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Atari Mega Archive 1
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Atari Mega Archive - Volume 1.iso
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xlispsrc.arc
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XLFIO.C
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C/C++ Source or Header
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1988-02-11
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474 lines
/* xlfio.c - xlisp file i/o */
/* Copyright (c) 1985, by David Michael Betz
All Rights Reserved
Permission is granted for unrestricted non-commercial use */
#include "xlisp.h"
/* external variables */
extern LVAL k_direction,k_input,k_output;
extern LVAL s_stdin,s_stdout,true;
extern unsigned char buf[];
extern int xlfsize;
/* external routines */
extern FILE *osaopen();
/* forward declarations */
FORWARD LVAL getstroutput();
FORWARD LVAL printit();
FORWARD LVAL flatsize();
FORWARD LVAL openit();
/* xread - read an expression */
LVAL xread()
{
LVAL fptr,eof,rflag,val;
/* get file pointer and eof value */
fptr = (moreargs() ? xlgetfile() : getvalue(s_stdin));
eof = (moreargs() ? xlgetarg() : NIL);
rflag = (moreargs() ? xlgetarg() : NIL);
xllastarg();
/* read an expression */
if (!xlread(fptr,&val,rflag != NIL))
val = eof;
/* return the expression */
return (val);
}
/* xprint - built-in function 'print' */
LVAL xprint()
{
return (printit(TRUE,TRUE));
}
/* xprin1 - built-in function 'prin1' */
LVAL xprin1()
{
return (printit(TRUE,FALSE));
}
/* xprinc - built-in function princ */
LVAL xprinc()
{
return (printit(FALSE,FALSE));
}
/* xterpri - terminate the current print line */
LVAL xterpri()
{
LVAL fptr;
/* get file pointer */
fptr = (moreargs() ? xlgetfile() : getvalue(s_stdout));
xllastarg();
/* terminate the print line and return nil */
xlterpri(fptr);
return (NIL);
}
/* printit - common print function */
LOCAL LVAL printit(pflag,tflag)
int pflag,tflag;
{
LVAL fptr,val;
/* get expression to print and file pointer */
val = xlgetarg();
fptr = (moreargs() ? xlgetfile() : getvalue(s_stdout));
xllastarg();
/* print the value */
xlprint(fptr,val,pflag);
/* terminate the print line if necessary */
if (tflag)
xlterpri(fptr);
/* return the result */
return (val);
}
/* xflatsize - compute the size of a printed representation using prin1 */
LVAL xflatsize()
{
return (flatsize(TRUE));
}
/* xflatc - compute the size of a printed representation using princ */
LVAL xflatc()
{
return (flatsize(FALSE));
}
/* flatsize - compute the size of a printed expression */
LOCAL LVAL flatsize(pflag)
int pflag;
{
LVAL val;
/* get the expression */
val = xlgetarg();
xllastarg();
/* print the value to compute its size */
xlfsize = 0;
xlprint(NIL,val,pflag);
/* return the length of the expression */
return (cvfixnum((FIXTYPE)xlfsize));
}
/* xopen - open a file */
LVAL xopen()
{
char *name,*mode;
FILE *fp;
LVAL dir;
/* get the file name and direction */
name = (char *)getstring(xlgetfname());
if (!xlgetkeyarg(k_direction,&dir))
dir = k_input;
/* get the mode */
if (dir == k_input)
mode = "r";
else if (dir == k_output)
mode = "w";
else
xlerror("bad direction",dir);
/* try to open the file */
return ((fp = osaopen(name,mode)) ? cvfile(fp) : NIL);
}
/* xclose - close a file */
LVAL xclose()
{
LVAL fptr;
/* get file pointer */
fptr = xlgastream();
xllastarg();
/* make sure the file exists */
if (getfile(fptr) == NULL)
xlfail("file not open");
/* close the file */
osclose(getfile(fptr));
setfile(fptr,NULL);
/* return nil */
return (NIL);
}
/* xrdchar - read a character from a file */
LVAL xrdchar()
{
LVAL fptr;
int ch;
/* get file pointer */
fptr = (moreargs() ? xlgetfile() : getvalue(s_stdin));
xllastarg();
/* get character and check for eof */
return ((ch = xlgetc(fptr)) == EOF ? NIL : cvchar(ch));
}
/* xrdbyte - read a byte from a file */
LVAL xrdbyte()
{
LVAL fptr;
int ch;
/* get file pointer */
fptr = (moreargs() ? xlgetfile() : getvalue(s_stdin));
xllastarg();
/* get character and check for eof */
return ((ch = xlgetc(fptr)) == EOF ? NIL : cvfixnum((FIXTYPE)ch));
}
/* xpkchar - peek at a character from a file */
LVAL xpkchar()
{
LVAL flag,fptr;
int ch;
/* peek flag and get file pointer */
flag = (moreargs() ? xlgetarg() : NIL);
fptr = (moreargs() ? xlgetfile() : getvalue(s_stdin));
xllastarg();
/* skip leading white space and get a character */
if (flag)
while ((ch = xlpeek(fptr)) != EOF && isspace(ch))
xlgetc(fptr);
else
ch = xlpeek(fptr);
/* return the character */
return (ch == EOF ? NIL : cvchar(ch));
}
/* xwrchar - write a character to a file */
LVAL xwrchar()
{
LVAL fptr,chr;
/* get the character and file pointer */
chr = xlgachar();
fptr = (moreargs() ? xlgetfile() : getvalue(s_stdout));
xllastarg();
/* put character to the file */
xlputc(fptr,getchcode(chr));
/* return the character */
return (chr);
}
/* xwrbyte - write a byte to a file */
LVAL xwrbyte()
{
LVAL fptr,chr;
/* get the byte and file pointer */
chr = xlgafixnum();
fptr = (moreargs() ? xlgetfile() : getvalue(s_stdout));
xllastarg();
/* put byte to the file */
xlputc(fptr,(int)getfixnum(chr));
/* return the character */
return (chr);
}
/* xreadline - read a line from a file */
LVAL xreadline()
{
unsigned char buf[STRMAX+1],*p,*sptr;
LVAL fptr,str,newstr;
int len,blen,ch;
/* protect some pointers */
xlsave1(str);
/* get file pointer */
fptr = (moreargs() ? xlgetfile() : getvalue(s_stdin));
xllastarg();
/* get character and check for eof */
len = blen = 0; p = buf;
while ((ch = xlgetc(fptr)) != EOF && ch != '\n') {
/* check for buffer overflow */
if (blen >= STRMAX) {
newstr = newstring(len + STRMAX + 1);
sptr = getstring(newstr); *sptr = '\0';
if (str) strcat(sptr,getstring(str));
*p = '\0'; strcat(sptr,buf);
p = buf; blen = 0;
len += STRMAX;
str = newstr;
}
/* store the character */
*p++ = ch; ++blen;
}
/* check for end of file */
if (len == 0 && p == buf && ch == EOF) {
xlpop();
return (NIL);
}
/* append the last substring */
if (str == NIL || blen) {
newstr = newstring(len + blen + 1);
sptr = getstring(newstr); *sptr = '\0';
if (str) strcat(sptr,getstring(str));
*p = '\0'; strcat(sptr,buf);
str = newstr;
}
/* restore the stack */
xlpop();
/* return the string */
return (str);
}
/* xmkstrinput - make a string input stream */
LVAL xmkstrinput()
{
int start,end,len,i;
unsigned char *str;
LVAL string,val;
/* protect the return value */
xlsave1(val);
/* get the string and length */
string = xlgastring();
str = getstring(string);
len = getslength(string) - 1;
/* get the starting offset */
if (moreargs()) {
val = xlgafixnum();
start = (int)getfixnum(val);
}
else start = 0;
/* get the ending offset */
if (moreargs()) {
val = xlgafixnum();
end = (int)getfixnum(val);
}
else end = len;
xllastarg();
/* check the bounds */
if (start < 0 || start > len)
xlerror("string index out of bounds",cvfixnum((FIXTYPE)start));
if (end < 0 || end > len)
xlerror("string index out of bounds",cvfixnum((FIXTYPE)end));
/* make the stream */
val = newustream();
/* copy the substring into the stream */
for (i = start; i < end; ++i)
xlputc(val,str[i]);
/* restore the stack */
xlpop();
/* return the new stream */
return (val);
}
/* xmkstroutput - make a string output stream */
LVAL xmkstroutput()
{
return (newustream());
}
/* xgetstroutput - get output stream string */
LVAL xgetstroutput()
{
LVAL stream;
stream = xlgaustream();
xllastarg();
return (getstroutput(stream));
}
/* xgetlstoutput - get output stream list */
LVAL xgetlstoutput()
{
LVAL stream,val;
/