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) 1995-2021, 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_Warning; 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 : String_Access; 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 : String_List; 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 "=" 91 (Left : String_List_Access; 92 Right : String_List_Access) return Boolean renames Strings."="; 93 94 procedure Free (Arg : in out String_List_Access) 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. This 102 -- is the type returned by the File_Time_Stamp functions to obtain the time 103 -- stamp of a specified file. Functions and a procedure (modeled after the 104 -- similar subprograms in package Calendar) are provided for extracting 105 -- information from a value of this type. Although these are called GM, the 106 -- intention in the case of time stamps is not that they provide GMT times 107 -- in all cases but rather the actual (time-zone independent) time stamp of 108 -- the 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 function "<" (X : OS_Time; Y : OS_Time) return Boolean; 114 function ">" (X : OS_Time; Y : OS_Time) return Boolean; 115 function ">=" (X : OS_Time; Y : OS_Time) return Boolean; 116 function "<=" (X : OS_Time; Y : OS_Time) return Boolean; 117 -- Basic comparison operators on OS_Time with obvious meanings. Note that 118 -- these have Intrinsic convention, so for example it is not permissible 119 -- to create accesses to any of these functions. 120 121 subtype Year_Type is Integer range 1900 .. 2099; 122 subtype Month_Type is Integer range 1 .. 12; 123 subtype Day_Type is Integer range 1 .. 31; 124 subtype Hour_Type is Integer range 0 .. 23; 125 subtype Minute_Type is Integer range 0 .. 59; 126 subtype Second_Type is Integer range 0 .. 59; 127 -- Declarations similar to those in Calendar, breaking down the time 128 129 function Current_Time return OS_Time; 130 -- Return the system clock value as OS_Time 131 132 function Current_Time_String return String; 133 -- Returns current local time in the form YYYY-MM-DD HH:MM:SS. The result 134 -- has bounds 1 .. 19. 135 136 function GM_Year (Date : OS_Time) return Year_Type; 137 function GM_Month (Date : OS_Time) return Month_Type; 138 function GM_Day (Date : OS_Time) return Day_Type; 139 function GM_Hour (Date : OS_Time) return Hour_Type; 140 function GM_Minute (Date : OS_Time) return Minute_Type; 141 function GM_Second (Date : OS_Time) return Second_Type; 142 -- Functions to extract information from OS_Time value in GMT form 143 144 procedure GM_Split 145 (Date : OS_Time; 146 Year : out Year_Type; 147 Month : out Month_Type; 148 Day : out Day_Type; 149 Hour : out Hour_Type; 150 Minute : out Minute_Type; 151 Second : out Second_Type); 152 -- Analogous to the Split routine in Ada.Calendar, takes an OS_Time and 153 -- provides a representation of it as a set of component parts, to be 154 -- interpreted as a date point in UTC. 155 156 function GM_Time_Of 157 (Year : Year_Type; 158 Month : Month_Type; 159 Day : Day_Type; 160 Hour : Hour_Type; 161 Minute : Minute_Type; 162 Second : Second_Type) return OS_Time; 163 -- Analogous to the Time_Of routine in Ada.Calendar, takes a set of time 164 -- component parts to be interpreted in the local time zone, and returns 165 -- an OS_Time. Returns Invalid_Time if the creation fails. 166 167 ------------------ 168 -- Time_t Stuff -- 169 ------------------ 170 171 -- Note: Do not use time_t in the compiler and host-based tools; instead 172 -- use OS_Time. 173 174 subtype time_t is Long_Long_Integer; 175 -- C time_t can be either long or long long, so we choose the Ada 176 -- equivalent of the latter because eventually that will be the 177 -- type used out of necessity. This may affect some user code on 32-bit 178 -- targets that have not yet migrated to the Posix 2008 standard, 179 -- particularly pre version 5 32-bit Linux. Do not change this 180 -- declaration without coordinating it with conversions in Ada.Calendar. 181 182 function To_C (Time : OS_Time) return time_t; 183 -- Convert OS_Time to C time_t type 184 185 function To_Ada (Time : time_t) return OS_Time; 186 -- Convert C time_t type to OS_Time 187 188 ---------------- 189 -- File Stuff -- 190 ---------------- 191 192 -- These routines give access to the open/creat/close/read/write level of 193 -- I/O routines in the typical C library (these functions are not part of 194 -- the ANSI C standard, but are typically available in all systems). See 195 -- also package Interfaces.C_Streams for access to the stream level 196 -- routines. 197 198 -- Note on file names. If a file name is passed as type String in any of 199 -- the following specifications, then the name is a normal Ada string and 200 -- need not be NUL-terminated. However, a trailing NUL character is 201 -- permitted, and will be ignored (more accurately, the NUL and any 202 -- characters that follow it will be ignored). 203 204 type File_Descriptor is new Integer; 205 -- Corresponds to the int file handle values used in the C routines 206 207 Standin : constant File_Descriptor := 0; 208 Standout : constant File_Descriptor := 1; 209 Standerr : constant File_Descriptor := 2; 210 -- File descriptors for standard input output files 211 212 Invalid_FD : constant File_Descriptor := -1; 213 -- File descriptor returned when error in opening/creating file 214 215 Null_FD : constant File_Descriptor := -2; 216 -- Uninitialized file descriptor 217 218 procedure Close (FD : File_Descriptor; Status : out Boolean); 219 -- Close file referenced by FD. Status is False if the underlying service 220 -- failed. Reasons for failure include: disk full, disk quotas exceeded 221 -- and invalid file descriptor (the file may have been closed twice). 222 223 procedure Close (FD : File_Descriptor); 224 -- Close file referenced by FD. This form is used when the caller wants to 225 -- ignore any possible error (see above for error cases). 226 227 type Copy_Mode is 228 (Copy, 229 -- Copy the file. It is an error if the target file already exists. The 230 -- time stamps and other file attributes are preserved in the copy. 231 232 Overwrite, 233 -- If the target file exists, the file is replaced otherwise the file 234 -- is just copied. The time stamps and other file attributes are 235 -- preserved in the copy. 236 237 Append); 238 -- If the target file exists, the contents of the source file is 239 -- appended at the end. Otherwise the source file is just copied. The 240 -- time stamps and other file attributes are preserved if the 241 -- destination file does not exist. 242 243 type Attribute is 244 (Time_Stamps, 245 -- Copy time stamps from source file to target file. All other 246 -- attributes are set to normal default values for file creation. 247 248 Full, 249 -- All attributes are copied from the source file to the target file. 250 -- This includes the timestamps, and for example also includes 251 -- read/write/execute attributes in Unix systems. 252 253 None); 254 -- No attributes are copied. All attributes including the time stamp 255 -- values are set to normal default values for file creation. 256 257 -- Note: The default is Time_Stamps, which corresponds to the normal 258 -- default on Windows style systems. Full corresponds to the typical 259 -- effect of "cp -p" on Unix systems, and None corresponds to the typical 260 -- effect of "cp" on Unix systems. 261 262 -- Note: Time_Stamps and Full are not supported on VxWorks 5 263 264 procedure Copy_File 265 (Name : String; 266 Pathname : String; 267 Success : out Boolean; 268 Mode : Copy_Mode := Copy; 269 Preserve : Attribute := Time_Stamps); 270 -- Copy a file. Name must designate a single file (no wildcards allowed). 271 -- Pathname can be a filename or directory name. In the latter case Name 272 -- is copied into the directory preserving the same file name. Mode 273 -- defines the kind of copy, see above with the default being a normal 274 -- copy in which the target file must not already exist. Success is set to 275 -- True or False indicating if the copy is successful (depending on the 276 -- specified Mode). 277 278 procedure Copy_File_Attributes 279 (From : String; 280 To : String; 281 Success : out Boolean; 282 Copy_Timestamp : Boolean := True; 283 Copy_Permissions : Boolean := True); 284 -- Copy some of the file attributes from one file to another. Both files 285 -- must exist, or Success is set to False. 286 287 procedure Copy_Time_Stamps 288 (Source : String; 289 Dest : String; 290 Success : out Boolean); 291 -- Copy Source file time stamps (last modification and last access time 292 -- stamps) to Dest file. Source and Dest must be valid filenames, 293 -- furthermore Dest must be writable. Success will be set to True if the 294 -- operation was successful and False otherwise. 295 -- 296 -- Note: this procedure is not supported on VxWorks 5. On this platform, 297 -- Success is always set to False. 298 299 type Mode is (Binary, Text); 300 for Mode'Size use Integer'Size; 301 for Mode use (Binary => 0, Text => 1); 302 -- Used in all the Open and Create calls to specify if the file is to be 303 -- opened in binary mode or text mode. In systems like Unix, this has no 304 -- effect, but in systems capable of text mode translation, the use of 305 -- Text as the mode parameter causes the system to do CR/LF translation 306 -- and also to recognize the DOS end of file character on input. The use 307 -- of Text where appropriate allows programs to take a portable Unix view 308 -- of DOS-format files and process them appropriately. 309 310 function Create_File 311 (Name : String; 312 Fmode : Mode) return File_Descriptor; 313 -- Creates new file with given name for writing, returning file descriptor 314 -- for subsequent use in Write calls. If the file already exists, it is 315 -- overwritten. File descriptor returned is Invalid_FD if file cannot be 316 -- successfully created. 317 318 function Create_New_File 319 (Name : String; 320 Fmode : Mode) return File_Descriptor; 321 -- Create new file with given name for writing, returning file descriptor 322 -- for subsequent use in Write calls. This differs from Create_File in 323 -- that it fails if the file already exists. File descriptor returned is 324 -- Invalid_FD if the file exists or cannot be created. 325 326 function Create_Output_Text_File (Name : String) return File_Descriptor; 327 -- Creates new text file with given name suitable to redirect standard 328 -- output, returning file descriptor. File descriptor returned is 329 -- Invalid_FD if file cannot be successfully created. 330 331 Temp_File_Len : constant Integer := 12; 332 -- Length of name returned by Create_Temp_File call (GNAT-XXXXXX & NUL) 333 334 subtype Temp_File_Name is String (1 .. Temp_File_Len); 335 -- String subtype set by Create_Temp_File 336 337 procedure Create_Temp_File 338 (FD : out File_Descriptor; 339 Name : out Temp_File_Name); 340 -- Create and open for writing a temporary file in the current working 341 -- directory. The name of the file and the File Descriptor are returned. 342 -- The File Descriptor returned is Invalid_FD in the case of failure. No 343 -- mode parameter is provided. Since this is a temporary file, there is no 344 -- point in doing text translation on it. 345 -- 346 -- On some operating systems, the maximum number of temp files that can be 347 -- created with this procedure may be limited. When the maximum is reached, 348 -- this procedure returns Invalid_FD. On some operating systems, there may 349 -- be a race condition between processes trying to create temp files at the 350 -- same time in the same directory using this procedure. 351 352 procedure Create_Temp_File 353 (FD : out File_Descriptor; 354 Name : out String_Access); 355 -- Create and open for writing a temporary file in the current working 356 -- directory. The name of the file and the File Descriptor are returned. 357 -- It is the responsibility of the caller to deallocate the access value 358 -- returned in Name. 359 -- 360 -- The file is opened in binary mode (no text translation). 361 -- 362 -- This procedure will always succeed if the current working directory is 363 -- writable. If the current working directory is not writable, then 364 -- Invalid_FD is returned for the file descriptor and null for the Name. 365 -- There is no race condition problem between processes trying to create 366 -- temp files at the same time in the same directory. 367 368 procedure Create_Temp_Output_File 369 (FD : out File_Descriptor; 370 Name : out String_Access); 371 -- Create and open for writing a temporary file in the current working 372 -- directory suitable to redirect standard output. The name of the file and 373 -- the File Descriptor are returned. It is the responsibility of the caller 374 -- to deallocate the access value returned in Name. 375 -- 376 -- The file is opened in text mode 377 -- 378 -- This procedure will always succeed if the current working directory is 379 -- writable. If the current working directory is not writable, then 380 -- Invalid_FD is returned for the file descriptor and null for the Name. 381 -- There is no race condition problem between processes trying to create 382 -- temp files at the same time in the same directory. 383 384 procedure Delete_File (Name : String; Success : out Boolean); 385 -- Deletes file. Success is set True or False indicating if the delete is 386 -- successful. 387 388 function File_Length (FD : File_Descriptor) return Long_Integer; 389 pragma Import (C, File_Length, "__gnat_file_length_long"); 390 391 type Large_File_Size is range -2**63 .. 2**63 - 1; 392 -- Maximum supported size for a file (8 exabytes = 8 million terabytes, 393 -- should be enough to accommodate all possible needs for quite a while). 394 395 function File_Length64 (FD : File_Descriptor) return Large_File_Size; 396 pragma Import (C, File_Length64, "__gnat_file_length"); 397 -- Get length of file from file descriptor FD 398 399 function File_Time_Stamp (Name : String) return OS_Time; 400 -- Given the name of a file or directory, Name, obtains and returns the 401 -- time stamp. This function can be used for an unopened file. Returns 402 -- Invalid_Time if Name doesn't correspond to an existing file. 403 404 function File_Time_Stamp (FD : File_Descriptor) return OS_Time; 405 -- Get time stamp of file from file descriptor FD Returns Invalid_Time is 406 -- FD doesn't correspond to an existing file. 407 408 function Get_Debuggable_Suffix return String_Access; 409 -- Return the debuggable suffix convention. Usually this is the same as 410 -- the convention for Get_Executable_Suffix. The result is allocated on 411 -- the heap and should be freed after use to avoid storage leaks. 412 413 function Get_Executable_Suffix return String_Access; 414 -- Return the executable suffix convention. The result is allocated on the 415 -- heap and should be freed after use to avoid storage leaks. 416 417 function Get_Object_Suffix return String_Access; 418 -- Return the object suffix convention. The result is allocated on the heap 419 -- and should be freed after use to avoid storage leaks. 420 421 function Get_Target_Debuggable_Suffix return String_Access; 422 -- Return the target debuggable suffix convention. Usually this is the same 423 -- as the convention for Get_Executable_Suffix. The result is allocated on 424 -- the heap and should be freed after use to avoid storage leaks. 425 426 function Get_Target_Executable_Suffix return String_Access; 427 -- Return the target executable suffix convention. The result is allocated 428 -- on the heap and should be freed after use to avoid storage leaks. 429 430 function Get_Target_Object_Suffix return String_Access; 431 -- Return the target object suffix convention. The result is allocated on 432 -- the heap and should be freed after use to avoid storage leaks. 433 434 function Is_Absolute_Path (Name : String) return Boolean; 435 -- Returns True if Name is an absolute path name, i.e. it designates a 436 -- file or directory absolutely rather than relative to another directory. 437 438 function Is_Directory (Name : String) return Boolean; 439 -- Determines if the given string, Name, is the name of a directory. 440 -- Returns True if so, False otherwise. Name may be an absolute path 441 -- name or a relative path name, including a simple file name. If it is 442 -- a relative path name, it is relative to the current working directory. 443 444 function Is_Executable_File (Name : String) return Boolean; 445 -- Determines if the given string, Name, is the name of an existing file 446 -- that is executable. Returns True if so, False otherwise. Note that this 447 -- function simply interrogates the file attributes (e.g. using the C 448 -- function stat), so it does not indicate a situation in which a file may 449 -- not actually be readable due to some other process having exclusive 450 -- access. 451 452 function Is_Owner_Readable_File (Name : String) return Boolean; 453 -- Determines if the given string, Name, is the name of an existing file 454 -- that is readable. Returns True if so, False otherwise. Note that this 455 -- function simply interrogates the file attributes (e.g. using the C 456 -- function stat), so it does not indicate a situation in which a file may 457 -- not actually be readable due to some other process having exclusive 458 -- access. 459 460 function Is_Regular_File (Name : String) return Boolean; 461 -- Determines if the given string, Name, is the name of an existing 462 -- regular file. Returns True if so, False otherwise. Name may be an 463 -- absolute path name or a relative path name, including a simple file 464 -- name. If it is a relative path name, it is relative to the current 465 -- working directory. 466 467 function Is_Symbolic_Link (Name : String) return Boolean; 468 -- Determines if the given string, Name, is the path of a symbolic link on 469 -- systems that support it. Returns True if so, False if the path is not a 470 -- symbolic link or if the system does not support symbolic links. 471 -- 472 -- A symbolic link is an indirect pointer to a file; its directory entry 473 -- contains the name of the file to which it is linked. Symbolic links may 474 -- span file systems and may refer to directories. 475 476 function Is_Owner_Writable_File (Name : String) return Boolean; 477 -- Determines if the given string, Name, is the name of an existing file 478 -- that is writable. Returns True if so, False otherwise. Note that this 479 -- function simply interrogates the file attributes (e.g. using the C 480 -- function stat), so it does not indicate a situation in which a file may 481 -- not actually be writable due to some other process having exclusive 482 -- access. 483 484 function Is_Read_Accessible_File (Name : String) return Boolean; 485 -- Determines if the given string, Name, is the name of an existing file 486 -- that is readable. Returns True if so, False otherwise. 487 488 function Is_Write_Accessible_File (Name : String) return Boolean; 489 -- Determines if the given string, Name, is the name of an existing file 490 -- that is writable. Returns True if so, False otherwise. 491 492 function Is_Readable_File (Name : String) return Boolean 493 renames Is_Read_Accessible_File; 494 function Is_Writable_File (Name : String) return Boolean 495 renames Is_Write_Accessible_File; 496 -- These subprograms provided for backward compatibility and should not be 497 -- used. Use Is_Owner_Readable_File/Is_Owner_Writable_File or 498 -- Is_Read_Accessible_File/Is_Write_Accessible_File instead. 499 500 function Locate_Exec_On_Path (Exec_Name : String) return String_Access; 501 -- Try to locate an executable whose name is given by Exec_Name in the 502 -- directories listed in the environment Path. If the Exec_Name does not 503 -- have the executable suffix, it will be appended before the search. 504 -- Otherwise works like Locate_Regular_File below. If the executable is 505 -- not found, null is returned. 506 -- 507 -- Note that this function allocates memory for the returned value. This 508 -- memory needs to be deallocated after use. 509 510 function Locate_Regular_File 511 (File_Name : String; 512 Path : String) return String_Access; 513 -- Try to locate a regular file whose name is given by File_Name in the 514 -- directories listed in Path. If a file is found, its full pathname is 515 -- returned; otherwise, a null pointer is returned. If the File_Name given 516 -- is an absolute pathname, then Locate_Regular_File just checks that the 517 -- file exists and is a regular file. Otherwise, if the File_Name given 518 -- includes directory information, Locate_Regular_File first checks if the 519 -- file exists relative to the current directory. If it does not, or if 520 -- the File_Name given is a simple file name, the Path argument is parsed 521 -- according to OS conventions, and for each directory in the Path a check 522 -- is made if File_Name is a relative pathname of a regular file from that 523 -- directory. 524 -- 525 -- Note that this function allocates some memory for the returned value. 526 -- This memory needs to be deallocated after use. 527 528 Seek_Cur : constant := 1; 529 Seek_End : constant := 2; 530 Seek_Set : constant := 0; 531 -- Used to indicate origin for Lseek call 532 533 procedure Lseek 534 (FD : File_Descriptor; 535 offset : Long_Integer; 536 origin : Integer); 537 pragma Import (C, Lseek, "__gnat_lseek"); 538 -- Sets the current file pointer to the indicated offset value, relative 539 -- to the current position (origin = SEEK_CUR), end of file (origin = 540 -- SEEK_END), or start of file (origin = SEEK_SET). 541 542 function Normalize_Pathname 543 (Name : String; 544 Directory : String := ""; 545 Resolve_Links : Boolean := True; 546 Case_Sensitive : Boolean := True) return String; 547 -- Returns a file name as an absolute path name, resolving all relative 548 -- directories, and symbolic links. If Name is a relative path, it is 549 -- interpreted relative to Directory, or to the current directory if 550 -- Directory is the empty string (the default). The result returned is 551 -- the normalized name of the file, containing no "." or ".." components, 552 -- and no duplicated directory separators. For most cases, if two file 553 -- names designate the same file through different paths, 554 -- Normalize_Pathname will return the same canonical name in both cases. 555 -- However, there are cases when this is not true; for example, this is 556 -- not true in Unix for two hard links designating the same file. 557 -- 558 -- On Windows, the returned path will start with a drive letter. If 559 -- Directory is empty (the default) and Name is a relative path or an 560 -- absolute path without drive letter, the letter of the current drive 561 -- will start the returned path. If Case_Sensitive is True (the default), 562 -- then this drive letter will be forced to upper case ("C:\..."). 563 -- 564 -- If Resolve_Links is set to True, then the symbolic links, on systems 565 -- that support them, will be fully converted to the name of the file or 566 -- directory pointed to. This is slightly less efficient, since it 567 -- requires system calls. 568 -- 569 -- If Name is empty or the path contains symbolic links that can't be 570 -- resolved (for example there is a symbolic link circularity, 571 -- e.g. A is a symbolic link for B, and B is a symbolic link for A), then 572 -- Normalize_Pathname returns an empty string. 573 -- 574 -- For case-sensitive file systems, the value of Case_Sensitive parameter 575 -- is ignored. For file systems that are not case-sensitive, such as 576 -- Windows, if this parameter is set to False, then the file and directory 577 -- names are folded to lower case. This allows checking whether two files 578 -- are the same by applying this function to their names and comparing the 579 -- results. If Case_Sensitive is set to True, this function does not change 580 -- the casing of file and directory names. 581 582 function Open_Append 583 (Name : String; 584 Fmode : Mode) return File_Descriptor; 585 -- Opens file Name for appending, returning its file descriptor. File 586 -- descriptor returned is Invalid_FD if the file cannot be successfully 587 -- opened. 588 589 function Open_Read 590 (Name : String; 591 Fmode : Mode) return File_Descriptor; 592 -- Open file Name for reading, returning its file descriptor. File 593 -- descriptor returned is Invalid_FD if the file cannot be opened. 594 595 function Open_Read_Write 596 (Name : String; 597 Fmode : Mode) return File_Descriptor; 598 -- Open file Name for both reading and writing, returning its file 599 -- descriptor. File descriptor returned is Invalid_FD if the file 600 -- cannot be opened. 601 602 function Read 603 (FD : File_Descriptor; 604 A : System.Address; 605 N : Integer) return Integer; 606 -- Read N bytes to address A from file referenced by FD. Returned value is 607 -- count of bytes actually read, which can be less than N at EOF. 608 609 procedure Rename_File 610 (Old_Name : String; 611 New_Name : String; 612 Success : out Boolean); 613 -- Rename a file. Success is set True or False indicating if the rename is 614 -- successful or not. 615 -- 616 -- WARNING: In one very important respect, this function is significantly 617 -- non-portable. If New_Name already exists then on Unix systems, the call 618 -- deletes the existing file, and the call signals success. On Windows, the 619 -- call fails, without doing the rename operation. See also the procedure 620 -- Ada.Directories.Rename, which portably provides the windows semantics, 621 -- i.e. fails if the output file already exists. 622 623 -- The following defines the mode for the Copy_File procedure below. Note 624 -- that "time stamps and other file attributes" in the descriptions below 625 -- refers to the creation and last modification times, and also the file 626 -- access (read/write/execute) status flags. 627 628 procedure Set_Close_On_Exec 629 (FD : File_Descriptor; 630 Close_On_Exec : Boolean; 631 Status : out Boolean); 632 -- When Close_On_Exec is True, mark FD to be closed automatically when new 633 -- program is executed by the calling process (i.e. prevent FD from being 634 -- inherited by child processes). When Close_On_Exec is False, mark FD to 635 -- not be closed on exec (i.e. allow it to be inherited). Status is False 636 -- if the operation could not be performed. 637 638 S_Owner : constant := 1; 639 S_Group : constant := 2; 640 S_Others : constant := 4; 641 -- Constants for use in Mode parameter to Set_Executable 642 643 procedure Set_Executable (Name : String; Mode : Positive := S_Owner); 644 -- Change permissions on the file given by Name to make it executable 645 -- for its owner, group or others, according to the setting of Mode. 646 -- As indicated, the default if no Mode parameter is given is owner. 647 648 procedure Set_File_Last_Modify_Time_Stamp (Name : String; Time : OS_Time); 649 -- Given the name of a file or directory, Name, set the last modification 650 -- time stamp. This function must be used for an unopened file. 651 652 procedure Set_Non_Readable (Name : String); 653 -- Change permissions on the named file to make it non-readable for 654 -- its owner. The writable and executable permissions are not 655 -- modified. 656 657 procedure Set_Non_Writable (Name : String); 658 -- Change permissions on the named file to make it non-writable for its 659 -- owner. The readable and executable permissions are not modified. 660 661 procedure Set_Read_Only (Name : String) renames Set_Non_Writable; 662 -- This renaming is provided for backwards compatibility with previous 663 -- versions. The use of Set_Non_Writable is preferred (clearer name). 664 665 procedure Set_Readable (Name : String); 666 -- Change permissions on the named file to make it readable for its 667 -- owner. 668 669 procedure Set_Writable (Name : String); 670 -- Change permissions on the named file to make it writable for its owner 671 672 function Write 673 (FD : File_Descriptor; 674 A : System.Address; 675 N : Integer) return Integer; 676 -- Write N bytes from address A to file referenced by FD. The returned 677 -- value is the number of bytes written, which can be less than N if a 678 -- disk full condition was detected. 679 680 -- The following section contains low-level routines using addresses to 681 -- pass file name and executable name. In each routine the name must be 682 -- Nul-Terminated. For complete documentation refer to the equivalent 683 -- routine (using String in place of C_File_Name) defined above. 684 685 subtype C_File_Name is System.Address; 686 -- This subtype is used to document that a parameter is the address of a 687 -- null-terminated string containing the name of a file. 688 689 procedure Copy_File 690 (Name : C_File_Name; 691 Pathname : C_File_Name; 692 Success : out Boolean; 693 Mode : Copy_Mode := Copy; 694 Preserve : Attribute := Time_Stamps); 695 696 procedure Copy_Time_Stamps 697 (Source : C_File_Name; 698 Dest : C_File_Name; 699 Success : out Boolean); 700 701 function Create_File 702 (Name : C_File_Name; 703 Fmode : Mode) return File_Descriptor; 704 705 function Create_New_File 706 (Name : C_File_Name; 707 Fmode : Mode) return File_Descriptor; 708 709 procedure Delete_File (Name : C_File_Name; Success : out Boolean); 710 711 function File_Time_Stamp (Name : C_File_Name) return OS_Time; 712 713 function Is_Directory (Name : C_File_Name) return Boolean; 714 function Is_Executable_File (Name : C_File_Name) return Boolean; 715 function Is_Owner_Readable_File (Name : C_File_Name) return Boolean; 716 function Is_Regular_File (Name : C_File_Name) return Boolean; 717 function Is_Symbolic_Link (Name : C_File_Name) return Boolean; 718 function Is_Owner_Writable_File (Name : C_File_Name) return Boolean; 719 720 function Locate_Regular_File 721 (File_Name : C_File_Name; 722 Path : C_File_Name) return String_Access; 723 724 function Open_Append 725 (Name : C_File_Name; 726 Fmode : Mode) return File_Descriptor; 727 728 function Open_Read 729 (Name : C_File_Name; 730 Fmode : Mode) return File_Descriptor; 731 732 function Open_Read_Write 733 (Name : C_File_Name; 734 Fmode : Mode) return File_Descriptor; 735 736 procedure Rename_File 737 (Old_Name : C_File_Name; 738 New_Name : C_File_Name; 739 Success : out Boolean); 740 741 ------------------ 742 -- Subprocesses -- 743 ------------------ 744 745 subtype Argument_List is String_List; 746 -- Type used for argument list in call to Spawn. The lower bound of the 747 -- array should be 1, and the length of the array indicates the number of 748 -- arguments. 749 750 subtype Argument_List_Access is String_List_Access; 751 -- Type used to return Argument_List without dragging in secondary stack. 752 -- Note that there is a Free procedure declared for this subtype which 753 -- frees the array and all referenced strings. 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 Current_Process_Id return Process_Id; 764 -- Returns the current process id or Invalid_Pid if not supported by the 765 -- runtime. 766 767 function Argument_String_To_List 768 (Arg_String : String) return Argument_List_Access; 769 -- Take a string that is a program and its arguments and parse it into an 770 -- Argument_List. Note that the result is allocated on the heap, and must 771 -- be freed by the programmer (when it is no longer needed) to avoid 772 -- memory leaks. 773 -- On Windows, backslashes are used as directory separators. On Unix, 774 -- however, they are used to escape the following character, so that for 775 -- instance "-d=name\ with\ space" is a single argument. In the result 776 -- list, the backslashes have been cleaned up when needed. The previous 777 -- example will thus result a single-element array, where the element is 778 -- "-d=name with space" (Unix) or "-d=name\ with\ space" (windows). 779 780 procedure Kill (Pid : Process_Id; Hard_Kill : Boolean := True); 781 -- Kill the process designated by Pid. Does nothing if Pid is Invalid_Pid 782 -- or on platforms where it is not supported, such as VxWorks. Hard_Kill 783 -- is True by default, and when True the process is terminated immediately. 784 -- If Hard_Kill is False, then a signal SIGINT is sent to the process on 785 -- POSIX OS or a ctrl-C event on Windows, allowing the process a chance to 786 -- terminate properly using a corresponding handler. 787 788 procedure Kill_Process_Tree (Pid : Process_Id; Hard_Kill : Boolean := True); 789 -- Kill the process designated by Pid and all it's children processes. 790 -- Does nothing if Pid is Invalid_Pid or on platforms where it is not 791 -- supported, such as VxWorks. Hard_Kill is True by default, and when True 792 -- the processes are terminated immediately. If Hard_Kill is False, then a 793 -- signal SIGINT is sent to the processes on POSIX OS or a ctrl-C event 794 -- on Windows, allowing the processes a chance to terminate properly 795 -- using a corresponding handler. 796 -- 797 -- Note that this routine is not atomic and is supported only on Linux 798 -- and Windows. On other OS it will only kill the process identified by 799 -- Pid. 800 801 function Non_Blocking_Spawn 802 (Program_Name : String; 803 Args : Argument_List) return Process_Id; 804 -- This is a non blocking call. The Process_Id of the spawned process is 805 -- returned. Parameters are to be used as in Spawn. If Invalid_Pid is 806 -- returned the program could not be spawned. 807 -- 808 -- Spawning processes from tasking programs is not recommended. See 809 -- "NOTE: Spawn in tasking programs" below. 810 -- 811 -- This function will always return Invalid_Pid under VxWorks, since there 812 -- is no notion of executables under this OS. 813 814 function Non_Blocking_Spawn 815 (Program_Name : String; 816 Args : Argument_List; 817 Output_File_Descriptor : File_Descriptor; 818 Err_To_Out : Boolean := True) return Process_Id; 819 -- Similar to the procedure above, but redirects the output to the file 820 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the 821 -- Standard Error output is also redirected. Invalid_Pid is returned 822 -- if the program could not be spawned successfully. 823 -- 824 -- Spawning processes from tasking programs is not recommended. See 825 -- "NOTE: Spawn in tasking programs" below. 826 -- 827 -- This function will always return Invalid_Pid under VxWorks, since there 828 -- is no notion of executables under this OS. 829 830 function Non_Blocking_Spawn 831 (Program_Name : String; 832 Args : Argument_List; 833 Output_File : String; 834 Err_To_Out : Boolean := True) return Process_Id; 835 -- Similar to the procedure above, but saves the output of the command to 836 -- a file with the name Output_File. 837 -- 838 -- Invalid_Pid is returned if the output file could not be created or if 839 -- the program could not be spawned successfully. 840 -- 841 -- Spawning processes from tasking programs is not recommended. See 842 -- "NOTE: Spawn in tasking programs" below. 843 -- 844 -- This function will always return Invalid_Pid under VxWorks, since there 845 -- is no notion of executables under this OS. 846 847 function Non_Blocking_Spawn 848 (Program_Name : String; 849 Args : Argument_List; 850 Stdout_File : String; 851 Stderr_File : String) return Process_Id; 852 -- Similar to the procedure above, but saves the standard output of the 853 -- command to a file with the name Stdout_File and the standard output 854 -- of the command to a file with the name Stderr_File. 855 856 procedure Normalize_Arguments (Args : in out Argument_List); 857 -- Normalize all arguments in the list. This ensure that the argument list 858 -- is compatible with the running OS and will works fine with Spawn and 859 -- Non_Blocking_Spawn for example. If Normalize_Arguments is called twice 860 -- on the same list it will do nothing the second time. Note that Spawn 861 -- and Non_Blocking_Spawn call Normalize_Arguments automatically, but 862 -- since there is a guarantee that a second call does nothing, this 863 -- internal call will have no effect if Normalize_Arguments is called 864 -- before calling Spawn. The call to Normalize_Arguments assumes that the 865 -- individual referenced arguments in Argument_List are on the heap, and 866 -- may free them and reallocate if they are modified. 867 868 function Pid_To_Integer (Pid : Process_Id) return Integer; 869 -- Convert a process id to an Integer. Useful for writing hash functions 870 -- for type Process_Id or to compare two Process_Id (e.g. for sorting). 871 872 procedure Spawn 873 (Program_Name : String; 874 Args : Argument_List; 875 Success : out Boolean); 876 -- This procedure spawns a program with a given list of arguments. The 877 -- first parameter of is the name of the executable. The second parameter 878 -- contains the arguments to be passed to this program. Success is False 879 -- if the named program could not be spawned or its execution completed 880 -- unsuccessfully. Note that the caller will be blocked until the 881 -- execution of the spawned program is complete. For maximum portability, 882 -- use a full path name for the Program_Name argument. On some systems 883 -- (notably Unix systems) a simple file name may also work (if the 884 -- executable can be located in the path). 885 -- 886 -- Spawning processes from tasking programs is not recommended. See 887 -- "NOTE: Spawn in tasking programs" below. 888 -- 889 -- Note: Arguments in Args that contain spaces and/or quotes such as 890 -- "--GCC=gcc -v" or "--GCC=""gcc -v""" are not portable across all 891 -- operating systems, and would not have the desired effect if they were 892 -- passed directly to the operating system. To avoid this problem, Spawn 893 -- makes an internal call to Normalize_Arguments, which ensures that such 894 -- arguments are modified in a manner that ensures that the desired effect 895 -- is obtained on all operating systems. The caller may call 896 -- Normalize_Arguments explicitly before the call (e.g. to print out the 897 -- exact form of arguments passed to the operating system). In this case 898 -- the guarantee a second call to Normalize_Arguments has no effect 899 -- ensures that the internal call will not affect the result. Note that 900 -- the implicit call to Normalize_Arguments may free and reallocate some 901 -- of the individual arguments. 902 -- 903 -- This function will always set Success to False under VxWorks and other 904 -- similar operating systems which have no notion of the concept of 905 -- dynamically executable file. Otherwise Success is set True if the exit 906 -- status of the spawned process is zero. 907 908 function Spawn 909 (Program_Name : String; 910 Args : Argument_List) return Integer; 911 -- Similar to the above procedure, but returns the actual status returned 912 -- by the operating system, or -1 under VxWorks and any other similar 913 -- operating systems which have no notion of separately spawnable programs. 914 -- 915 -- Spawning processes from tasking programs is not recommended. See 916 -- "NOTE: Spawn in tasking programs" below. 917 918 procedure Spawn 919 (Program_Name : String; 920 Args : Argument_List; 921 Output_File_Descriptor : File_Descriptor; 922 Return_Code : out Integer; 923 Err_To_Out : Boolean := True); 924 -- Similar to the procedure above, but redirects the output to the file 925 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the 926 -- Standard Error output is also redirected. 927 -- Return_Code is set to the status code returned by the operating system 928 -- 929 -- Spawning processes from tasking programs is not recommended. See 930 -- "NOTE: Spawn in tasking programs" below. 931 932 procedure Spawn 933 (Program_Name : String; 934 Args : Argument_List; 935 Output_File : String; 936 Success : out Boolean; 937 Return_Code : out Integer; 938 Err_To_Out : Boolean := True); 939 -- Similar to the procedure above, but saves the output of the command to 940 -- a file with the name Output_File. 941 -- 942 -- Success is set to True if the command is executed and its output 943 -- successfully written to the file. If Success is True, then Return_Code 944 -- will be set to the status code returned by the operating system. 945 -- Otherwise, Return_Code is undefined. 946 -- 947 -- Spawning processes from tasking programs is not recommended. See 948 -- "NOTE: Spawn in tasking programs" below. 949 950 procedure Wait_Process (Pid : out Process_Id; Success : out Boolean); 951 -- Wait for the completion of any of the processes created by previous 952 -- calls to Non_Blocking_Spawn. The caller will be suspended until one of 953 -- these processes terminates (normally or abnormally). If any of these 954 -- subprocesses terminates prior to the call to Wait_Process (and has not 955 -- been returned by a previous call to Wait_Process), then the call to 956 -- Wait_Process is immediate. Pid identifies the process that has 957 -- terminated (matching the value returned from Non_Blocking_Spawn). 958 -- Success is set to True if this sub-process terminated successfully. If 959 -- Pid = Invalid_Pid, there were no subprocesses left to wait on. 960 -- 961 -- This function will always set success to False under VxWorks, since 962 -- there is no notion of executables under this OS. 963 964 procedure Non_Blocking_Wait_Process 965 (Pid : out Process_Id; Success : out Boolean); 966 -- Same as Wait_Process, except if there are no completed child processes, 967 -- return immediately without blocking, and return Invalid_Pid in Pid. 968 -- Not supported on all platforms; Success = False if not supported. 969 970 ------------------------------------- 971 -- NOTE: Spawn in Tasking Programs -- 972 ------------------------------------- 973 974 -- Spawning processes in tasking programs using the above Spawn and 975 -- Non_Blocking_Spawn subprograms is not recommended, because there are 976 -- subtle interactions between creating a process and signals/locks that 977 -- can cause trouble. These issues are not specific to Ada; they depend 978 -- primarily on the operating system. 979 980 -- If you need to spawn processes in a tasking program, you will need to 981 -- understand the semantics of your operating system, and you are likely to 982 -- write non-portable code, because operating systems differ in this area. 983 984 -- The Spawn and Non_Blocking_Spawn subprograms call the following 985 -- operating system functions: 986 987 -- On Windows: spawnvp (blocking) or CreateProcess (non-blocking) 988 989 -- On Solaris: fork1, followed in the child process by execv 990 991 -- On other Unix-like systems: fork, followed in the child 992 -- process by execv. 993 994 -- On vxworks, spawning of processes is not supported 995 996 -- For details, look at the functions __gnat_portable_spawn and 997 -- __gnat_portable_no_block_spawn in adaint.c. 998 999 -- You should read the operating-system-specific documentation for the 1000 -- above functions, paying special attention to subtle interactions with 1001 -- threading, signals, locks, and file descriptors. Most of the issues are 1002 -- related to the fact that on Unix, there is a window of time between fork 1003 -- and execv; Windows does not have this problem, because spawning is done 1004 -- in a single operation. 1005 1006 -- On Posix-compliant systems, such as Linux, fork duplicates just the 1007 -- calling thread. (On Solaris, fork1 is the Posix-compliant version of 1008 -- fork.) 1009 1010 -- You should avoid using signals while spawning. This includes signals 1011 -- used internally by the Ada run-time system, such as timer signals used 1012 -- to implement delay statements. 1013 1014 -- It is best to spawn any subprocesses very early, before the parent 1015 -- process creates tasks, locks, or installs signal handlers. Certainly 1016 -- avoid doing simultaneous spawns from multiple threads of the same 1017 -- process. 1018 1019 -- There is no problem spawning a subprocess that uses tasking: the 1020 -- problems are caused only by tasking in the parent. 1021 1022 -- If the parent is using tasking, and needs to spawn subprocesses at 1023 -- arbitrary times, one technique is for the parent to spawn (very early) 1024 -- a particular spawn-manager subprocess whose job is to spawn other 1025 -- processes. The spawn-manager must avoid tasking. The parent sends 1026 -- messages to the spawn-manager requesting it to spawn processes, using 1027 -- whatever inter-process communication mechanism you like, such as 1028 -- sockets. 1029 1030 -- In short, mixing spawning of subprocesses with tasking is a tricky 1031 -- business, and should be avoided if possible, but if it is necessary, 1032 -- the above guidelines should be followed, and you should beware of 1033 -- portability problems. 1034 1035 ------------------- 1036 -- Miscellaneous -- 1037 ------------------- 1038 1039 function Errno return Integer; 1040 pragma Import (C, Errno, "__get_errno"); 1041 -- Return the task-safe last error number 1042 1043 function Errno_Message 1044 (Err : Integer := Errno; 1045 Default : String := "") return String; 1046 -- Return a message describing the given Errno value. If none is provided 1047 -- by the system, return Default if not empty, else return a generic 1048 -- message indicating the numeric errno value. 1049 1050 function Getenv (Name : String) return String_Access; 1051 -- Get the value of the environment variable. Returns an access to the 1052 -- empty string if the environment variable does not exist or has an 1053 -- explicit null value (in some operating systems these are distinct 1054 -- cases, in others they are not; this interface abstracts away that 1055 -- difference. The argument is allocated on the heap (even in the null 1056 -- case), and needs to be freed explicitly when no longer needed to avoid 1057 -- memory leaks. 1058 1059 procedure OS_Abort; 1060 pragma Import (C, OS_Abort, "abort"); 1061 pragma No_Return (OS_Abort); 1062 -- Exit to OS signalling an abort (traceback or other appropriate 1063 -- diagnostic information should be given if possible, or entry made to 1064 -- the debugger if that is possible). 1065 1066 procedure OS_Exit (Status : Integer); 1067 pragma No_Return (OS_Exit); 1068 -- Exit to OS with given status code (program is terminated). Note that 1069 -- this is abrupt termination. All tasks are immediately terminated. There 1070 -- are no finalization or other Ada-specific cleanup actions performed. On 1071 -- systems with atexit handlers (such as Unix and Windows), atexit handlers 1072 -- are called. 1073 1074 type OS_Exit_Subprogram is access procedure (Status : Integer); 1075 1076 procedure OS_Exit_Default (Status : Integer); 1077 pragma No_Return (OS_Exit_Default); 1078 -- Default implementation of procedure OS_Exit 1079 1080 OS_Exit_Ptr : OS_Exit_Subprogram := OS_Exit_Default'Access; 1081 -- OS_Exit is implemented through this access value. It it then possible to 1082 -- change the implementation of OS_Exit by redirecting OS_Exit_Ptr to an 1083 -- other implementation. 1084 1085 procedure Set_Errno (Errno : Integer); 1086 pragma Import (C, Set_Errno, "__set_errno"); 1087 -- Set the task-safe error number 1088 1089 procedure Setenv (Name : String; Value : String); 1090 -- Set the value of the environment variable Name to Value. This call 1091 -- modifies the current environment, but does not modify the parent 1092 -- process environment. After a call to Setenv, Getenv (Name) will always 1093 -- return a String_Access referencing the same String as Value. This is 1094 -- true also for the null string case (the actual effect may be to either 1095 -- set an explicit null as the value, or to remove the entry, this is 1096 -- operating system dependent). Note that any following calls to Spawn 1097 -- will pass an environment to the spawned process that includes the 1098 -- changes made by Setenv calls. 1099 1100 Directory_Separator : constant Character; 1101 -- The character that is used to separate parts of a pathname 1102 1103 Path_Separator : constant Character; 1104 -- The character to separate paths in an environment variable value 1105 1106private 1107 pragma Import (C, Path_Separator, "__gnat_path_separator"); 1108 pragma Import (C, Directory_Separator, "__gnat_dir_separator"); 1109 pragma Import (C, Current_Time, "__gnat_current_time"); 1110 pragma Import (C, Current_Process_Id, "__gnat_current_process_id"); 1111 1112 type OS_Time is 1113 range -(2 ** 63) .. +(2 ** 63 - 1); 1114 -- Type used for timestamps in the compiler. This type is used to hold 1115 -- time stamps, but may have a different representation than C's time_t. 1116 -- This type needs to match the declaration of OS_Time in adaint.h. 1117 1118 Invalid_Time : constant OS_Time := -1; 1119 -- This value should match the return value from __gnat_file_time_* 1120 1121 pragma Import (Intrinsic, "<"); 1122 pragma Import (Intrinsic, ">"); 1123 pragma Import (Intrinsic, "<="); 1124 pragma Import (Intrinsic, ">="); 1125 pragma Inline (To_C); 1126 pragma Inline (To_Ada); 1127 1128 type Process_Id is new Integer; 1129 Invalid_Pid : constant Process_Id := -1; 1130 1131end System.OS_Lib; 1132