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 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 -- File Stuff -- 169 ---------------- 170 171 -- These routines give access to the open/creat/close/read/write level of 172 -- I/O routines in the typical C library (these functions are not part of 173 -- the ANSI C standard, but are typically available in all systems). See 174 -- also package Interfaces.C_Streams for access to the stream level 175 -- routines. 176 177 -- Note on file names. If a file name is passed as type String in any of 178 -- the following specifications, then the name is a normal Ada string and 179 -- need not be NUL-terminated. However, a trailing NUL character is 180 -- permitted, and will be ignored (more accurately, the NUL and any 181 -- characters that follow it will be ignored). 182 183 type File_Descriptor is new Integer; 184 -- Corresponds to the int file handle values used in the C routines 185 186 Standin : constant File_Descriptor := 0; 187 Standout : constant File_Descriptor := 1; 188 Standerr : constant File_Descriptor := 2; 189 -- File descriptors for standard input output files 190 191 Invalid_FD : constant File_Descriptor := -1; 192 -- File descriptor returned when error in opening/creating file 193 194 procedure Close (FD : File_Descriptor; Status : out Boolean); 195 -- Close file referenced by FD. Status is False if the underlying service 196 -- failed. Reasons for failure include: disk full, disk quotas exceeded 197 -- and invalid file descriptor (the file may have been closed twice). 198 199 procedure Close (FD : File_Descriptor); 200 -- Close file referenced by FD. This form is used when the caller wants to 201 -- ignore any possible error (see above for error cases). 202 203 type Copy_Mode is 204 (Copy, 205 -- Copy the file. It is an error if the target file already exists. The 206 -- time stamps and other file attributes are preserved in the copy. 207 208 Overwrite, 209 -- If the target file exists, the file is replaced otherwise the file 210 -- is just copied. The time stamps and other file attributes are 211 -- preserved in the copy. 212 213 Append); 214 -- If the target file exists, the contents of the source file is 215 -- appended at the end. Otherwise the source file is just copied. The 216 -- time stamps and other file attributes are preserved if the 217 -- destination file does not exist. 218 219 type Attribute is 220 (Time_Stamps, 221 -- Copy time stamps from source file to target file. All other 222 -- attributes are set to normal default values for file creation. 223 224 Full, 225 -- All attributes are copied from the source file to the target file. 226 -- This includes the timestamps, and for example also includes 227 -- read/write/execute attributes in Unix systems. 228 229 None); 230 -- No attributes are copied. All attributes including the time stamp 231 -- values are set to normal default values for file creation. 232 233 -- Note: The default is Time_Stamps, which corresponds to the normal 234 -- default on Windows style systems. Full corresponds to the typical 235 -- effect of "cp -p" on Unix systems, and None corresponds to the typical 236 -- effect of "cp" on Unix systems. 237 238 -- Note: Time_Stamps and Full are not supported on VxWorks 5 239 240 procedure Copy_File 241 (Name : String; 242 Pathname : String; 243 Success : out Boolean; 244 Mode : Copy_Mode := Copy; 245 Preserve : Attribute := Time_Stamps); 246 -- Copy a file. Name must designate a single file (no wild cards allowed). 247 -- Pathname can be a filename or directory name. In the latter case Name 248 -- is copied into the directory preserving the same file name. Mode 249 -- defines the kind of copy, see above with the default being a normal 250 -- copy in which the target file must not already exist. Success is set to 251 -- True or False indicating if the copy is successful (depending on the 252 -- specified Mode). 253 254 procedure Copy_File_Attributes 255 (From : String; 256 To : String; 257 Success : out Boolean; 258 Copy_Timestamp : Boolean := True; 259 Copy_Permissions : Boolean := True); 260 -- Copy some of the file attributes from one file to another. Both files 261 -- must exist, or Success is set to False. 262 263 procedure Copy_Time_Stamps 264 (Source : String; 265 Dest : String; 266 Success : out Boolean); 267 -- Copy Source file time stamps (last modification and last access time 268 -- stamps) to Dest file. Source and Dest must be valid filenames, 269 -- furthermore Dest must be writable. Success will be set to True if the 270 -- operation was successful and False otherwise. 271 -- 272 -- Note: this procedure is not supported on VxWorks 5. On this platform, 273 -- Success is always set to False. 274 275 type Mode is (Binary, Text); 276 for Mode'Size use Integer'Size; 277 for Mode use (Binary => 0, Text => 1); 278 -- Used in all the Open and Create calls to specify if the file is to be 279 -- opened in binary mode or text mode. In systems like Unix, this has no 280 -- effect, but in systems capable of text mode translation, the use of 281 -- Text as the mode parameter causes the system to do CR/LF translation 282 -- and also to recognize the DOS end of file character on input. The use 283 -- of Text where appropriate allows programs to take a portable Unix view 284 -- of DOS-format files and process them appropriately. 285 286 function Create_File 287 (Name : String; 288 Fmode : Mode) return File_Descriptor; 289 -- Creates new file with given name for writing, returning file descriptor 290 -- for subsequent use in Write calls. If the file already exists, it is 291 -- overwritten. File descriptor returned is Invalid_FD if file cannot be 292 -- successfully created. 293 294 function Create_New_File 295 (Name : String; 296 Fmode : Mode) return File_Descriptor; 297 -- Create new file with given name for writing, returning file descriptor 298 -- for subsequent use in Write calls. This differs from Create_File in 299 -- that it fails if the file already exists. File descriptor returned is 300 -- Invalid_FD if the file exists or cannot be created. 301 302 function Create_Output_Text_File (Name : String) return File_Descriptor; 303 -- Creates new text file with given name suitable to redirect standard 304 -- output, returning file descriptor. File descriptor returned is 305 -- Invalid_FD if file cannot be successfully created. 306 307 Temp_File_Len : constant Integer := 12; 308 -- Length of name returned by Create_Temp_File call (GNAT-XXXXXX & NUL) 309 310 subtype Temp_File_Name is String (1 .. Temp_File_Len); 311 -- String subtype set by Create_Temp_File 312 313 procedure Create_Temp_File 314 (FD : out File_Descriptor; 315 Name : out Temp_File_Name); 316 -- Create and open for writing a temporary file in the current working 317 -- directory. The name of the file and the File Descriptor are returned. 318 -- The File Descriptor returned is Invalid_FD in the case of failure. No 319 -- mode parameter is provided. Since this is a temporary file, there is no 320 -- point in doing text translation on it. 321 -- 322 -- On some operating systems, the maximum number of temp files that can be 323 -- created with this procedure may be limited. When the maximum is reached, 324 -- this procedure returns Invalid_FD. On some operating systems, there may 325 -- be a race condition between processes trying to create temp files at the 326 -- same time in the same directory using this procedure. 327 328 procedure Create_Temp_File 329 (FD : out File_Descriptor; 330 Name : out String_Access); 331 -- Create and open for writing a temporary file in the current working 332 -- directory. The name of the file and the File Descriptor are returned. 333 -- It is the responsibility of the caller to deallocate the access value 334 -- returned in Name. 335 -- 336 -- The file is opened in binary mode (no text translation). 337 -- 338 -- This procedure will always succeed if the current working directory is 339 -- writable. If the current working directory is not writable, then 340 -- Invalid_FD is returned for the file descriptor and null for the Name. 341 -- There is no race condition problem between processes trying to create 342 -- temp files at the same time in the same directory. 343 344 procedure Create_Temp_Output_File 345 (FD : out File_Descriptor; 346 Name : out String_Access); 347 -- Create and open for writing a temporary file in the current working 348 -- directory suitable to redirect standard output. The name of the file and 349 -- the File Descriptor are returned. It is the responsibility of the caller 350 -- to deallocate the access value returned in Name. 351 -- 352 -- The file is opened in text mode 353 -- 354 -- This procedure will always succeed if the current working directory is 355 -- writable. If the current working directory is not writable, then 356 -- Invalid_FD is returned for the file descriptor and null for the Name. 357 -- There is no race condition problem between processes trying to create 358 -- temp files at the same time in the same directory. 359 360 procedure Delete_File (Name : String; Success : out Boolean); 361 -- Deletes file. Success is set True or False indicating if the delete is 362 -- successful. 363 364 function File_Length (FD : File_Descriptor) return Long_Integer; 365 pragma Import (C, File_Length, "__gnat_file_length_long"); 366 367 type Large_File_Size is range -2**63 .. 2**63 - 1; 368 -- Maximum supported size for a file (8 exabytes = 8 million terabytes, 369 -- should be enough to accomodate all possible needs for quite a while). 370 371 function File_Length64 (FD : File_Descriptor) return Large_File_Size; 372 pragma Import (C, File_Length64, "__gnat_file_length"); 373 -- Get length of file from file descriptor FD 374 375 function File_Time_Stamp (Name : String) return OS_Time; 376 -- Given the name of a file or directory, Name, obtains and returns the 377 -- time stamp. This function can be used for an unopened file. Returns 378 -- Invalid_Time is Name doesn't correspond to an existing file. 379 380 function File_Time_Stamp (FD : File_Descriptor) return OS_Time; 381 -- Get time stamp of file from file descriptor FD Returns Invalid_Time is 382 -- FD doesn't correspond to an existing file. 383 384 function Get_Debuggable_Suffix return String_Access; 385 -- Return the debuggable suffix convention. Usually this is the same as 386 -- the convention for Get_Executable_Suffix. The result is allocated on 387 -- the heap and should be freed after use to avoid storage leaks. 388 389 function Get_Executable_Suffix return String_Access; 390 -- Return the executable suffix convention. The result is allocated on the 391 -- heap and should be freed after use to avoid storage leaks. 392 393 function Get_Object_Suffix return String_Access; 394 -- Return the object suffix convention. The result is allocated on the heap 395 -- and should be freed after use to avoid storage leaks. 396 397 function Get_Target_Debuggable_Suffix return String_Access; 398 -- Return the target debuggable suffix convention. Usually this is the same 399 -- as the convention for Get_Executable_Suffix. The result is allocated on 400 -- the heap and should be freed after use to avoid storage leaks. 401 402 function Get_Target_Executable_Suffix return String_Access; 403 -- Return the target executable suffix convention. The result is allocated 404 -- on the heap and should be freed after use to avoid storage leaks. 405 406 function Get_Target_Object_Suffix return String_Access; 407 -- Return the target object suffix convention. The result is allocated on 408 -- the heap and should be freed after use to avoid storage leaks. 409 410 function Is_Absolute_Path (Name : String) return Boolean; 411 -- Returns True if Name is an absolute path name, i.e. it designates a 412 -- file or directory absolutely rather than relative to another directory. 413 414 function Is_Directory (Name : String) return Boolean; 415 -- Determines if the given string, Name, is the name of a directory. 416 -- Returns True if so, False otherwise. Name may be an absolute path 417 -- name or a relative path name, including a simple file name. If it is 418 -- a relative path name, it is relative to the current working directory. 419 420 function Is_Executable_File (Name : String) return Boolean; 421 -- Determines if the given string, Name, is the name of an existing file 422 -- that is executable. Returns True if so, False otherwise. Note that this 423 -- function simply interrogates the file attributes (e.g. using the C 424 -- function stat), so it does not indicate a situation in which a file may 425 -- not actually be readable due to some other process having exclusive 426 -- access. 427 428 function Is_Readable_File (Name : String) return Boolean; 429 -- Determines if the given string, Name, is the name of an existing file 430 -- that is readable. Returns True if so, False otherwise. Note that this 431 -- function simply interrogates the file attributes (e.g. using the C 432 -- function stat), so it does not indicate a situation in which a file may 433 -- not actually be readable due to some other process having exclusive 434 -- access. 435 436 function Is_Regular_File (Name : String) return Boolean; 437 -- Determines if the given string, Name, is the name of an existing 438 -- regular file. Returns True if so, False otherwise. Name may be an 439 -- absolute path name or a relative path name, including a simple file 440 -- name. If it is a relative path name, it is relative to the current 441 -- working directory. 442 443 function Is_Symbolic_Link (Name : String) return Boolean; 444 -- Determines if the given string, Name, is the path of a symbolic link on 445 -- systems that support it. Returns True if so, False if the path is not a 446 -- symbolic link or if the system does not support symbolic links. 447 -- 448 -- A symbolic link is an indirect pointer to a file; its directory entry 449 -- contains the name of the file to which it is linked. Symbolic links may 450 -- span file systems and may refer to directories. 451 452 function Is_Writable_File (Name : String) return Boolean; 453 -- Determines if the given string, Name, is the name of an existing file 454 -- that is writable. 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 writeable due to some other process having exclusive 458 -- access. 459 460 function Locate_Exec_On_Path (Exec_Name : String) return String_Access; 461 -- Try to locate an executable whose name is given by Exec_Name in the 462 -- directories listed in the environment Path. If the Exec_Name does not 463 -- have the executable suffix, it will be appended before the search. 464 -- Otherwise works like Locate_Regular_File below. If the executable is 465 -- not found, null is returned. 466 -- 467 -- Note that this function allocates memory for the returned value. This 468 -- memory needs to be deallocated after use. 469 470 function Locate_Regular_File 471 (File_Name : String; 472 Path : String) return String_Access; 473 -- Try to locate a regular file whose name is given by File_Name in the 474 -- directories listed in Path. If a file is found, its full pathname is 475 -- returned; otherwise, a null pointer is returned. If the File_Name given 476 -- is an absolute pathname, then Locate_Regular_File just checks that the 477 -- file exists and is a regular file. Otherwise, if the File_Name given 478 -- includes directory information, Locate_Regular_File first checks if the 479 -- file exists relative to the current directory. If it does not, or if 480 -- the File_Name given is a simple file name, the Path argument is parsed 481 -- according to OS conventions, and for each directory in the Path a check 482 -- is made if File_Name is a relative pathname of a regular file from that 483 -- directory. 484 -- 485 -- Note that this function allocates some memory for the returned value. 486 -- This memory needs to be deallocated after use. 487 488 Seek_Cur : constant := 1; 489 Seek_End : constant := 2; 490 Seek_Set : constant := 0; 491 -- Used to indicate origin for Lseek call 492 493 procedure Lseek 494 (FD : File_Descriptor; 495 offset : Long_Integer; 496 origin : Integer); 497 pragma Import (C, Lseek, "__gnat_lseek"); 498 -- Sets the current file pointer to the indicated offset value, relative 499 -- to the current position (origin = SEEK_CUR), end of file (origin = 500 -- SEEK_END), or start of file (origin = SEEK_SET). 501 502 function Normalize_Pathname 503 (Name : String; 504 Directory : String := ""; 505 Resolve_Links : Boolean := True; 506 Case_Sensitive : Boolean := True) return String; 507 -- Returns a file name as an absolute path name, resolving all relative 508 -- directories, and symbolic links. If Name is a relative path, it is 509 -- interpreted relative to Directory, or to the current directory if 510 -- Directory is the empty string (the default). The result returned is 511 -- the normalized name of the file, containing no "." or ".." components, 512 -- and no duplicated directory separators. For most cases, if two file 513 -- names designate the same file through different paths, 514 -- Normalize_Pathname will return the same canonical name in both cases. 515 -- However, there are cases when this is not true; for example, this is 516 -- not true in Unix for two hard links designating the same file. 517 -- 518 -- On Windows, the returned path will start with a drive letter. If 519 -- Directory is empty (the default) and Name is a relative path or an 520 -- absolute path without drive letter, the letter of the current drive 521 -- will start the returned path. If Case_Sensitive is True (the default), 522 -- then this drive letter will be forced to upper case ("C:\..."). 523 -- 524 -- If Resolve_Links is set to True, then the symbolic links, on systems 525 -- that support them, will be fully converted to the name of the file or 526 -- directory pointed to. This is slightly less efficient, since it 527 -- requires system calls. 528 -- 529 -- If Name cannot be resolved, is invalid (for example if it is too big) or 530 -- is null on entry (for example if there is symbolic link circularity, 531 -- e.g. A is a symbolic link for B, and B is a symbolic link for A), then 532 -- Normalize_Pathname returns an empty string. 533 -- 534 -- For case-sensitive file systems, the value of Case_Sensitive parameter 535 -- is ignored. For file systems that are not case-sensitive, such as 536 -- Windows, if this parameter is set to False, then the file and directory 537 -- names are folded to lower case. This allows checking whether two files 538 -- are the same by applying this function to their names and comparing the 539 -- results. If Case_Sensitive is set to True, this function does not change 540 -- the casing of file and directory names. 541 542 function Open_Append 543 (Name : String; 544 Fmode : Mode) return File_Descriptor; 545 -- Opens file Name for appending, returning its file descriptor. File 546 -- descriptor returned is Invalid_FD if the file cannot be successfully 547 -- opened. 548 549 function Open_Read 550 (Name : String; 551 Fmode : Mode) return File_Descriptor; 552 -- Open file Name for reading, returning its file descriptor. File 553 -- descriptor returned is Invalid_FD if the file cannot be opened. 554 555 function Open_Read_Write 556 (Name : String; 557 Fmode : Mode) return File_Descriptor; 558 -- Open file Name for both reading and writing, returning its file 559 -- descriptor. File descriptor returned is Invalid_FD if the file 560 -- cannot be opened. 561 562 function Read 563 (FD : File_Descriptor; 564 A : System.Address; 565 N : Integer) return Integer; 566 -- Read N bytes to address A from file referenced by FD. Returned value is 567 -- count of bytes actually read, which can be less than N at EOF. 568 569 procedure Rename_File 570 (Old_Name : String; 571 New_Name : String; 572 Success : out Boolean); 573 -- Rename a file. Success is set True or False indicating if the rename is 574 -- successful or not. 575 -- 576 -- WARNING: In one very important respect, this function is significantly 577 -- non-portable. If New_Name already exists then on Unix systems, the call 578 -- deletes the existing file, and the call signals success. On Windows, the 579 -- call fails, without doing the rename operation. See also the procedure 580 -- Ada.Directories.Rename, which portably provides the windows semantics, 581 -- i.e. fails if the output file already exists. 582 583 -- The following defines the mode for the Copy_File procedure below. Note 584 -- that "time stamps and other file attributes" in the descriptions below 585 -- refers to the creation and last modification times, and also the file 586 -- access (read/write/execute) status flags. 587 588 procedure Set_Close_On_Exec 589 (FD : File_Descriptor; 590 Close_On_Exec : Boolean; 591 Status : out Boolean); 592 -- When Close_On_Exec is True, mark FD to be closed automatically when new 593 -- program is executed by the calling process (i.e. prevent FD from being 594 -- inherited by child processes). When Close_On_Exec is False, mark FD to 595 -- not be closed on exec (i.e. allow it to be inherited). Status is False 596 -- if the operation could not be performed. 597 598 S_Owner : constant := 1; 599 S_Group : constant := 2; 600 S_Others : constant := 4; 601 -- Constants for use in Mode parameter to Set_Executable 602 603 procedure Set_Executable (Name : String; Mode : Positive := S_Owner); 604 -- Change permissions on the file given by Name to make it executable 605 -- for its owner, group or others, according to the setting of Mode. 606 -- As indicated, the default if no Mode parameter is given is owner. 607 608 procedure Set_File_Last_Modify_Time_Stamp (Name : String; Time : OS_Time); 609 -- Given the name of a file or directory, Name, set the last modification 610 -- time stamp. This function must be used for an unopened file. 611 612 procedure Set_Non_Readable (Name : String); 613 -- Change permissions on the named file to make it non-readable for 614 -- its owner. The writable and executable permissions are not 615 -- modified. 616 617 procedure Set_Non_Writable (Name : String); 618 -- Change permissions on the named file to make it non-writable for its 619 -- owner. The readable and executable permissions are not modified. 620 621 procedure Set_Read_Only (Name : String) renames Set_Non_Writable; 622 -- This renaming is provided for backwards compatibility with previous 623 -- versions. The use of Set_Non_Writable is preferred (clearer name). 624 625 procedure Set_Readable (Name : String); 626 -- Change permissions on the named file to make it readable for its 627 -- owner. 628 629 procedure Set_Writable (Name : String); 630 -- Change permissions on the named file to make it writable for its owner 631 632 function Write 633 (FD : File_Descriptor; 634 A : System.Address; 635 N : Integer) return Integer; 636 -- Write N bytes from address A to file referenced by FD. The returned 637 -- value is the number of bytes written, which can be less than N if a 638 -- disk full condition was detected. 639 640 -- The following section contains low-level routines using addresses to 641 -- pass file name and executable name. In each routine the name must be 642 -- Nul-Terminated. For complete documentation refer to the equivalent 643 -- routine (using String in place of C_File_Name) defined above. 644 645 subtype C_File_Name is System.Address; 646 -- This subtype is used to document that a parameter is the address of a 647 -- null-terminated string containing the name of a file. 648 649 -- All the following functions need comments ??? 650 651 procedure Copy_File 652 (Name : C_File_Name; 653 Pathname : C_File_Name; 654 Success : out Boolean; 655 Mode : Copy_Mode := Copy; 656 Preserve : Attribute := Time_Stamps); 657 658 procedure Copy_Time_Stamps 659 (Source : C_File_Name; 660 Dest : C_File_Name; 661 Success : out Boolean); 662 663 function Create_File 664 (Name : C_File_Name; 665 Fmode : Mode) return File_Descriptor; 666 667 function Create_New_File 668 (Name : C_File_Name; 669 Fmode : Mode) return File_Descriptor; 670 671 procedure Delete_File (Name : C_File_Name; Success : out Boolean); 672 673 function File_Time_Stamp (Name : C_File_Name) return OS_Time; 674 -- Returns Invalid_Time is Name doesn't correspond to an existing file 675 676 function Is_Directory (Name : C_File_Name) return Boolean; 677 function Is_Executable_File (Name : C_File_Name) return Boolean; 678 function Is_Readable_File (Name : C_File_Name) return Boolean; 679 function Is_Regular_File (Name : C_File_Name) return Boolean; 680 function Is_Symbolic_Link (Name : C_File_Name) return Boolean; 681 function Is_Writable_File (Name : C_File_Name) return Boolean; 682 683 function Locate_Regular_File 684 (File_Name : C_File_Name; 685 Path : C_File_Name) return String_Access; 686 687 function Open_Append 688 (Name : C_File_Name; 689 Fmode : Mode) return File_Descriptor; 690 691 function Open_Read 692 (Name : C_File_Name; 693 Fmode : Mode) return File_Descriptor; 694 695 function Open_Read_Write 696 (Name : C_File_Name; 697 Fmode : Mode) return File_Descriptor; 698 699 procedure Rename_File 700 (Old_Name : C_File_Name; 701 New_Name : C_File_Name; 702 Success : out Boolean); 703 704 ------------------ 705 -- Subprocesses -- 706 ------------------ 707 708 subtype Argument_List is String_List; 709 -- Type used for argument list in call to Spawn. The lower bound of the 710 -- array should be 1, and the length of the array indicates the number of 711 -- arguments. 712 713 subtype Argument_List_Access is String_List_Access; 714 -- Type used to return Argument_List without dragging in secondary stack. 715 -- Note that there is a Free procedure declared for this subtype which 716 -- frees the array and all referenced strings. 717 718 type Process_Id is private; 719 -- A private type used to identify a process activated by the following 720 -- non-blocking calls. The only meaningful operation on this type is a 721 -- comparison for equality. 722 723 Invalid_Pid : constant Process_Id; 724 -- A special value used to indicate errors, as described below 725 726 function Argument_String_To_List 727 (Arg_String : String) return Argument_List_Access; 728 -- Take a string that is a program and its arguments and parse it into an 729 -- Argument_List. Note that the result is allocated on the heap, and must 730 -- be freed by the programmer (when it is no longer needed) to avoid 731 -- memory leaks. 732 -- On Windows, backslashes are used as directory separators. On Unix, 733 -- however, they are used to escape the following character, so that for 734 -- instance "-d=name\ with\ space" is a single argument. In the result 735 -- list, the backslashes have been cleaned up when needed. The previous 736 -- example will thus result a single-element array, where the element is 737 -- "-d=name with space" (Unix) or "-d=name\ with\ space" (windows). 738 739 procedure Kill (Pid : Process_Id; Hard_Kill : Boolean := True); 740 -- Kill the process designated by Pid. Does nothing if Pid is Invalid_Pid 741 -- or on platforms where it is not supported, such as VxWorks. Hard_Kill 742 -- is True by default, and when True the process is terminated immediately. 743 -- If Hard_Kill is False, then a signal SIGINT is sent to the process on 744 -- POSIX OS or a ctrl-C event on Windows, allowing the process a chance to 745 -- terminate properly using a corresponding handler. 746 747 procedure Kill_Process_Tree (Pid : Process_Id; Hard_Kill : Boolean := True); 748 -- Kill the process designated by Pid and all it's children processes. 749 -- Does nothing if Pid is Invalid_Pid or on platforms where it is not 750 -- supported, such as VxWorks. Hard_Kill is True by default, and when True 751 -- the processes are terminated immediately. If Hard_Kill is False, then a 752 -- signal SIGINT is sent to the processes on POSIX OS or a ctrl-C event 753 -- on Windows, allowing the processes a chance to terminate properly 754 -- using a corresponding handler. 755 -- 756 -- Note that this routine is not atomic and is supported only on Linux 757 -- and Windows. On other OS it will only kill the process identified by 758 -- Pid. 759 760 function Non_Blocking_Spawn 761 (Program_Name : String; 762 Args : Argument_List) return Process_Id; 763 -- This is a non blocking call. The Process_Id of the spawned process is 764 -- returned. Parameters are to be used as in Spawn. If Invalid_Pid is 765 -- returned the program could not be spawned. 766 -- 767 -- Spawning processes from tasking programs is not recommended. See 768 -- "NOTE: Spawn in tasking programs" below. 769 -- 770 -- This function will always return Invalid_Pid under VxWorks, since there 771 -- is no notion of executables under this OS. 772 773 function Non_Blocking_Spawn 774 (Program_Name : String; 775 Args : Argument_List; 776 Output_File_Descriptor : File_Descriptor; 777 Err_To_Out : Boolean := True) return Process_Id; 778 -- Similar to the procedure above, but redirects the output to the file 779 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the 780 -- Standard Error output is also redirected. Invalid_Pid is returned 781 -- if the program could not be spawned successfully. 782 -- 783 -- Spawning processes from tasking programs is not recommended. See 784 -- "NOTE: Spawn in tasking programs" below. 785 -- 786 -- This function will always return Invalid_Pid under VxWorks, since there 787 -- is no notion of executables under this OS. 788 789 function Non_Blocking_Spawn 790 (Program_Name : String; 791 Args : Argument_List; 792 Output_File : String; 793 Err_To_Out : Boolean := True) return Process_Id; 794 -- Similar to the procedure above, but saves the output of the command to 795 -- a file with the name Output_File. 796 -- 797 -- Invalid_Pid is returned if the output file could not be created or if 798 -- the program could not be spawned successfully. 799 -- 800 -- Spawning processes from tasking programs is not recommended. See 801 -- "NOTE: Spawn in tasking programs" below. 802 -- 803 -- This function will always return Invalid_Pid under VxWorks, since there 804 -- is no notion of executables under this OS. 805 806 function Non_Blocking_Spawn 807 (Program_Name : String; 808 Args : Argument_List; 809 Stdout_File : String; 810 Stderr_File : String) return Process_Id; 811 -- Similar to the procedure above, but saves the standard output of the 812 -- command to a file with the name Stdout_File and the standard output 813 -- of the command to a file with the name Stderr_File. 814 815 procedure Normalize_Arguments (Args : in out Argument_List); 816 -- Normalize all arguments in the list. This ensure that the argument list 817 -- is compatible with the running OS and will works fine with Spawn and 818 -- Non_Blocking_Spawn for example. If Normalize_Arguments is called twice 819 -- on the same list it will do nothing the second time. Note that Spawn 820 -- and Non_Blocking_Spawn call Normalize_Arguments automatically, but 821 -- since there is a guarantee that a second call does nothing, this 822 -- internal call will have no effect if Normalize_Arguments is called 823 -- before calling Spawn. The call to Normalize_Arguments assumes that the 824 -- individual referenced arguments in Argument_List are on the heap, and 825 -- may free them and reallocate if they are modified. 826 827 function Pid_To_Integer (Pid : Process_Id) return Integer; 828 -- Convert a process id to an Integer. Useful for writing hash functions 829 -- for type Process_Id or to compare two Process_Id (e.g. for sorting). 830 831 procedure Spawn 832 (Program_Name : String; 833 Args : Argument_List; 834 Success : out Boolean); 835 -- This procedure spawns a program with a given list of arguments. The 836 -- first parameter of is the name of the executable. The second parameter 837 -- contains the arguments to be passed to this program. Success is False 838 -- if the named program could not be spawned or its execution completed 839 -- unsuccessfully. Note that the caller will be blocked until the 840 -- execution of the spawned program is complete. For maximum portability, 841 -- use a full path name for the Program_Name argument. On some systems 842 -- (notably Unix systems) a simple file name may also work (if the 843 -- executable can be located in the path). 844 -- 845 -- Spawning processes from tasking programs is not recommended. See 846 -- "NOTE: Spawn in tasking programs" below. 847 -- 848 -- Note: Arguments in Args that contain spaces and/or quotes such as 849 -- "--GCC=gcc -v" or "--GCC=""gcc -v""" are not portable across all 850 -- operating systems, and would not have the desired effect if they were 851 -- passed directly to the operating system. To avoid this problem, Spawn 852 -- makes an internal call to Normalize_Arguments, which ensures that such 853 -- arguments are modified in a manner that ensures that the desired effect 854 -- is obtained on all operating systems. The caller may call 855 -- Normalize_Arguments explicitly before the call (e.g. to print out the 856 -- exact form of arguments passed to the operating system). In this case 857 -- the guarantee a second call to Normalize_Arguments has no effect 858 -- ensures that the internal call will not affect the result. Note that 859 -- the implicit call to Normalize_Arguments may free and reallocate some 860 -- of the individual arguments. 861 -- 862 -- This function will always set Success to False under VxWorks and other 863 -- similar operating systems which have no notion of the concept of 864 -- dynamically executable file. Otherwise Success is set True if the exit 865 -- status of the spawned process is zero. 866 867 function Spawn 868 (Program_Name : String; 869 Args : Argument_List) return Integer; 870 -- Similar to the above procedure, but returns the actual status returned 871 -- by the operating system, or -1 under VxWorks and any other similar 872 -- operating systems which have no notion of separately spawnable programs. 873 -- 874 -- Spawning processes from tasking programs is not recommended. See 875 -- "NOTE: Spawn in tasking programs" below. 876 877 procedure Spawn 878 (Program_Name : String; 879 Args : Argument_List; 880 Output_File_Descriptor : File_Descriptor; 881 Return_Code : out Integer; 882 Err_To_Out : Boolean := True); 883 -- Similar to the procedure above, but redirects the output to the file 884 -- designated by Output_File_Descriptor. If Err_To_Out is True, then the 885 -- Standard Error output is also redirected. 886 -- Return_Code is set to the status code returned by the operating system 887 -- 888 -- Spawning processes from tasking programs is not recommended. See 889 -- "NOTE: Spawn in tasking programs" below. 890 891 procedure Spawn 892 (Program_Name : String; 893 Args : Argument_List; 894 Output_File : String; 895 Success : out Boolean; 896 Return_Code : out Integer; 897 Err_To_Out : Boolean := True); 898 -- Similar to the procedure above, but saves the output of the command to 899 -- a file with the name Output_File. 900 -- 901 -- Success is set to True if the command is executed and its output 902 -- successfully written to the file. If Success is True, then Return_Code 903 -- will be set to the status code returned by the operating system. 904 -- Otherwise, Return_Code is undefined. 905 -- 906 -- Spawning processes from tasking programs is not recommended. See 907 -- "NOTE: Spawn in tasking programs" below. 908 909 procedure Wait_Process (Pid : out Process_Id; Success : out Boolean); 910 -- Wait for the completion of any of the processes created by previous 911 -- calls to Non_Blocking_Spawn. The caller will be suspended until one of 912 -- these processes terminates (normally or abnormally). If any of these 913 -- subprocesses terminates prior to the call to Wait_Process (and has not 914 -- been returned by a previous call to Wait_Process), then the call to 915 -- Wait_Process is immediate. Pid identifies the process that has 916 -- terminated (matching the value returned from Non_Blocking_Spawn). 917 -- Success is set to True if this sub-process terminated successfully. If 918 -- Pid = Invalid_Pid, there were no subprocesses left to wait on. 919 -- 920 -- This function will always set success to False under VxWorks, since 921 -- there is no notion of executables under this OS. 922 923 ------------------------------------- 924 -- NOTE: Spawn in Tasking Programs -- 925 ------------------------------------- 926 927 -- Spawning processes in tasking programs using the above Spawn and 928 -- Non_Blocking_Spawn subprograms is not recommended, because there are 929 -- subtle interactions between creating a process and signals/locks that 930 -- can cause trouble. These issues are not specific to Ada; they depend 931 -- primarily on the operating system. 932 933 -- If you need to spawn processes in a tasking program, you will need to 934 -- understand the semantics of your operating system, and you are likely to 935 -- write non-portable code, because operating systems differ in this area. 936 937 -- The Spawn and Non_Blocking_Spawn subprograms call the following 938 -- operating system functions: 939 940 -- On Windows: spawnvp (blocking) or CreateProcess (non-blocking) 941 942 -- On Solaris: fork1, followed in the child process by execv 943 944 -- On other Unix-like systems: fork, followed in the child 945 -- process by execv. 946 947 -- On vxworks, spawning of processes is not supported 948 949 -- For details, look at the functions __gnat_portable_spawn and 950 -- __gnat_portable_no_block_spawn in adaint.c. 951 952 -- You should read the operating-system-specific documentation for the 953 -- above functions, paying special attention to subtle interactions with 954 -- threading, signals, locks, and file descriptors. Most of the issues are 955 -- related to the fact that on Unix, there is a window of time between fork 956 -- and execv; Windows does not have this problem, because spawning is done 957 -- in a single operation. 958 959 -- On Posix-compliant systems, such as Linux, fork duplicates just the 960 -- calling thread. (On Solaris, fork1 is the Posix-compliant version of 961 -- fork.) 962 963 -- You should avoid using signals while spawning. This includes signals 964 -- used internally by the Ada run-time system, such as timer signals used 965 -- to implement delay statements. 966 967 -- It is best to spawn any subprocesses very early, before the parent 968 -- process creates tasks, locks, or installs signal handlers. Certainly 969 -- avoid doing simultaneous spawns from multiple threads of the same 970 -- process. 971 972 -- There is no problem spawning a subprocess that uses tasking: the 973 -- problems are caused only by tasking in the parent. 974 975 -- If the parent is using tasking, and needs to spawn subprocesses at 976 -- arbitrary times, one technique is for the parent to spawn (very early) 977 -- a particular spawn-manager subprocess whose job is to spawn other 978 -- processes. The spawn-manager must avoid tasking. The parent sends 979 -- messages to the spawn-manager requesting it to spawn processes, using 980 -- whatever inter-process communication mechanism you like, such as 981 -- sockets. 982 983 -- In short, mixing spawning of subprocesses with tasking is a tricky 984 -- business, and should be avoided if possible, but if it is necessary, 985 -- the above guidelines should be followed, and you should beware of 986 -- portability problems. 987 988 ------------------- 989 -- Miscellaneous -- 990 ------------------- 991 992 function Errno return Integer; 993 pragma Import (C, Errno, "__get_errno"); 994 -- Return the task-safe last error number 995 996 function Errno_Message 997 (Err : Integer := Errno; 998 Default : String := "") return String; 999 -- Return a message describing the given Errno value. If none is provided 1000 -- by the system, return Default if not empty, else return a generic 1001 -- message indicating the numeric errno value. 1002 1003 function Getenv (Name : String) return String_Access; 1004 -- Get the value of the environment variable. Returns an access to the 1005 -- empty string if the environment variable does not exist or has an 1006 -- explicit null value (in some operating systems these are distinct 1007 -- cases, in others they are not; this interface abstracts away that 1008 -- difference. The argument is allocated on the heap (even in the null 1009 -- case), and needs to be freed explicitly when no longer needed to avoid 1010 -- memory leaks. 1011 1012 procedure OS_Abort; 1013 pragma Import (C, OS_Abort, "abort"); 1014 pragma No_Return (OS_Abort); 1015 -- Exit to OS signalling an abort (traceback or other appropriate 1016 -- diagnostic information should be given if possible, or entry made to 1017 -- the debugger if that is possible). 1018 1019 procedure OS_Exit (Status : Integer); 1020 pragma No_Return (OS_Exit); 1021 -- Exit to OS with given status code (program is terminated). Note that 1022 -- this is abrupt termination. All tasks are immediately terminated. There 1023 -- are no finalization or other Ada-specific cleanup actions performed. On 1024 -- systems with atexit handlers (such as Unix and Windows), atexit handlers 1025 -- are called. 1026 1027 type OS_Exit_Subprogram is access procedure (Status : Integer); 1028 1029 procedure OS_Exit_Default (Status : Integer); 1030 pragma No_Return (OS_Exit_Default); 1031 -- Default implementation of procedure OS_Exit 1032 1033 OS_Exit_Ptr : OS_Exit_Subprogram := OS_Exit_Default'Access; 1034 -- OS_Exit is implemented through this access value. It it then possible to 1035 -- change the implementation of OS_Exit by redirecting OS_Exit_Ptr to an 1036 -- other implementation. 1037 1038 procedure Set_Errno (Errno : Integer); 1039 pragma Import (C, Set_Errno, "__set_errno"); 1040 -- Set the task-safe error number 1041 1042 procedure Setenv (Name : String; Value : String); 1043 -- Set the value of the environment variable Name to Value. This call 1044 -- modifies the current environment, but does not modify the parent 1045 -- process environment. After a call to Setenv, Getenv (Name) will always 1046 -- return a String_Access referencing the same String as Value. This is 1047 -- true also for the null string case (the actual effect may be to either 1048 -- set an explicit null as the value, or to remove the entry, this is 1049 -- operating system dependent). Note that any following calls to Spawn 1050 -- will pass an environment to the spawned process that includes the 1051 -- changes made by Setenv calls. 1052 1053 Directory_Separator : constant Character; 1054 -- The character that is used to separate parts of a pathname 1055 1056 Path_Separator : constant Character; 1057 -- The character to separate paths in an environment variable value 1058 1059private 1060 pragma Import (C, Path_Separator, "__gnat_path_separator"); 1061 pragma Import (C, Directory_Separator, "__gnat_dir_separator"); 1062 pragma Import (C, Current_Time, "__gnat_current_time"); 1063 1064 type OS_Time is 1065 range -(2 ** (Standard'Address_Size - Integer'(1))) .. 1066 +(2 ** (Standard'Address_Size - Integer'(1)) - 1); 1067 -- Type used for timestamps in the compiler. This type is used to hold 1068 -- time stamps, but may have a different representation than C's time_t. 1069 -- This type needs to match the declaration of OS_Time in adaint.h. 1070 1071 -- Add pragma Inline statements for comparison operations on OS_Time. It 1072 -- would actually be nice to use pragma Import (Intrinsic) here, but this 1073 -- was not properly supported till GNAT 3.15a, so that would cause 1074 -- bootstrap path problems. To be changed later ??? 1075 1076 Invalid_Time : constant OS_Time := -1; 1077 -- This value should match the return value from __gnat_file_time_* 1078 1079 pragma Inline ("<"); 1080 pragma Inline (">"); 1081 pragma Inline ("<="); 1082 pragma Inline (">="); 1083 1084 type Process_Id is new Integer; 1085 Invalid_Pid : constant Process_Id := -1; 1086 1087end System.OS_Lib; 1088