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) 1998-2018, 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
40with System;
41with Ada.Strings.Maps;
42
43package 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
247private
248
249   type Dir_Type_Value is new System.Address;
250   --  Low-level address directory structure as returned by opendir in C
251
252   type Dir_Type is access Dir_Type_Value;
253
254   Null_Dir : constant Dir_Type := null;
255
256   pragma Import (C, Dir_Separator, "__gnat_dir_separator");
257
258   Dir_Seps : constant Ada.Strings.Maps.Character_Set :=
259                Ada.Strings.Maps.To_Set ("/\");
260   --  UNIX and DOS style directory separators
261
262end GNAT.Directory_Operations;
263