File:  [gforth] / gforth / kernel / paths.fs
Revision 1.35: download - view: text, annotated - select for diffs
Thu Dec 30 21:46:14 2010 UTC (13 years, 3 months ago) by pazsan
Branches: MAIN
CVS tags: HEAD
Changed path.fs to use string.fs to fix buffer overflow bug

    1: \ paths.fs path file handling                                    03may97jaw
    2: 
    3: \ Copyright (C) 1995,1996,1997,1998,2000,2003,2004,2005,2006,2007,2008 Free Software Foundation, Inc.
    4: 
    5: \ This file is part of Gforth.
    6: 
    7: \ Gforth is free software; you can redistribute it and/or
    8: \ modify it under the terms of the GNU General Public License
    9: \ as published by the Free Software Foundation, either version 3
   10: \ of the License, or (at your option) any later version.
   11: 
   12: \ This program is distributed in the hope that it will be useful,
   13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15: \ GNU General Public License for more details.
   16: 
   17: \ You should have received a copy of the GNU General Public License
   18: \ along with this program. If not, see http://www.gnu.org/licenses/.
   19: 
   20: \ -Changing the search-path:
   21: \ fpath+ <path> 	adds a directory to the searchpath
   22: \ fpath= <path>|<path>	makes complete now searchpath
   23: \ 			seperator is |
   24: \ .fpath		displays the search path
   25: \ remark I: 
   26: \ a ./ in the beginning of filename is expanded to the directory the
   27: \ current file comes from. ./ can also be included in the search-path!
   28: \ ~+/ loads from the current working directory
   29: 
   30: \ remark II:
   31: \ if there is no sufficient space for the search path increase it!
   32: 
   33: 
   34: \ -Creating custom paths:
   35: 
   36: \ It is possible to use the search mechanism on yourself.
   37: 
   38: \ Make a buffer for the path:
   39: \ create mypath	100 path,
   40: \ mypath path+ 
   41: \ mypath path=
   42: \ mypath .path
   43: 
   44: \ do a open with the search path:
   45: \ open-path-file ( adr len path -- fd adr len ior )
   46: \ the file is opened read-only; if the file is not found an error is generated
   47: 
   48: \ questions to: wilke@jwdt.com
   49: 
   50: include string.fs
   51: 
   52: [IFUNDEF] +place
   53: : +place ( adr len adr )
   54:         2dup >r >r
   55:         dup c@ char+ + swap move
   56:         r> r> dup c@ rot + swap c! ;
   57: [THEN]
   58: 
   59: [IFUNDEF] place
   60: : place ( c-addr1 u c-addr2 )
   61:         2dup c! char+ swap move ;
   62: [THEN]
   63: 
   64: Variable fpath ( -- path-addr ) \ gforth
   65: Variable ofile
   66: Variable tfile
   67: 
   68: : make-path ( addr -- )  >r r@ off s" " r> $! ;
   69: 
   70: : os-cold ( -- )
   71:     fpath make-path
   72:     ofile make-path
   73:     tfile make-path
   74:     pathstring 2@ fpath only-path 
   75:     init-included-files ;
   76: 
   77: \ The path Gforth uses for @code{included} and friends.
   78: 
   79: : also-path ( c-addr len path-addr -- ) \ gforth
   80:     \G add the directory @i{c-addr len} to @i{path-addr}.
   81:     >r
   82:     r@ $@len IF  \ add separator if necessary
   83: 	s" |" r@ $+!  0 r@ $@ + 1- c!
   84:     THEN
   85:     r> $+! ;
   86: 
   87: : clear-path ( path-addr -- ) \ gforth
   88:     \G Set the path @i{path-addr} to empty.
   89:     s" " rot $! ;
   90: 
   91: : only-path ( adr len path -- )
   92:     dup clear-path also-path ;
   93: 
   94: : path+ ( path-addr  "dir" -- ) \ gforth
   95:     \G Add the directory @var{dir} to the search path @var{path-addr}.
   96:     name rot also-path ;
   97: 
   98: : fpath+ ( "dir" ) \ gforth
   99:     \G Add directory @var{dir} to the Forth search path.
  100:     fpath path+ ;
  101: 
  102: : path= ( path-addr "dir1|dir2|dir3" ) \ gforth
  103:     \G Make a complete new search path; the path separator is |.
  104:     name 2dup bounds ?DO i c@ '| = IF 0 i c! THEN LOOP
  105:     rot only-path ;
  106: 
  107: : fpath= ( "dir1|dir2|dir3" ) \ gforth
  108:     \G Make a complete new Forth search path; the path separator is |.
  109:     fpath path= ;
  110: 
  111: : path>string ( path -- c-addr u )
  112:     \ string contains NULs to separate/terminate components
  113:     $@ ;
  114: 
  115: : next-path ( addr u -- addr1 u1 addr2 u2 )
  116:     \ addr2 u2 is the first component of the path, addr1 u1 is the rest
  117:     0 $split 2swap ;
  118: 
  119: : .path ( path-addr -- ) \ gforth
  120:     \G Display the contents of the search path @var{path-addr}.
  121:     path>string
  122:     BEGIN next-path dup WHILE type space REPEAT 2drop 2drop ;
  123: 
  124: : .fpath ( -- ) \ gforth
  125:     \G Display the contents of the Forth search path.
  126:     fpath .path ;
  127: 
  128: : absolut-path? ( addr u -- flag ) \ gforth
  129:     \G A path is absolute if it starts with a / or a ~ (~ expansion),
  130:     \G or if it is in the form ./*, extended regexp: ^[/~]|./, or if
  131:     \G it has a colon as second character ("C:...").  Paths simply
  132:     \G containing a / are not absolute!
  133:     2dup 2 u> swap 1+ c@ ': = and >r \ dos absoulte: c:/....
  134:     over c@ '/ = >r
  135:     over c@ '~ = >r
  136:     \ 2dup S" ../" string-prefix? r> or >r \ not catered for in expandtopic
  137:     S" ./" string-prefix?
  138:     r> r> r> or or or ;
  139: 
  140: : pathsep? dup [char] / = swap [char] \ = or ;
  141: 
  142: : need/   ofile $@ 1- + c@ pathsep? 0= IF s" /" ofile $+! THEN ;
  143: 
  144: : extractpath ( adr len -- adr len2 )
  145:   BEGIN dup WHILE 1-
  146:         2dup + c@ pathsep? IF EXIT THEN
  147:   REPEAT ;
  148: 
  149: : remove~+ ( -- )
  150:     ofile $@ s" ~+/" string-prefix?
  151:     IF
  152: 	ofile 0 3 $del
  153:     THEN ;
  154: 
  155: : expandtopic ( -- ) \ stack effect correct? - anton
  156:     \ expands "./" into an absolute name
  157:     ofile $@ s" ./" string-prefix?
  158:     IF
  159: 	ofile $@ 1 /string tfile $!
  160: 	includefilename 2@ extractpath ofile $!
  161: 	\ care of / only if there is a directory
  162: 	ofile $@len IF need/ THEN
  163: 	tfile $@ over c@ pathsep? IF 1 /string THEN
  164: 	ofile $+!
  165:     THEN ;
  166: 
  167: : del-string ( addr u u1 -- addr u2 )
  168:     \ delete u1 characters from string by moving stuff from further up
  169:     2 pick >r /string r@ over >r swap cmove 2r> ;
  170: 
  171: : del-./s ( addr u -- addr u2 )
  172:     \ deletes (/*./)* at the start of the string
  173:     BEGIN ( current-addr u )
  174: 	BEGIN ( current-addr u )
  175: 	    over c@ '/ = WHILE
  176: 		1 del-string
  177: 	REPEAT
  178: 	2dup s" ./" string-prefix? WHILE
  179: 	    2 del-string
  180:     REPEAT ;
  181: 
  182: : preserve-root ( addr1 u1 -- addr2 u2 )
  183:     over c@ '/ = if \ preserve / at start
  184: 	1 /string
  185:     endif ;
  186: 
  187: 
  188: : skip-..-prefixes ( addr1 u1 -- addr2 u2 )
  189:     \ deal with ../ at start
  190:     begin ( current-addr u )
  191: 	del-./s 2dup s" ../" string-prefix? while
  192: 	    3 /string
  193:     repeat ;
  194:     
  195: : compact-filename ( addr u1 -- addr u2 )
  196:     \ rewrite filename in place, eliminating multiple slashes, "./", and "x/.."
  197:     over swap preserve-root skip-..-prefixes
  198:     ( start current-addr u )
  199:     over swap '/ scan dup if ( start addr3 addr4 u4 )
  200: 	1 /string del-./s recurse
  201: 	2dup s" ../" string-prefix? if ( start addr3 addr4 u4 )
  202: 	    3 /string ( start to from count )
  203: 	    >r swap 2dup r@ move r>
  204: 	endif
  205:     endif
  206:     + nip over - ;
  207: 
  208: \ test cases:
  209: \ s" z/../../../a" compact-filename type cr
  210: \ s" ../z/../../../a/c" compact-filename type cr
  211: \ s" /././//./../..///x/y/../z/.././..//..//a//b/../c" compact-filename type cr
  212: 
  213: : reworkdir ( -- )
  214:   remove~+
  215:   ofile $@ compact-filename
  216:   nip ofile $!len ;
  217: 
  218: : open-ofile ( -- fid ior )
  219:     \G opens the file whose name is in ofile
  220:     expandtopic reworkdir
  221:     ofile $@ r/o open-file ;
  222: 
  223: : check-path ( adr1 len1 adr2 len2 -- fid 0 | 0 ior )
  224:   >r >r ofile $! need/
  225:   r> r> ofile $+!
  226:   open-ofile ;
  227: 
  228: \ !! allow arbitrary FAMs, not just R/O
  229: : open-path-file ( addr1 u1 path-addr -- wfileid addr2 u2 0 | ior ) \ gforth
  230: \G Look in path @var{path-addr} for the file specified by @var{addr1
  231: \G u1}.  If found, the resulting path and and (read-only) open file
  232: \G descriptor are returned. If the file is not found, @var{ior} is
  233: \G what came back from the last attempt at opening the file (in the
  234: \G current implementation).
  235:     >r
  236:     2dup absolut-path? IF
  237:         rdrop
  238:         ofile $! open-ofile
  239:         dup 0= IF
  240:             >r ofile $@ r> THEN
  241:         EXIT
  242:     ELSE
  243:         r> -&37 >r path>string BEGIN
  244:             next-path dup WHILE
  245:                 r> drop
  246:                 5 pick 5 pick check-path dup 0= IF
  247:                     drop >r 2drop 2drop r> ofile $@ 0 EXIT
  248:                 ELSE
  249:                     >r drop
  250:                 THEN
  251:         REPEAT
  252:         2drop 2drop 2drop r>
  253:   THEN ;
  254: 
  255: : open-fpath-file ( addr1 u1 -- wfileid addr2 u2 0 | ior ) \ gforth
  256:     \G Look in the Forth search path for the file specified by @var{addr1 u1}.
  257:     \G If found, the resulting path and an open file descriptor
  258:     \G are returned. If the file is not found, @var{ior} is non-zero.
  259:     fpath open-path-file ;

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