/* br.c  by RJB CSUSB 1987    Program to word wrap text. #define, backtrack,...
Purpose:
   This program word wraps text.
	   br wout <in >out
   reads 'stdin' as text
	and writes out the same text word wrapped to width wout.
Note: Example of the Jackson JSP/JSD style

*/
/*#define DEBUG*/
#include <stdio.h>
#ifdef DEBUG
#define db(f,x) fprintf(stderr," "#x" =<"#f">\n",x);
#define dbs(x) fprintf(stderr,"%s\n",x);
#else
#define db(f,x)  ;
#define dbs(s)  ;
#endif
#define SP ' '
#define HT '\t'
#define HTWIDTH 8
#define CR '\n'
#define DEL (int)0377
#define BUFSIZE 250
#define MAXWD BUFSIZE
#define MINWOUT 10

int wout=75;  /* width of desired output in characters*/

/*K & R p79 backtrackable input package:getch and ungetch*/
/*Misfeature - getchar after EOF stopped, RJB May 87 */
int buf[BUFSIZE];
int bp=0;/*next free in buf*/
int getch()
{ static int lastgetchar=0;
  dbs("getch")
       return( (bp > 0)          ? buf [ --bp ] 
	      :(lastgetchar!=EOF)? (lastgetchar=getchar())
              :lastgetchar
            );
}

ungetch(c)
int c;
{ dbs("ungetch")
   if(bp>BUFSIZE){fprintf(stderr,"br: word too long to handle\n");exit(1);}
  else buf[bp++]=c;
}


main(argc,argv)
int argc; char *argv[];
{
   int ch,n;
   int wd[MAXWD], ws[MAXWD];
       /* WARNING - these are not null terminated strings.
          wdp (resp. wsp) point to the next empty place in wd (resp. ws)
          Only  wd[0..wdp-1] are actual characters (resp. ws[0...wsp-1])
       */
   int *wdp, *wsp, *p;
   if(argc>2){fprintf(stderr,"usage: br width_out\n");exit(1);}
   else if(argc==2) wout=abs(atoi(argv[1]));
   else /*assume default width*/
     if(wout>MAXWD)
     {fprintf(stderr,"br: %d too large > %d for this version\n",wout,MAXWD);
      exit(1);
     }

   if(wout<MINWOUT)
     {fprintf(stderr,"br: width is too small(<MINWOUT)!");exit(1);}

db(%d,wout);

    ch=getch();

    /*C_i_line...*/  while(ch!=EOF){dbs("C_i_line") db(%o,ch)

      /* P_line...*/ while(1){dbs("P_line")
          wdp=wd;n=0;

           while(n<wout){dbs("n<wout")
              if(ch<=SP || ch==DEL) goto nohyphen;
              n++; *wdp++ = ch;/*wdp-wd<=n<=wout<MAXWD*/
              ch=getch();
            }

           for(p=wd;p<wdp;p++)putc(*p,stdout);wdp=wd;

           putc('-',stdout); putc(CR,stdout); 
        goto end_of_line;

nohyphen: if(wdp>wd){
                  ungetch(ch);

                  while(wdp>wd)ungetch(*--wdp);

                  ch=getch();
                 }

       while(1){n=0;dbs("posit break")

        while(1){dbs("posit fits")
          if(ch>SP && ch<DEL){dbs("CP_word")
           /*CP_word*/             
              wdp=wd;

              while(ch>SP && ch!=DEL){dbs("wdch") db(%o,ch)
		    if(n==wout) goto didnotfit;
                n++; *wdp++ = ch;/*wdp-wd<=n<=wout<MAXWD*/
                ch=getch();
                }

           for(p=wd;p<wdp;p++)putc(*p,stdout); wdp=wd;
          }
          else{dbs("wsb")
           /* CP_wsb*/
             wsp=ws;

             while(ch<=SP||ch==DEL){dbs("ws") db(%o,ch)
		if(ch==CR||ch==EOF)goto nobreaks;
                  if(ch==HT) n+=HTWIDTH;
                  else if(ch==SP) n++;
                  *wsp++ = ch; /*wsp-wd<=n<=wout<MAXWD*/
                   ch=getch();
                }
    if(n>wout-1)goto didnotfit; 
                for(p=ws;p<wsp;p++)putc(*p,stdout);
           }
          }
        }
didnotfit:dbs("did not fit")
      if(wdp>wd){
          ungetch(ch);
          while(wdp>wd)ungetch(*--wdp);
          ch=getch();
         }
        putc(CR,stdout);
end_of_line:dbs("end of line")
        }
nobreaks:/*CP_ok_line*/
      dbs("end of input line")
      putc(CR,stdout);
      ch=getch();
    }
    exit(0);
}