🚀 go-pugleaf

I have two C problems.

PROBLEM 1 :

int main(int argc,char *argv[])
{
     FILE *file;
     char x,ch,width,height,back,fore,stringpos;
     int numlines,linenum;
     text_info info;
     nodetypeptr listptr,posptr;


     if (argc<2)
     {
          cputs("\nUsage : show file name [fore ground color] [back ground color] . . .\n");
     }
     else
     {
          file=fopen(argv[1],"rt");
          if (file==NULL)
          {
               cprintf("\nFile %s not found . . .\n",argv[1]);
          }
          else
          {
               rewind(file);
               initialize(&listptr);
               linenum=1;
               while (fgets(line,maxstring,file)!=NULL)
               {
                    removelineends(line,maxstring);
                    add(&listptr,line,linenum);
                    linenum++;
               }
               numlines=linenum--;
               fclose(file);
               posptr=listptr;
               gettextinfo(&info);
               if (argc>2)
               {
                    getcolors(&fore,&back,argv[2],argv[3]);
               }
               else
               {
                    fore=LIGHTGRAY;
                    back=BLACK;
               }
               height=info.screenheight;
               width=info.screenwidth;
               strcpy(bottomline,"  \30  \31  \33  \32  pgup  pgdn  s (search)  help (h) esc (quit)");
               for(x=strlen(bottomline)+1;x<width;x++)
               {
                    strcat(bottomline," ");
               }
               _setcursortype(_NOCURSOR);
               clrscr();
               textcolor(back);
               textbackground(fore);
               gotoxy(1,height);
               cputs(bottomline);
               textcolor(fore);
               textbackground(back);
               height--;
               linenum=1;
               stringpos=0;
               writescreenfull(width,height,posptr,stringpos,searchstring,fore,back);
               ch=space;
               while (ch!=escape)
               {
                    while ((ch!=up) && (ch!=down) && (ch!=pageup) &&
                           (ch!=pagedown) && (ch!=escape) && (ch!=left) &&
                           (ch!=right) && (ch!=end_) && (ch!=home) &&
                           (ch!=search) && (ch!=help))
                    {
                         ch=getch();
                         if (ch==nul)
                         {
                              ch=getch();
                         }
                    }
                    if (ch==up)
                    {
                         if ((linenum-1)>=1)
                         {
                              linenum--;
                         }
                         else
                         {
                              linenum=1;
                         }
                         setpos(&posptr,linenum);

                    }
                    else if (ch==down)
                    {
                         if ((linenum+1+height)<=numlines)
                         {
                              linenum++;
                         }
                         else
                         {
                              linenum=numlines-height+1;
                         }
                         setpos(&posptr,linenum);
                    }
                    else if (ch==pageup)
                    {
                         if ((linenum-height+1)>=1)
                         {
                              linenum=linenum-height+1;
                         }
                         else
                         {
                              linenum=1;
                         }
                         setpos(&posptr,linenum);
                    }
                    else if (ch==pagedown)
                    {
                         if (((linenum+height-1)<=numlines) && ((numlines-(linenum+height-1))>=(height-1)))
                         {
                              linenum=linenum+height-1;
                         }
                         else
                         {
                              linenum=numlines-height+1;
                         }
                         setpos(&posptr,linenum);
                    }
                    else if (ch==left)
                    {
                         if (stringpos>0)
                         {
                              stringpos--;
                         }
                    }
                    else if (ch==right)
                    {
                         if (stringpos<=(maxstring-width))
                         {
                              stringpos++;
                         }
                    }
                    else if (ch==end_)
                    {
                         stringpos=maxstring-width+1;
                    }
                    else if (ch==home)
                    {
                         stringpos=0;
                    }
                    else if (ch==help)
                    {
                         displayhelp(fore,width,height);
                    }
                    else if (ch==search)
                    {
                         readstring(searchstring,bottomline,height,fore,back);
                    }
                    if (ch!=escape)
                    {
                         ch=space;
                    }
                    writescreenfull(width,height,posptr,stringpos,searchstring,fore,back);
               }
               while (!empty(listptr))
               {
                    remove(&listptr);
               }
               height++;
               window(1,1,width,height);
               clrscr();
               _setcursortype(_NORMALCURSOR);
          }
     }
     return(0);
}

This program should exit such that the screen is clear with the DOS prompt
in the upper left corner, but no, it exits with a short line of text on the
first line and then the DOS prompt on the next line. I never (or rarely)
have these sort of problems with Pascal so why do they continuously crop up
with C.

PROBLEM 2 :

const escape=27;
const cr=13;
const bs=8;

while (ch!=cr)
{
     .
     .
     .
}

while (ch!=escape)
{
     .
     .
     .
}

If I replace the 27 with \27' or the 13 with '\13' then these loops don't
work i.e. an infinite loop results. WHY?

Also if I want to do somthing like this : puts("\24 \25"); which should
print the up and down arrows on the screen (ASCII 24 and 25), but no, it
prints some other ASCII characters. As far as I can tell C has its own
unique character table, at least for the control characters. WHY?

Sometimes I wonder whether some one needs to go back an rewrite the damn
language so that it works sensibly and predictably like Pascal can be
relied upon to do.