IMPLEMENTATION MODULE StrIO ;
FROM ASCII IMPORT cr, nul, lf, bel, del, bs, nak, etb, ff, eof ;
FROM StdIO IMPORT Read, Write ;
FROM libc IMPORT isatty ;
VAR
IsATTY: BOOLEAN ;
PROCEDURE WriteLn ;
BEGIN
Echo( cr ) ;
Write( lf )
END WriteLn ;
PROCEDURE ReadString (VAR a: ARRAY OF CHAR) ;
VAR
n ,
high : CARDINAL ;
ch : CHAR ;
BEGIN
high := HIGH( a ) ;
n := 0 ;
REPEAT
Read( ch ) ;
IF (ch=del) OR (ch=bs)
THEN
IF n=0
THEN
Write( bel )
ELSE
Erase ;
DEC( n )
END
ELSIF ch=nak
THEN
WHILE n>0 DO
Erase ;
DEC( n )
END
ELSIF ch=etb
THEN
IF n=0
THEN
Echo( bel )
ELSIF AlphaNum(a[n-1])
THEN
REPEAT
Erase ;
DEC(n)
UNTIL (n=0) OR (NOT AlphaNum(a[n-1]))
ELSE
Erase ;
DEC(n)
END
ELSIF n <= high
THEN
IF ch = cr
THEN
a[n] := nul ;
INC( n )
ELSIF ch=ff
THEN
a[0] := ch ;
IF high>0
THEN
a[1] := nul
END ;
ch := cr
ELSIF ch>=' '
THEN
Echo( ch ) ;
a[n] := ch ;
INC( n )
ELSIF ch=eof
THEN
a[n] := ch ;
INC( n ) ;
ch := cr;
IF n<=high
THEN
a[n] := nul
END
END
ELSIF ch#cr
THEN
Echo( bel )
END
UNTIL ch = cr
END ReadString ;
PROCEDURE WriteString (a: ARRAY OF CHAR) ;
VAR
n ,
high : CARDINAL ;
BEGIN
high := HIGH( a ) ;
n := 0 ;
WHILE (n <= high) AND (a[n] # nul) DO
Write( a[n] ) ;
INC( n )
END
END WriteString ;
PROCEDURE Erase ;
BEGIN
Echo( bs ) ;
Echo(' ') ;
Echo( bs )
END Erase ;
PROCEDURE Echo (ch: CHAR) ;
BEGIN
IF IsATTY
THEN
Write(ch)
END
END Echo ;
PROCEDURE AlphaNum (ch: CHAR) : BOOLEAN ;
BEGIN
RETURN ((ch>='a') AND (ch<='z')) OR
((ch>='A') AND (ch<='Z')) OR
((ch>='0') AND (ch<='9'))
END AlphaNum ;
BEGIN
IsATTY := FALSE
END StrIO.