gcc/ada/g-dirope.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --            G N A T . D I R E C T O R Y _ O P E R A T I O N S             --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --                     Copyright (C) 1998-2014, AdaCore                     --
  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 --  Directory operations
  33
  34 --  This package provides routines for manipulating directories. A directory
  35 --  can be treated as a file, using open and close routines, and a scanning
  36 --  routine is provided for iterating through the entries in a directory.
  37
  38 --  See also child package GNAT.Directory_Operations.Iteration
  39
  40 with System;
  41 with Ada.Strings.Maps;
  42
  43 package GNAT.Directory_Operations is
  44
  45    subtype Dir_Name_Str is String;
  46    --  A subtype used in this package to represent string values that are
  47    --  directory names. A directory name is a prefix for files that appear
  48    --  with in the directory. This means that for UNIX systems, the string
  49    --  includes a final '/', and for DOS-like systems, it includes a final
  50    --  '\' character. It can also include drive letters if the operating
  51    --  system provides for this. The final '/' or '\' in a Dir_Name_Str is
  52    --  optional when passed as a procedure or function in parameter.
  53
  54    type Dir_Type is limited private;
  55    --  A value used to reference a directory. Conceptually this value includes
  56    --  the identity of the directory, and a sequential position within it.
  57
  58    Null_Dir : constant Dir_Type;
  59    --  Represent the value for an uninitialized or closed directory
  60
  61    Directory_Error : exception;
  62    --  Exception raised if the directory cannot be opened, read, closed,
  63    --  created or if it is not possible to change the current execution
  64    --  environment directory.
  65
  66    Dir_Separator : constant Character;
  67    --  Running system default directory separator
  68
  69    --------------------------------
  70    -- Basic Directory operations --
  71    --------------------------------
  72
  73    procedure Change_Dir (Dir_Name : Dir_Name_Str);
  74    --  Changes the working directory of the current execution environment
  75    --  to the directory named by Dir_Name. Raises Directory_Error if Dir_Name
  76    --  does not exist.
  77
  78    procedure Make_Dir (Dir_Name : Dir_Name_Str);
  79    --  Create a new directory named Dir_Name. Raises Directory_Error if
  80    --  Dir_Name cannot be created.
  81
  82    procedure Remove_Dir
  83      (Dir_Name  : Dir_Name_Str;
  84       Recursive : Boolean := False);
  85    --  Remove the directory named Dir_Name. If Recursive is set to True, then
  86    --  Remove_Dir removes all the subdirectories and files that are in
  87    --  Dir_Name. Raises Directory_Error if Dir_Name cannot be removed.
  88
  89    function Get_Current_Dir return Dir_Name_Str;
  90    --  Returns the current working directory for the execution environment
  91
  92    procedure Get_Current_Dir (Dir : out Dir_Name_Str; Last : out Natural);
  93    --  Returns the current working directory for the execution environment
  94    --  The name is returned in Dir_Name. Last is the index in Dir_Name such
  95    --  that Dir_Name (Last) is the last character written. If Dir_Name is
  96    --  too small for the directory name, the name will be truncated before
  97    --  being copied to Dir_Name.
  98
  99    -------------------------
 100    -- Pathname Operations --
 101    -------------------------
 102
 103    subtype Path_Name is String;
 104    --  All routines using Path_Name handle both styles (UNIX and DOS) of
 105    --  directory separators (either slash or back slash).
 106
 107    function Dir_Name (Path : Path_Name) return Dir_Name_Str;
 108    --  Returns directory name for Path. This is similar to the UNIX dirname
 109    --  command. Everything after the last directory separator is removed. If
 110    --  there is no directory separator the current working directory is
 111    --  returned. Note that the contents of Path is case-sensitive on
 112    --  systems that have case-sensitive file names (like Unix), and
 113    --  non-case-sensitive on systems where the file system is also non-
 114    --  case-sensitive (such as Windows).
 115
 116    function Base_Name
 117      (Path   : Path_Name;
 118       Suffix : String := "") return String;
 119    --  Any directory prefix is removed. A directory prefix is defined as
 120    --  text up to and including the last directory separator character in
 121    --  the input string. In addition if Path ends with the string given for
 122    --  Suffix, then it is also removed. Note that Suffix here can be an
 123    --  arbitrary string (it is not required to be a file extension). This
 124    --  is equivalent to the UNIX basename command. The following rule is
 125    --  always true:
 126    --
 127    --    'Path' and 'Dir_Name (Path) & Dir_Separator & Base_Name (Path)'
 128    --    represent the same file.
 129    --
 130    --  The comparison of Suffix is case-insensitive on systems like Windows
 131    --  where the file search is case-insensitive (e.g. on such systems,
 132    --  Base_Name ("/Users/AdaCore/BB12.patch", ".Patch") returns "BB12").
 133    --
 134    --  Note that the index bounds of the result match the corresponding indexes
 135    --  in the Path string (you cannot assume that the lower bound of the
 136    --  returned string is one).
 137
 138    function File_Extension (Path : Path_Name) return String;
 139    --  Return the file extension. This is defined as the string after the
 140    --  last dot, including the dot itself. For example, if the file name
 141    --  is "file1.xyz.adq", then the returned value would be ".adq". If no
 142    --  dot is present in the file name, or the last character of the file
 143    --  name is a dot, then the null string is returned.
 144
 145    function File_Name (Path : Path_Name) return String;
 146    --  Returns the file name and the file extension if present. It removes all
 147    --  path information. This is equivalent to Base_Name with default Extension
 148    --  value.
 149
 150    type Path_Style is (UNIX, DOS, System_Default);
 151    function Format_Pathname
 152      (Path  : Path_Name;
 153       Style : Path_Style := System_Default) return Path_Name;
 154    --  Removes all double directory separator and converts all '\' to '/' if
 155    --  Style is UNIX and converts all '/' to '\' if Style is set to DOS. This
 156    --  function will help to provide a consistent naming scheme running for
 157    --  different environments. If style is set to System_Default the routine
 158    --  will use the default directory separator on the running environment.
 159    --
 160    --  The Style argument indicates the syntax to be used for path names:
 161    --
 162    --    DOS
 163    --      Use '\' as the directory separator (default on Windows)
 164    --
 165    --    UNIX
 166    --      Use '/' as the directory separator (default on all other systems)
 167    --
 168    --    System_Default
 169    --      Use the default style for the current system
 170
 171    type Environment_Style is (UNIX, DOS, Both, System_Default);
 172    function Expand_Path
 173      (Path : Path_Name;
 174       Mode : Environment_Style := System_Default) return Path_Name;
 175    --  Returns Path with environment variables replaced by the current
 176    --  environment variable value. For example, $HOME/mydir will be replaced
 177    --  by /home/joe/mydir if $HOME environment variable is set to /home/joe and
 178    --  Mode is UNIX. If an environment variable does not exist the variable
 179    --  will be replaced by the empty string. Two dollar or percent signs are
 180    --  replaced by a single dollar/percent sign. Note that a variable must
 181    --  start with a letter.
 182    --
 183    --  The Mode argument indicates the recognized syntax for environment
 184    --  variables as follows:
 185    --
 186    --    UNIX
 187    --      Environment variables use $ as prefix and can use curly brackets
 188    --      as in ${HOME}/mydir. If there is no closing curly bracket for an
 189    --      opening one then no translation is done, so for example ${VAR/toto
 190    --      is returned as ${VAR/toto. The use of {} brackets is required if
 191    --      the environment variable name contains other than alphanumeric
 192    --      characters.
 193    --
 194    --    DOS
 195    --      Environment variables uses % as prefix and suffix (e.g. %HOME%/dir).
 196    --      The name DOS refer to "DOS-like" environment. This includes all
 197    --      Windows systems.
 198    --
 199    --    Both
 200    --      Recognize both forms described above.
 201    --
 202    --    System_Default
 203    --      Uses either DOS on Windows, and UNIX on all other systems, depending
 204    --      on the running environment.
 205
 206    ---------------
 207    -- Iterators --
 208    ---------------
 209
 210    procedure Open (Dir : out Dir_Type; Dir_Name : Dir_Name_Str);
 211    --  Opens the directory named by Dir_Name and returns a Dir_Type value
 212    --  that refers to this directory, and is positioned at the first entry.
 213    --  Raises Directory_Error if Dir_Name cannot be accessed. In that case
 214    --  Dir will be set to Null_Dir.
 215
 216    procedure Close (Dir : in out Dir_Type);
 217    --  Closes the directory stream referred to by Dir. After calling Close
 218    --  Is_Open will return False. Dir will be set to Null_Dir.
 219    --  Raises Directory_Error if Dir has not be opened (Dir = Null_Dir).
 220
 221    function Is_Open (Dir : Dir_Type) return Boolean;
 222    --  Returns True if Dir is open, or False otherwise
 223
 224    procedure Read
 225      (Dir  : Dir_Type;
 226       Str  : out String;
 227       Last : out Natural);
 228    --  Reads the next entry from the directory and sets Str to the name
 229    --  of that entry. Last is the index in Str such that Str (Last) is the
 230    --  last character written. Last is 0 when there are no more files in the
 231    --  directory. If Str is too small for the file name, the file name will
 232    --  be truncated before being copied to Str. The list of files returned
 233    --  includes directories in systems providing a hierarchical directory
 234    --  structure, including . (the current directory) and .. (the parent
 235    --  directory) in systems providing these entries. The directory is
 236    --  returned in target-OS form. Raises Directory_Error if Dir has not
 237    --  be opened (Dir = Null_Dir).
 238
 239    function Read_Is_Thread_Safe return Boolean;
 240    --  Indicates if procedure Read is thread safe. On systems where the
 241    --  target system supports this functionality, Read is thread safe,
 242    --  and this function returns True (e.g. this will be the case on any
 243    --  UNIX or UNIX-like system providing a correct implementation of the
 244    --  function readdir_r). If the system cannot provide a thread safe
 245    --  implementation of Read, then this function returns False.
 246
 247 private
 248
 249    type Dir_Type_Value is new System.Address;
 250    --  Low-level address directory structure as returned by opendir in C
 251    --
 252    --  Note that we used to define this type in the body of this package,
 253    --  but this was causing troubles in the context of .NET code generation
 254    --  (because Taft amendment types are not fully implemented and cause
 255    --  undefined references to the class), so we moved the type declaration
 256    --  to the spec's private part, which is no problem in any case here.
 257
 258    type Dir_Type is access Dir_Type_Value;
 259
 260    Null_Dir : constant Dir_Type := null;
 261
 262    pragma Import (C, Dir_Separator, "__gnat_dir_separator");
 263
 264    Dir_Seps : constant Ada.Strings.Maps.Character_Set :=
 265                 Ada.Strings.Maps.To_Set ("/\");
 266    --  UNIX and DOS style directory separators
 267
 268 end GNAT.Directory_Operations;