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 --                            $Revision$
  10 --                                                                          --
  11 --            Copyright (C) 1998-2001 Ada Core Technologies, Inc.           --
  12 --                                                                          --
  13 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  14 -- terms of the  GNU General Public License as published  by the Free Soft- --
  15 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  16 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  17 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  18 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  19 -- for  more details.  You should have  received  a copy of the GNU General --
  20 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  21 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  22 -- MA 02111-1307, USA.                                                      --
  23 --                                                                          --
  24 -- As a special exception,  if other files  instantiate  generics from this --
  25 -- unit, or you link  this unit with other files  to produce an executable, --
  26 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  27 -- covered  by the  GNU  General  Public  License.  This exception does not --
  28 -- however invalidate  any other reasons why  the executable file  might be --
  29 -- covered by the  GNU Public License.                                      --
  30 --                                                                          --
  31 -- GNAT is maintained by Ada Core Technologies Inc (http://www.gnat.com).   --
  32 --                                                                          --
  33 ------------------------------------------------------------------------------
  34
  35 --  Directory operations
  36
  37 --  This package provides routines for manipulating directories. A directory
  38 --  can be treated as a file, using open and close routines, and a scanning
  39 --  routine is provided for iterating through the entries in a directory.
  40
  41 --  See also child package GNAT.Directory_Operations.Iteration
  42
  43 with Ada.Strings.Maps;
  44
  45 package GNAT.Directory_Operations is
  46
  47    subtype Dir_Name_Str is String;
  48    --  A subtype used in this package to represent string values that are
  49    --  directory names. A directory name is a prefix for files that appear
  50    --  with in the directory. This means that for UNIX systems, the string
  51    --  includes a final '/', and for DOS-like systems, it includes a final
  52    --  '\' character. It can also include drive letters if the operating
  53    --  system provides for this. The final '/' or '\' in a Dir_Name_Str is
  54    --  optional when passed as a procedure or function in parameter.
  55
  56    type Dir_Type is limited private;
  57    --  A value used to reference a directory. Conceptually this value includes
  58    --  the identity of the directory, and a sequential position within it.
  59
  60    Null_Dir : constant Dir_Type;
  61    --  Represent the value for an uninitialized or closed directory
  62
  63    Directory_Error : exception;
  64    --  Exception raised if the directory cannot be opened, read, closed,
  65    --  created or if it is not possible to change the current execution
  66    --  environment directory.
  67
  68    Dir_Separator : constant Character;
  69    --  Running system default directory separator
  70
  71    --------------------------------
  72    -- Basic Directory operations --
  73    --------------------------------
  74
  75    procedure Change_Dir (Dir_Name : Dir_Name_Str);
  76    --  Changes the working directory of the current execution environment
  77    --  to the directory named by Dir_Name. Raises Directory_Error if Dir_Name
  78    --  does not exist.
  79
  80    procedure Make_Dir (Dir_Name : Dir_Name_Str);
  81    --  Create a new directory named Dir_Name. Raises Directory_Error if
  82    --  Dir_Name cannot be created.
  83
  84    procedure Remove_Dir (Dir_Name : Dir_Name_Str);
  85    --  Remove the directory named Dir_Name. Raises Directory_Error if Dir_Name
  86    --  cannot be removed.
  87
  88    function Get_Current_Dir return Dir_Name_Str;
  89    --  Returns the current working directory for the execution environment.
  90
  91    procedure Get_Current_Dir (Dir : out Dir_Name_Str; Last : out Natural);
  92    --  Returns the current working directory for the execution environment
  93    --  The name is returned in Dir_Name. Last is the index in Dir_Name such
  94    --  that Dir_Name (Last) is the last character written. If Dir_Name is
  95    --  too small for the directory name, the name will be truncated before
  96    --  being copied to Dir_Name.
  97
  98    -------------------------
  99    -- Pathname Operations --
 100    -------------------------
 101
 102    subtype Path_Name is String;
 103    --  All routines using Path_Name handle both styles (UNIX and DOS) of
 104    --  directory separators (either slash or back slash).
 105
 106    function Dir_Name (Path : Path_Name) return Dir_Name_Str;
 107    --  Returns directory name for Path. This is similar to the UNIX dirname
 108    --  command. Everything after the last directory separator is removed. If
 109    --  there is no directory separator the current working directory is
 110    --  returned.
 111
 112    function Base_Name
 113      (Path   : Path_Name;
 114       Suffix : String    := "")
 115       return   String;
 116    --  Any directory prefix is removed. If Suffix is non-empty and is a
 117    --  suffix of Path, it is removed. This is equivalent to the UNIX basename
 118    --  command. The following rule is always true:
 119    --
 120    --    'Path' and 'Dir_Name (Path) & Directory_Separator & Base_Name (Path)'
 121    --    represent the same file.
 122    --
 123    --  This function is not case-sensitive on systems that have a non
 124    --  case-sensitive file system like Windows, OS/2 and VMS.
 125
 126    function File_Extension (Path : Path_Name) return String;
 127    --  Return the file extension. This is the string after the last dot
 128    --  character in File_Name (Path). It returns the empty string if no
 129    --  extension is found. The returned value does contains the file
 130    --  extension separator (dot character).
 131
 132    function File_Name (Path : Path_Name) return String;
 133    --  Returns the file name and the file extension if present. It removes all
 134    --  path information. This is equivalent to Base_Name with default Extension
 135    --  value.
 136
 137    type Path_Style is (UNIX, DOS, System_Default);
 138
 139    function Normalize_Pathname
 140      (Path  : Path_Name;
 141       Style : Path_Style := System_Default)
 142       return  Path_Name;
 143    --  Removes all double directory separator and converts all '\' to '/' if
 144    --  Style is UNIX and converts all '/' to '\' if Style is set to DOS. This
 145    --  function will help to provide a consistent naming scheme running for
 146    --  different environments. If style is set to System_Default the routine
 147    --  will use the default directory separator on the running environment.
 148
 149    function Expand_Path (Path : Path_Name) return Path_Name;
 150    --  Returns Path with environment variables (string preceded by a dollar
 151    --  sign) replaced by the current environment variable value. For example,
 152    --  $HOME/mydir will be replaced by /home/joe/mydir if $HOME environment
 153    --  variable is set to /home/joe. The variable can be surrounded by the
 154    --  characters '{' and '}' (curly bracket) if needed as in ${HOME}/mydir.
 155    --  If an environment variable does not exists the variable will be replaced
 156    --  by the empty string. Two dollar signs are replaced by a single dollar
 157    --  sign. Note that a variable must start with a letter. If there is no
 158    --  closing curly bracket for an opening one there is no translation done,
 159    --  so for example ${VAR/toto is returned as ${VAR/toto.
 160
 161    ---------------
 162    -- Iterators --
 163    ---------------
 164
 165    procedure Open (Dir : out Dir_Type; Dir_Name : Dir_Name_Str);
 166    --  Opens the directory named by Dir_Name and returns a Dir_Type value
 167    --  that refers to this directory, and is positioned at the first entry.
 168    --  Raises Directory_Error if Dir_Name cannot be accessed. In that case
 169    --  Dir will be set to Null_Dir.
 170
 171    procedure Close (Dir : in out Dir_Type);
 172    --  Closes the directory stream refered to by Dir. After calling Close
 173    --  Is_Open will return False. Dir will be set to Null_Dir.
 174    --  Raises Directory_Error if Dir has not be opened (Dir = Null_Dir).
 175
 176    function Is_Open (Dir : Dir_Type) return Boolean;
 177    --  Returns True if Dir is open, or False otherwise.
 178
 179    procedure Read
 180      (Dir  : in out Dir_Type;
 181       Str  : out String;
 182       Last : out Natural);
 183    --  Reads the next entry from the directory and sets Str to the name
 184    --  of that entry. Last is the index in Str such that Str (Last) is the
 185    --  last character written. Last is 0 when there are no more files in the
 186    --  directory. If Str is too small for the file name, the file name will
 187    --  be truncated before being copied to Str. The list of files returned
 188    --  includes directories in systems providing a hierarchical directory
 189    --  structure, including . (the current directory) and .. (the parent
 190    --  directory) in systems providing these entries. The directory is
 191    --  returned in target-OS form. Raises Directory_Error if Dir has not
 192    --  be opened (Dir = Null_Dir).
 193
 194    function Read_Is_Thread_Safe return Boolean;
 195    --  Indicates if procedure Read is thread safe. On systems where the
 196    --  target system supports this functionality, Read is thread safe,
 197    --  and this function returns True (e.g. this will be the case on any
 198    --  UNIX or UNIX-like system providing a correct implementation of the
 199    --  function readdir_r). If the system cannot provide a thread safe
 200    --  implementation of Read, then this function returns False.
 201
 202 private
 203
 204    type Dir_Type_Value;
 205    type Dir_Type is access Dir_Type_Value;
 206
 207    Null_Dir : constant Dir_Type := null;
 208
 209    pragma Import (C, Dir_Separator, "__gnat_dir_separator");
 210
 211    Dir_Seps : constant Ada.Strings.Maps.Character_Set :=
 212                 Ada.Strings.Maps.To_Set ("/\");
 213    --  UNIX and DOS style directory separators.
 214
 215 end GNAT.Directory_Operations;