its full pathname is
511 -- returned; otherwise, a null pointer is returned. If the File_Name given
512 -- is an absolute pathname, then Locate_Regular_File just checks that the
513 -- file exists and is a regular file. Otherwise, if the File_Name given
514 -- includes directory information, Locate_Regular_File first checks if the
515 -- file exists relative to the current directory. If it does not, or if
516 -- the File_Name given is a simple file name, the Path argument is parsed
517 -- according to OS conventions, and for each directory in the Path a check
518 -- is made if File_Name is a relative pathname of a regular file from that
521 -- Note that this function allocates some memory for the returned value.
522 -- This memory needs to be deallocated after use.
524 function Get_Debuggable_Suffix return String_Access;
525 -- Return the debuggable suffix convention. Usually this is the same as
526 -- the convention for Get_Executable_Suffix. The result is allocated on
527 -- the heap and should be freed after use to avoid storage leaks.
529 function Get_Target_Debuggable_Suffix return String_Access;
530 -- Return the target debuggable suffix convention. Usually this is the
531 -- same as the convention for Get_Executable_Suffix. The result is
532 -- allocated on the heap and should be freed after use to avoid storage
535 function Get_Executable_Suffix return String_Access;
536 -- Return the executable suffix convention. The result is allocated on the
537 -- heap and should be freed after use to avoid storage leaks.
539 function Get_Object_Suffix return String_Access;
540 -- Return the object suffix convention. The result is allocated on the heap
541 -- and should be freed after use to avoid storage leaks.
543 function Get_Target_Executable_Suffix return String_Access;
544 -- Return the target executable suffix convention. The result is allocated
545 -- on the heap and should be freed after use to avoid storage leaks.
547 function Get_Target_Object_Suffix return String_Access;
548 -- Return the target object suffix convention. The result is allocated on
549 -- the heap and should be freed after use to avoid storage leaks.
551 -- The following section contains low-level routines using addresses to
552 -- pass file name and executable name. In each routine the name must be
553 -- Nul-Terminated. For complete documentation refer to the equivalent
554 -- routine (using String in place of C_File_Name) defined above.
556 subtype C_File_Name is System.Address;
557 -- This subtype is used to document that a parameter is the address of a
558 -- null-terminated string containing the name of a file.
560 -- All the following functions need comments ???
564 Fmode : Mode) return File_Descriptor;
566 function Open_Read_Write
568 Fmode : Mode) return File_Descriptor;
572 Fmode : Mode) return File_Descriptor;
574 function Create_New_File
576 Fmode : Mode) return File_Descriptor;
578 procedure Delete_File (Name : C_File_Name; Success : out Boolean);
580 procedure Rename_File
581 (Old_Name : C_File_Name;
582 New_Name : C_File_Name;
583 Success : out Boolean);
587 Pathname : C_File_Name;
588 Success : out Boolean;
589 Mode : Copy_Mode := Copy;
590 Preserve : Attribute := Time_Stamps);
592 procedure Copy_Time_Stamps
593 (Source, Dest : C_File_Name;
594 Success : out Boolean);
596 function File_Time_Stamp (Name : C_File_Name) return OS_Time;
597 -- Returns Invalid_Time is Name doesn't correspond to an existing file
599 function Is_Regular_File (Name : C_File_Name) return Boolean;
600 function Is_Directory (Name : C_File_Name) return Boolean;
601 function Is_Readable_File (Name : C_File_Name) return Boolean;
602 function Is_Writable_File (Name : C_File_Name) return Boolean;
603 function Is_Symbolic_Link (Name : C_File_Name) return Boolean;
605 function Locate_Regular_File
606 (File_Name : C_File_Name;
607 Path : C_File_Name) return String_Access;
613 subtype Argument_List is String_List;
614 -- Type used for argument list in call to Spawn. The lower bound of the
615 -- array should be 1, and the length of the array indicates the number of
618 subtype Argument_List_Access is String_List_Access;
619 -- Type used to return Argument_List without dragging in secondary stack.
620 -- Note that there is a Free procedure declared for this subtype which
621 -- frees the array and all referenced strings.
623 procedure Normalize_Arguments (Args : in out Argument_List);
624 -- Normalize all arguments in the list. This ensure that the argument list
625 -- is compatible with the running OS and will works fine with Spawn and
626 -- Non_Blocking_Spawn for example. If Normalize_Arguments is called twice
627 -- on the same list it will do nothing the second time. Note that Spawn
628 -- and Non_Blocking_Spawn call Normalize_Arguments automatically, but
629 -- since there is a guarantee that a second call does nothing, this
630 -- internal call will have no effect if Normalize_Arguments is called
631 -- before calling Spawn. The call to Normalize_Arguments assumes that the
632 -- individual referenced arguments in Argument_List are on the heap, and
633 -- may free them and reallocate if they are modified.
636 (Program_Name : String;
637 Args : Argument_List;
638 Success : out Boolean);
639 -- This procedure spawns a program with a given list of arguments. The
640 -- first parameter of is the name of the executable. The second parameter
641 -- contains the arguments to be passed to this program. Success is False
642 -- if the named program could not be spawned or its execution completed
643 -- unsuccessfully. Note that the caller will be blocked until the
644 -- execution of the spawned program is complete. For maximum portability,
645 -- use a full path name for the Program_Name argument. On some systems
646 -- (notably Unix systems) a simple file name may also work (if the
647 -- executable can be located in the path).
649 -- "Spawn" should not be used in tasking applications. Why not??? More
650 -- documentation would be helpful here ??? Is it really tasking programs,
651 -- or tasking activity that cause trouble ???
653 -- Note: Arguments in Args that contain spaces and/or quotes such as
654 -- "--GCC=gcc -v" or "--GCC=""gcc -v""" are not portable across all
655 -- operating systems, and would not have the desired effect if they were
656 -- passed directly to the operating system. To avoid this problem, Spawn
657 -- makes an internal call to Normalize_Arguments, which ensures that such
658 -- arguments are modified in a manner that ensures that the desired effect
659 -- is obtained on all operating systems. The caller may call
660 -- Normalize_Arguments explicitly before the call (e.g. to print out the
661 -- exact form of arguments passed to the operating system). In this case
662 -- the guarantee a second call to Normalize_Arguments has no effect
663 -- ensures that the internal call will not affect the result. Note that
664 -- the implicit call to Normalize_Arguments may free and reallocate some
665 -- of the individual arguments.
667 -- This function will always set Success to False under VxWorks and other
668 -- similar operating systems which have no notion of the concept of
669 -- dynamically executable file.
672 (Program_Name : String;
673 Args : Argument_List) return Integer;
674 -- Similar to the above procedure, but returns the actual status returned
675 -- by the operating system, or -1 under VxWorks and any other similar
676 -- operating systems which have no notion of separately spawnable programs.
678 -- "Spawn" should not be used in tasking applications.
681 (Program_Name : String;
682 Args : Argument_List;
683 Output_File_Descriptor : File_Descriptor;
684 Return_Code : out Integer;
685 Err_To_Out : Boolean := True);
686 -- Similar to the procedure above, but redirects the output to the file
687 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the
688 -- Standard Error output is also redirected.
689 -- Return_Code is set to the status code returned by the operating system
691 -- "Spawn" should not be used in tasking applications.
694 (Program_Name : String;
695 Args : Argument_List;
696 Output_File : String;
697 Success : out Boolean;
698 Return_Code : out Integer;
699 Err_To_Out : Boolean := True);
700 -- Similar to the procedure above, but saves the output of the command to
701 -- a file with the name Output_File.
703 -- Success is set to True if the command is executed and its output
704 -- successfully written to the file. If Success is True, then Return_Code
705 -- will be set to the status code returned by the operating system.
706 -- Otherwise, Return_Code is undefined.
708 -- "Spawn" should not be used in tasking applications.
710 type Process_Id is private;
711 -- A private type used to identify a process activated by the following
712 -- non-blocking calls. The only meaningful operation on this type is a
713 -- comparison for equality.
715 Invalid_Pid : constant Process_Id;
716 -- A special value used to indicate errors, as described below
718 function Pid_To_Integer (Pid : Process_Id) return Integer;
719 -- Convert a process id to an Integer. Useful for writing hash functions
720 -- for type Process_Id or to compare two Process_Id (e.g. for sorting).
722 function Non_Blocking_Spawn
723 (Program_Name : String;
724 Args : Argument_List) return Process_Id;
725 -- This is a non blocking call. The Process_Id of the spawned process is
726 -- returned. Parameters are to be used as in Spawn. If Invalid_Pid is
727 -- returned the program could not be spawned.
729 -- "Non_Blocking_Spawn" should not be used in tasking applications.
731 -- This function will always return Invalid_Pid under VxWorks, since there
732 -- is no notion of executables under this OS.
734 function Non_Blocking_Spawn
735 (Program_Name : String;
736 Args : Argument_List;
737 Output_File_Descriptor : File_Descriptor;
738 Err_To_Out : Boolean := True) return Process_Id;
739 -- Similar to the procedure above, but redirects the output to the file
740 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the
741 -- Standard Error output is also redirected. Invalid_Pid is returned
742 -- if the program could not be spawned successfully.
744 -- "Non_Blocking_Spawn" should not be used in tasking applications.
746 -- This function will always return Invalid_Pid under VxWorks, since there
747 -- is no notion of executables under this OS.
749 function Non_Blocking_Spawn
750 (Program_Name : String;
751 Args : Argument_List;
752 Output_File : String;
753 Err_To_Out : Boolean := True) return Process_Id;
754 -- Similar to the procedure above, but saves the output of the command to
755 -- a file with the name Output_File.
757 -- Success is set to True if the command is executed and its output
758 -- successfully written to the file. Invalid_Pid is returned if the output
759 -- file could not be created or if the program could not be spawned
762 -- "Non_Blocking_Spawn" should not be used in tasking applications.
764 -- This function will always return Invalid_Pid under VxWorks, since there
765 -- is no notion of executables under this OS.
767 procedure Wait_Process (Pid : out Process_Id; Success : out Boolean);
768 -- Wait for the completion of any of the processes created by previous
769 -- calls to Non_Blocking_Spawn. The caller will be suspended until one of
770 -- these processes terminates (normally or abnormally). If any of these
771 -- subprocesses terminates prior to the call to Wait_Process (and has not
772 -- been returned by a previous call to Wait_Process), then the call to
773 -- Wait_Process is immediate. Pid identifies the process that has
774 -- terminated (matching the value returned from Non_Blocking_Spawn).
775 -- Success is set to True if this sub-process terminated successfully. If
776 -- Pid = Invalid_Pid, there were no subprocesses left to wait on.
778 -- This function will always set success to False under VxWorks, since
779 -- there is no notion of executables under this OS.
781 function Argument_String_To_List
782 (Arg_String : String) return Argument_List_Access;
783 -- Take a string that is a program and its arguments and parse it into an
784 -- Argument_List. Note that the result is allocated on the heap, and must
785 -- be freed by the programmer (when it is no longer needed) to avoid
792 function Getenv (Name : String) return String_Access;
793 -- Get the value of the environment variable. Returns an access to the
794 -- empty string if the environment variable does not exist or has an
795 -- explicit null value (in some operating systems these are distinct
796 -- cases, in others they are not; this interface abstracts away that
797 -- difference. The argument is allocated on the heap (even in the null
798 -- case), and needs to be freed explicitly when no longer needed to avoid
801 procedure Setenv (Name : String; Value : String);
802 -- Set the value of the environment variable Name to Value. This call
803 -- modifies the current environment, but does not modify the parent
804 -- process environment. After a call to Setenv, Getenv (Name) will always
805 -- return a String_Access referencing the same String as Value. This is
806 -- true also for the null string case (the actual effect may be to either
807 -- set an explicit null as the value, or to remove the entry, this is
808 -- operating system dependent). Note that any following calls to Spawn
809 -- will pass an environment to the spawned process that includes the
810 -- changes made by Setenv calls. This procedure is not available on VMS.
812 procedure OS_Exit (Status : Integer);
813 pragma Import (C, OS_Exit, "__gnat_os_exit");
814 pragma No_Return (OS_Exit);
815 -- Exit to OS with given status code (program is terminated). Note that
816 -- this is abrupt termination. All tasks are immediately terminated. There
817 -- is no finalization or other cleanup actions performed.
820 pragma Import (C, OS_Abort, "abort");
821 pragma No_Return (OS_Abort);
822 -- Exit to OS signalling an abort (traceback or other appropriate
823 -- diagnostic information should be given if possible, or entry made to
824 -- the debugger if that is possible).
826 function Errno return Integer;
827 pragma Import (C, Errno, "__get_errno");
828 -- Return the task-safe last error number
830 procedure Set_Errno (Errno : Integer);
831 pragma Import (C, Set_Errno, "__set_errno");
832 -- Set the task-safe error number
834 Directory_Separator : constant Character;
835 -- The character that is used to separate parts of a pathname
837 Path_Separator : constant Character;
838 -- The character to separate paths in an environment variable value
841 pragma Import (C, Path_Separator, "__gnat_path_separator");
842 pragma Import (C, Directory_Separator, "__gnat_dir_separator");
843 pragma Import (C, Current_Time, "__gnat_current_time");
845 type OS_Time is new Long_Integer;
846 -- Type used for timestamps in the compiler. This type is used to hold
847 -- time stamps, but may have a different representation than C's time_t.
848 -- This type needs to match the declaration of OS_Time in adaint.h.
850 -- Add pragma Inline statements for comparison operations on OS_Time. It
851 -- would actually be nice to use pragma Import (Intrinsic) here, but this
852 -- was not properly supported till GNAT 3.15a, so that would cause
853 -- bootstrap path problems. To be changed later ???
855 Invalid_Time : constant OS_Time := -1;
856 -- This value should match the return valud by __gnat_file_time_*
860 pragma Inline ("<=");
861 pragma Inline (">=");
863 type Process_Id is new Integer;
864 Invalid_Pid : constant Process_Id := -1;