1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- G N A T . O S _ L I B --
9 -- Copyright (C) 1995-2005, 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 : in 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 : in 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 : in 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 GM_Year (Date : OS_Time) return Year_Type;
118 function GM_Month (Date : OS_Time) return Month_Type;
119 function GM_Day (Date : OS_Time) return Day_Type;
120 function GM_Hour (Date : OS_Time) return Hour_Type;
121 function GM_Minute (Date : OS_Time) return Minute_Type;
122 function GM_Second (Date : OS_Time) return Second_Type;
123 -- Functions to extract information from OS_Time value
125 function "<" (X, Y : OS_Time) return Boolean;
126 function ">" (X, Y : OS_Time) return Boolean;
127 function ">=" (X, Y : OS_Time) return Boolean;
128 function "<=" (X, Y : OS_Time) return Boolean;
129 -- Basic comparison operators on OS_Time with obvious meanings. Note that
130 -- these have Intrinsic convention, so for example it is not permissible
131 -- to create accesses to any of these functions.
135 Year : out Year_Type;
136 Month : out Month_Type;
138 Hour : out Hour_Type;
139 Minute : out Minute_Type;
140 Second : out Second_Type);
141 -- Analogous to the routine of similar name in Calendar, takes an OS_Time
142 -- and splits it into its component parts with obvious meanings.
148 -- These routines give access to the open/creat/close/read/write level of
149 -- I/O routines in the typical C library (these functions are not part of
150 -- the ANSI C standard, but are typically available in all systems). See
151 -- also package Interfaces.C_Streams for access to the stream level
154 -- Note on file names. If a file name is passed as type String in any of
155 -- the following specifications, then the name is a normal Ada string and
156 -- need not be NUL-terminated. However, a trailing NUL character is
157 -- permitted, and will be ignored (more accurately, the NUL and any
158 -- characters that follow it will be ignored).
160 type File_Descriptor is new Integer;
161 -- Corresponds to the int file handle values used in the C routines
163 Standin : constant File_Descriptor := 0;
164 Standout : constant File_Descriptor := 1;
165 Standerr : constant File_Descriptor := 2;
166 -- File descriptors for standard input output files
168 Invalid_FD : constant File_Descriptor := -1;
169 -- File descriptor returned when error in opening/creating file;
171 type Mode is (Binary, Text);
172 for Mode'Size use Integer'Size;
173 for Mode use (Binary => 0, Text => 1);
174 -- Used in all the Open and Create calls to specify if the file is to be
175 -- opened in binary mode or text mode. In systems like Unix, this has no
176 -- effect, but in systems capable of text mode translation, the use of
177 -- Text as the mode parameter causes the system to do CR/LF translation
178 -- and also to recognize the DOS end of file character on input. The use
179 -- of Text where appropriate allows programs to take a portable Unix view
180 -- of DOS-format files and process them appropriately.
184 Fmode : Mode) return File_Descriptor;
185 -- Open file Name for reading, returning file descriptor File descriptor
186 -- returned is Invalid_FD if file cannot be opened.
188 function Open_Read_Write
190 Fmode : Mode) return File_Descriptor;
191 -- Open file Name for both reading and writing, returning file descriptor.
192 -- File descriptor returned is Invalid_FD if file cannot be opened.
196 Fmode : Mode) return File_Descriptor;
197 -- Creates new file with given name for writing, returning file descriptor
198 -- for subsequent use in Write calls. File descriptor returned is
199 -- Invalid_FD if file cannot be successfully created.
201 function Create_Output_Text_File (Name : String) return File_Descriptor;
202 -- Creates new text file with given name suitable to redirect standard
203 -- output, returning file descriptor. File descriptor returned is
204 -- Invalid_FD if file cannot be successfully created.
206 function Create_New_File
208 Fmode : Mode) return File_Descriptor;
209 -- Create new file with given name for writing, returning file descriptor
210 -- for subsequent use in Write calls. This differs from Create_File in
211 -- that it fails if the file already exists. File descriptor returned is
212 -- Invalid_FD if the file exists or cannot be created.
214 Temp_File_Len : constant Integer := 12;
215 -- Length of name returned by Create_Temp_File call (GNAT-XXXXXX & NUL)
217 subtype Temp_File_Name is String (1 .. Temp_File_Len);
218 -- String subtype set by Create_Temp_File
220 procedure Create_Temp_File
221 (FD : out File_Descriptor;
222 Name : out Temp_File_Name);
223 -- Create and open for writing a temporary file in the current working
224 -- directory. The name of the file and the File Descriptor are returned.
225 -- The File Descriptor returned is Invalid_FD in the case of failure. No
226 -- mode parameter is provided. Since this is a temporary file, there is no
227 -- point in doing text translation on it.
229 -- On some OSes, the maximum number of temp files that can be created with
230 -- this procedure may be limited. When the maximum is reached, this
231 -- procedure returns Invalid_FD. On some OSes, there may be a race
232 -- condition between processes trying to create temp files at the same
233 -- time in the same directory using this procedure.
235 procedure Create_Temp_File
236 (FD : out File_Descriptor;
237 Name : out String_Access);
238 -- Create and open for writing a temporary file in the current working
239 -- directory. The name of the file and the File Descriptor are returned.
240 -- No mode parameter is provided. Since this is a temporary file, there is
241 -- no point in doing text translation on it. It is the responsibility of
242 -- the caller to deallocate the access value returned in Name.
244 -- This procedure will always succeed if the current working directory is
245 -- writable. If the current working directory is not writable, then
246 -- Invalid_FD is returned for the file descriptor and null for the Name.
247 -- There is no race condition problem between processes trying to create
248 -- temp files at the same time in the same directory.
250 procedure Close (FD : File_Descriptor; Status : out Boolean);
251 -- Close file referenced by FD. Status is False if the underlying service
252 -- failed. Reasons for failure include: disk full, disk quotas exceeded
253 -- and invalid file descriptor (the file may have been closed twice).
255 procedure Close (FD : File_Descriptor);
256 -- Close file referenced by FD. This form is used when the caller wants to
257 -- ignore any possible error (see above for error cases).
259 procedure Set_Close_On_Exec
260 (FD : File_Descriptor;
261 Close_On_Exec : Boolean;
262 Status : out Boolean);
263 -- When Close_On_Exec is True, mark FD to be closed automatically when new
264 -- program is executed by the calling process (i.e. prevent FD from being
265 -- inherited by child processes). When Close_On_Exec is False, mark FD to
266 -- not be closed on exec (i.e. allow it to be inherited). Status is False
267 -- if the operation could not be performed.
269 procedure Delete_File (Name : String; Success : out Boolean);
270 -- Deletes file. Success is set True or False indicating if the delete is
273 procedure Rename_File
276 Success : out Boolean);
277 -- Rename a file. Success is set True or False indicating if the rename is
278 -- successful or not.
280 -- The following defines the mode for the Copy_File procedure below. Note
281 -- that "time stamps and other file attributes" in the descriptions below
282 -- refers to the creation and last modification times, and also the file
283 -- access (read/write/execute) status flags.
287 -- Copy the file. It is an error if the target file already exists. The
288 -- time stamps and other file attributes are preserved in the copy.
291 -- If the target file exists, the file is replaced otherwise the file
292 -- is just copied. The time stamps and other file attributes are
293 -- preserved in the copy.
296 -- If the target file exists, the contents of the source file is
297 -- appended at the end. Otherwise the source file is just copied. The
298 -- time stamps and other file attributes are are preserved if the
299 -- destination file does not exist.
303 -- Copy time stamps from source file to target file. All other
304 -- attributes are set to normal default values for file creation.
307 -- All attributes are copied from the source file to the target file.
308 -- This includes the timestamps, and for example also includes
309 -- read/write/execute attributes in Unix systems.
312 -- No attributes are copied. All attributes including the time stamp
313 -- values are set to normal default values for file creation.
315 -- Note: The default is Time_Stamps, which corresponds to the normal
316 -- default on Windows style systems. Full corresponds to the typical
317 -- effect of "cp -p" on Unix systems, and None corresponds to the typical
318 -- effect of "cp" on Unix systems.
320 -- Note: Time_Stamps and Full are not supported on VMS and VxWorks
325 Success : out Boolean;
326 Mode : Copy_Mode := Copy;
327 Preserve : Attribute := Time_Stamps);
328 -- Copy a file. Name must designate a single file (no wild cards allowed).
329 -- Pathname can be a filename or directory name. In the latter case Name
330 -- is copied into the directory preserving the same file name. Mode
331 -- defines the kind of copy, see above with the default being a normal
332 -- copy in which the target file must not already exist. Success is set to
333 -- True or False indicating if the copy is successful (depending on the
336 -- Note: this procedure is only supported to a very limited extent on VMS.
337 -- The only supported mode is Overwrite, and the only supported value for
338 -- Preserve is None, resulting in the default action which for Overwrite
339 -- is to leave attributes unchanged. Furthermore, the copy only works for
340 -- simple text files.
342 procedure Copy_Time_Stamps (Source, Dest : String; Success : out Boolean);
343 -- Copy Source file time stamps (last modification and last access time
344 -- stamps) to Dest file. Source and Dest must be valid filenames,
345 -- furthermore Dest must be writable. Success will be set to True if the
346 -- operation was successful and False otherwise.
348 -- Note: this procedure is not supported on VMS and VxWorks. On these
349 -- platforms, Success is always set to False.
352 (FD : File_Descriptor;
354 N : Integer) return Integer;
355 -- Read N bytes to address A from file referenced by FD. Returned value is
356 -- count of bytes actually read, which can be less than N at EOF.
359 (FD : File_Descriptor;
361 N : Integer) return Integer;
362 -- Write N bytes from address A to file referenced by FD. The returned
363 -- value is the number of bytes written, which can be less than N if a
364 -- disk full condition was detected.
366 Seek_Cur : constant := 1;
367 Seek_End : constant := 2;
368 Seek_Set : constant := 0;
369 -- Used to indicate origin for Lseek call
372 (FD : File_Descriptor;
373 offset : Long_Integer;
375 pragma Import (C, Lseek, "__gnat_lseek");
376 -- Sets the current file pointer to the indicated offset value, relative
377 -- to the current position (origin = SEEK_CUR), end of file (origin =
378 -- SEEK_END), or start of file (origin = SEEK_SET).
380 function File_Length (FD : File_Descriptor) return Long_Integer;
381 pragma Import (C, File_Length, "__gnat_file_length");
382 -- Get length of file from file descriptor FD
384 function File_Time_Stamp (Name : String) return OS_Time;
385 -- Given the name of a file or directory, Name, obtains and returns the
386 -- time stamp. This function can be used for an unopened file. Returns
387 -- Invalid_Time is Name doesn't correspond to an existing file.
389 function File_Time_Stamp (FD : File_Descriptor) return OS_Time;
390 -- Get time stamp of file from file descriptor FD Returns Invalid_Time is
391 -- FD doesn't correspond to an existing file.
393 function Normalize_Pathname
395 Directory : String := "";
396 Resolve_Links : Boolean := True;
397 Case_Sensitive : Boolean := True) return String;
398 -- Returns a file name as an absolute path name, resolving all relative
399 -- directories, and symbolic links. The parameter Directory is a fully
400 -- resolved path name for a directory, or the empty string (the default).
401 -- Name is the name of a file, which is either relative to the given
402 -- directory name, if Directory is non-null, or to the current working
403 -- directory if Directory is null. The result returned is the normalized
404 -- name of the file. For most cases, if two file names designate the same
405 -- file through different paths, Normalize_Pathname will return the same
406 -- canonical name in both cases. However, there are cases when this is not
407 -- true; for example, this is not true in Unix for two hard links
408 -- designating the same file.
410 -- On Windows, the returned path will start with a drive letter except
411 -- when Directory is not empty and does not include a drive letter. If
412 -- Directory is empty (the default) and Name is a relative path or an
413 -- absolute path without drive letter, the letter of the current drive
414 -- will start the returned path. If Case_Sensitive is True (the default),
415 -- then this drive letter will be forced to upper case ("C:\...").
417 -- If Resolve_Links is set to True, then the symbolic links, on systems
418 -- that support them, will be fully converted to the name of the file or
419 -- directory pointed to. This is slightly less efficient, since it
420 -- requires system calls.
422 -- If Name cannot be resolved or is null on entry (for example if there is
423 -- symbolic link circularity, e.g. A is a symbolic link for B, and B is a
424 -- symbolic link for A), then Normalize_Pathname returns an empty string.
426 -- In VMS, if Name follows the VMS syntax file specification, it is first
427 -- converted into Unix syntax. If the conversion fails, Normalize_Pathname
428 -- returns an empty string.
430 -- For case-sensitive file systems, the value of Case_Sensitive parameter
431 -- is ignored. For file systems that are not case-sensitive, such as
432 -- Windows and OpenVMS, if this parameter is set to False, then the file
433 -- and directory names are folded to lower case. This allows checking
434 -- whether two files are the same by applying this function to their names
435 -- and comparing the results. If Case_Sensitive is set to True, this
436 -- function does not change the casing of file and directory names.
438 function Is_Absolute_Path (Name : String) return Boolean;
439 -- Returns True if Name is an absolute path name, i.e. it designates a
440 -- file or directory absolutely rather than relative to another directory.
442 function Is_Regular_File (Name : String) return Boolean;
443 -- Determines if the given string, Name, is the name of an existing
444 -- regular file. Returns True if so, False otherwise. Name may be an
445 -- absolute path name or a relative path name, including a simple file
446 -- name. If it is a relative path name, it is relative to the current
447 -- working directory.
449 function Is_Directory (Name : String) return Boolean;
450 -- Determines if the given string, Name, is the name of a directory.
451 -- Returns True if so, False otherwise. Name may be an absolute path
452 -- name or a relative path name, including a simple file name. If it is
453 -- a relative path name, it is relative to the current working directory.
455 function Is_Readable_File (Name : String) return Boolean;
456 -- Determines if the given string, Name, is the name of an existing file
457 -- that is readable. Returns True if so, False otherwise. Note that this
458 -- function simply interrogates the file attributes (e.g. using the C
459 -- function stat), so it does not indicate a situation in which a file may
460 -- not actually be readable due to some other process having exclusive
463 function Is_Writable_File (Name : String) return Boolean;
464 -- Determines if the given string, Name, is the name of an existing file
465 -- that is writable. 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 writeable due to some other process having exclusive
471 function Is_Symbolic_Link (Name : String) return Boolean;
472 -- Determines if the given string, Name, is the path of a symbolic link on
473 -- systems that support it. Returns True if so, False if the path is not a
474 -- symbolic link or if the system does not support symbolic links.
476 -- A symbolic link is an indirect pointer to a file; its directory entry
477 -- contains the name of the file to which it is linked. Symbolic links may
478 -- span file systems and may refer to directories.
480 procedure Set_Writable (Name : String);
481 -- Change the permissions on the named file to make it writable
484 procedure Set_Read_Only (Name : String);
485 -- Change the permissions on the named file to make it non-writable
488 procedure Set_Executable (Name : String);
489 -- Change the permissions on the named file to make it executable
492 function Locate_Exec_On_Path
493 (Exec_Name : String) return String_Access;
494 -- Try to locate an executable whose name is given by Exec_Name in the
495 -- directories listed in the environment Path. If the Exec_Name doesn't
496 -- have the executable suffix, it will be appended before the search.
497 -- Otherwise works like Locate_Regular_File below.
499 -- Note that this function allocates some memory for the returned value.
500 -- This memory needs to be deallocated after use.
502 function Locate_Regular_File
504 Path : String) return String_Access;
505 -- Try to locate a regular file whose name is given by File_Name in the
506 -- directories listed in Path. If a file is found, its full pathname is
507 -- returned; otherwise, a null pointer is returned. If the File_Name given
508 -- is an absolute pathname, then Locate_Regular_File just checks that the
509 -- file exists and is a regular file. Otherwise, if the File_Name given
510 -- includes directory information, Locate_Regular_File first checks if the
511 -- file exists relative to the current directory. If it does not, or if
512 -- the File_Name given is a simple file name, the Path argument is parsed
513 -- according to OS conventions, and for each directory in the Path a check
514 -- is made if File_Name is a relative pathname of a regular file from that
517 -- Note that this function allocates some memory for the returned value.
518 -- This memory needs to be deallocated after use.
520 function Get_Debuggable_Suffix return String_Access;
521 -- Return the debuggable suffix convention. Usually this is the same as
522 -- the convention for Get_Executable_Suffix. The result is allocated on
523 -- the heap and should be freed after use to avoid storage leaks.
525 function Get_Target_Debuggable_Suffix return String_Access;
526 -- Return the target debuggable suffix convention. Usually this is the
527 -- same as the convention for Get_Executable_Suffix. The result is
528 -- allocated on the heap and should be freed after use to avoid storage
531 function Get_Executable_Suffix return String_Access;
532 -- Return the executable suffix convention. The result is allocated on the
533 -- heap and should be freed after use to avoid storage leaks.
535 function Get_Object_Suffix return String_Access;
536 -- Return the object suffix convention. The result is allocated on the heap
537 -- and should be freed after use to avoid storage leaks.
539 function Get_Target_Executable_Suffix return String_Access;
540 -- Return the target executable suffix convention. The result is allocated
541 -- on the heap and should be freed after use to avoid storage leaks.
543 function Get_Target_Object_Suffix return String_Access;
544 -- Return the target object suffix convention. The result is allocated on
545 -- the heap and should be freed after use to avoid storage leaks.
547 -- The following section contains low-level routines using addresses to
548 -- pass file name and executable name. In each routine the name must be
549 -- Nul-Terminated. For complete documentation refer to the equivalent
550 -- routine (using String in place of C_File_Name) defined above.
552 subtype C_File_Name is System.Address;
553 -- This subtype is used to document that a parameter is the address of a
554 -- null-terminated string containing the name of a file.
556 -- All the following functions need comments ???
560 Fmode : Mode) return File_Descriptor;
562 function Open_Read_Write
564 Fmode : Mode) return File_Descriptor;
568 Fmode : Mode) return File_Descriptor;
570 function Create_New_File
572 Fmode : Mode) return File_Descriptor;
574 procedure Delete_File (Name : C_File_Name; Success : out Boolean);
576 procedure Rename_File
577 (Old_Name : C_File_Name;
578 New_Name : C_File_Name;
579 Success : out Boolean);
583 Pathname : C_File_Name;
584 Success : out Boolean;
585 Mode : Copy_Mode := Copy;
586 Preserve : Attribute := Time_Stamps);
588 procedure Copy_Time_Stamps
589 (Source, Dest : C_File_Name;
590 Success : out Boolean);
592 function File_Time_Stamp (Name : C_File_Name) return OS_Time;
593 -- Returns Invalid_Time is Name doesn't correspond to an existing file
595 function Is_Regular_File (Name : C_File_Name) return Boolean;
596 function Is_Directory (Name : C_File_Name) return Boolean;
597 function Is_Readable_File (Name : C_File_Name) return Boolean;
598 function Is_Writable_File (Name : C_File_Name) return Boolean;
599 function Is_Symbolic_Link (Name : C_File_Name) return Boolean;
601 function Locate_Regular_File
602 (File_Name : C_File_Name;
604 return String_Access;
610 subtype Argument_List is String_List;
611 -- Type used for argument list in call to Spawn. The lower bound of the
612 -- array should be 1, and the length of the array indicates the number of
615 subtype Argument_List_Access is String_List_Access;
616 -- Type used to return Argument_List without dragging in secondary stack.
617 -- Note that there is a Free procedure declared for this subtype which
618 -- frees the array and all referenced strings.
620 procedure Normalize_Arguments (Args : in out Argument_List);
621 -- Normalize all arguments in the list. This ensure that the argument list
622 -- is compatible with the running OS and will works fine with Spawn and
623 -- Non_Blocking_Spawn for example. If Normalize_Arguments is called twice
624 -- on the same list it will do nothing the second time. Note that Spawn
625 -- and Non_Blocking_Spawn call Normalize_Arguments automatically, but
626 -- since there is a guarantee that a second call does nothing, this
627 -- internal call will have no effect if Normalize_Arguments is called
628 -- before calling Spawn. The call to Normalize_Arguments assumes that the
629 -- individual referenced arguments in Argument_List are on the heap, and
630 -- may free them and reallocate if they are modified.
633 (Program_Name : String;
634 Args : Argument_List;
635 Success : out Boolean);
636 -- This procedure spawns a program with a given list of arguments. The
637 -- first parameter of is the name of the executable. The second parameter
638 -- contains the arguments to be passed to this program. Success is False
639 -- if the named program could not be spawned or its execution completed
640 -- unsuccessfully. Note that the caller will be blocked until the
641 -- execution of the spawned program is complete. For maximum portability,
642 -- use a full path name for the Program_Name argument. On some systems
643 -- (notably Unix systems) a simple file name may also work (if the
644 -- executable can be located in the path).
646 -- "Spawn" should not be used in tasking applications. Why not??? More
647 -- documentation would be helpful here ??? Is it really tasking programs,
648 -- or tasking activity that cause trouble ???
650 -- Note: Arguments in Args that contain spaces and/or quotes such as
651 -- "--GCC=gcc -v" or "--GCC=""gcc -v""" are not portable across all
652 -- operating systems, and would not have the desired effect if they were
653 -- passed directly to the operating system. To avoid this problem, Spawn
654 -- makes an internal call to Normalize_Arguments, which ensures that such
655 -- arguments are modified in a manner that ensures that the desired effect
656 -- is obtained on all operating systems. The caller may call
657 -- Normalize_Arguments explicitly before the call (e.g. to print out the
658 -- exact form of arguments passed to the operating system). In this case
659 -- the guarantee a second call to Normalize_Arguments has no effect
660 -- ensures that the internal call will not affect the result. Note that
661 -- the implicit call to Normalize_Arguments may free and reallocate some
662 -- of the individual arguments.
664 -- This function will always set Success to False under VxWorks and other
665 -- similar operating systems which have no notion of the concept of
666 -- dynamically executable file.
669 (Program_Name : String;
670 Args : Argument_List)
672 -- Similar to the above procedure, but returns the actual status returned
673 -- by the operating system, or -1 under VxWorks and any other similar
674 -- operating systems which have no notion of separately spawnable programs.
676 -- "Spawn" should not be used in tasking applications.
679 (Program_Name : String;
680 Args : Argument_List;
681 Output_File_Descriptor : File_Descriptor;
682 Return_Code : out Integer;
683 Err_To_Out : Boolean := True);
684 -- Similar to the procedure above, but redirects the output to the file
685 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the
686 -- Standard Error output is also redirected.
687 -- Return_Code is set to the status code returned by the operating system
689 -- "Spawn" should not be used in tasking applications.
692 (Program_Name : String;
693 Args : Argument_List;
694 Output_File : String;
695 Success : out Boolean;
696 Return_Code : out Integer;
697 Err_To_Out : Boolean := True);
698 -- Similar to the procedure above, but saves the output of the command to
699 -- a file with the name Output_File.
701 -- Success is set to True if the command is executed and its output
702 -- successfully written to the file. If Success is True, then Return_Code
703 -- will be set to the status code returned by the operating system.
704 -- Otherwise, Return_Code is undefined.
706 -- "Spawn" should not be used in tasking applications.
708 type Process_Id is private;
709 -- A private type used to identify a process activated by the following
710 -- non-blocking call. The only meaningful operation on this type is a
711 -- comparison for equality.
713 Invalid_Pid : constant Process_Id;
714 -- A special value used to indicate errors, as described below
716 function Non_Blocking_Spawn
717 (Program_Name : String;
718 Args : Argument_List)
720 -- This is a non blocking call. The Process_Id of the spawned process is
721 -- returned. Parameters are to be used as in Spawn. If Invalid_Pid is
722 -- returned the program could not be spawned.
724 -- "Non_Blocking_Spawn" should not be used in tasking applications.
726 -- This function will always return Invalid_Pid under VxWorks, since there
727 -- is no notion of executables under this OS.
729 function Non_Blocking_Spawn
730 (Program_Name : String;
731 Args : Argument_List;
732 Output_File_Descriptor : File_Descriptor;
733 Err_To_Out : Boolean := True) return Process_Id;
734 -- Similar to the procedure above, but redirects the output to the file
735 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the
736 -- Standard Error output is also redirected. Invalid_Pid is returned
737 -- if the program could not be spawned successfully.
739 -- "Non_Blocking_Spawn" should not be used in tasking applications.
741 -- This function will always return Invalid_Pid under VxWorks, since there
742 -- is no notion of executables under this OS.
744 function Non_Blocking_Spawn
745 (Program_Name : String;
746 Args : Argument_List;
747 Output_File : String;
748 Err_To_Out : Boolean := True)
750 -- Similar to the procedure above, but saves the output of the command to
751 -- a file with the name Output_File.
753 -- Success is set to True if the command is executed and its output
754 -- successfully written to the file. Invalid_Pid is returned if the output
755 -- file could not be created or if the program could not be spawned
758 -- "Non_Blocking_Spawn" should not be used in tasking applications.
760 -- This function will always return Invalid_Pid under VxWorks, since there
761 -- is no notion of executables under this OS.
763 procedure Wait_Process (Pid : out Process_Id; Success : out Boolean);
764 -- Wait for the completion of any of the processes created by previous
765 -- calls to Non_Blocking_Spawn. The caller will be suspended until one of
766 -- these processes terminates (normally or abnormally). If any of these
767 -- subprocesses terminates prior to the call to Wait_Process (and has not
768 -- been returned by a previous call to Wait_Process), then the call to
769 -- Wait_Process is immediate. Pid identifies the process that has
770 -- terminated (matching the value returned from Non_Blocking_Spawn).
771 -- Success is set to True if this sub-process terminated successfully. If
772 -- Pid = Invalid_Pid, there were no subprocesses left to wait on.
774 -- This function will always set success to False under VxWorks, since
775 -- there is no notion of executables under this OS.
777 function Argument_String_To_List
778 (Arg_String : String) return Argument_List_Access;
779 -- Take a string that is a program and its arguments and parse it into an
780 -- Argument_List. Note that the result is allocated on the heap, and must
781 -- be freed by the programmer (when it is no longer needed) to avoid
788 function Getenv (Name : String) return String_Access;
789 -- Get the value of the environment variable. Returns an access to the
790 -- empty string if the environment variable does not exist or has an
791 -- explicit null value (in some operating systems these are distinct
792 -- cases, in others they are not; this interface abstracts away that
793 -- difference. The argument is allocated on the heap (even in the null
794 -- case), and needs to be freed explicitly when no longer needed to avoid
797 procedure Setenv (Name : String; Value : String);
798 -- Set the value of the environment variable Name to Value. This call
799 -- modifies the current environment, but does not modify the parent
800 -- process environment. After a call to Setenv, Getenv (Name) will always
801 -- return a String_Access referencing the same String as Value. This is
802 -- true also for the null string case (the actual effect may be to either
803 -- set an explicit null as the value, or to remove the entry, this is
804 -- operating system dependent). Note that any following calls to Spawn
805 -- will pass an environment to the spawned process that includes the
806 -- changes made by Setenv calls. This procedure is not available on VMS.
808 procedure OS_Exit (Status : Integer);
809 pragma Import (C, OS_Exit, "__gnat_os_exit");
810 pragma No_Return (OS_Exit);
811 -- Exit to OS with given status code (program is terminated)
814 pragma Import (C, OS_Abort, "abort");
815 pragma No_Return (OS_Abort);
816 -- Exit to OS signalling an abort (traceback or other appropriate
817 -- diagnostic information should be given if possible, or entry made to
818 -- the debugger if that is possible).
820 function Errno return Integer;
821 pragma Import (C, Errno, "__get_errno");
822 -- Return the task-safe last error number
824 procedure Set_Errno (Errno : Integer);
825 pragma Import (C, Set_Errno, "__set_errno");
826 -- Set the task-safe error number
828 Directory_Separator : constant Character;
829 -- The character that is used to separate parts of a pathname
831 Path_Separator : constant Character;
832 -- The character to separate paths in an environment variable value
835 pragma Import (C, Path_Separator, "__gnat_path_separator");
836 pragma Import (C, Directory_Separator, "__gnat_dir_separator");
838 type OS_Time is new Long_Integer;
839 -- Type used for timestamps in the compiler. This type is used to hold
840 -- time stamps, but may have a different representation than C's time_t.
841 -- This type needs to match the declaration of OS_Time in adaint.h.
843 -- Add pragma Inline statements for comparison operations on OS_Time. It
844 -- would actually be nice to use pragma Import (Intrinsic) here, but this
845 -- was not properly supported till GNAT 3.15a, so that would cause
846 -- bootstrap path problems. To be changed later ???
848 Invalid_Time : constant OS_Time := -1;
849 -- This value should match the return valud by __gnat_file_time_*
853 pragma Inline ("<=");
854 pragma Inline (">=");
856 type Process_Id is new Integer;
857 Invalid_Pid : constant Process_Id := -1;
OSDN Git Service
