/* shorten.c  Strip trailing spaces and lines and DOS-isms in a text file.
 * DWF  2/21/92
 *
 * Somewhat improved at the cost of uglifying the code 4/15/94 DWF.
 *    -- Lines longer than 1000 characters are now handled correctly
 *    -- Trailing tab characters are also stripped
 *
 * Bugs:
 *    Vertical tabs and form feeds at the end of the file should be removed.
 */

#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <stdlib.h>

#define blocksize 1000

/* Vertical tabs and form feeds are retained.  Backspaces are retained because
 * they might be destructive on somebody's terminal.
 */
int spacey (char a)
{
  return (a == ' ' || a == '\n' || a == '\r' || a == '\t');
}

#define append {longbuflen += l; \
               assert (longbuf = (char *) realloc (longbuf, longbuflen)); \
               memcpy (longbuf+longbuflen-l, linrec, l);}

/* Careful not to evaluate longbuf[-1] */
#define endspace (l ? spacey (longbuf[l-1]) : 0)

main ()
{
  char linrec[blocksize], *longbuf=NULL;
  int bcount=0;
  size_t longbuflen=0, l;
  while (fgets (linrec, blocksize, stdin)) {
    assert (l = strlen (linrec));
    if (linrec[l-1] != '\n')
      append
    else {
      if (!longbuflen)
        longbuf = linrec;
      else {
        l++;      /* Get the \0 */
        append
        l = longbuflen - 1;
      }
      while (endspace) longbuf[--l] = '\0';
      if (!l)
        bcount++;
      else {
        for (; bcount; bcount--)
          printf ("\n");
        printf ("%s\n", longbuf);
      }
      if (longbuflen) {
        longbuflen = 0;
        free (longbuf);
      }
      longbuf = NULL;
    }
  }

  if (longbuflen) {
    /* The last line wasn't terminated. */
    linrec[0] = '\0';
    l = 1;
    append
    l = longbuflen - 1;
    while (endspace) longbuf[--l] = '\0';
    if (l) {
      for (; bcount; bcount--)
        printf ("\n");
      printf ("%s", longbuf);
    }
  }

  return 0;
}