stddef.h Definitions for common types, NULL, and errno

/* stddef.h

Definitions for common types, NULL, and errno.

Copyright (c) Borland International 1987,1988
All Rights Reserved.
*/
#if __STDC__
#define _Cdecl
#else
#define _Cdecl cdecl
#endif

#ifndef _STDDEF
#define _STDDEF
#ifndef _PTRDIFF_T
#define _PTRDIFF_T
#if defined(__LARGE__) || defined(__HUGE__) || defined(__COMPACT__)
typedef long ptrdiff_t;
#else
typedef int ptrdiff_t;
#endif
#endif
#ifndef _SIZE_T
#define _SIZE_T
typedef unsigned size_t;
#endif

#ifndef NULL
#if defined(__TINY__) || defined(__SMALL__) || defined(__MEDIUM__)
#define NULL 0
#else
#define NULL 0L
#endif
#endif

extern int _Cdecl errno;

#endif


stdarg.h Definitions for accessing parameters in functions that accept a variable number of arguments

/* stdarg.h

Definitions for accessing parameters in functions that accept
a variable number of arguments.

Copyright (c) Borland International 1987,1988
All Rights Reserved.
*/
#if __STDC__
#define _Cdecl
#else
#define _Cdecl cdecl
#endif

#if !defined(__STDARG)
#define __STDARG

typedef void *va_list;

#define va_start(ap, parmN) (ap = ...)
#define va_arg(ap, type) (*((type *)(ap))++)
#define va_end(ap)
#define _va_ptr (...)
#endif


stat.h Definitions used for file status functions

/* stat.h

Definitions used for file status functions

Copyright (c) Borland International 1987,1988
All Rights Reserved.
*/
#if __STDC__
#define _Cdecl
#else
#define _Cdecl cdecl
#endif

#ifndef _STAT_H
#define _STAT_H 1

#define S_IFMT 0xF000 /* file type mask */
#define S_IFDIR 0x4000 /* directory */
#define S_IFIFO 0x1000 /* FIFO special */
#define S_IFCHR 0x2000 /* character special */
#define S_IFBLK 0x3000 /* block special */
#define S_IFREG 0x8000 /* or just 0x0000, regular */
#define S_IREAD 0x0100 /* owner may read */
#define S_IWRITE 0x0080 /* owner may write */
#define S_IEXEC 0x0040 /* owner may execute <directory search> */

struct stat
{
short st_dev;
short st_ino;
short st_mode;
short st_nlink;
int   st_uid;
int   st_gid;
short st_rdev;
long  st_size;
long  st_atime;
long  st_mtime;
long  st_ctime;
};

int  _Cdecl fstat (int handle, struct stat *statbuf);
int  _Cdecl stat  (char *path, struct stat *statbuf);

#endif /* _STAT_H */


signal.h Definitions for ANSI defined signaling capability

/*      signal.h
 
        Definitions for ANSI defined signaling capability

        Copyright (c) Borland International 1988
        All Rights Reserved.
*/

#ifndef __SIGNAL_H
#define __SIGNAL_H


#if __STDC__
#define _Cdecl
#else
#define _Cdecl cdecl
#endif

typedef int sig_atomic_t; /* Atomic entity type (ANSI) */

#define SIG_DFL ((void (* _Cdecl)(int))0) /* Default action */
#define SIG_IGN ((void (* _Cdecl)(int))1) /* Ignore action */

#ifdef __OS2__
#define SIG_SGE ((void (* _Cdecl)(int))3) /* Signal gets error */
#define SIG_ACK ((void (* _Cdecl)(int))4) /* Signal acknowlege */
#endif

#define SIG_ERR ((void (* _Cdecl)(int))-1) /* Error return */

#define SIGABRT 22
#define SIGFPE 8 /* Floating point trap */
#define SIGILL 4 /* Illegal instruction */
#define SIGINT 2
#define SIGSEGV 11 /* Memory access violation */
#define SIGTERM 15

#ifdef __OS2__
#define SIGBREAK 21 /* OS/2 Ctrl-Brk signal */
#define SIGUSR1 16 /* OS/2 process flag A */
#define SIGUSR2 17 /* OS/2 process flag B */
#define SIGUSR3 20 /* OS/2 process flag C */
#endif

int _Cdecl raise(int sig);
void (* _Cdecl signal(int sig, void (*func)(/* int */))) (int);

#endif


setjmp.h Defines typedef and functions for setjmp/longjmp.

/* setjmp.h

Defines typedef and functions for setjmp/longjmp.

Copyright (c) Borland International 1987,1988
All Rights Reserved.
*/
#if __STDC__
#define _Cdecl
#else
#define _Cdecl cdecl
#endif

#ifndef _SETJMP
#define _SETJMP
typedef struct {
unsigned j_sp;
unsigned j_ss;
unsigned j_flag;
unsigned j_cs;
unsigned j_ip;
unsigned j_bp;
unsigned j_di;
unsigned j_es;
unsigned j_si;
unsigned j_ds;
} jmp_buf[1];

void _Cdecl longjmp(jmp_buf jmpb, int retval);
int _Cdecl setjmp(jmp_buf jmpb);
#endif



MCOMMAND Programming in C

/* Turbo C - (C) Copyright 1987, 1988 by Borland International */

#include <string.h>
#include <mem.h>
#include <stdio.h>
#include <math.h>
#include <io.h>
#include <fcntl.h>
#include <conio.h>
#include "mcalc.h"

char *name = MSGNAME;

void moverowup(void)
/* Moves up 1 row */
{
 displaycell(curcol, currow, NOHIGHLIGHT, NOUPDATE);
 if (currow > toprow)
  currow--;
 else if (toprow != 0)
 {
  scroll(DOWN, 1, LEFTMARGIN + 1, 3, 80, SCREENROWS + 2, WHITE);
  displayrow(--toprow, NOUPDATE);
  currow--;
  setbottomrow();
 }
} /* moverowup */

void moverowdown(void)
/* Moves down one row */
{
 displaycell(curcol, currow, NOHIGHLIGHT, NOUPDATE);
 if (currow < bottomrow)
  currow++;
 else if (bottomrow < (MAXROWS - 1))
 {
  scroll(UP, 1, LEFTMARGIN + 1, 3, 80, SCREENROWS + 2, WHITE);
  toprow++;
  currow++;
  setbottomrow();
  displayrow(bottomrow, NOUPDATE);
 }
} /* moverowdown */

void movecolleft(void)
/* Moves left one column */
{
 int col, oldleftcol;
 unsigned char oldcolstart[SCREENCOLS];

 oldleftcol = leftcol;
 movmem(colstart, oldcolstart, sizeof(colstart));
 displaycell(curcol, currow, NOHIGHLIGHT, NOUPDATE);
 if (curcol > leftcol)
  curcol--;
 else if (leftcol != 0)
 {
  curcol--;
  leftcol--;
  setrightcol();
  setleftcol();
  if (oldleftcol <= rightcol)
   scroll(RIGHT, colstart[oldleftcol - leftcol] - LEFTMARGIN, LEFTMARGIN + 1,
          3, 80, SCREENROWS + 2, WHITE);
  clearlastcol();
  for (col = leftcol; col <= oldleftcol - 1; col++)
   displaycol(col, NOUPDATE);
 }
} /* movecolleft */

void movecolright(void)
/* Moves right one column */
{
 int col, oldleftcol, oldrightcol;
 unsigned char oldcolstart[SCREENCOLS];

 movmem(colstart, oldcolstart, sizeof(colstart));
 oldleftcol = leftcol;
 oldrightcol = rightcol;
 displaycell(curcol, currow, NOHIGHLIGHT, NOUPDATE);
 if (curcol < rightcol)
  curcol++;
 else if (rightcol < (MAXCOLS - 1))
 {
  curcol++;
  rightcol++;
  setleftcol();
  setrightcol();
  if (oldrightcol >= leftcol)
   scroll(LEFT, oldcolstart[leftcol - oldleftcol] - LEFTMARGIN,
          LEFTMARGIN + 1, 3, 80, SCREENROWS + 2, WHITE);
  clearlastcol();
  for (col = oldrightcol + 1; col <= rightcol; col++)
   displaycol(col, NOUPDATE);
 }
} /* movecolright */

void recalc(void)
/* Recalculates all of the numbers in the speadsheet */
{
 int col, row, dummy;

 for (col = 0; col <= lastcol; col++)
 {
  for (row = 0; row <= lastrow; row++)
  {
   if ((cell[col][row] != NULL) && (cell[col][row]->attrib == FORMULA))
    cell[col][row]->v.f.fvalue = parse(cell[col][row]->v.f.formula, &dummy);
  }
 }
 displayscreen(UPDATE);
} /* recalc */

void changeautocalc(int newmode)
/* Changes and prints the current AutoCalc value on the screen */
{
 char s[15];

 if (!autocalc && newmode)
  recalc();
 autocalc = newmode;
 if (autocalc)
  strcpy(s, MSGAUTOCALC);
 else
  s[0] = 0;
 writef(73, 1, MSGAUTOCALCCOLOR, strlen(MSGAUTOCALC), s);
} /* autocalc */

void changeformdisplay(int newmode)
/* Changes and prints the current formula display value on the screen */
{
 char s[15];

 formdisplay = newmode;
 if (formdisplay)
  strcpy(s, MSGFORMDISPLAY);
 else
  s[0] = 0;
 writef(65, 1, MSGFORMDISPLAYCOLOR, strlen(MSGFORMDISPLAY), s);
} /* autocalc */

void editcell(CELLPTR ecell)
/* Edits a selected cell */
{
 char s[MAXINPUT + 1];

 if (ecell == NULL)
  return;
 switch(ecell->attrib)
 {
  case TEXT :
   strcpy(s, ecell->v.text);
   break;
  case VALUE :
   if (ecell->v.value == HUGE_VAL)
    strcpy(s, "0");
   else
    sprintf(s, "%.*f", MAXPLACES, ecell->v.value);
   break;
  case FORMULA :
   strcpy(s, ecell->v.f.formula);
   break;
 } /* switch */
 if (!editstring(s, "", MAXINPUT) || (s[0] == 0))
  return;
 act(s);
 changed = TRUE;
} /* editcell */

void clearsheet(void)
/* Clears the current spreadsheet */
{
 int col, row;

 for (row = 0; row <= lastrow; row++)
 {
  for (col = 0; col <= lastcol; col++)
   deletecell(col, row, NOUPDATE);
 }
 initvars();
 setrightcol();
 setbottomrow();
 displayscreen(NOUPDATE);
 printfreemem();
 changed = FALSE;
} /* clearsheet */

struct CELLREC rec;

void loadsheet(char *filename)
/* Loads a new spreadsheet */
{
 int size, allocated, reallastcol = 0, reallastrow = 0, file;
 char check[81];

 if (filename[0] == 0)
 {
  writeprompt(MSGFILENAME);
  if (!editstring(filename, "", MAXINPUT))
   return;
 }
 if (access(filename, 0))
 {
  errormsg(MSGNOEXIST);
  return;
 }
 if ((file = open(filename, O_RDWR | O_BINARY)) == -1)
 {
  errormsg(MSGNOOPEN);
  return;
 }
 read(file, check, strlen(name) + 1);
 if (strcmp(check, name) != 0)
 {
  errormsg(MSGNOMICROCALC);
  close(file);
  return;
 }
 writef(1, 25, PROMPTCOLOR, 79, MSGLOADING);
 gotoxy(strlen(MSGLOADING) + 1, 25);
 clearsheet();
 read(file, (char *)&size, 1);
 read(file, (char *)&lastcol, 2);
 read(file, (char *)&lastrow, 2);
 read(file, (char *)&size, 2);
 read(file, colwidth, sizeof(colwidth));
 do
 {
  if (read(file, (char *)&curcol, 2) <= 0)
   break;
  read(file, (char *)&currow, 2);
  read(file, &format[curcol][currow], 1);
  read(file, (char *)&size, 2);
  read(file, (char *)&rec, size);
  switch (rec.attrib)
  {
   case TEXT :
    if ((allocated = alloctext(curcol, currow, rec.v.text)) == TRUE)
     setoflags(curcol, currow, NOUPDATE);
    break;
   case VALUE :
    allocated = allocvalue(curcol, currow, rec.v.value);
    break;
   case FORMULA :
    allocated = allocformula(curcol, currow, rec.v.f.formula, rec.v.f.fvalue);
    break;
  } /* switch */
  if (!allocated)
  {
   errormsg(MSGFILELOMEM);
   lastrow = reallastrow;
   lastcol = reallastcol;
   format[curcol][currow] = DEFAULTFORMAT;
   break;
  }
  else
  {
   if (curcol > reallastcol)
    reallastcol = curcol;
   if (currow > reallastrow)
    reallastrow = currow;
  }
 }
 while (TRUE);
 writef(1, 25, WHITE, strlen(MSGLOADING), "");
 gotoxy(1, 25);
 printfreemem();
 close(file);
 curcol = currow = 0;
 setrightcol();
 displayscreen(NOUPDATE);
 changed = FALSE;
} /* loadsheet */

void savesheet(void)
/* Saves the current spreadsheet */
{
 char filename[MAXINPUT+1], eof = 26;
 int size, col, row, overwrite, file;
 CELLPTR cellptr;

 filename[0] = 0;
 writeprompt(MSGFILENAME);
 if (!editstring(filename, "", MAXINPUT))
  return;
 if (!access(filename, 0))
 {
  if (!getyesno(&overwrite, MSGOVERWRITE) || (overwrite == 'N'))
   return;
 }
 if ((file = open(filename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY,
  S_IREAD | S_IWRITE)) == -1)
 {
  errormsg(MSGNOOPEN);
  return;
 }
 writef(1, 25, PROMPTCOLOR, 79, MSGSAVING);
 gotoxy(strlen(MSGSAVING) + 1, 25);
 write(file, name, strlen(name) + 1);
 write(file, &eof, 1);
 write(file, (char *)&lastcol, 2);
 write(file, (char *)&lastrow, 2);
 size = MAXCOLS;
 write(file, (char *)&size, 2);
 write(file, colwidth, sizeof(colwidth));
 for (row = 0; row <= lastrow; row++)
 {
  for (col = lastcol; col >= 0; col--)
  {
   if (cell[col][row] != NULL)
   {
    cellptr = cell[col][row];
    switch(cellptr->attrib)
    {
     case TEXT :
      size = strlen(cellptr->v.text) + 2;
      break;
     case VALUE :
      size = sizeof(double) + 1;
      break;
     case FORMULA :
      size = strlen(cellptr->v.f.formula) + 2 + sizeof(double);
      break;
    } /* switch */
    write(file, (char *)&col, 2);
    write(file, (char *)&row, 2);
    write(file, (char *)&format[col][row], 1);
    write(file, (char *)&size, 2);
    write(file, (char *)cellptr, size);
   }
  }
 }
 close(file);
 writef(1, 25, WHITE, strlen(MSGSAVING), "");
 gotoxy(1, 25);
 changed = FALSE;
} /* savesheet */

int pagerows(int row, int toppage, int border)
/* Returns the number of rows to print */
{
 int rows;

 rows = toppage ? 66 - TOPMARGIN : 66;
 if (border)
  rows--;
 if (row + rows - 1 > lastrow)
  return(lastrow - row + 1);
 else
  return(rows);
} /* pagerows */

int pagecols(int col, int border, int columns)
/* Returns the number of columns to print starting at col */
{
 int len = ((col == 0) && (border)) ? columns - LEFTMARGIN : columns;
 int firstcol = col;

 while ((len > 0) && (col <= lastcol))
  len -= colwidth[col++];
 if (len < 0)
  col--;
 return(col - firstcol);
} /* pagecols */

void printsheet(void)
/* Prints a copy of the spreadsheet to a file or to the printer */
{
 char filename[MAXINPUT + 1], s[133], colstr[MAXCOLWIDTH + 1];
 FILE *file;
 int columns, counter1, counter2, counter3, col = 0, row, border, toppage,
  lcol, lrow, dummy, printed, oldlastcol;

 filename[0] = 0;
 writeprompt(MSGPRINT);
 if (!editstring(filename, "", MAXINPUT))
  return;
 if (filename[0] == 0)
  strcpy(filename, "PRN");
 if ((file = fopen(filename, "wt")) == NULL)
 {
  errormsg(MSGNOOPEN);
  return;
 }
 oldlastcol = lastcol;
 for (counter1 = 0; counter1 <= lastrow; counter1++)
 {
  for (counter2 = lastcol; counter2 < MAXCOLS; counter2++)
  {
   if (format[counter2][counter1] >= OVERWRITE)
    lastcol = counter2;
  }
 }
 if (!getyesno(&columns, MSGCOLUMNS))
  return;
 columns = (columns == 'Y') ? 131 : 79;
 if (!getyesno(&border, MSGBORDER))
  return;
 border = (border == 'Y');
 while (col <= lastcol)
 {
  row = 0;
  toppage = TRUE;
  lcol = pagecols(col, border, columns) + col;
  while (row <= lastrow)
  {
   lrow = pagerows(row, toppage, border) + row;
   printed = 0;
   if (toppage)
   {
    for (counter1 = 0; counter1 < TOPMARGIN; counter1++)
    {
     fprintf(file, "\n");
     printed++;
    }
   }
   for (counter1 = row; counter1 < lrow; counter1++)
   {
    if ((border) && (counter1 == row) && (toppage))
    {
     if ((col == 0) && (border))
      sprintf(s, "%*s", LEFTMARGIN, "");
     else
      s[0] = 0;
     for (counter3 = col; counter3 < lcol; counter3++)
     {
      centercolstring(counter3, colstr);
      strcat(s, colstr);
     }
     fprintf(file, "%s\n", s);
     printed++;
    }
    if ((col == 0) && (border))
     sprintf(s, "%-*d", LEFTMARGIN, counter1 + 1);
    else
     s[0] = 0;
    for (counter2 = col; counter2 < lcol; counter2++)
     strcat(s, cellstring(counter2, counter1, &dummy, FORMAT));
    fprintf(file, "%s\n", s);
    printed++;
   }
   row = lrow;
   toppage = FALSE;
   if (printed < 66)
    fprintf(file, "%c", FORMFEED);
  }
  col = lcol;
 }
 fclose(file);
 lastcol = oldlastcol;
} /* printsheet */

void setcolwidth(int col)
/* Sets the new column width for a selected column */
{
 int width, row;

 writeprompt(MSGCOLWIDTH);
 if (!getint(&width, MINCOLWIDTH, MAXCOLWIDTH))
  return;
 colwidth[col] = width;
 setrightcol();
 if (rightcol < col)
 {
  rightcol = col;
  setleftcol();
  setrightcol();
 }
 for (row = 0; row <= lastrow; row++)
 {
  if ((cell[col][row] != NULL) && (cell[col][row]->attrib == TEXT))
   clearoflags(col + 1, row, NOUPDATE);
  else
   clearoflags(col, row, NOUPDATE);
  updateoflags(col, row, NOUPDATE);
 }
 displayscreen(NOUPDATE);
 changed = TRUE;
} /* setcolwidth */

void gotocell()
/* Moves to a selected cell */
{
 writeprompt(MSGGOTO);
 if (!getcell(&curcol, &currow))
  return;
 leftcol = curcol;
 toprow = currow;
 setbottomrow();
 setrightcol();
 setleftcol();
 displayscreen(NOUPDATE);
} /* gotocell */

void formatcells(void)
/* Prompts the user for a selected format and range of cells */
{
 int col, row, col1, col2, row1, row2, temp, newformat = 0;

 writeprompt(MSGCELL1);
 if (!getcell(&col1, &row1))
  return;
 writeprompt(MSGCELL2);
 if (!getcell(&col2, &row2))
  return;
 if ((col1 != col2) && (row1 != row2))
  errormsg(MSGDIFFCOLROW);
 else
 {
  if (col1 > col2)
   swap(&col1, &col2);
  if (row1 > row2)
   swap(&row1, &row2);
  if (!getyesno(&temp, MSGRIGHTJUST))
   return;
  newformat += (temp == 'Y') * RJUSTIFY;
  if (!getyesno(&temp, MSGDOLLAR))
   return;
  newformat += (temp == 'Y') * DOLLAR;
  if (!getyesno(&temp, MSGCOMMAS))
   return;
  newformat += (temp == 'Y') * COMMAS;
  if (newformat & DOLLAR)
   newformat += 2;
  else
  {
   writeprompt(MSGPLACES);
   if (!getint(&temp, 0, MAXPLACES))
    return;
   newformat += temp;
  }
  for (col = col1; col <= col2; col++)
  {
   for (row = row1; row <= row2; row++)
   {
    format[col][row] = (format[col][row] & OVERWRITE) | newformat;
    if ((col >= leftcol) && (col <= rightcol) &&
     (row >= toprow) && (row <= bottomrow))
     displaycell(col, row, NOHIGHLIGHT, NOUPDATE);
   }
  }
 }
 changed = TRUE;
} /* formatcells */

void deletecol(int col)
/* Deletes a column */
{
 int counter, row;

 for (counter = 0; counter <= lastrow; counter++)
  deletecell(col, counter, NOUPDATE);
 printfreemem();
 if (col != MAXCOLS - 1)
 {
  movmem(&cell[col + 1][0], &cell[col][0], MAXROWS * sizeof(CELLPTR) *
   (MAXCOLS - col - 1));
  movmem(&format[col + 1][0], &format[col][0], MAXROWS * (MAXCOLS - col - 1));
  movmem(&colwidth[col + 1], &colwidth[col], MAXCOLS - col - 1);
 }
 setmem(&cell[MAXCOLS - 1][0], MAXROWS * sizeof(CELLPTR), 0);
 setmem(&format[MAXCOLS - 1][0], MAXROWS, DEFAULTFORMAT);
 colwidth[MAXCOLS - 1] = DEFAULTWIDTH;
 if ((lastcol >= col) && (lastcol > 0))
  lastcol--;
 setrightcol();
 if (curcol > rightcol)
 {
  rightcol++;
  setleftcol();
 }
 clearlastcol();
 for (counter = 0; counter <= lastcol; counter++)
 {
  for (row = 0; row <= lastrow; row++)
  {
   if ((cell[counter][row] != NULL) &&
    (cell[counter][row]->attrib == FORMULA))
    fixformula(counter, row, COLDEL, col);
   updateoflags(col, row, NOUPDATE);
  }
 }
 while (col <= rightcol)
  displaycol(col++, NOUPDATE);
 changed = TRUE;
 recalc();
} /* deletecol */

void insertcol(int col)
/* Inserts a column */
{
 int counter, row;

 if (lastcol == MAXCOLS - 1)
 {
  for (counter = 0; counter <= lastrow; counter++)
   deletecell(lastcol, counter, NOUPDATE);
  printfreemem();
 }
 if (col != MAXCOLS - 1)
 {
  movmem(&cell[col][0], &cell[col + 1][0], MAXROWS * sizeof(CELLPTR) *
   (MAXCOLS - col - 1));
  movmem(&format[col][0], &format[col + 1][0], MAXROWS * (MAXCOLS - col - 1));
  movmem(&colwidth[col], &colwidth[col + 1], MAXCOLS - col - 1);
 }
 setmem(&cell[col][0], MAXROWS * sizeof(CELLPTR), 0);
 setmem(&format[col][0], MAXROWS, DEFAULTFORMAT);
 colwidth[col] = DEFAULTWIDTH;
 lastcol = MAXCOLS - 1;
 setlastcol();
 setrightcol();
 if (curcol > rightcol)
 {
  rightcol++;
  setleftcol();
 }
 for (counter = 0; counter <= lastcol; counter++)
 {
  for (row = 0; row <= lastrow; row++)
  {
   if ((cell[counter][row] != NULL) &&
    (cell[counter][row]->attrib == FORMULA))
    fixformula(counter, row, COLADD, col);
   updateoflags(col, row, NOUPDATE);
  }
 }
 while (col <= rightcol)
  displaycol(col++, NOUPDATE);
 changed = TRUE;
 recalc();
} /* insertcol */

void deleterow(int row)
/* Deletes a row */
{
 int counter, rowc;

 for (counter = 0; counter <= lastcol; counter++)
  deletecell(counter, row, NOUPDATE);
 printfreemem();
 if (row != MAXROWS - 1)
 {
  for (counter = 0; counter < MAXCOLS; counter++)
  {
   movmem(&cell[counter][row + 1], &cell[counter][row],
    sizeof(CELLPTR) * (MAXROWS - row - 1));
   movmem(&format[counter][row + 1], &format[counter][row], MAXROWS - row - 1);
  }
 }
 else
 {
  for (counter = 0; counter <= lastcol; counter++)
  {
   cell[counter][MAXROWS - 1] = NULL;
   format[counter][MAXROWS - 1] = DEFAULTFORMAT;
  }
 }
 if ((lastrow >= row) && (lastrow > 0))
  lastrow--;
 for (counter = 0; counter <= lastcol; counter++)
 {
  for (rowc = 0; rowc <= lastrow; rowc++)
  {
   if ((cell[counter][rowc] != NULL) &&
    (cell[counter][rowc]->attrib == FORMULA))
    fixformula(counter, rowc, ROWDEL, row);
  }
 }
 while (row <= bottomrow)
  displayrow(row++, NOUPDATE);
 changed = TRUE;
 recalc();
} /* deleterow */

void insertrow(int row)
/* Inserts a row */
{
 int counter, rowc;

 if (lastrow == MAXROWS - 1)
 {
  for (counter = 0; counter <= lastcol; counter++)
   deletecell(counter, lastrow, NOUPDATE);
  printfreemem();
 }
 if (row != MAXROWS - 1)
 {
  for (counter = 0; counter < MAXCOLS; counter++)
  {
   movmem(&cell[counter][row], &cell[counter][row + 1],
    sizeof(CELLPTR) * (MAXROWS - row - 1));
   movmem(&format[counter][row], &format[counter][row + 1], MAXROWS - row - 1);
  }
 }
 for (counter = 0; counter < MAXCOLS; counter++)
 {
  cell[counter][row] = NULL;
  format[counter][row] = DEFAULTFORMAT;
 }
 lastrow = MAXROWS - 1;
 setlastrow();
 for (counter = 0; counter <= lastcol; counter++)
 {
  for (rowc = 0; rowc <= lastrow; rowc++)
  {
   if ((cell[counter][rowc] != NULL) &&
    (cell[counter][rowc]->attrib == FORMULA))
    fixformula(counter, rowc, ROWADD, row);
  }
 }
 while (row <= bottomrow)
  displayrow(row++, NOUPDATE);
 changed = TRUE;
 recalc();
} /* insertrow */

void smenu(void)
/* Executes the commands in the spreadsheet menu */
{
 char filename[MAXINPUT + 1];

 filename[0] = 0;
 switch(getcommand(SMENU, SCOMMAND))
 {
  case 0 :
   checkforsave();
   loadsheet(filename);
   break;
  case 1 :
   savesheet();
   break;
  case 2 :
   printsheet();
   break;
  case 3 :
   checkforsave();
   clearsheet();
   break;
 } /* switch */
} /* smenu */

void cmenu(void)
/* Executes the commands in the column menu */
{
 switch(getcommand(CMENU, CCOMMAND))
 {
  case 0 :
   insertcol(curcol);
   break;
  case 1 :
   deletecol(curcol);
   break;
  case 2 :
   setcolwidth(curcol);
   break;
 } /* switch */
} /* cmenu */

void rmenu(void)
/* Executes the commands in the row menu */
{
 switch(getcommand(RMENU, RCOMMAND))
 {
  case 0 :
   insertrow(currow);
   break;
  case 1 :
   deleterow(currow);
   break;
 } /* switch */
} /* rmenu */

void umenu(void)
/* Executes the commands in the utility menu */
{
 switch(getcommand(UMENU, UCOMMAND))
 {
  case 0 :
   recalc();
   break;
  case 1 :
   changeformdisplay(!formdisplay);
   displayscreen(UPDATE);
   break;
 } /* switch */
} /* umenu */

void mainmenu(void)
/* Executes the commands in the main menu */
{
 switch(getcommand(MENU, COMMAND))
 {
  case 0 :
   smenu();
   break;
  case 1 :
   formatcells();
   break;
  case 2 :
   deletecell(curcol, currow, UPDATE);
   printfreemem();
   if (autocalc)
    recalc();
   break;
  case 3 :
   gotocell();
   break;
  case 4 :
   cmenu();
   break;
  case 5 :
   rmenu();
   break;
  case 6 :
   editcell(curcell);
   break;
  case 7 :
   umenu();
   break;
  case 8 :
   changeautocalc(!autocalc);
   break;
  case 9 :
   checkforsave();
   stop = TRUE;
   break;
 } /* switch */
} /* mainmenu */

MCINPUT Programming in C

/* Turbo C - (C) Copyright 1987,1988 by Borland International */

#include <string.h>
#include <mem.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <bios.h>
#include <conio.h>
#include <string.h>
#include "mcalc.h"

int getkey(void)
/* Uses the BIOS to read the next keyboard character */
{
 int key, lo, hi;

 key = bioskey(0);
 lo = key & 0X00FF;
 hi = (key & 0XFF00) >> 8;
 return((lo == 0) ? hi + 256 : lo);
} /* getkey */

int editstring(char *s, char *legal, int maxlength)
/* Allows the user to edit a string with only certain characters allowed -
   Returns TRUE if ESC was not pressed, FALSE is ESC was pressed.
*/
{
 int c, len = strlen(s), pos = len, insert = TRUE;

 changecursor(insert);
 do
 {
  writef(1, 25, WHITE, 79, "%s", s);
  gotoxy(pos + 1, 25);
  switch(c = getkey())
  {
   case HOMEKEY :
    pos = 0;
    break;
   case ENDKEY :
    pos = len;
    break;
   case INSKEY :
    insert = !insert;
    changecursor(insert);
    break;
   case LEFTKEY :
    if (pos > 0)
     pos--;
    break;
   case RIGHTKEY :
    if (pos < len)
     pos++;
    break;
   case BS :
    if (pos > 0)
    {
     movmem(&s[pos], &s[pos - 1], len - pos + 1);
     pos--;
     len--;
    }
    break;
   case DELKEY :
    if (pos < len)
    {
     movmem(&s[pos + 1], &s[pos], len - pos);
     len--;
    }
    break;
   case CR :
    break;
   case UPKEY :
    c = CR;
    break;
   case DOWNKEY :
    c = CR;
    break;
   case ESC :
    len = 0;
    break;
   default :
    if (((legal[0] == 0) || (strchr(legal, c) != NULL)) &&
        ((c >= ' ') && (c <= '~')) &&
        (len < maxlength))
    {
     if (insert)
     {
      memmove(&s[pos + 1], &s[pos], len - pos + 1);
      len++;
     }
     else if (pos >= len)
      len++;
     s[pos++] = c;
    }
    break;
  } /* switch */
  s[len] = 0;
 }
 while ((c != CR) && (c != ESC));
 clearinput();
 changecursor(FALSE);
 setcursor(nocursor);
 return(c != ESC);
} /* editstring */

void getinput(int c)
/* Reads and acts on an input string from the keyboard that started with c. */
{
 char s[MAXINPUT + 1];

 s[0] = c;
 s[1] = 0;
 if (!editstring(s, "", MAXINPUT) || (s[0] == 0))
  return;
 act(s);
 changed = TRUE;
} /* getinput */

int getint(int *number, int low, int high)
/* Reads in a positive integer from low to high */
{
 int i, good = FALSE;
 char s[5], message[81];

 s[0] = 0;
 sprintf(message, MSGBADNUMBER, low, high);
 do
 {
  if (!editstring(s, "1234567890", 4))
   return(FALSE);
  i = atoi(s);
  if ((good = ((i >= low) && (i <= high))) == 0)
   errormsg(message);
 }
 while (!good);
 *number = i;
 return(TRUE);
} /* getint */

int getcell(int *col, int *row)
/* Reads in a cell name that was typed in - Returns FALSE if ESC was pressed */
{
 int first = TRUE, good = FALSE, len, numlen = rowwidth(MAXROWS),
     oldcol = *col, oldrow = *row;
 char data[10], *input, *start, numstring[6];

 data[0] = 0;
 do
 {
  if (!first)
   errormsg(MSGBADCELL);
  first = FALSE;
  input = data;
  if (!editstring(data, "", numlen + 2))
  {
   *col = oldcol;
   *row = oldrow;
   return(FALSE);
  }
  *col = toupper(*(input++)) - 'A';
  if (isalpha(*input))
  {
   *col *= 26;
   *col += toupper(*(input++)) - 'A' + 26;
  }
  if (*col >= MAXCOLS)
   continue;
  start = input;
  for (len = 0; len < numlen; len++)
  {
   if (!isdigit(*(input++)))
   {
    input--;
    break;
   }
  }
  if (len == 0)
   continue;
  strncpy(numstring, start, len);
  numstring[len] = 0;
  *row = atoi(numstring) - 1;
  if ((*row >= MAXROWS) || (*row == -1) || (*input != 0))
   continue;
  good = TRUE;
 }
 while (!good);
 return(TRUE);
} /* getcell */

int getyesno(int *yesno, char *prompt)
/* Prints a prompt and gets a yes or no answer - returns TRUE if ESC was
   pressed, FALSE if not.
*/
{
 writeprompt(prompt);
 setcursor(shortcursor);
 do
 {
  *yesno = toupper(getkey());
  if (*yesno == ESC)
  {
   setcursor(nocursor);
   return(FALSE);
  }
 }
 while (strchr("YN", *yesno) == NULL);
 setcursor(nocursor);
 return(TRUE);
} /* getyesno */

MCDISPLY Programming in C

/* Turbo C - (C) Copyright 1987,1988 by Borland International */

#include <dos.h>
#include <stdio.h>
#include <string.h>
#include <mem.h>
#include <conio.h>
#include "mcalc.h"

static unsigned char colortable[256];

void setcolor(int color)
/* Sets the current color using the color table */
{
  textattr(colortable[color]);
} /* setcolor */

void writef(int col, int row, int color, int width, va_list arg_list, ...)
/* Prints a string in video memory at a selected location in a color */
{
 va_list arg_ptr;
 char *format;
 char output[81];
 int len;

 va_start(arg_ptr, arg_list);
 format = arg_list;
 vsprintf(output, format, arg_ptr);
 output[width] = 0;
 if ((len = strlen(output)) < width)
  setmem(&output[len], width - len, ' ');
 setcolor(color);
 gotoxy(col, row);
 cprintf(output);
} /* writef */

void scroll(int direction, int lines, int x1, int y1, int x2, int y2,
            int attrib)
/* Scrolls an area of the screen */
{
  if (lines == 0)
    window(x1, y1, x2, y2);
  else switch(direction)
  {
    case UP :
      movetext(x1, y1 + lines, x2, y2, x1, y1);
      window(x1, y2 - lines + 1, x2, y2);
      break;
    case DOWN :
      movetext(x1, y1, x2, y2 - lines, x1, y1 + lines);
      window(x1, y1, x2, y1 + lines - 1);
      break;
    case LEFT :
      movetext(x1 + lines, y1, x2, y2, x1, y1);
      window(x2 - lines + 1, y1, x2, y2);
      break;
    case RIGHT :
      movetext(x1, y1, x2 - lines, y2, x1 + lines, y1);
      window(x1, y1, x1 + lines - 1, y2);
      break;
  } /* switch */
  setcolor(attrib);
  clrscr();
  window(1, 1, 80, 25);
} /* scroll */

void setcursor(unsigned int shape)
/* Sets the shape of the cursor */
{
 union REGS reg;

 reg.h.ah = 1;
 reg.x.cx = shape;
 int86(0X10, &reg, &reg);
} /* setcursor */

unsigned int getcursor(void)
/* Returns the shape of the current cursor */
{
 union REGS reg;

 reg.h.ah = 3;
 reg.h.bh = 0;
 int86(0X10, &reg, &reg);
 return(reg.x.cx);
} /* getcursor */

void changecursor(insmode)
/* Changes the cursor shape based on the current insert mode */
{
 if (insmode)
  setcursor(tallcursor);
 else
  setcursor(shortcursor);
} /* changecursor */

void printcol(void)
/* Prints the column headings */
{
 int col;
 char colstr[MAXCOLWIDTH + 1];

 scroll(UP, 0, 1, 2, 80, 2, HEADERCOLOR);
 for (col = leftcol; col <= rightcol; col++)
 {
  centercolstring(col, colstr);
  writef(colstart[col - leftcol] + 1, 2, HEADERCOLOR, colwidth[col], colstr);
 }
} /* printcol */

void clearlastcol()
/* Clears any data left in the last column */
{
 int col;

 if ((col = colstart[rightcol - leftcol] + colwidth[rightcol]) < 80)
  scroll(UP, 0, col + 1, 3, 80, SCREENROWS + 2, WHITE);
} /* clearlastcol */

void printrow(void)
/* Prints the row headings */
{
 int row;

 for (row = 0; row < SCREENROWS; row++)
  writef(1, row + 3, HEADERCOLOR, LEFTMARGIN, "%-d", row + toprow + 1);
} /* printrow */

void displaycell(int col, int row, int highlighting, int updating)
/* Displays the contents of a cell */
{
 int color;
 char *s;

 if ((updating) &&
     ((cell[col][row] == NULL) || (cell[col][row]->attrib != FORMULA)))
  return;
 s = cellstring(col, row, &color, FORMAT);
 if (highlighting)
 {
  if (color == ERRORCOLOR)
   color = HIGHLIGHTERRORCOLOR;
  else
   color = HIGHLIGHTCOLOR;
 }
 writef(colstart[col - leftcol] + 1, row - toprow + 3, color, colwidth[col],
        "%s", s);
} /* displaycell */

void displaycol(int col, int updating)
/* Displays a column on the screen */
{
 int row;

 for (row = toprow; row <= bottomrow; row++)
  displaycell(col, row, NOHIGHLIGHT, updating);
} /* displaycol */

void displayrow(int row, int updating)
/* Displays a row on the screen */
{
 int col;

 for (col = leftcol; col <= rightcol; col++)
  displaycell(col, row, NOHIGHLIGHT, updating);
} /* displayrow */

void displayscreen(int updating)
/* Displays the current screen of the spreadsheet */
{
 int row;

 for (row = toprow; row <= bottomrow; row++)
  displayrow(row, updating);
 clearlastcol();
} /* displayscreen */

void clearinput(void)
/* Clears the input line */
{
 scroll(UP, 0, 1, 25, 80, 25, WHITE);
 gotoxy(1, 25);
} /* clearinput */

void showcelltype(void)
/* Prints the type of cell and what is in it */
{
 char colstr[3], *s;
 int color;

 formdisplay = !formdisplay;
 s = cellstring(curcol, currow, &color, NOFORMAT);
 colstring(curcol, colstr);
 if (curcell == NULL)
  writef(1, 23, CELLTYPECOLOR, 80, "%s%d %s", colstr, currow + 1, MSGEMPTY);
 else switch(curcell->attrib)
 {
  case TEXT :
   writef(1, 23, CELLTYPECOLOR, 80, "%s%d %s", colstr, currow + 1,
          MSGTEXT);
   break;
  case VALUE :
   writef(1, 23, CELLTYPECOLOR, 80, "%s%d %s", colstr, currow + 1,
          MSGVALUE);
   break;
  case FORMULA :
   writef(1, 23, CELLTYPECOLOR, 80, "%s%d %s", colstr, currow + 1,
          MSGFORMULA);
   break;
 } /* switch */
 writef(1, 24, CELLCONTENTSCOLOR, 80, "%s", s);
 formdisplay = !formdisplay;
} /* showcelltype */

void redrawscreen(void)
/* Displays the entire screen */
{
 setrightcol();
 setbottomrow();
 writef(1, 1, MSGMEMORYCOLOR, strlen(MSGMEMORY), MSGMEMORY);
 writef(29, 1, PROMPTCOLOR, strlen(MSGCOMMAND), MSGCOMMAND);
 changeautocalc(autocalc);
 changeformdisplay(formdisplay);
 printfreemem();
 displayscreen(NOUPDATE);
} /* redrawscreen */

void initcursor(void)
/* Initializes the different cursor types */
{
 struct text_info ti;

 gettextinfo(&ti);
 oldcursor = getcursor();
 if (ti.currmode == MONO)
 {
  shortcursor = 0x0A0C;
  tallcursor = 0x090C;
 }
 else
 {
  shortcursor = 0x0607;
  tallcursor = 0x0507;
 }
} /* initcursor */

void initcolortable(void)
/* Sets up the color table */
{
  int color, fg, bg, fcolor, bcolor;
  struct text_info ti;

  gettextinfo(&ti);
  if (ti.currmode == C80)
  {
    for (color = 0; color <= 255; color++)
      colortable[color] = color;
  }
  else
  {
    for (fg = BLACK; fg <= WHITE; fg++)
    {
      if (fg == BLACK)
        fcolor = BLACK;
      else if (fg <= LIGHTGRAY)
        fcolor = LIGHTGRAY;
      else
        fcolor = WHITE;
      for (bg = BLACK; bg <= LIGHTGRAY; bg++)
      {
        if (bg == BLACK)
          bcolor = BLACK;
        else
  {
          if (fcolor == WHITE)
            fcolor = BLACK;
          bcolor = LIGHTGRAY;
        }
        colortable[fg + (bg << 4)] = fcolor + (bcolor << 4);
      }
    }
    for (fg = 128; fg <= 255; fg++)
      colortable[fg] = colortable[fg - 128] | 0x80;
  }
} /* initcolortable */

MCALC Turbo C Programming

/* Turbo C - (C) Copyright 1987,1988 by Borland International */

#define MAIN

#include <string.h>
#include <alloc.h>
#include <stdarg.h>
#include <dos.h>
#include <conio.h>
#include "mcalc.h"

CELLPTR cell[MAXCOLS][MAXROWS], curcell;
unsigned char format[MAXCOLS][MAXROWS];
unsigned char colwidth[MAXCOLS];
unsigned char colstart[SCREENCOLS];
int leftcol, rightcol, toprow, bottomrow, curcol, currow, lastcol, lastrow;
char changed = FALSE;
char formdisplay = FALSE;
char autocalc = TRUE;
char stop = FALSE;
char colortable[128];
char colorcard;
char snow;
char far *displayptr;
long memleft;
unsigned int oldcursor, shortcursor, tallcursor, nocursor = 0x2000;

void run()
/* The main program loop */
{
 int input;

 do
 {
  displaycell(curcol, currow, HIGHLIGHT, NOUPDATE);
  curcell = cell[curcol][currow];
  showcelltype();
  input = getkey();
  switch(input)
  {
   case '/' :
    mainmenu();
    break;
   case F1 :
    recalc();
    break;
   case F2 :
    editcell(curcell);
    break;
   case DELKEY :
    deletecell(curcol, currow, UPDATE);
    printfreemem();
    if (autocalc)
     recalc();
    break;
   case PGUPKEY :
    toprow -= 20;
    currow -= 20;
    if (currow < 0)
     currow = toprow = 0;
    else if (toprow < 0)
    {
     currow -= toprow;
     toprow = 0;
    }
    setbottomrow();
    displayscreen(NOUPDATE);
    break;
   case PGDNKEY :
    toprow += 20;
    currow += 20;
    if ((currow >= MAXROWS) && (toprow >= MAXROWS))
    {
     currow = MAXROWS - 1;
     toprow = MAXROWS - 20;
    }
    else if (toprow > (MAXROWS - 20))
    {
     currow -= (toprow + 20 - MAXROWS);
     toprow = MAXROWS - 20;
    }
    setbottomrow();
    displayscreen(NOUPDATE);
    break;
   case CTRLLEFTKEY :
    displaycell(curcol, currow, NOHIGHLIGHT, NOUPDATE);
    if (leftcol == 0)
     curcol = 0;
    else
    {
     curcol = rightcol = leftcol - 1;
     setleftcol();
     setrightcol();
     displayscreen(NOUPDATE);
    }
    break;
   case CTRLRIGHTKEY :
    displaycell(curcol, currow, NOHIGHLIGHT, NOUPDATE);
    if (rightcol == MAXCOLS - 1)
     curcol = rightcol;
    else
    {
     curcol = leftcol = rightcol + 1;
     setrightcol();
     setleftcol();
     displayscreen(NOUPDATE);
    }
    break;
   case HOMEKEY :
    currow = curcol = leftcol = toprow = 0;
    setrightcol();
    setbottomrow();
    displayscreen(NOUPDATE);
    break;
   case ENDKEY :
    rightcol = curcol = lastcol;
    currow = bottomrow = lastrow;
    settoprow();
    setleftcol();
    setrightcol();
    displayscreen(NOUPDATE);
    break;
   case UPKEY :
    moverowup();
    break;
   case DOWNKEY :
    moverowdown();
    break;
   case LEFTKEY :
    movecolleft();
    break;
   case RIGHTKEY :
    movecolright();
    break;
   default :
    if ((input >= ' ') && (input <= '~'))
     getinput(input);
    break;
  } /* switch */
 }
 while (!stop);
} /* run */

void main(int argc, char *argv[])
{
 window(1, 1, 80, 25);
 initcursor();
 initcolortable();
 setcursor(nocursor);
 setcolor(WHITE);
 clrscr();
 writef((80 - strlen(MSGHEADER)) >> 1, 11, MSGHEADERCOLOR, strlen(MSGHEADER),
        MSGHEADER);
 writef((80 - strlen(MSGKEYPRESS)) >> 1, 13, PROMPTCOLOR,
        strlen(MSGKEYPRESS), MSGKEYPRESS);
 gotoxy(80, 25);
 getkey();
 setcolor(WHITE);
 clrscr();
 initvars();
 memleft = memsize;
 redrawscreen();
 if (argc > 1)
  loadsheet(argv[1]);
 clearinput();
 run();
 setcolor(LIGHTGRAY);
 clrscr();
 setcursor(oldcursor);
}

using namespace std; in C++

All the elements of the standard C++ library are declared within what is called a namespace, the
namespace with the name std. So in order to access its functionality we declare with this expression that
we will be using these entities. This line is very frequent in C++ programs that use the standard library,
and in fact it will be included in most of the source codes

cout << "Hello World!"; in C++

cout << "Hello World!";
This line is a C++ statement. A statement is a simple or compound expression that can actually produce
some effect. In fact, this statement performs the only action that generates a visible effect in our first
program.
cout represents the standard output stream in C++, and the meaning of the entire statement is to insert
a sequence of characters (in this case the Hello World sequence of characters) into the standard output
stream (which usually is the screen).
cout is declared in the iostream standard file within the std namespace, so that's why we needed to
include that specific file and to declare that we were going to use this specific namespace earlier in our
code.
Notice that the statement ends with a semicolon character (;). This character is used to mark the end of
the statement and in fact it must be included at the end of all expression statements in all C++ programs
(one of the most common syntax errors is indeed to forget to include some semicolon after a statement).

int main() in C++ Language

This line corresponds to the beginning of the definition of the main function. The main function is the point
by where all C++ programs start their execution, independently of its location within the source code. It
does not matter whether there are other functions with other names defined before or after it - the
instructions contained within this function's definition will always be the first ones to be executed in any
C++ program. For that same reason, it is essential that all C++ programs have a main function.
The word main is followed in the code by a pair of parentheses (()). That is because it is a function
declaration: In C++, what differentiates a function declaration from other types of expressions are these
parentheses that follow its name. Optionally, these parentheses may enclose a list of parameters within
them.
Right after these parentheses we can find the body of the main function enclosed in braces ({}). What is
contained within these braces is what the function does when it is executed.

return 0; in C++

return 0;
The return statement causes the main function to finish. return may be followed by a return code (in our
example is followed by the return code 0). A return code of 0 for the main function is generally interpreted
as the program worked as expected without any errors during its execution. This is the most usual way to
end a C++ console program.

Introduction in String in C++

Variables that can store non-numerical values that are longer than one single character are known as strings.
The C++ language library provides support for strings through the standard string class. This is not a
fundamental type, but it behaves in a similar way as fundamental types do in its most basic usage.

A first difference with fundamental data types is that in order to declare and use objects (variables) of this type we
need to include an additional header file in our source code: <string> and have access to the std namespace
(which we already had in all our previous programs thanks to the using namespace statement).
// my first string
#include <iostream>
#include <string>
using namespace std;
int main ()
{
string mystring = "This is a string";
cout << mystring;
return 0;
}
This is a string
As you may see in the previous example, strings can be initialized with any valid string literal just like numerical
type variables can be initialized to any valid numerical literal. Both initialization formats are valid with strings:
string mystring = "This is a string";
string mystring ("This is a string");
Strings can also perform all the other basic operations that fundamental data types can, like being declared without
an initial value and being assigned values during execution:
// my first string
#include <iostream>
#include <string>
using namespace std;
int main ()
{
string mystring;
mystring = "This is the initial string content";
cout << mystring << endl;
mystring = "This is a different string content";
cout << mystring << endl;
return 0;
}
This is the initial string content
This is a different string content

Constants in C++

Constants are expressions with a fixed value.

Literals
Literals are used to express particular values within the source code of a program. We have already used these
previously to give concrete values to variables or to express messages we wanted our programs to print out, for
example, when we wrote:
a = 5;
the 5 in this piece of code was a literal constant.
Literal constants can be divided in Integer Numerals, Floating-Point Numerals, Characters, Strings and Boolean
Values.
Integer Numerals
1776
707
-273
They are numerical constants that identify integer decimal values. Notice that to express a numerical constant we
do not have to write quotes (") nor any special character. There is no doubt that it is a constant: whenever we
write 1776 in a program, we will be referring to the value 1776.
In addition to decimal numbers (those that all of us are used to use every day) C++ allows the use as literal
constants of octal numbers (base 8) and hexadecimal numbers (base 16). If we want to express an octal number
we have to precede it with a 0 (zero character). And in order to express a hexadecimal number we have to precede
it with the characters 0x (zero, x). For example, the following literal constants are all equivalent to each other:
75 // decimal
0113 // octal
0x4b // hexadecimal
All of these represent the same number: 75 (seventy-five) expressed as a base-10 numeral, octal numeral and
hexadecimal numeral, respectively.
Literal constants, like variables, are considered to have a specific data type. By default, integer literals are of type
int. However, we can force them to either be unsigned by appending the u character to it, or long by appending l:
75 // int
75u // unsigned int
75l // long
75ul // unsigned long
In both cases, the suffix can be specified using either upper or lowercase letters.
Floating Point Numbers
They express numbers with decimals and/or exponents. They can include either a decimal point, an e character
(that expresses "by ten at the Xth height", where X is an integer value that follows the e character), or both a
decimal point and an e character:

3.14159 // 3.14159
6.02e23 // 6.02 x 10^23
1.6e-19 // 1.6 x 10^-19
3.0 // 3.0
These are four valid numbers with decimals expressed in C++. The first number is PI, the second one is the
number of Avogadro, the third is the electric charge of an electron (an extremely small number) -all of them
approximated- and the last one is the number three expressed as a floating-point numeric literal.
The default type for floating point literals is double. If you explicitly want to express a float or long double
numerical literal, you can use the f or l suffixes respectively:
3.14159L // long double
6.02e23f // float
Any of the letters that can be part of a floating-point numerical constant (e, f, l) can be written using either lower
or uppercase letters without any difference in their meanings.
Character and string literals
There also exist non-numerical constants, like:
'z'
'p'
"Hello world"
"How do you do?"
The first two expressions represent single character constants, and the following two represent string literals
composed of several characters. Notice that to represent a single character we enclose it between single quotes (')
and to express a string (which generally consists of more than one character) we enclose it between double quotes
(").
When writing both single character and string literals, it is necessary to put the quotation marks surrounding them
to distinguish them from possible variable identifiers or reserved keywords. Notice the difference between these
two expressions:
x
'x'
x alone would refer to a variable whose identifier is x, whereas 'x' (enclosed within single quotation marks) would
refer to the character constant 'x'.
Character and string literals have certain peculiarities, like the escape codes. These are special characters that are
difficult or impossible to express otherwise in the source code of a program, like newline (\n) or tab (\t). All of
them are preceded by a backslash (\). Here you have a list of some of such escape codes:

\n newline
\r carriage return
\t tab
\v vertical tab
\b backspace
\f form feed (page feed)
\a alert (beep)
\' single quote (')
\" double quote (")
\? question mark (?)
\\ backslash (\)
For example:
'\n'
'\t'
"Left \t Right"
"one\ntwo\nthree"

Additionally, you can express any character by its numerical ASCII code by writing a backslash character (\)
followed by the ASCII code expressed as an octal (base-8) or hexadecimal (base-16) number. In the first case
(octal) the digits must immediately follow the backslash (for example \23 or \40), in the second case
(hexadecimal), an x character must be written before the digits themselves (for example \x20 or \x4A).
String literals can extend to more than a single line of code by putting a backslash sign (\) at the end of each
unfinished line.
"string expressed in \
two lines"
You can also concatenate several string constants separating them by one or several blank spaces, tabulators,
newline or any other valid blank character:
"this forms" "a single" "string" "of characters"
Finally, if we want the string literal to be explicitly made of wide characters (wchar_t), instead of narrow characters
(char), we can precede the constant with the L prefix:
L"This is a wide character string"
Wide characters are used mainly to represent non-English or exotic character sets.Boolean literals
There are only two valid Boolean values: true and false. These can be expressed in C++ as values of type bool by
using the Boolean literals true and false.
Defined constants (#define)
You can define your own names for constants that you use very often without having to resort to memoryconsuming
variables, simply by using the #define preprocessor directive. Its format is:

Boolean literals
There are only two valid Boolean values: true and false. These can be expressed in C++ as values of type bool by
using the Boolean literals true and false.
Defined constants (#define)
You can define your own names for constants that you use very often without having to resort to memoryconsuming
variables, simply by using the #define preprocessor directive. Its format is:

#define identifier value
For example:
#define PI 3.14159
#define NEWLINE '\n'
This defines two new constants: PI and NEWLINE. Once they are defined, you can use them in the rest of the code
as if they were any other regular constant, for example:
// defined constants: calculate circumference
#include <iostream>
using namespace std;
#define PI 3.14159
#define NEWLINE '\n'
int main ()
{
double r=5.0; // radius
double circle;
circle = 2 * PI * r;
cout << circle;
cout << NEWLINE;
return 0;
}
31.4159
In fact the only thing that the compiler preprocessor does when it encounters #define directives is to literally
replace any occurrence of their identifier (in the previous example, these were PI and NEWLINE) by the code to
which they have been defined (3.14159 and '\n' respectively).
The #define directive is not a C++ statement but a directive for the preprocessor; therefore it assumes the entire
line as the directive and does not require a semicolon (;) at its end. If you append a semicolon character (;) at the
end, it will also be appended in all occurrences within the body of the program that the preprocessor replaces.
Declared constants (const)
With the const prefix you can declare constants with a specific type in the same way as you would do with a
variable:
const int pathwidth = 100;
const char tabulator = '\t';
Here, pathwidth and tabulator are two typed constants. They are treated just like regular variables except that
their values cannot be modified after their definition.

Calculate Cirrcumfrence Program in C++

#include <iostream>
using namespace std;
#define PI 3.14159
#define NEWLINE '\n'
int main ()
{
double r=5.0; // radius
double circle;
circle = 2 * PI * r;
cout << circle;
cout << NEWLINE;
return 0;
}
output :
31.4159

Structure of a program in C++ Learn

Data+Structure+C+++Programs

C++ Programming Language

Probably the best way to start learning a programming language is by writing a program. Therefore, here is our
first program:
// my first program in C++
#include <iostream>
using namespace std;
int main ()
{
cout << "Hello World!";
return 0;
}
Hello World!
The first panel shows the source code for our first program. The second one shows the result of the program once
compiled and executed. The way to edit and compile a program depends on the compiler you are using. Depending
on whether it has a Development Interface or not and on its version. Consult the compilers section and the manual
or help included with your compiler if you have doubts on how to compile a C++ console program.

alloc.h Memory Management Functions and Variables

Copyright (c) Borland International 1987,1988
All Rights Reserved.
*/
#if __STDC__
#define _Cdecl
#else
#define _Cdecl cdecl
#endif

#ifndef _STDDEF
#define _STDDEF
#ifndef _PTRDIFF_T
#define _PTRDIFF_T
#if defined(__LARGE__) || defined(__HUGE__) || defined(__COMPACT__)
typedef long ptrdiff_t;
#else
typedef int ptrdiff_t;
#endif
#endif
#ifndef _SIZE_T
#define _SIZE_T
typedef unsigned size_t;
#endif
#endif

#ifndef NULL
#if defined(__TINY__) || defined(__SMALL__) || defined(__MEDIUM__)
#define NULL 0
#else
#define NULL 0L
#endif
#endif

int _Cdecl brk (void *addr);
void *_Cdecl calloc (size_t nitems, size_t size);

#if defined(__COMPACT__) || defined(__LARGE__) || defined(__HUGE__)
unsigned long _Cdecl coreleft (void);
#else
unsigned _Cdecl coreleft (void);
#endif

void _Cdecl free (void *block);
void *_Cdecl malloc (size_t size);
void *_Cdecl realloc (void *block, size_t size);
void *_Cdecl sbrk (int incr);

#if !__STDC__
void far  * _Cdecl farcalloc (unsigned long nunits, unsigned long unitsz);
unsigned long _Cdecl farcoreleft(void);
void _Cdecl      farfree (void far *block);
void far  *_Cdecl farmalloc (unsigned long nbytes);
void far  *_Cdecl farrealloc (void far *oldblock, unsigned long nbytes);
#endif

Defines structs, unions, macros, and functions for dealing with MSDOS and the Intel iAPX86 microprocessor family

Copyright (c) Borland International 1987,1988
All Rights Reserved.
*/
#if __STDC__
#define _Cdecl
#else
#define _Cdecl cdecl
#endif

#if     !defined(__DOS_DEF_)
#define __DOS_DEF_

/* Variables */
extern int _Cdecl _8087;
extern int _Cdecl _argc;
extern char      **_Cdecl _argv;
extern char      **_Cdecl  environ;
extern int _Cdecl _doserrno;
extern unsigned _Cdecl _heaplen;
extern unsigned char _Cdecl _osmajor;
extern unsigned char _Cdecl _osminor;
extern unsigned _Cdecl _psp;
extern unsigned _Cdecl _stklen;
extern unsigned _Cdecl _version;

#define FA_RDONLY 0x01 /* Read only attribute */
#define FA_HIDDEN 0x02 /* Hidden file */
#define FA_SYSTEM 0x04 /* System file */
#define FA_LABEL 0x08 /* Volume label */
#define FA_DIREC 0x10 /* Directory */
#define FA_ARCH 0x20 /* Archive */

#define NFDS 20 /* Maximum number of fds */

struct fcb {
char fcb_drive; /* 0 = default, 1 = A, 2 = B */
char fcb_name[8]; /* File name */
char fcb_ext[3]; /* File extension */
short fcb_curblk; /* Current block number */
short fcb_recsize; /* Logical record size in bytes */
long fcb_filsize; /* File size in bytes */
short fcb_date; /* Date file was last written */
char fcb_resv[10]; /* Reserved for DOS */
char fcb_currec; /* Current record in block */
long fcb_random; /* Random record number */
};

struct xfcb {
char xfcb_flag; /* Contains 0xff to indicate xfcb */
char xfcb_resv[5]; /* Reserved for DOS */
char xfcb_attr; /* Search attribute */
struct fcb xfcb_fcb; /* The standard fcb */
};

struct country {
int co_date;
char co_curr[5];
char co_thsep[2];
char co_desep[2];
char co_dtsep[2];
char co_tmsep[2];
char co_currstyle;
char co_digits;
char co_time;
long co_case;
char co_dasep[2];
char co_fill[10];
};

struct DOSERROR {
int exterror;
char class;
char action;
char locus;
};

struct dfree {
unsigned df_avail;
unsigned df_total;
unsigned df_bsec;
unsigned df_sclus;
};

struct fatinfo {
char fi_sclus;
char fi_fatid;
int fi_nclus;
int fi_bysec;
};

struct devhdr {
long dh_next; /* Next device pointer */
short dh_attr; /* Attributes */
unsigned short dh_strat; /* Driver strategy routine */
unsigned short dh_inter; /* Driver interrupt routine */
char dh_name[8]; /* Device name */
};

struct time {
unsigned char ti_min; /* Minutes */
unsigned char ti_hour; /* Hours */
unsigned char ti_hund; /* Hundredths of seconds */
unsigned char ti_sec; /* Seconds */
};

struct date {
int da_year; /* Year - 1980 */
char da_day; /* Day of the month */
char da_mon; /* Month (1 = Jan) */
};

struct WORDREGS {
unsigned int ax, bx, cx, dx, si, di, cflag, flags;
};

struct BYTEREGS {
unsigned char al, ah, bl, bh, cl, ch, dl, dh;
};

union REGS {
struct WORDREGS x;
struct BYTEREGS h;
};

struct SREGS {
unsigned int es;
unsigned int cs;
unsigned int ss;
unsigned int ds;
};

struct REGPACK {
unsigned r_ax, r_bx, r_cx, r_dx;
unsigned r_bp, r_si, r_di, r_ds, r_es, r_flags;
};

#define FP_OFF(fp) ((unsigned)(fp))
#define FP_SEG(fp) ((unsigned)((unsigned long)(fp) >> 16))


typedef struct {
char drive; /* do not change */
char pattern [13]; /*  these fields, */
char reserved [7]; /*   Microsoft reserved */
char attrib;
short time;
short date;
long size;
char nameZ [13]; /* result of the search, asciiz */
} dosSearchInfo; /* used with DOS functions 4E, 4F */


int _Cdecl absread (int drive, int nsects, int lsect, void *buffer);
int _Cdecl abswrite(int drive, int nsects, int lsect, void *buffer);
int _Cdecl allocmem(unsigned size, unsigned *segp);
int _Cdecl bdos (int dosfun, unsigned dosdx, unsigned dosal);
int _Cdecl bdosptr (int dosfun, void *argument, unsigned dosal);
struct country *_Cdecl country (int xcode, struct country *cp);
void _Cdecl ctrlbrk (int _Cdecl (*handler)(void));
void _Cdecl delay (unsigned milliseconds);
void _Cdecl disable (void);
int _Cdecl dosexterr (struct DOSERROR *eblkp);
long _Cdecl dostounix (struct date *d, struct time *t);
void          __emit__();
void _Cdecl enable (void);
int _Cdecl freemem (unsigned segx);
int _Cdecl getcbrk (void);
void _Cdecl getdate (struct date *datep);
void _Cdecl getdfree(unsigned char drive, struct dfree *dtable);
void _Cdecl getfat (unsigned char drive, struct fatinfo *dtable);
void _Cdecl getfatd (struct fatinfo *dtable);
unsigned _Cdecl getpsp (void);
int _Cdecl getswitchar (void);
void _Cdecl gettime (struct time *timep);
void interrupt (* _Cdecl getvect(int interruptno)) ();
int _Cdecl getverify (void);
void _Cdecl harderr (int _Cdecl (*handler)());
void _Cdecl hardresume (int axret);
void _Cdecl hardretn(int retn);
int _Cdecl inport (int portid);
unsigned char _Cdecl inportb(int portid);
int _Cdecl int86 (int intno, union REGS *inregs, union REGS *outregs);
int _Cdecl int86x (int intno, union REGS *inregs, union REGS *outregs,
struct SREGS *segregs);
int _Cdecl intdos (union REGS *inregs, union REGS *outregs);
int _Cdecl intdosx (union REGS *inregs, union REGS *outregs,
struct SREGS *segregs);
void _Cdecl intr (int intno, struct REGPACK *preg);
void _Cdecl keep (unsigned char status, unsigned size);
void _Cdecl nosound (void);
void _Cdecl outport (int portid, int value);
void _Cdecl outportb(int portid, unsigned char value);
char *_Cdecl parsfnm (const char *cmdline, struct fcb *fcb, int opt);
int _Cdecl peek (unsigned segment, unsigned offset);
char _Cdecl peekb (unsigned segment, unsigned offset);
void _Cdecl poke (unsigned segment, unsigned offset, int value);
void _Cdecl pokeb (unsigned segment, unsigned offset, char value);
int _Cdecl randbrd (struct fcb *fcb, int rcnt);
int _Cdecl randbwr (struct fcb *fcb, int rcnt);
void _Cdecl segread (struct SREGS *segp);
int _Cdecl setblock(unsigned segx, unsigned newsize);
int _Cdecl setcbrk (int cbrkvalue);
void _Cdecl setdate (struct date *datep);
void _Cdecl setswitchar (char ch);
void _Cdecl settime (struct time *timep);
void _Cdecl setvect (int interruptno, void interrupt (*isr) ());
void _Cdecl setverify (int value);
void _Cdecl sleep (unsigned seconds);
void _Cdecl sound (unsigned frequency);
void _Cdecl unixtodos (long time, struct date *d, struct time *t);
int _Cdecl unlink (const char *path);

/* These are in-line functions.  These prototypes just clean up
  some syntax checks and code generation.
*/

void _Cdecl __cli__ (void);
void _Cdecl __sti__ (void);
unsigned char _Cdecl __inportb__(int portid);
void _Cdecl __outportb__ (int portid, unsigned char value);
void _Cdecl __int__ (int interruptnum);

#define disable() __cli__() /* Clear interrupt flag */
#define enable() __sti__() /* Set interrupt flag */
#define inportb(portid) __inportb__(portid) /* Byte IN instruction */
#define outportb(portid, v) __outportb__(portid,v)/* Byte OUT instruction */
#define geninterrupt(i) __int__(i) /* Interrupt instruction */

/* some other compilers use inp, outp for inportb, outportb */
#define inp(portid) inportb(portid)
#define outp(portid,v) outportb(portid,v)

#if !__STDC__
char far *cdecl getdta(void);
void  cdecl setdta(char far *dta);

#define MK_FP(seg,ofs) ((void far *) \
  (((unsigned long)(seg) << 16) | (unsigned)(ofs)))

#define poke(a,b,c) (*((int  far*)MK_FP((a),(b))) = (int)(c))
#define pokeb(a,b,c) (*((char far*)MK_FP((a),(b))) = (char)(c))
#define peek(a,b) (*((int  far*)MK_FP((a),(b))))
#define peekb(a,b) (*((char far*)MK_FP((a),(b))))
#endif

#endif