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) 1995-2015, 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 51-- Note: a distinct body for this spec is included in the .NET runtime library 52-- and must be kept in sync with changes made in this file. 53 54pragma Compiler_Unit_Warning; 55 56with System; 57with System.Strings; 58 59package System.OS_Lib is 60 pragma Preelaborate; 61 62 ----------------------- 63 -- String Operations -- 64 ----------------------- 65 66 -- These are reexported from package Strings (which was introduced to 67 -- avoid different packages declaring different types unnecessarily). 68 -- See package System.Strings for details. 69 70 subtype String_Access is Strings.String_Access; 71 72 function "=" (Left, Right : String_Access) return Boolean 73 renames Strings."="; 74 75 procedure Free (X : in out String_Access) renames Strings.Free; 76 77 subtype String_List is Strings.String_List; 78 79 function "=" (Left, Right : String_List) return Boolean 80 renames Strings."="; 81 82 function "&" (Left : String_Access; Right : String_Access) 83 return String_List renames Strings."&"; 84 function "&" (Left : String_Access; Right : String_List) 85 return String_List renames Strings."&"; 86 function "&" (Left : String_List; Right : String_Access) 87 return String_List renames Strings."&"; 88 function "&" (Left : String_List; Right : String_List) 89 return String_List renames Strings."&"; 90 91 subtype String_List_Access is Strings.String_List_Access; 92 93 function "=" (Left, Right : String_List_Access) return Boolean 94 renames Strings."="; 95 96 procedure Free (Arg : in out String_List_Access) 97 renames Strings.Free; 98 99 --------------------- 100 -- Time/Date Stuff -- 101 --------------------- 102 103 type OS_Time is private; 104 -- The OS's notion of time is represented by the private type OS_Time. This 105 -- is the type returned by the File_Time_Stamp functions to obtain the time 106 -- stamp of a specified file. Functions and a procedure (modeled after the 107 -- similar subprograms in package Calendar) are provided for extracting 108 -- information from a value of this type. Although these are called GM, the 109 -- intention in the case of time stamps is not that they provide GMT times 110 -- in all cases but rather the actual (time-zone independent) time stamp of 111 -- the file (of course in Unix systems, this *is* in GMT form). 112 113 Invalid_Time : constant OS_Time; 114 -- A special unique value used to flag an invalid time stamp value 115 116 subtype Year_Type is Integer range 1900 .. 2099; 117 subtype Month_Type is Integer range 1 .. 12; 118 subtype Day_Type is Integer range 1 .. 31; 119 subtype Hour_Type is Integer range 0 .. 23; 120 subtype Minute_Type is Integer range 0 .. 59; 121 subtype Second_Type is Integer range 0 .. 59; 122 -- Declarations similar to those in Calendar, breaking down the time 123 124 function Current_Time return OS_Time; 125 -- Return the system clock value as OS_Time 126 127 function GM_Year (Date : OS_Time) return Year_Type; 128 function GM_Month (Date : OS_Time) return Month_Type; 129 function GM_Day (Date : OS_Time) return Day_Type; 130 function GM_Hour (Date : OS_Time) return Hour_Type; 131 function GM_Minute (Date : OS_Time) return Minute_Type; 132 function GM_Second (Date : OS_Time) return Second_Type; 133 -- Functions to extract information from OS_Time value in GMT form 134 135 function "<" (X, Y : OS_Time) return Boolean; 136 function ">" (X, Y : OS_Time) return Boolean; 137 function ">=" (X, Y : OS_Time) return Boolean; 138 function "<=" (X, Y : OS_Time) return Boolean; 139 -- Basic comparison operators on OS_Time with obvious meanings. Note that 140 -- these have Intrinsic convention, so for example it is not permissible 141 -- to create accesses to any of these functions. 142 143 procedure GM_Split 144 (Date : OS_Time; 145 Year : out Year_Type; 146 Month : out Month_Type; 147 Day : out Day_Type; 148 Hour : out Hour_Type; 149 Minute : out Minute_Type; 150 Second : out Second_Type); 151 -- Analogous to the Split routine in Ada.Calendar, takes an OS_Time and 152 -- provides a representation of it as a set of component parts, to be 153 -- interpreted as a date point in UTC. 154 155 function GM_Time_Of 156 (Year : Year_Type; 157 Month : Month_Type; 158 Day : Day_Type; 159 Hour : Hour_Type; 160 Minute : Minute_Type; 161 Second : Second_Type) return OS_Time; 162 -- Analogous to the Time_Of routine in Ada.Calendar, takes a set of time 163 -- component parts to be interpreted in the local time zone, and returns 164 -- an OS_Time. Returns Invalid_Time if the creation fails. 165 166 function Current_Time_String return String; 167 -- Returns current local time in the form YYYY-MM-DD HH:MM:SS. The result 168 -- has bounds 1 .. 19. 169 170 ---------------- 171 -- File Stuff -- 172 ---------------- 173 174 -- These routines give access to the open/creat/close/read/write level of 175 -- I/O routines in the typical C library (these functions are not part of 176 -- the ANSI C standard, but are typically available in all systems). See 177 -- also package Interfaces.C_Streams for access to the stream level 178 -- routines. 179 180 -- Note on file names. If a file name is passed as type String in any of 181 -- the following specifications, then the name is a normal Ada string and 182 -- need not be NUL-terminated. However, a trailing NUL character is 183 -- permitted, and will be ignored (more accurately, the NUL and any 184 -- characters that follow it will be ignored). 185 186 type File_Descriptor is new Integer; 187 -- Corresponds to the int file handle values used in the C routines 188 189 Standin : constant File_Descriptor := 0; 190 Standout : constant File_Descriptor := 1; 191 Standerr : constant File_Descriptor := 2; 192 -- File descriptors for standard input output files 193 194 Invalid_FD : constant File_Descriptor := -1; 195 -- File descriptor returned when error in opening/creating file 196 197 type Mode is (Binary, Text); 198 for Mode'Size use Integer'Size; 199 for Mode use (Binary => 0, Text => 1); 200 -- Used in all the Open and Create calls to specify if the file is to be 201 -- opened in binary mode or text mode. In systems like Unix, this has no 202 -- effect, but in systems capable of text mode translation, the use of 203 -- Text as the mode parameter causes the system to do CR/LF translation 204 -- and also to recognize the DOS end of file character on input. The use 205 -- of Text where appropriate allows programs to take a portable Unix view 206 -- of DOS-format files and process them appropriately. 207 208 function Open_Read 209 (Name : String; 210 Fmode : Mode) return File_Descriptor; 211 -- Open file Name for reading, returning its file descriptor. File 212 -- descriptor returned is Invalid_FD if the file cannot be opened. 213 214 function Open_Read_Write 215 (Name : String; 216 Fmode : Mode) return File_Descriptor; 217 -- Open file Name for both reading and writing, returning its file 218 -- descriptor. File descriptor returned is Invalid_FD if the file 219 -- cannot be opened. 220 221 function Open_Append 222 (Name : String; 223 Fmode : Mode) return File_Descriptor; 224 -- Opens file Name for appending, returning its file descriptor. File 225 -- descriptor returned is Invalid_FD if the file cannot be successfully 226 -- opened. 227 228 function Create_File 229 (Name : String; 230 Fmode : Mode) return File_Descriptor; 231 -- Creates new file with given name for writing, returning file descriptor 232 -- for subsequent use in Write calls. If the file already exists, it is 233 -- overwritten. File descriptor returned is Invalid_FD if file cannot be 234 -- successfully created. 235 236 function Create_Output_Text_File (Name : String) return File_Descriptor; 237 -- Creates new text file with given name suitable to redirect standard 238 -- output, returning file descriptor. File descriptor returned is 239 -- Invalid_FD if file cannot be successfully created. 240 241 function Create_New_File 242 (Name : String; 243 Fmode : Mode) return File_Descriptor; 244 -- Create new file with given name for writing, returning file descriptor 245 -- for subsequent use in Write calls. This differs from Create_File in 246 -- that it fails if the file already exists. File descriptor returned is 247 -- Invalid_FD if the file exists or cannot be created. 248 249 Temp_File_Len : constant Integer := 12; 250 -- Length of name returned by Create_Temp_File call (GNAT-XXXXXX & NUL) 251 252 subtype Temp_File_Name is String (1 .. Temp_File_Len); 253 -- String subtype set by Create_Temp_File 254 255 procedure Create_Temp_File 256 (FD : out File_Descriptor; 257 Name : out Temp_File_Name); 258 -- Create and open for writing a temporary file in the current working 259 -- directory. The name of the file and the File Descriptor are returned. 260 -- The File Descriptor returned is Invalid_FD in the case of failure. No 261 -- mode parameter is provided. Since this is a temporary file, there is no 262 -- point in doing text translation on it. 263 -- 264 -- On some operating systems, the maximum number of temp files that can be 265 -- created with this procedure may be limited. When the maximum is reached, 266 -- this procedure returns Invalid_FD. On some operating systems, there may 267 -- be a race condition between processes trying to create temp files at the 268 -- same time in the same directory using this procedure. 269 270 procedure Create_Temp_File 271 (FD : out File_Descriptor; 272 Name : out String_Access); 273 -- Create and open for writing a temporary file in the current working 274 -- directory. The name of the file and the File Descriptor are returned. 275 -- It is the responsibility of the caller to deallocate the access value 276 -- returned in Name. 277 -- 278 -- The file is opened in binary mode (no text translation). 279 -- 280 -- This procedure will always succeed if the current working directory is 281 -- writable. If the current working directory is not writable, then 282 -- Invalid_FD is returned for the file descriptor and null for the Name. 283 -- There is no race condition problem between processes trying to create 284 -- temp files at the same time in the same directory. 285 286 procedure Create_Temp_Output_File 287 (FD : out File_Descriptor; 288 Name : out String_Access); 289 -- Create and open for writing a temporary file in the current working 290 -- directory suitable to redirect standard output. The name of the file and 291 -- the File Descriptor are returned. It is the responsibility of the caller 292 -- to deallocate the access value returned in Name. 293 -- 294 -- The file is opened in text mode 295 -- 296 -- This procedure will always succeed if the current working directory is 297 -- writable. If the current working directory is not writable, then 298 -- Invalid_FD is returned for the file descriptor and null for the Name. 299 -- There is no race condition problem between processes trying to create 300 -- temp files at the same time in the same directory. 301 302 procedure Close (FD : File_Descriptor; Status : out Boolean); 303 -- Close file referenced by FD. Status is False if the underlying service 304 -- failed. Reasons for failure include: disk full, disk quotas exceeded 305 -- and invalid file descriptor (the file may have been closed twice). 306 307 procedure Close (FD : File_Descriptor); 308 -- Close file referenced by FD. This form is used when the caller wants to 309 -- ignore any possible error (see above for error cases). 310 311 procedure Set_Close_On_Exec 312 (FD : File_Descriptor; 313 Close_On_Exec : Boolean; 314 Status : out Boolean); 315 -- When Close_On_Exec is True, mark FD to be closed automatically when new 316 -- program is executed by the calling process (i.e. prevent FD from being 317 -- inherited by child processes). When Close_On_Exec is False, mark FD to 318 -- not be closed on exec (i.e. allow it to be inherited). Status is False 319 -- if the operation could not be performed. 320 321 procedure Delete_File (Name : String; Success : out Boolean); 322 -- Deletes file. Success is set True or False indicating if the delete is 323 -- successful. 324 325 procedure Rename_File 326 (Old_Name : String; 327 New_Name : String; 328 Success : out Boolean); 329 -- Rename a file. Success is set True or False indicating if the rename is 330 -- successful or not. 331 -- 332 -- WARNING: In one very important respect, this function is significantly 333 -- non-portable. If New_Name already exists then on Unix systems, the call 334 -- deletes the existing file, and the call signals success. On Windows, the 335 -- call fails, without doing the rename operation. See also the procedure 336 -- Ada.Directories.Rename, which portably provides the windows semantics, 337 -- i.e. fails if the output file already exists. 338 339 -- The following defines the mode for the Copy_File procedure below. Note 340 -- that "time stamps and other file attributes" in the descriptions below 341 -- refers to the creation and last modification times, and also the file 342 -- access (read/write/execute) status flags. 343 344 type Copy_Mode is 345 (Copy, 346 -- Copy the file. It is an error if the target file already exists. The 347 -- time stamps and other file attributes are preserved in the copy. 348 349 Overwrite, 350 -- If the target file exists, the file is replaced otherwise the file 351 -- is just copied. The time stamps and other file attributes are 352 -- preserved in the copy. 353 354 Append); 355 -- If the target file exists, the contents of the source file is 356 -- appended at the end. Otherwise the source file is just copied. The 357 -- time stamps and other file attributes are preserved if the 358 -- destination file does not exist. 359 360 type Attribute is 361 (Time_Stamps, 362 -- Copy time stamps from source file to target file. All other 363 -- attributes are set to normal default values for file creation. 364 365 Full, 366 -- All attributes are copied from the source file to the target file. 367 -- This includes the timestamps, and for example also includes 368 -- read/write/execute attributes in Unix systems. 369 370 None); 371 -- No attributes are copied. All attributes including the time stamp 372 -- values are set to normal default values for file creation. 373 374 -- Note: The default is Time_Stamps, which corresponds to the normal 375 -- default on Windows style systems. Full corresponds to the typical 376 -- effect of "cp -p" on Unix systems, and None corresponds to the typical 377 -- effect of "cp" on Unix systems. 378 379 -- Note: Time_Stamps and Full are not supported on VxWorks 5 380 381 procedure Copy_File 382 (Name : String; 383 Pathname : String; 384 Success : out Boolean; 385 Mode : Copy_Mode := Copy; 386 Preserve : Attribute := Time_Stamps); 387 -- Copy a file. Name must designate a single file (no wild cards allowed). 388 -- Pathname can be a filename or directory name. In the latter case Name 389 -- is copied into the directory preserving the same file name. Mode 390 -- defines the kind of copy, see above with the default being a normal 391 -- copy in which the target file must not already exist. Success is set to 392 -- True or False indicating if the copy is successful (depending on the 393 -- specified Mode). 394 -- 395 procedure Copy_Time_Stamps (Source, Dest : String; Success : out Boolean); 396 -- Copy Source file time stamps (last modification and last access time 397 -- stamps) to Dest file. Source and Dest must be valid filenames, 398 -- furthermore Dest must be writable. Success will be set to True if the 399 -- operation was successful and False otherwise. 400 -- 401 -- Note: this procedure is not supported on VxWorks 5. On this platform, 402 -- Success is always set to False. 403 404 procedure Set_File_Last_Modify_Time_Stamp (Name : String; Time : OS_Time); 405 -- Given the name of a file or directory, Name, set the last modification 406 -- time stamp. This function must be used for an unopened file. 407 408 function Read 409 (FD : File_Descriptor; 410 A : System.Address; 411 N : Integer) return Integer; 412 -- Read N bytes to address A from file referenced by FD. Returned value is 413 -- count of bytes actually read, which can be less than N at EOF. 414 415 function Write 416 (FD : File_Descriptor; 417 A : System.Address; 418 N : Integer) return Integer; 419 -- Write N bytes from address A to file referenced by FD. The returned 420 -- value is the number of bytes written, which can be less than N if a 421 -- disk full condition was detected. 422 423 Seek_Cur : constant := 1; 424 Seek_End : constant := 2; 425 Seek_Set : constant := 0; 426 -- Used to indicate origin for Lseek call 427 428 procedure Lseek 429 (FD : File_Descriptor; 430 offset : Long_Integer; 431 origin : Integer); 432 pragma Import (C, Lseek, "__gnat_lseek"); 433 -- Sets the current file pointer to the indicated offset value, relative 434 -- to the current position (origin = SEEK_CUR), end of file (origin = 435 -- SEEK_END), or start of file (origin = SEEK_SET). 436 437 type Large_File_Size is range -2**63 .. 2**63 - 1; 438 -- Maximum supported size for a file (8 exabytes = 8 million terabytes, 439 -- should be enough to accomodate all possible needs for quite a while). 440 441 function File_Length (FD : File_Descriptor) return Long_Integer; 442 pragma Import (C, File_Length, "__gnat_file_length_long"); 443 444 function File_Length64 (FD : File_Descriptor) return Large_File_Size; 445 pragma Import (C, File_Length64, "__gnat_file_length"); 446 -- Get length of file from file descriptor FD 447 448 function File_Time_Stamp (Name : String) return OS_Time; 449 -- Given the name of a file or directory, Name, obtains and returns the 450 -- time stamp. This function can be used for an unopened file. Returns 451 -- Invalid_Time is Name doesn't correspond to an existing file. 452 453 function File_Time_Stamp (FD : File_Descriptor) return OS_Time; 454 -- Get time stamp of file from file descriptor FD Returns Invalid_Time is 455 -- FD doesn't correspond to an existing file. 456 457 function Normalize_Pathname 458 (Name : String; 459 Directory : String := ""; 460 Resolve_Links : Boolean := True; 461 Case_Sensitive : Boolean := True) return String; 462 -- Returns a file name as an absolute path name, resolving all relative 463 -- directories, and symbolic links. The parameter Directory is a fully 464 -- resolved path name for a directory, or the empty string (the default). 465 -- Name is the name of a file, which is either relative to the given 466 -- directory name, if Directory is non-null, or to the current working 467 -- directory if Directory is null. The result returned is the normalized 468 -- name of the file. For most cases, if two file names designate the same 469 -- file through different paths, Normalize_Pathname will return the same 470 -- canonical name in both cases. However, there are cases when this is not 471 -- true; for example, this is not true in Unix for two hard links 472 -- designating the same file. 473 -- 474 -- On Windows, the returned path will start with a drive letter except 475 -- when Directory is not empty and does not include a drive letter. If 476 -- Directory is empty (the default) and Name is a relative path or an 477 -- absolute path without drive letter, the letter of the current drive 478 -- will start the returned path. If Case_Sensitive is True (the default), 479 -- then this drive letter will be forced to upper case ("C:\..."). 480 -- 481 -- If Resolve_Links is set to True, then the symbolic links, on systems 482 -- that support them, will be fully converted to the name of the file or 483 -- directory pointed to. This is slightly less efficient, since it 484 -- requires system calls. 485 -- 486 -- If Name cannot be resolved, is invalid (for example if it is too big) or 487 -- is null on entry (for example if there is symbolic link circularity, 488 -- e.g. A is a symbolic link for B, and B is a symbolic link for A), then 489 -- Normalize_Pathname returns an empty string. 490 -- 491 -- For case-sensitive file systems, the value of Case_Sensitive parameter 492 -- is ignored. For file systems that are not case-sensitive, such as 493 -- Windows, if this parameter is set to False, then the file and directory 494 -- names are folded to lower case. This allows checking whether two files 495 -- are the same by applying this function to their names and comparing the 496 -- results. If Case_Sensitive is set to True, this function does not change 497 -- the casing of file and directory names. 498 499 function Is_Absolute_Path (Name : String) return Boolean; 500 -- Returns True if Name is an absolute path name, i.e. it designates a 501 -- file or directory absolutely rather than relative to another directory. 502 503 function Is_Regular_File (Name : String) return Boolean; 504 -- Determines if the given string, Name, is the name of an existing 505 -- regular file. Returns True if so, False otherwise. Name may be an 506 -- absolute path name or a relative path name, including a simple file 507 -- name. If it is a relative path name, it is relative to the current 508 -- working directory. 509 510 function Is_Directory (Name : String) return Boolean; 511 -- Determines if the given string, Name, is the name of a directory. 512 -- Returns True if so, False otherwise. Name may be an absolute path 513 -- name or a relative path name, including a simple file name. If it is 514 -- a relative path name, it is relative to the current working directory. 515 516 function Is_Readable_File (Name : String) return Boolean; 517 -- Determines if the given string, Name, is the name of an existing file 518 -- that is readable. Returns True if so, False otherwise. Note that this 519 -- function simply interrogates the file attributes (e.g. using the C 520 -- function stat), so it does not indicate a situation in which a file may 521 -- not actually be readable due to some other process having exclusive 522 -- access. 523 524 function Is_Executable_File (Name : String) return Boolean; 525 -- Determines if the given string, Name, is the name of an existing file 526 -- that is executable. Returns True if so, False otherwise. Note that this 527 -- function simply interrogates the file attributes (e.g. using the C 528 -- function stat), so it does not indicate a situation in which a file may 529 -- not actually be readable due to some other process having exclusive 530 -- access. 531 532 function Is_Writable_File (Name : String) return Boolean; 533 -- Determines if the given string, Name, is the name of an existing file 534 -- that is writable. Returns True if so, False otherwise. Note that this 535 -- function simply interrogates the file attributes (e.g. using the C 536 -- function stat), so it does not indicate a situation in which a file may 537 -- not actually be writeable due to some other process having exclusive 538 -- access. 539 540 function Is_Symbolic_Link (Name : String) return Boolean; 541 -- Determines if the given string, Name, is the path of a symbolic link on 542 -- systems that support it. Returns True if so, False if the path is not a 543 -- symbolic link or if the system does not support symbolic links. 544 -- 545 -- A symbolic link is an indirect pointer to a file; its directory entry 546 -- contains the name of the file to which it is linked. Symbolic links may 547 -- span file systems and may refer to directories. 548 549 procedure Set_Writable (Name : String); 550 -- Change permissions on the named file to make it writable for its owner 551 552 procedure Set_Non_Writable (Name : String); 553 -- Change permissions on the named file to make it non-writable for its 554 -- owner. The readable and executable permissions are not modified. 555 556 procedure Set_Read_Only (Name : String) renames Set_Non_Writable; 557 -- This renaming is provided for backwards compatibility with previous 558 -- versions. The use of Set_Non_Writable is preferred (clearer name). 559 560 S_Owner : constant := 1; 561 S_Group : constant := 2; 562 S_Others : constant := 4; 563 -- Constants for use in Mode parameter to Set_Executable 564 565 procedure Set_Executable (Name : String; Mode : Positive := S_Owner); 566 -- Change permissions on the file given by Name to make it executable 567 -- for its owner, group or others, according to the setting of Mode. 568 -- As indicated, the default if no Mode parameter is given is owner. 569 570 procedure Set_Readable (Name : String); 571 -- Change permissions on the named file to make it readable for its 572 -- owner. 573 574 procedure Set_Non_Readable (Name : String); 575 -- Change permissions on the named file to make it non-readable for 576 -- its owner. The writable and executable permissions are not 577 -- modified. 578 579 function Locate_Exec_On_Path 580 (Exec_Name : String) return String_Access; 581 -- Try to locate an executable whose name is given by Exec_Name in the 582 -- directories listed in the environment Path. If the Exec_Name does not 583 -- have the executable suffix, it will be appended before the search. 584 -- Otherwise works like Locate_Regular_File below. If the executable is 585 -- not found, null is returned. 586 -- 587 -- Note that this function allocates memory for the returned value. This 588 -- memory needs to be deallocated after use. 589 590 function Locate_Regular_File 591 (File_Name : String; 592 Path : String) return String_Access; 593 -- Try to locate a regular file whose name is given by File_Name in the 594 -- directories listed in Path. If a file is found, its full pathname is 595 -- returned; otherwise, a null pointer is returned. If the File_Name given 596 -- is an absolute pathname, then Locate_Regular_File just checks that the 597 -- file exists and is a regular file. Otherwise, if the File_Name given 598 -- includes directory information, Locate_Regular_File first checks if the 599 -- file exists relative to the current directory. If it does not, or if 600 -- the File_Name given is a simple file name, the Path argument is parsed 601 -- according to OS conventions, and for each directory in the Path a check 602 -- is made if File_Name is a relative pathname of a regular file from that 603 -- directory. 604 -- 605 -- Note that this function allocates some memory for the returned value. 606 -- This memory needs to be deallocated after use. 607 608 function Get_Debuggable_Suffix return String_Access; 609 -- Return the debuggable suffix convention. Usually this is the same as 610 -- the convention for Get_Executable_Suffix. The result is allocated on 611 -- the heap and should be freed after use to avoid storage leaks. 612 613 function Get_Target_Debuggable_Suffix return String_Access; 614 -- Return the target debuggable suffix convention. Usually this is the same 615 -- as the convention for Get_Executable_Suffix. The result is allocated on 616 -- the heap and should be freed after use to avoid storage leaks. 617 618 function Get_Executable_Suffix return String_Access; 619 -- Return the executable suffix convention. The result is allocated on the 620 -- heap and should be freed after use to avoid storage leaks. 621 622 function Get_Object_Suffix return String_Access; 623 -- Return the object suffix convention. The result is allocated on the heap 624 -- and should be freed after use to avoid storage leaks. 625 626 function Get_Target_Executable_Suffix return String_Access; 627 -- Return the target executable suffix convention. The result is allocated 628 -- on the heap and should be freed after use to avoid storage leaks. 629 630 function Get_Target_Object_Suffix return String_Access; 631 -- Return the target object suffix convention. The result is allocated on 632 -- the heap and should be freed after use to avoid storage leaks. 633 634 -- The following section contains low-level routines using addresses to 635 -- pass file name and executable name. In each routine the name must be 636 -- Nul-Terminated. For complete documentation refer to the equivalent 637 -- routine (using String in place of C_File_Name) defined above. 638 639 subtype C_File_Name is System.Address; 640 -- This subtype is used to document that a parameter is the address of a 641 -- null-terminated string containing the name of a file. 642 643 -- All the following functions need comments ??? 644 645 function Open_Read 646 (Name : C_File_Name; 647 Fmode : Mode) return File_Descriptor; 648 649 function Open_Read_Write 650 (Name : C_File_Name; 651 Fmode : Mode) return File_Descriptor; 652 653 function Open_Append 654 (Name : C_File_Name; 655 Fmode : Mode) return File_Descriptor; 656 657 function Create_File 658 (Name : C_File_Name; 659 Fmode : Mode) return File_Descriptor; 660 661 function Create_New_File 662 (Name : C_File_Name; 663 Fmode : Mode) return File_Descriptor; 664 665 procedure Delete_File (Name : C_File_Name; Success : out Boolean); 666 667 procedure Rename_File 668 (Old_Name : C_File_Name; 669 New_Name : C_File_Name; 670 Success : out Boolean); 671 672 procedure Copy_File 673 (Name : C_File_Name; 674 Pathname : C_File_Name; 675 Success : out Boolean; 676 Mode : Copy_Mode := Copy; 677 Preserve : Attribute := Time_Stamps); 678 679 procedure Copy_Time_Stamps 680 (Source, Dest : C_File_Name; 681 Success : out Boolean); 682 683 function File_Time_Stamp (Name : C_File_Name) return OS_Time; 684 -- Returns Invalid_Time is Name doesn't correspond to an existing file 685 686 function Is_Regular_File (Name : C_File_Name) return Boolean; 687 function Is_Directory (Name : C_File_Name) return Boolean; 688 function Is_Readable_File (Name : C_File_Name) return Boolean; 689 function Is_Executable_File (Name : C_File_Name) return Boolean; 690 function Is_Writable_File (Name : C_File_Name) return Boolean; 691 function Is_Symbolic_Link (Name : C_File_Name) return Boolean; 692 693 function Locate_Regular_File 694 (File_Name : C_File_Name; 695 Path : C_File_Name) return String_Access; 696 697 ------------------ 698 -- Subprocesses -- 699 ------------------ 700 701 subtype Argument_List is String_List; 702 -- Type used for argument list in call to Spawn. The lower bound of the 703 -- array should be 1, and the length of the array indicates the number of 704 -- arguments. 705 706 subtype Argument_List_Access is String_List_Access; 707 -- Type used to return Argument_List without dragging in secondary stack. 708 -- Note that there is a Free procedure declared for this subtype which 709 -- frees the array and all referenced strings. 710 711 procedure Normalize_Arguments (Args : in out Argument_List); 712 -- Normalize all arguments in the list. This ensure that the argument list 713 -- is compatible with the running OS and will works fine with Spawn and 714 -- Non_Blocking_Spawn for example. If Normalize_Arguments is called twice 715 -- on the same list it will do nothing the second time. Note that Spawn 716 -- and Non_Blocking_Spawn call Normalize_Arguments automatically, but 717 -- since there is a guarantee that a second call does nothing, this 718 -- internal call will have no effect if Normalize_Arguments is called 719 -- before calling Spawn. The call to Normalize_Arguments assumes that the 720 -- individual referenced arguments in Argument_List are on the heap, and 721 -- may free them and reallocate if they are modified. 722 723 procedure Spawn 724 (Program_Name : String; 725 Args : Argument_List; 726 Success : out Boolean); 727 -- This procedure spawns a program with a given list of arguments. The 728 -- first parameter of is the name of the executable. The second parameter 729 -- contains the arguments to be passed to this program. Success is False 730 -- if the named program could not be spawned or its execution completed 731 -- unsuccessfully. Note that the caller will be blocked until the 732 -- execution of the spawned program is complete. For maximum portability, 733 -- use a full path name for the Program_Name argument. On some systems 734 -- (notably Unix systems) a simple file name may also work (if the 735 -- executable can be located in the path). 736 -- 737 -- Spawning processes from tasking programs is not recommended. See 738 -- "NOTE: Spawn in tasking programs" below. 739 -- 740 -- Note: Arguments in Args that contain spaces and/or quotes such as 741 -- "--GCC=gcc -v" or "--GCC=""gcc -v""" are not portable across all 742 -- operating systems, and would not have the desired effect if they were 743 -- passed directly to the operating system. To avoid this problem, Spawn 744 -- makes an internal call to Normalize_Arguments, which ensures that such 745 -- arguments are modified in a manner that ensures that the desired effect 746 -- is obtained on all operating systems. The caller may call 747 -- Normalize_Arguments explicitly before the call (e.g. to print out the 748 -- exact form of arguments passed to the operating system). In this case 749 -- the guarantee a second call to Normalize_Arguments has no effect 750 -- ensures that the internal call will not affect the result. Note that 751 -- the implicit call to Normalize_Arguments may free and reallocate some 752 -- of the individual arguments. 753 -- 754 -- This function will always set Success to False under VxWorks and other 755 -- similar operating systems which have no notion of the concept of 756 -- dynamically executable file. Otherwise Success is set True if the exit 757 -- status of the spawned process is zero. 758 759 function Spawn 760 (Program_Name : String; 761 Args : Argument_List) return Integer; 762 -- Similar to the above procedure, but returns the actual status returned 763 -- by the operating system, or -1 under VxWorks and any other similar 764 -- operating systems which have no notion of separately spawnable programs. 765 -- 766 -- Spawning processes from tasking programs is not recommended. See 767 -- "NOTE: Spawn in tasking programs" below. 768 769 procedure Spawn 770 (Program_Name : String; 771 Args : Argument_List; 772 Output_File_Descriptor : File_Descriptor; 773 Return_Code : out Integer; 774 Err_To_Out : Boolean := True); 775 -- Similar to the procedure above, but redirects the output to the file 776 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the 777 -- Standard Error output is also redirected. 778 -- Return_Code is set to the status code returned by the operating system 779 -- 780 -- Spawning processes from tasking programs is not recommended. See 781 -- "NOTE: Spawn in tasking programs" below. 782 783 procedure Spawn 784 (Program_Name : String; 785 Args : Argument_List; 786 Output_File : String; 787 Success : out Boolean; 788 Return_Code : out Integer; 789 Err_To_Out : Boolean := True); 790 -- Similar to the procedure above, but saves the output of the command to 791 -- a file with the name Output_File. 792 -- 793 -- Success is set to True if the command is executed and its output 794 -- successfully written to the file. If Success is True, then Return_Code 795 -- will be set to the status code returned by the operating system. 796 -- Otherwise, Return_Code is undefined. 797 -- 798 -- Spawning processes from tasking programs is not recommended. See 799 -- "NOTE: Spawn in tasking programs" below. 800 801 type Process_Id is private; 802 -- A private type used to identify a process activated by the following 803 -- non-blocking calls. The only meaningful operation on this type is a 804 -- comparison for equality. 805 806 Invalid_Pid : constant Process_Id; 807 -- A special value used to indicate errors, as described below 808 809 function Pid_To_Integer (Pid : Process_Id) return Integer; 810 -- Convert a process id to an Integer. Useful for writing hash functions 811 -- for type Process_Id or to compare two Process_Id (e.g. for sorting). 812 813 function Non_Blocking_Spawn 814 (Program_Name : String; 815 Args : Argument_List) return Process_Id; 816 -- This is a non blocking call. The Process_Id of the spawned process is 817 -- returned. Parameters are to be used as in Spawn. If Invalid_Pid is 818 -- returned the program could not be spawned. 819 -- 820 -- Spawning processes from tasking programs is not recommended. See 821 -- "NOTE: Spawn in tasking programs" below. 822 -- 823 -- This function will always return Invalid_Pid under VxWorks, since there 824 -- is no notion of executables under this OS. 825 826 function Non_Blocking_Spawn 827 (Program_Name : String; 828 Args : Argument_List; 829 Output_File_Descriptor : File_Descriptor; 830 Err_To_Out : Boolean := True) return Process_Id; 831 -- Similar to the procedure above, but redirects the output to the file 832 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the 833 -- Standard Error output is also redirected. Invalid_Pid is returned 834 -- if the program could not be spawned successfully. 835 -- 836 -- Spawning processes from tasking programs is not recommended. See 837 -- "NOTE: Spawn in tasking programs" below. 838 -- 839 -- This function will always return Invalid_Pid under VxWorks, since there 840 -- is no notion of executables under this OS. 841 842 function Non_Blocking_Spawn 843 (Program_Name : String; 844 Args : Argument_List; 845 Output_File : String; 846 Err_To_Out : Boolean := True) return Process_Id; 847 -- Similar to the procedure above, but saves the output of the command to 848 -- a file with the name Output_File. 849 -- 850 -- Invalid_Pid is returned if the output file could not be created or if 851 -- the program could not be spawned successfully. 852 -- 853 -- Spawning processes from tasking programs is not recommended. See 854 -- "NOTE: Spawn in tasking programs" below. 855 -- 856 -- This function will always return Invalid_Pid under VxWorks, since there 857 -- is no notion of executables under this OS. 858 859 function Non_Blocking_Spawn 860 (Program_Name : String; 861 Args : Argument_List; 862 Stdout_File : String; 863 Stderr_File : String) return Process_Id; 864 -- Similar to the procedure above, but saves the standard output of the 865 -- command to a file with the name Stdout_File and the standard output 866 -- of the command to a file with the name Stderr_File. 867 868 procedure Wait_Process (Pid : out Process_Id; Success : out Boolean); 869 -- Wait for the completion of any of the processes created by previous 870 -- calls to Non_Blocking_Spawn. The caller will be suspended until one of 871 -- these processes terminates (normally or abnormally). If any of these 872 -- subprocesses terminates prior to the call to Wait_Process (and has not 873 -- been returned by a previous call to Wait_Process), then the call to 874 -- Wait_Process is immediate. Pid identifies the process that has 875 -- terminated (matching the value returned from Non_Blocking_Spawn). 876 -- Success is set to True if this sub-process terminated successfully. If 877 -- Pid = Invalid_Pid, there were no subprocesses left to wait on. 878 -- 879 -- This function will always set success to False under VxWorks, since 880 -- there is no notion of executables under this OS. 881 882 function Argument_String_To_List 883 (Arg_String : String) return Argument_List_Access; 884 -- Take a string that is a program and its arguments and parse it into an 885 -- Argument_List. Note that the result is allocated on the heap, and must 886 -- be freed by the programmer (when it is no longer needed) to avoid 887 -- memory leaks. 888 889 ------------------------------------- 890 -- NOTE: Spawn in Tasking Programs -- 891 ------------------------------------- 892 893 -- Spawning processes in tasking programs using the above Spawn and 894 -- Non_Blocking_Spawn subprograms is not recommended, because there are 895 -- subtle interactions between creating a process and signals/locks that 896 -- can cause trouble. These issues are not specific to Ada; they depend 897 -- primarily on the operating system. 898 899 -- If you need to spawn processes in a tasking program, you will need to 900 -- understand the semantics of your operating system, and you are likely to 901 -- write non-portable code, because operating systems differ in this area. 902 903 -- The Spawn and Non_Blocking_Spawn subprograms call the following 904 -- operating system functions: 905 906 -- On Windows: spawnvp (blocking) or CreateProcess (non-blocking) 907 908 -- On Solaris: fork1, followed in the child process by execv 909 910 -- On other Unix-like systems: fork, followed in the child 911 -- process by execv. 912 913 -- On vxworks, spawning of processes is not supported 914 915 -- For details, look at the functions __gnat_portable_spawn and 916 -- __gnat_portable_no_block_spawn in adaint.c. 917 918 -- You should read the operating-system-specific documentation for the 919 -- above functions, paying special attention to subtle interactions with 920 -- threading, signals, locks, and file descriptors. Most of the issues are 921 -- related to the fact that on Unix, there is a window of time between fork 922 -- and execv; Windows does not have this problem, because spawning is done 923 -- in a single operation. 924 925 -- On Posix-compliant systems, such as Linux, fork duplicates just the 926 -- calling thread. (On Solaris, fork1 is the Posix-compliant version of 927 -- fork.) 928 929 -- You should avoid using signals while spawning. This includes signals 930 -- used internally by the Ada run-time system, such as timer signals used 931 -- to implement delay statements. 932 933 -- It is best to spawn any subprocesses very early, before the parent 934 -- process creates tasks, locks, or installs signal handlers. Certainly 935 -- avoid doing simultaneous spawns from multiple threads of the same 936 -- process. 937 938 -- There is no problem spawning a subprocess that uses tasking: the 939 -- problems are caused only by tasking in the parent. 940 941 -- If the parent is using tasking, and needs to spawn subprocesses at 942 -- arbitrary times, one technique is for the parent to spawn (very early) 943 -- a particular spawn-manager subprocess whose job is to spawn other 944 -- processes. The spawn-manager must avoid tasking. The parent sends 945 -- messages to the spawn-manager requesting it to spawn processes, using 946 -- whatever inter-process communication mechanism you like, such as 947 -- sockets. 948 949 -- In short, mixing spawning of subprocesses with tasking is a tricky 950 -- business, and should be avoided if possible, but if it is necessary, 951 -- the above guidelines should be followed, and you should beware of 952 -- portability problems. 953 954 ------------------- 955 -- Miscellaneous -- 956 ------------------- 957 958 function Getenv (Name : String) return String_Access; 959 -- Get the value of the environment variable. Returns an access to the 960 -- empty string if the environment variable does not exist or has an 961 -- explicit null value (in some operating systems these are distinct 962 -- cases, in others they are not; this interface abstracts away that 963 -- difference. The argument is allocated on the heap (even in the null 964 -- case), and needs to be freed explicitly when no longer needed to avoid 965 -- memory leaks. 966 967 procedure Setenv (Name : String; Value : String); 968 -- Set the value of the environment variable Name to Value. This call 969 -- modifies the current environment, but does not modify the parent 970 -- process environment. After a call to Setenv, Getenv (Name) will always 971 -- return a String_Access referencing the same String as Value. This is 972 -- true also for the null string case (the actual effect may be to either 973 -- set an explicit null as the value, or to remove the entry, this is 974 -- operating system dependent). Note that any following calls to Spawn 975 -- will pass an environment to the spawned process that includes the 976 -- changes made by Setenv calls. 977 978 procedure OS_Exit (Status : Integer); 979 pragma No_Return (OS_Exit); 980 -- Exit to OS with given status code (program is terminated). Note that 981 -- this is abrupt termination. All tasks are immediately terminated. There 982 -- are no finalization or other Ada-specific cleanup actions performed. On 983 -- systems with atexit handlers (such as Unix and Windows), atexit handlers 984 -- are called. 985 986 type OS_Exit_Subprogram is access procedure (Status : Integer); 987 988 procedure OS_Exit_Default (Status : Integer); 989 pragma No_Return (OS_Exit_Default); 990 -- Default implementation of procedure OS_Exit 991 992 OS_Exit_Ptr : OS_Exit_Subprogram := OS_Exit_Default'Access; 993 -- OS_Exit is implemented through this access value. It it then possible to 994 -- change the implementation of OS_Exit by redirecting OS_Exit_Ptr to an 995 -- other implementation. 996 997 procedure OS_Abort; 998 pragma Import (C, OS_Abort, "abort"); 999 pragma No_Return (OS_Abort); 1000 -- Exit to OS signalling an abort (traceback or other appropriate 1001 -- diagnostic information should be given if possible, or entry made to 1002 -- the debugger if that is possible). 1003 1004 function Errno return Integer; 1005 pragma Import (C, Errno, "__get_errno"); 1006 -- Return the task-safe last error number 1007 1008 procedure Set_Errno (Errno : Integer); 1009 pragma Import (C, Set_Errno, "__set_errno"); 1010 -- Set the task-safe error number 1011 1012 function Errno_Message 1013 (Err : Integer := Errno; 1014 Default : String := "") return String; 1015 -- Return a message describing the given Errno value. If none is provided 1016 -- by the system, return Default if not empty, else return a generic 1017 -- message indicating the numeric errno value. 1018 1019 Directory_Separator : constant Character; 1020 -- The character that is used to separate parts of a pathname 1021 1022 Path_Separator : constant Character; 1023 -- The character to separate paths in an environment variable value 1024 1025private 1026 pragma Import (C, Path_Separator, "__gnat_path_separator"); 1027 pragma Import (C, Directory_Separator, "__gnat_dir_separator"); 1028 pragma Import (C, Current_Time, "__gnat_current_time"); 1029 1030 type OS_Time is 1031 range -(2 ** (Standard'Address_Size - Integer'(1))) .. 1032 +(2 ** (Standard'Address_Size - Integer'(1)) - 1); 1033 -- Type used for timestamps in the compiler. This type is used to hold 1034 -- time stamps, but may have a different representation than C's time_t. 1035 -- This type needs to match the declaration of OS_Time in adaint.h. 1036 1037 -- Add pragma Inline statements for comparison operations on OS_Time. It 1038 -- would actually be nice to use pragma Import (Intrinsic) here, but this 1039 -- was not properly supported till GNAT 3.15a, so that would cause 1040 -- bootstrap path problems. To be changed later ??? 1041 1042 Invalid_Time : constant OS_Time := -1; 1043 -- This value should match the return value from __gnat_file_time_* 1044 1045 pragma Inline ("<"); 1046 pragma Inline (">"); 1047 pragma Inline ("<="); 1048 pragma Inline (">="); 1049 1050 type Process_Id is new Integer; 1051 Invalid_Pid : constant Process_Id := -1; 1052 1053end System.OS_Lib; 1054