1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S Y S T E M . O S _ L I B -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1995-2012, Free Software Foundation, Inc. -- 10-- -- 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 3, 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. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- Operating system interface facilities 33 34-- This package contains types and procedures for interfacing to the 35-- underlying OS. It is used by the GNAT compiler and by tools associated 36-- with the GNAT compiler, and therefore works for the various operating 37-- systems to which GNAT has been ported. This package will undoubtedly grow 38-- as new services are needed by various tools. 39 40-- This package tends to use fairly low-level Ada in order to not bring in 41-- large portions of the RTL. For example, functions return access to string 42-- as part of avoiding functions returning unconstrained types. 43 44-- Except where specifically noted, these routines are portable across all 45-- GNAT implementations on all supported operating systems. 46 47-- Note: this package is in the System hierarchy so that it can be directly 48-- be used by other predefined packages. User access to this package is via 49-- a renaming of this package in GNAT.OS_Lib (file g-os_lib.ads). 50 51pragma Compiler_Unit; 52 53with System; 54with System.Strings; 55 56package System.OS_Lib is 57 pragma Preelaborate; 58 59 ----------------------- 60 -- String Operations -- 61 ----------------------- 62 63 -- These are reexported from package Strings (which was introduced to 64 -- avoid different packages declaring different types unnecessarily). 65 -- See package System.Strings for details. 66 67 subtype String_Access is Strings.String_Access; 68 69 function "=" (Left, Right : String_Access) return Boolean 70 renames Strings."="; 71 72 procedure Free (X : in out String_Access) renames Strings.Free; 73 74 subtype String_List is Strings.String_List; 75 76 function "=" (Left, Right : String_List) return Boolean 77 renames Strings."="; 78 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."&"; 87 88 subtype String_List_Access is Strings.String_List_Access; 89 90 function "=" (Left, Right : String_List_Access) return Boolean 91 renames Strings."="; 92 93 procedure Free (Arg : in out String_List_Access) 94 renames Strings.Free; 95 96 --------------------- 97 -- Time/Date Stuff -- 98 --------------------- 99 100 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). 109 110 Invalid_Time : constant OS_Time; 111 -- A special unique value used to flag an invalid time stamp value 112 113 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 120 121 function Current_Time return OS_Time; 122 -- Return the system clock value as OS_Time 123 124 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 131 132 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. 139 140 procedure GM_Split 141 (Date : OS_Time; 142 Year : out Year_Type; 143 Month : out Month_Type; 144 Day : out Day_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 and 149 -- provides a representation of it as a set of component parts, to be 150 -- interpreted as a date point in UTC. 151 152 ---------------- 153 -- File Stuff -- 154 ---------------- 155 156 -- 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 160 -- routines. 161 162 -- 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). 167 168 type File_Descriptor is new Integer; 169 -- Corresponds to the int file handle values used in the C routines 170 171 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 175 176 Invalid_FD : constant File_Descriptor := -1; 177 -- File descriptor returned when error in opening/creating file 178 179 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. 189 190 function Open_Read 191 (Name : String; 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. 195 196 function Open_Read_Write 197 (Name : String; 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. 201 202 function Create_File 203 (Name : String; 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. If the file already exists, it is 207 -- overwritten. File descriptor returned is Invalid_FD if file cannot be 208 -- successfully created. 209 210 function Create_Output_Text_File (Name : String) return File_Descriptor; 211 -- Creates new text file with given name suitable to redirect standard 212 -- output, returning file descriptor. File descriptor returned is 213 -- Invalid_FD if file cannot be successfully created. 214 215 function Create_New_File 216 (Name : String; 217 Fmode : Mode) return File_Descriptor; 218 -- Create new file with given name for writing, returning file descriptor 219 -- for subsequent use in Write calls. This differs from Create_File in 220 -- that it fails if the file already exists. File descriptor returned is 221 -- Invalid_FD if the file exists or cannot be created. 222 223 Temp_File_Len : constant Integer := 12; 224 -- Length of name returned by Create_Temp_File call (GNAT-XXXXXX & NUL) 225 226 subtype Temp_File_Name is String (1 .. Temp_File_Len); 227 -- String subtype set by Create_Temp_File 228 229 procedure Create_Temp_File 230 (FD : out File_Descriptor; 231 Name : out Temp_File_Name); 232 -- Create and open for writing a temporary file in the current working 233 -- directory. The name of the file and the File Descriptor are returned. 234 -- The File Descriptor returned is Invalid_FD in the case of failure. No 235 -- mode parameter is provided. Since this is a temporary file, there is no 236 -- point in doing text translation on it. 237 -- 238 -- On some operating systems, the maximum number of temp files that can be 239 -- created with this procedure may be limited. When the maximum is reached, 240 -- this procedure returns Invalid_FD. On some operating systems, there may 241 -- be a race condition between processes trying to create temp files at the 242 -- same time in the same directory using this procedure. 243 244 procedure Create_Temp_File 245 (FD : out File_Descriptor; 246 Name : out String_Access); 247 -- Create and open for writing a temporary file in the current working 248 -- directory. The name of the file and the File Descriptor are returned. 249 -- It is the responsibility of the caller to deallocate the access value 250 -- returned in Name. 251 -- 252 -- The file is opened in binary mode (no text translation). 253 -- 254 -- This procedure will always succeed if the current working directory is 255 -- writable. If the current working directory is not writable, then 256 -- Invalid_FD is returned for the file descriptor and null for the Name. 257 -- There is no race condition problem between processes trying to create 258 -- temp files at the same time in the same directory. 259 260 procedure Create_Temp_Output_File 261 (FD : out File_Descriptor; 262 Name : out String_Access); 263 -- Create and open for writing a temporary file in the current working 264 -- directory suitable to redirect standard output. The name of the file and 265 -- the File Descriptor are returned. It is the responsibility of the caller 266 -- to deallocate the access value returned in Name. 267 -- 268 -- The file is opened in text mode 269 -- 270 -- This procedure will always succeed if the current working directory is 271 -- writable. If the current working directory is not writable, then 272 -- Invalid_FD is returned for the file descriptor and null for the Name. 273 -- There is no race condition problem between processes trying to create 274 -- temp files at the same time in the same directory. 275 276 procedure Close (FD : File_Descriptor; Status : out Boolean); 277 -- Close file referenced by FD. Status is False if the underlying service 278 -- failed. Reasons for failure include: disk full, disk quotas exceeded 279 -- and invalid file descriptor (the file may have been closed twice). 280 281 procedure Close (FD : File_Descriptor); 282 -- Close file referenced by FD. This form is used when the caller wants to 283 -- ignore any possible error (see above for error cases). 284 285 procedure Set_Close_On_Exec 286 (FD : File_Descriptor; 287 Close_On_Exec : Boolean; 288 Status : out Boolean); 289 -- When Close_On_Exec is True, mark FD to be closed automatically when new 290 -- program is executed by the calling process (i.e. prevent FD from being 291 -- inherited by child processes). When Close_On_Exec is False, mark FD to 292 -- not be closed on exec (i.e. allow it to be inherited). Status is False 293 -- if the operation could not be performed. 294 295 procedure Delete_File (Name : String; Success : out Boolean); 296 -- Deletes file. Success is set True or False indicating if the delete is 297 -- successful. 298 299 procedure Rename_File 300 (Old_Name : String; 301 New_Name : String; 302 Success : out Boolean); 303 -- Rename a file. Success is set True or False indicating if the rename is 304 -- successful or not. 305 306 -- The following defines the mode for the Copy_File procedure below. Note 307 -- that "time stamps and other file attributes" in the descriptions below 308 -- refers to the creation and last modification times, and also the file 309 -- access (read/write/execute) status flags. 310 311 type Copy_Mode is 312 (Copy, 313 -- Copy the file. It is an error if the target file already exists. The 314 -- time stamps and other file attributes are preserved in the copy. 315 316 Overwrite, 317 -- If the target file exists, the file is replaced otherwise the file 318 -- is just copied. The time stamps and other file attributes are 319 -- preserved in the copy. 320 321 Append); 322 -- If the target file exists, the contents of the source file is 323 -- appended at the end. Otherwise the source file is just copied. The 324 -- time stamps and other file attributes are preserved if the 325 -- destination file does not exist. 326 327 type Attribute is 328 (Time_Stamps, 329 -- Copy time stamps from source file to target file. All other 330 -- attributes are set to normal default values for file creation. 331 332 Full, 333 -- All attributes are copied from the source file to the target file. 334 -- This includes the timestamps, and for example also includes 335 -- read/write/execute attributes in Unix systems. 336 337 None); 338 -- No attributes are copied. All attributes including the time stamp 339 -- values are set to normal default values for file creation. 340 341 -- Note: The default is Time_Stamps, which corresponds to the normal 342 -- default on Windows style systems. Full corresponds to the typical 343 -- effect of "cp -p" on Unix systems, and None corresponds to the typical 344 -- effect of "cp" on Unix systems. 345 346 -- Note: Time_Stamps and Full are not supported on VMS and VxWorks 5 347 348 procedure Copy_File 349 (Name : String; 350 Pathname : String; 351 Success : out Boolean; 352 Mode : Copy_Mode := Copy; 353 Preserve : Attribute := Time_Stamps); 354 -- Copy a file. Name must designate a single file (no wild cards allowed). 355 -- Pathname can be a filename or directory name. In the latter case Name 356 -- is copied into the directory preserving the same file name. Mode 357 -- defines the kind of copy, see above with the default being a normal 358 -- copy in which the target file must not already exist. Success is set to 359 -- True or False indicating if the copy is successful (depending on the 360 -- specified Mode). 361 -- 362 -- Note: this procedure is only supported to a very limited extent on VMS. 363 -- The only supported mode is Overwrite, and the only supported value for 364 -- Preserve is None, resulting in the default action which for Overwrite 365 -- is to leave attributes unchanged. Furthermore, the copy only works for 366 -- simple text files. 367 368 procedure Copy_Time_Stamps (Source, Dest : String; Success : out Boolean); 369 -- Copy Source file time stamps (last modification and last access time 370 -- stamps) to Dest file. Source and Dest must be valid filenames, 371 -- furthermore Dest must be writable. Success will be set to True if the 372 -- operation was successful and False otherwise. 373 -- 374 -- Note: this procedure is not supported on VMS and VxWorks 5. On these 375 -- platforms, Success is always set to False. 376 377 function Read 378 (FD : File_Descriptor; 379 A : System.Address; 380 N : Integer) return Integer; 381 -- Read N bytes to address A from file referenced by FD. Returned value is 382 -- count of bytes actually read, which can be less than N at EOF. 383 384 function Write 385 (FD : File_Descriptor; 386 A : System.Address; 387 N : Integer) return Integer; 388 -- Write N bytes from address A to file referenced by FD. The returned 389 -- value is the number of bytes written, which can be less than N if a 390 -- disk full condition was detected. 391 392 Seek_Cur : constant := 1; 393 Seek_End : constant := 2; 394 Seek_Set : constant := 0; 395 -- Used to indicate origin for Lseek call 396 397 procedure Lseek 398 (FD : File_Descriptor; 399 offset : Long_Integer; 400 origin : Integer); 401 pragma Import (C, Lseek, "__gnat_lseek"); 402 -- Sets the current file pointer to the indicated offset value, relative 403 -- to the current position (origin = SEEK_CUR), end of file (origin = 404 -- SEEK_END), or start of file (origin = SEEK_SET). 405 406 function File_Length (FD : File_Descriptor) return Long_Integer; 407 pragma Import (C, File_Length, "__gnat_file_length"); 408 -- Get length of file from file descriptor FD 409 410 function File_Time_Stamp (Name : String) return OS_Time; 411 -- Given the name of a file or directory, Name, obtains and returns the 412 -- time stamp. This function can be used for an unopened file. Returns 413 -- Invalid_Time is Name doesn't correspond to an existing file. 414 415 function File_Time_Stamp (FD : File_Descriptor) return OS_Time; 416 -- Get time stamp of file from file descriptor FD Returns Invalid_Time is 417 -- FD doesn't correspond to an existing file. 418 419 function Normalize_Pathname 420 (Name : String; 421 Directory : String := ""; 422 Resolve_Links : Boolean := True; 423 Case_Sensitive : Boolean := True) return String; 424 -- Returns a file name as an absolute path name, resolving all relative 425 -- directories, and symbolic links. The parameter Directory is a fully 426 -- resolved path name for a directory, or the empty string (the default). 427 -- Name is the name of a file, which is either relative to the given 428 -- directory name, if Directory is non-null, or to the current working 429 -- directory if Directory is null. The result returned is the normalized 430 -- name of the file. For most cases, if two file names designate the same 431 -- file through different paths, Normalize_Pathname will return the same 432 -- canonical name in both cases. However, there are cases when this is not 433 -- true; for example, this is not true in Unix for two hard links 434 -- designating the same file. 435 -- 436 -- On Windows, the returned path will start with a drive letter except 437 -- when Directory is not empty and does not include a drive letter. If 438 -- Directory is empty (the default) and Name is a relative path or an 439 -- absolute path without drive letter, the letter of the current drive 440 -- will start the returned path. If Case_Sensitive is True (the default), 441 -- then this drive letter will be forced to upper case ("C:\..."). 442 -- 443 -- If Resolve_Links is set to True, then the symbolic links, on systems 444 -- that support them, will be fully converted to the name of the file or 445 -- directory pointed to. This is slightly less efficient, since it 446 -- requires system calls. 447 -- 448 -- If Name cannot be resolved or is null on entry (for example if there is 449 -- symbolic link circularity, e.g. A is a symbolic link for B, and B is a 450 -- symbolic link for A), then Normalize_Pathname returns an empty string. 451 -- 452 -- In VMS, if Name follows the VMS syntax file specification, it is first 453 -- converted into Unix syntax. If the conversion fails, Normalize_Pathname 454 -- returns an empty string. 455 -- 456 -- For case-sensitive file systems, the value of Case_Sensitive parameter 457 -- is ignored. For file systems that are not case-sensitive, such as 458 -- Windows and OpenVMS, if this parameter is set to False, then the file 459 -- and directory names are folded to lower case. This allows checking 460 -- whether two files are the same by applying this function to their names 461 -- and comparing the results. If Case_Sensitive is set to True, this 462 -- function does not change the casing of file and directory names. 463 464 function Is_Absolute_Path (Name : String) return Boolean; 465 -- Returns True if Name is an absolute path name, i.e. it designates a 466 -- file or directory absolutely rather than relative to another directory. 467 468 function Is_Regular_File (Name : String) return Boolean; 469 -- Determines if the given string, Name, is the name of an existing 470 -- regular file. Returns True if so, False otherwise. Name may be an 471 -- absolute path name or a relative path name, including a simple file 472 -- name. If it is a relative path name, it is relative to the current 473 -- working directory. 474 475 function Is_Directory (Name : String) return Boolean; 476 -- Determines if the given string, Name, is the name of a directory. 477 -- Returns True if so, False otherwise. Name may be an absolute path 478 -- name or a relative path name, including a simple file name. If it is 479 -- a relative path name, it is relative to the current working directory. 480 481 function Is_Readable_File (Name : String) return Boolean; 482 -- Determines if the given string, Name, is the name of an existing file 483 -- that is readable. Returns True if so, False otherwise. Note that this 484 -- function simply interrogates the file attributes (e.g. using the C 485 -- function stat), so it does not indicate a situation in which a file may 486 -- not actually be readable due to some other process having exclusive 487 -- access. 488 489 function Is_Executable_File (Name : String) return Boolean; 490 -- Determines if the given string, Name, is the name of an existing file 491 -- that is executable. Returns True if so, False otherwise. Note that this 492 -- function simply interrogates the file attributes (e.g. using the C 493 -- function stat), so it does not indicate a situation in which a file may 494 -- not actually be readable due to some other process having exclusive 495 -- access. 496 497 function Is_Writable_File (Name : String) return Boolean; 498 -- Determines if the given string, Name, is the name of an existing file 499 -- that is writable. Returns True if so, False otherwise. Note that this 500 -- function simply interrogates the file attributes (e.g. using the C 501 -- function stat), so it does not indicate a situation in which a file may 502 -- not actually be writeable due to some other process having exclusive 503 -- access. 504 505 function Is_Symbolic_Link (Name : String) return Boolean; 506 -- Determines if the given string, Name, is the path of a symbolic link on 507 -- systems that support it. Returns True if so, False if the path is not a 508 -- symbolic link or if the system does not support symbolic links. 509 -- 510 -- A symbolic link is an indirect pointer to a file; its directory entry 511 -- contains the name of the file to which it is linked. Symbolic links may 512 -- span file systems and may refer to directories. 513 514 procedure Set_Writable (Name : String); 515 -- Change permissions on the named file to make it writable for its owner 516 517 procedure Set_Non_Writable (Name : String); 518 -- Change permissions on the named file to make it non-writable for its 519 -- owner. The readable and executable permissions are not modified. 520 521 procedure Set_Read_Only (Name : String) renames Set_Non_Writable; 522 -- This renaming is provided for backwards compatibility with previous 523 -- versions. The use of Set_Non_Writable is preferred (clearer name). 524 525 procedure Set_Executable (Name : String); 526 -- Change permissions on the named file to make it executable for its owner 527 528 procedure Set_Readable (Name : String); 529 -- Change permissions on the named file to make it readable for its 530 -- owner. 531 532 procedure Set_Non_Readable (Name : String); 533 -- Change permissions on the named file to make it non-readable for 534 -- its owner. The writable and executable permissions are not 535 -- modified. 536 537 function Locate_Exec_On_Path 538 (Exec_Name : String) return String_Access; 539 -- Try to locate an executable whose name is given by Exec_Name in the 540 -- directories listed in the environment Path. If the Exec_Name does not 541 -- have the executable suffix, it will be appended before the search. 542 -- Otherwise works like Locate_Regular_File below. If the executable is 543 -- not found, null is returned. 544 -- 545 -- Note that this function allocates memory for the returned value. This 546 -- memory needs to be deallocated after use. 547 548 function Locate_Regular_File 549 (File_Name : String; 550 Path : String) return String_Access; 551 -- Try to locate a regular file whose name is given by File_Name in the 552 -- directories listed in Path. If a file is found, its full pathname is 553 -- returned; otherwise, a null pointer is returned. If the File_Name given 554 -- is an absolute pathname, then Locate_Regular_File just checks that the 555 -- file exists and is a regular file. Otherwise, if the File_Name given 556 -- includes directory information, Locate_Regular_File first checks if the 557 -- file exists relative to the current directory. If it does not, or if 558 -- the File_Name given is a simple file name, the Path argument is parsed 559 -- according to OS conventions, and for each directory in the Path a check 560 -- is made if File_Name is a relative pathname of a regular file from that 561 -- directory. 562 -- 563 -- Note that this function allocates some memory for the returned value. 564 -- This memory needs to be deallocated after use. 565 566 function Get_Debuggable_Suffix return String_Access; 567 -- Return the debuggable suffix convention. Usually this is the same as 568 -- the convention for Get_Executable_Suffix. The result is allocated on 569 -- the heap and should be freed after use to avoid storage leaks. 570 571 function Get_Target_Debuggable_Suffix return String_Access; 572 -- Return the target debuggable suffix convention. Usually this is the same 573 -- as the convention for Get_Executable_Suffix. The result is allocated on 574 -- the heap and should be freed after use to avoid storage leaks. 575 576 function Get_Executable_Suffix return String_Access; 577 -- Return the executable suffix convention. The result is allocated on the 578 -- heap and should be freed after use to avoid storage leaks. 579 580 function Get_Object_Suffix return String_Access; 581 -- Return the object suffix convention. The result is allocated on the heap 582 -- and should be freed after use to avoid storage leaks. 583 584 function Get_Target_Executable_Suffix return String_Access; 585 -- Return the target executable suffix convention. The result is allocated 586 -- on the heap and should be freed after use to avoid storage leaks. 587 588 function Get_Target_Object_Suffix return String_Access; 589 -- Return the target object suffix convention. The result is allocated on 590 -- the heap and should be freed after use to avoid storage leaks. 591 592 -- The following section contains low-level routines using addresses to 593 -- pass file name and executable name. In each routine the name must be 594 -- Nul-Terminated. For complete documentation refer to the equivalent 595 -- routine (using String in place of C_File_Name) defined above. 596 597 subtype C_File_Name is System.Address; 598 -- This subtype is used to document that a parameter is the address of a 599 -- null-terminated string containing the name of a file. 600 601 -- All the following functions need comments ??? 602 603 function Open_Read 604 (Name : C_File_Name; 605 Fmode : Mode) return File_Descriptor; 606 607 function Open_Read_Write 608 (Name : C_File_Name; 609 Fmode : Mode) return File_Descriptor; 610 611 function Create_File 612 (Name : C_File_Name; 613 Fmode : Mode) return File_Descriptor; 614 615 function Create_New_File 616 (Name : C_File_Name; 617 Fmode : Mode) return File_Descriptor; 618 619 procedure Delete_File (Name : C_File_Name; Success : out Boolean); 620 621 procedure Rename_File 622 (Old_Name : C_File_Name; 623 New_Name : C_File_Name; 624 Success : out Boolean); 625 626 procedure Copy_File 627 (Name : C_File_Name; 628 Pathname : C_File_Name; 629 Success : out Boolean; 630 Mode : Copy_Mode := Copy; 631 Preserve : Attribute := Time_Stamps); 632 633 procedure Copy_Time_Stamps 634 (Source, Dest : C_File_Name; 635 Success : out Boolean); 636 637 function File_Time_Stamp (Name : C_File_Name) return OS_Time; 638 -- Returns Invalid_Time is Name doesn't correspond to an existing file 639 640 function Is_Regular_File (Name : C_File_Name) return Boolean; 641 function Is_Directory (Name : C_File_Name) return Boolean; 642 function Is_Readable_File (Name : C_File_Name) return Boolean; 643 function Is_Executable_File (Name : C_File_Name) return Boolean; 644 function Is_Writable_File (Name : C_File_Name) return Boolean; 645 function Is_Symbolic_Link (Name : C_File_Name) return Boolean; 646 647 function Locate_Regular_File 648 (File_Name : C_File_Name; 649 Path : C_File_Name) return String_Access; 650 651 ------------------ 652 -- Subprocesses -- 653 ------------------ 654 655 subtype Argument_List is String_List; 656 -- Type used for argument list in call to Spawn. The lower bound of the 657 -- array should be 1, and the length of the array indicates the number of 658 -- arguments. 659 660 subtype Argument_List_Access is String_List_Access; 661 -- Type used to return Argument_List without dragging in secondary stack. 662 -- Note that there is a Free procedure declared for this subtype which 663 -- frees the array and all referenced strings. 664 665 procedure Normalize_Arguments (Args : in out Argument_List); 666 -- Normalize all arguments in the list. This ensure that the argument list 667 -- is compatible with the running OS and will works fine with Spawn and 668 -- Non_Blocking_Spawn for example. If Normalize_Arguments is called twice 669 -- on the same list it will do nothing the second time. Note that Spawn 670 -- and Non_Blocking_Spawn call Normalize_Arguments automatically, but 671 -- since there is a guarantee that a second call does nothing, this 672 -- internal call will have no effect if Normalize_Arguments is called 673 -- before calling Spawn. The call to Normalize_Arguments assumes that the 674 -- individual referenced arguments in Argument_List are on the heap, and 675 -- may free them and reallocate if they are modified. 676 677 procedure Spawn 678 (Program_Name : String; 679 Args : Argument_List; 680 Success : out Boolean); 681 -- This procedure spawns a program with a given list of arguments. The 682 -- first parameter of is the name of the executable. The second parameter 683 -- contains the arguments to be passed to this program. Success is False 684 -- if the named program could not be spawned or its execution completed 685 -- unsuccessfully. Note that the caller will be blocked until the 686 -- execution of the spawned program is complete. For maximum portability, 687 -- use a full path name for the Program_Name argument. On some systems 688 -- (notably Unix systems) a simple file name may also work (if the 689 -- executable can be located in the path). 690 -- 691 -- Spawning processes from tasking programs is not recommended. See 692 -- "NOTE: Spawn in tasking programs" below. 693 -- 694 -- Note: Arguments in Args that contain spaces and/or quotes such as 695 -- "--GCC=gcc -v" or "--GCC=""gcc -v""" are not portable across all 696 -- operating systems, and would not have the desired effect if they were 697 -- passed directly to the operating system. To avoid this problem, Spawn 698 -- makes an internal call to Normalize_Arguments, which ensures that such 699 -- arguments are modified in a manner that ensures that the desired effect 700 -- is obtained on all operating systems. The caller may call 701 -- Normalize_Arguments explicitly before the call (e.g. to print out the 702 -- exact form of arguments passed to the operating system). In this case 703 -- the guarantee a second call to Normalize_Arguments has no effect 704 -- ensures that the internal call will not affect the result. Note that 705 -- the implicit call to Normalize_Arguments may free and reallocate some 706 -- of the individual arguments. 707 -- 708 -- This function will always set Success to False under VxWorks and other 709 -- similar operating systems which have no notion of the concept of 710 -- dynamically executable file. Otherwise Success is set True if the exit 711 -- status of the spawned process is zero. 712 713 function Spawn 714 (Program_Name : String; 715 Args : Argument_List) return Integer; 716 -- Similar to the above procedure, but returns the actual status returned 717 -- by the operating system, or -1 under VxWorks and any other similar 718 -- operating systems which have no notion of separately spawnable programs. 719 -- 720 -- Spawning processes from tasking programs is not recommended. See 721 -- "NOTE: Spawn in tasking programs" below. 722 723 procedure Spawn 724 (Program_Name : String; 725 Args : Argument_List; 726 Output_File_Descriptor : File_Descriptor; 727 Return_Code : out Integer; 728 Err_To_Out : Boolean := True); 729 -- Similar to the procedure above, but redirects the output to the file 730 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the 731 -- Standard Error output is also redirected. 732 -- Return_Code is set to the status code returned by the operating system 733 -- 734 -- Spawning processes from tasking programs is not recommended. See 735 -- "NOTE: Spawn in tasking programs" below. 736 737 procedure Spawn 738 (Program_Name : String; 739 Args : Argument_List; 740 Output_File : String; 741 Success : out Boolean; 742 Return_Code : out Integer; 743 Err_To_Out : Boolean := True); 744 -- Similar to the procedure above, but saves the output of the command to 745 -- a file with the name Output_File. 746 -- 747 -- Success is set to True if the command is executed and its output 748 -- successfully written to the file. If Success is True, then Return_Code 749 -- will be set to the status code returned by the operating system. 750 -- Otherwise, Return_Code is undefined. 751 -- 752 -- Spawning processes from tasking programs is not recommended. See 753 -- "NOTE: Spawn in tasking programs" below. 754 755 type Process_Id is private; 756 -- A private type used to identify a process activated by the following 757 -- non-blocking calls. The only meaningful operation on this type is a 758 -- comparison for equality. 759 760 Invalid_Pid : constant Process_Id; 761 -- A special value used to indicate errors, as described below 762 763 function Pid_To_Integer (Pid : Process_Id) return Integer; 764 -- Convert a process id to an Integer. Useful for writing hash functions 765 -- for type Process_Id or to compare two Process_Id (e.g. for sorting). 766 767 function Non_Blocking_Spawn 768 (Program_Name : String; 769 Args : Argument_List) return Process_Id; 770 -- This is a non blocking call. The Process_Id of the spawned process is 771 -- returned. Parameters are to be used as in Spawn. If Invalid_Pid is 772 -- returned the program could not be spawned. 773 -- 774 -- Spawning processes from tasking programs is not recommended. See 775 -- "NOTE: Spawn in tasking programs" below. 776 -- 777 -- This function will always return Invalid_Pid under VxWorks, since there 778 -- is no notion of executables under this OS. 779 780 function Non_Blocking_Spawn 781 (Program_Name : String; 782 Args : Argument_List; 783 Output_File_Descriptor : File_Descriptor; 784 Err_To_Out : Boolean := True) return Process_Id; 785 -- Similar to the procedure above, but redirects the output to the file 786 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the 787 -- Standard Error output is also redirected. Invalid_Pid is returned 788 -- if the program could not be spawned successfully. 789 -- 790 -- Spawning processes from tasking programs is not recommended. See 791 -- "NOTE: Spawn in tasking programs" below. 792 -- 793 -- This function will always return Invalid_Pid under VxWorks, since there 794 -- is no notion of executables under this OS. 795 796 function Non_Blocking_Spawn 797 (Program_Name : String; 798 Args : Argument_List; 799 Output_File : String; 800 Err_To_Out : Boolean := True) return Process_Id; 801 -- Similar to the procedure above, but saves the output of the command to 802 -- a file with the name Output_File. 803 -- 804 -- Success is set to True if the command is executed and its output 805 -- successfully written to the file. Invalid_Pid is returned if the output 806 -- file could not be created or if the program could not be spawned 807 -- successfully. 808 -- 809 -- Spawning processes from tasking programs is not recommended. See 810 -- "NOTE: Spawn in tasking programs" below. 811 -- 812 -- This function will always return Invalid_Pid under VxWorks, since there 813 -- is no notion of executables under this OS. 814 815 procedure Wait_Process (Pid : out Process_Id; Success : out Boolean); 816 -- Wait for the completion of any of the processes created by previous 817 -- calls to Non_Blocking_Spawn. The caller will be suspended until one of 818 -- these processes terminates (normally or abnormally). If any of these 819 -- subprocesses terminates prior to the call to Wait_Process (and has not 820 -- been returned by a previous call to Wait_Process), then the call to 821 -- Wait_Process is immediate. Pid identifies the process that has 822 -- terminated (matching the value returned from Non_Blocking_Spawn). 823 -- Success is set to True if this sub-process terminated successfully. If 824 -- Pid = Invalid_Pid, there were no subprocesses left to wait on. 825 -- 826 -- This function will always set success to False under VxWorks, since 827 -- there is no notion of executables under this OS. 828 829 function Argument_String_To_List 830 (Arg_String : String) return Argument_List_Access; 831 -- Take a string that is a program and its arguments and parse it into an 832 -- Argument_List. Note that the result is allocated on the heap, and must 833 -- be freed by the programmer (when it is no longer needed) to avoid 834 -- memory leaks. 835 836 ------------------------------------- 837 -- NOTE: Spawn in Tasking Programs -- 838 ------------------------------------- 839 840 -- Spawning processes in tasking programs using the above Spawn and 841 -- Non_Blocking_Spawn subprograms is not recommended, because there are 842 -- subtle interactions between creating a process and signals/locks that 843 -- can cause trouble. These issues are not specific to Ada; they depend 844 -- primarily on the operating system. 845 846 -- If you need to spawn processes in a tasking program, you will need to 847 -- understand the semantics of your operating system, and you are likely to 848 -- write non-portable code, because operating systems differ in this area. 849 850 -- The Spawn and Non_Blocking_Spawn subprograms call the following 851 -- operating system functions: 852 853 -- On Windows: spawnvp (blocking) or CreateProcess (non-blocking) 854 855 -- On Solaris: fork1, followed in the child process by execv 856 857 -- On other Unix-like systems, and on VMS: fork, followed in the child 858 -- process by execv. 859 860 -- On vxworks, nucleus, and RTX, spawning of processes is not supported 861 862 -- For details, look at the functions __gnat_portable_spawn and 863 -- __gnat_portable_no_block_spawn in adaint.c. 864 865 -- You should read the operating-system-specific documentation for the 866 -- above functions, paying special attention to subtle interactions with 867 -- threading, signals, locks, and file descriptors. Most of the issues are 868 -- related to the fact that on Unix, there is a window of time between fork 869 -- and execv; Windows does not have this problem, because spawning is done 870 -- in a single operation. 871 872 -- On Posix-compliant systems, such as Linux, fork duplicates just the 873 -- calling thread. (On Solaris, fork1 is the Posix-compliant version of 874 -- fork.) 875 876 -- You should avoid using signals while spawning. This includes signals 877 -- used internally by the Ada run-time system, such as timer signals used 878 -- to implement delay statements. 879 880 -- It is best to spawn any subprocesses very early, before the parent 881 -- process creates tasks, locks, or installs signal handlers. Certainly 882 -- avoid doing simultaneous spawns from multiple threads of the same 883 -- process. 884 885 -- There is no problem spawning a subprocess that uses tasking: the 886 -- problems are caused only by tasking in the parent. 887 888 -- If the parent is using tasking, and needs to spawn subprocesses at 889 -- arbitrary times, one technique is for the parent to spawn (very early) 890 -- a particular spawn-manager subprocess whose job is to spawn other 891 -- processes. The spawn-manager must avoid tasking. The parent sends 892 -- messages to the spawn-manager requesting it to spawn processes, using 893 -- whatever inter-process communication mechanism you like, such as 894 -- sockets. 895 896 -- In short, mixing spawning of subprocesses with tasking is a tricky 897 -- business, and should be avoided if possible, but if it is necessary, 898 -- the above guidelines should be followed, and you should beware of 899 -- portability problems. 900 901 ------------------- 902 -- Miscellaneous -- 903 ------------------- 904 905 function Getenv (Name : String) return String_Access; 906 -- Get the value of the environment variable. Returns an access to the 907 -- empty string if the environment variable does not exist or has an 908 -- explicit null value (in some operating systems these are distinct 909 -- cases, in others they are not; this interface abstracts away that 910 -- difference. The argument is allocated on the heap (even in the null 911 -- case), and needs to be freed explicitly when no longer needed to avoid 912 -- memory leaks. 913 914 procedure Setenv (Name : String; Value : String); 915 -- Set the value of the environment variable Name to Value. This call 916 -- modifies the current environment, but does not modify the parent 917 -- process environment. After a call to Setenv, Getenv (Name) will always 918 -- return a String_Access referencing the same String as Value. This is 919 -- true also for the null string case (the actual effect may be to either 920 -- set an explicit null as the value, or to remove the entry, this is 921 -- operating system dependent). Note that any following calls to Spawn 922 -- will pass an environment to the spawned process that includes the 923 -- changes made by Setenv calls. This procedure is not available on VMS. 924 925 procedure OS_Exit (Status : Integer); 926 pragma No_Return (OS_Exit); 927 928 -- Exit to OS with given status code (program is terminated). Note that 929 -- this is abrupt termination. All tasks are immediately terminated. There 930 -- are no finalization or other Ada-specific cleanup actions performed. On 931 -- systems with atexit handlers (such as Unix and Windows), atexit handlers 932 -- are called. 933 934 type OS_Exit_Subprogram is access procedure (Status : Integer); 935 936 procedure OS_Exit_Default (Status : Integer); 937 pragma No_Return (OS_Exit_Default); 938 -- Default implementation of procedure OS_Exit 939 940 OS_Exit_Ptr : OS_Exit_Subprogram := OS_Exit_Default'Access; 941 -- OS_Exit is implemented through this access value. It it then possible to 942 -- change the implementation of OS_Exit by redirecting OS_Exit_Ptr to an 943 -- other implementation. 944 945 procedure OS_Abort; 946 pragma Import (C, OS_Abort, "abort"); 947 pragma No_Return (OS_Abort); 948 -- Exit to OS signalling an abort (traceback or other appropriate 949 -- diagnostic information should be given if possible, or entry made to 950 -- the debugger if that is possible). 951 952 function Errno return Integer; 953 pragma Import (C, Errno, "__get_errno"); 954 -- Return the task-safe last error number 955 956 procedure Set_Errno (Errno : Integer); 957 pragma Import (C, Set_Errno, "__set_errno"); 958 -- Set the task-safe error number 959 960 Directory_Separator : constant Character; 961 -- The character that is used to separate parts of a pathname 962 963 Path_Separator : constant Character; 964 -- The character to separate paths in an environment variable value 965 966private 967 pragma Import (C, Path_Separator, "__gnat_path_separator"); 968 pragma Import (C, Directory_Separator, "__gnat_dir_separator"); 969 pragma Import (C, Current_Time, "__gnat_current_time"); 970 971 type OS_Time is 972 range -(2 ** (Standard'Address_Size - Integer'(1))) .. 973 +(2 ** (Standard'Address_Size - Integer'(1)) - 1); 974 -- Type used for timestamps in the compiler. This type is used to hold 975 -- time stamps, but may have a different representation than C's time_t. 976 -- This type needs to match the declaration of OS_Time in adaint.h. 977 978 -- Add pragma Inline statements for comparison operations on OS_Time. It 979 -- would actually be nice to use pragma Import (Intrinsic) here, but this 980 -- was not properly supported till GNAT 3.15a, so that would cause 981 -- bootstrap path problems. To be changed later ??? 982 983 Invalid_Time : constant OS_Time := -1; 984 -- This value should match the return value from __gnat_file_time_* 985 986 pragma Inline ("<"); 987 pragma Inline (">"); 988 pragma Inline ("<="); 989 pragma Inline (">="); 990 991 type Process_Id is new Integer; 992 Invalid_Pid : constant Process_Id := -1; 993 994end System.OS_Lib; 995