#include <stdio.h>
#ifdef __STDC__
# include <stdlib.h>
#endif
#include <ctype.h>
#include <string.h>

#define ML 512
#define streq(A,B) (strcmp((A),(B))==0)
#ifndef TRUE
# define TRUE 1
# define FALSE 0
#endif

int indent;
int wrap_index = 78;

#ifdef __STDC__
void kilspaces(char *t)
#else
kilspaces(t)
char *t;
#endif
{
     int i=0, j=0;

     strcat(t,"   ");

     while(t[i]!='\0')
     {
          while( t[i]!='\0' && strchr("\r\n ",t[i]) )
               i++;
          while( t[i]!='\0' && !strchr("\r\n ",t[i]) )
          {
               t[j]=t[i];
               j++;
               i++;
          }
          t[j++]=' ';
     }
     t[j]='\0';

     return;
}

#ifdef __STDC__
void force_out(char *t)
#else
force_out(t)
char *t;
#endif
{
     int i, j, nquad;
     char s[ML];

     kilspaces(t);

     if(t[0]=='\0')
     {
          putchar('\n');
          return;
     }

     for(nquad=0,i=0;t[i]!='\0';i++)
	  if(t[i]='\t')
	       nquad++;

     if(strlen(t)>wrap_index)
     {
          for(i=wrap_index-5*indent-4*nquad;t[i]!=' ';i--)
               ;
          t[i++]='\0';   /* i indexes the beginning of the next string */
     }
     else
          i=0;

     if(indent)
          fputs("     ",stdout);

     i=0;
     for(j=0;t[j]!='\0';j++)
     {
          if(t[j]=='~')
               s[i++]=' ';
          else if(t[j]=='.' && t[j+1]==' ')
	  {
	       s[i++]='.';
	       s[i++]=' ';
	  }
          else if(t[j]=='\t')
	  {
	       s[i]='\0';
	       strcat(s,"    ");
	       i += 4;
	  }
	  else
	       s[i++]=t[j];
     }
     printf("%s\n",s);

     if(i)
          strcpy(t,t+i);
     else
          t[0]='\0';

     indent=FALSE;

     return;
}

#ifdef __STDC__
void usage(void)
#else
usage()
#endif
{
     puts("usage: tex2asc [-w wrap_limit]");
     return;
}

#ifdef __STDC__
int main(int argc, char **argv)
#else
main(argc, argv)
int argc;
char **argv;
#endif
{
     char c, cc, s[ML], t[ML];
     int i, cr=0, t_index=0, chapter=1;
     int control=FALSE, print_line=FALSE, center=FALSE;
     int obeylines=FALSE;

     while(*++argv!=NULL)
     {
          if((*argv)[0]!='-')
          {
               usage();
               return 1;
          }
          else
               while(*(++*argv)!='\0')
                    switch(**argv)
                    {
                         case 'w':
                              if(*++argv!=NULL)
                              {
                                   wrap_index = atoi(*argv);
                                   *argv+=(strlen(*argv)-1);
                                   break;
                              }
                         default:
                              usage();
                              return 1;
                    }
     }

     indent=TRUE;
     memset(t,'\0',ML-1);
     while((c=getchar())!=EOF)
     {
	  if(c=='\t')		/* change tab characters to spaces */
	       c=' ';
          if(c=='%')             /* TeX comments */
	  {
	       while( (c=getchar())!=EOF && c!='\n' )
		    ;
	       continue;
	  }

          if(cr && c=='\n')
          {
               if(t_index)
               {
                    t[t_index]='\0';
                    while(t[0]!='\0')
                         force_out(t);
               }
               t_index=0;
               indent=TRUE;   /* paragraph beginning */
          }
          if(control && isspace(c))
               continue;
          else
               control=FALSE;
          if(strchr("${}",c))      /* ignore these characters: ${} */
               continue;
          if(c=='\n')
          {
               cr++;
	       if(obeylines)
		    print_line++;
               if(print_line)
               {
                    cr=0;
                    t[t_index]='\0';
                    kilspaces(t);
                    if(center && wrap_index > strlen(t))
                         for(i=0;i<(wrap_index-strlen(t))/2;i++)
                              putchar(' ');

                    for(i=0;t[i]!='\0';i++)
                         if(t[i]=='~')
                              putchar(' ');
                         else if(t[i]=='\t')
			      fputs("    ",stdout);
			 else
                              putchar(t[i]);
                    putchar('\n');

                    t_index = 0;
                    indent=FALSE;
                    print_line = FALSE;
                    center = FALSE;
                    memset(t,'\0',ML);

                    continue;
               }
               else
                    c=' ';
          }
          else
               cr=0;

          if(c!='\\')
               t[t_index++]=c;
          else
          {
            control_code:
               control=TRUE;
               i=0;
               while((c=getchar())!=EOF
                    && !strchr("{}\\",c)
                    && !isspace(c))
               {
                    s[i++]=c;
                    if(!isalnum(c))
                         break;
               }
               s[i]='\0';
               cc=c;
               if(streq(s,"-") || streq(s,"\""))
                    ;         /* ignore */
               else if(streq(s,"%"))
                    t[t_index++]='%';
               else if(streq(s,"bf"))
                    ;
               else if(streq(s,"bigskip"))
               {
                    t[t_index]='\0';
                    while(t[0]!='\0')
                         force_out(t);
                    putchar('\n');
                    t_index = 0;
               }
               else if(streq(s,"centerline"))
               {
                    center++;
                    print_line++;
               }
               else if(streq(s,"chap"))
               {
                    sprintf(t+t_index," [%d] ",chapter++);
                    if(chapter >= 100)
                         t_index+= 2;
                    else if(chapter >= 10)
                         t_index += 1;
                    t_index += strlen(" [1] ");
               }
               else if(streq(s,"dag"))
                    t[t_index++]='%';
               else if(streq(s,"end"))
                    ;
               else if(streq(s,"hbox"))
                    ;
               else if(streq(s,"input"))
                    while((c=getchar())!='\n')
                         ;
               else if(streq(s,"langle"))
                    t[t_index++]='<';
               else if(streq(s,"line"))
                    print_line++;
               else if(streq(s,"linline"))
               {
                    print_line++;
                    indent++;
               }
               else if(streq(s,"lline"))
                    print_line++;
               else if(streq(s,"narrower"))
                    ;
               else if(streq(s,"noindent"))
                    indent=FALSE;
	       else if(streq(s,"obeylines"))
		    obeylines=TRUE;
	       else if(streq(s,"quad"))
		    t[t_index++]='\t';
               else if(streq(s,"poetrysize"))
                    wrap_index=50;
               else if(streq(s,"raggedbottom"))
                    ;
               else if(streq(s,"rangle"))
                    t[t_index++]='>';
               else if(streq(s,"sc"))
                    ;
               else if(streq(s,"sec"))
                    ;
               else if(streq(s,"vbox"))
                    ;
               else if(streq(s,"vfill"))
                    ;
               if((c=cc)=='\\')
                    goto control_code;
          }
          if( !print_line && isspace(t[t_index-1]) && t_index >
                                                  wrap_index+20 )
          {
               t[t_index]='\0';
               force_out(t);
               t_index = strlen(t);
          }
     }
     puts("\n");  /* end with 2 carriage returns */
     return 0;
}