\ READ-LINE and WRITE-LINE
\
\ This code is part of pForth.
\
\ The pForth software code is dedicated to the public domain,
\ and any third party may reproduce, distribute and modify
\ the pForth software code or any derivative works thereof
\ without any compensation or license. The pForth software
\ code is provided on an "as is" basis without any warranty
\ of any kind, including, without limitation, the implied
\ warranties of merchantability and fitness for a particular
\ purpose and their equivalents under the laws of any jurisdiction.
private{
10 constant \N
13 constant \R
\ Unread one char from file FILEID.
: UNREAD { fileid -- ior }
fileid file-position ( ud ior )
?dup
IF nip nip \ IO error
ELSE 1 s>d d- fileid reposition-file
THEN
;
\ Read the next available char from file FILEID and if it is a \n then
\ skip it; otherwise unread it. IOR is non-zero if an error occured.
\ C-ADDR is a buffer that can hold at least one char.
: SKIP-\N { c-addr fileid -- ior }
c-addr 1 fileid read-file ( u ior )
?dup
IF \ Read error?
nip
ELSE ( u )
0=
IF \ End of file?
0
ELSE
c-addr c@ \n = ( is-it-a-\n? )
IF 0
ELSE fileid unread
THEN
THEN
THEN
;
\ This is just s\" \n" but s\" isn't yet available.
create (LINE-TERMINATOR) \n c,
: LINE-TERMINATOR ( -- c-addr u ) (line-terminator) 1 ;
\ Standard throw code
\ See: http://lars.nocrew.org/forth2012/exception.html#table:throw
-72 constant THROW_RENAME_FILE
\ Copy the string C-ADDR/U1 to C-ADDR2 and append a NUL.
: PLACE-CSTR ( c-addr1 u1 c-addr2 -- )
2dup 2>r ( c-addr1 u1 c-addr2 ) ( r: u1 c-addr2 )
swap cmove ( ) ( r: u1 c-addr2 )
0 2r> + c! ( )
;
: MULTI-LINE-COMMENT ( "comment<rparen>" -- )
BEGIN
>in @ ')' parse ( >in c-addr len )
nip + >in @ = ( delimiter-not-found? )
WHILE ( )
refill 0= IF EXIT THEN ( )
REPEAT
;
}private
\ This treats \n, \r\n, and \r as line terminator. Reading is done
\ one char at a time with READ-FILE hence READ-FILE should probably do
\ some form of buffering for good efficiency.
: READ-LINE ( c-addr u1 fileid -- u2 flag ior )
{ a u f }
u 0 ?DO
a i chars + 1 f read-file ( u ior' )
?dup IF nip i false rot UNLOOP EXIT THEN \ Read error? ( u )
0= IF i i 0<> 0 UNLOOP EXIT THEN \ End of file? ( )
a i chars + c@
CASE
\n OF i true 0 UNLOOP EXIT ENDOF
\r OF
\ Detect \r\n
a i chars + f skip-\n ( ior )
?dup IF i false rot UNLOOP EXIT THEN \ IO Error? ( )
i true 0 UNLOOP EXIT
ENDOF
ENDCASE
LOOP
\ Line doesn't fit in buffer
u true 0
;
: WRITE-LINE ( c-addr u fileid -- ior )
{ f }
f write-file ( ior )
?dup
IF \ IO error
ELSE line-terminator f write-file
THEN
;
: RENAME-FILE ( c-addr1 u1 c-addr2 u2 -- ior )
{ a1 u1 a2 u2 | new }
\ Convert the file-names to C-strings by copying them after HERE.
a1 u1 here place-cstr
here u1 1+ chars + to new
a2 u2 new place-cstr
here new (rename-file) 0=
IF 0
ELSE throw_rename_file
THEN
;
\ A limit used to perform a sanity check on the size argument for
\ RESIZE-FILE.
2variable RESIZE-FILE-LIMIT
10000000 0 resize-file-limit 2! \ 10MB is somewhat arbitrarily chosen
: RESIZE-FILE ( ud fileid -- ior )
-rot 2dup resize-file-limit 2@ d> ( fileid ud big? )
IF
." Argument (" 0 d.r ." ) is larger then RESIZE-FILE-LIMIT." cr
." (You can increase RESIZE-FILE-LIMIT with 2!)" cr
abort
ELSE
rot (resize-file)
THEN
;
: ( ( "comment<rparen>" -- )
source-id
CASE
-1 OF postpone ( ENDOF
0 OF postpone ( ENDOF
\ for input from files
multi-line-comment
ENDCASE
; immediate
\ We basically try to open the file in read-only mode. That seems to
\ be the best that we can do with ANSI C. If we ever want to do
\ something more sophisticated, like calling access(2), we must create
\ a proper primitive. (OTOH, portable programs can't assume much
\ about FILE-STATUS and non-portable programs could create a custom
\ function for access(2).)
: FILE-STATUS ( c-addr u -- 0 ior )
r/o bin open-file ( fileid ior1 )
?dup
IF nip 0 swap ( 0 ior1 )
ELSE close-file 0 swap ( 0 ior2 )
THEN
;
privatize