/*
 * Automated chapter numbering for Texinfo files.
 *
 * Restrictions:
 *
 *   1. Only supports @chapter and @section directives.
 *   2. The chapters and sections MUST be in their correct
 *      order, and all the sections MUST be between their
 *      parent chapter and the next chapter.
 *   3. Conditional (@ifset, @ifclear) and file inclusion
 *      (@include) directives not supported.  If you must
 *      have file inclusion, feed the program with expanded
 *      file (use -E switch to Makeinfo).
 *
 * Author: Eli Zaretskii <eliz@is.elta.co.il>
 *
 * Version: 1.1
 *
 * Last updated: 22 June, 1996
 *
 * ----------------------------------------------------------
 *
 * You can do whatever you like with this program, except:
 * (1) preventing other people (including the author) do
 * whatever they like, and (2) removing the author and
 * version info above.
 *
 * ----------------------------------------------------------
 *
 */

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

#ifdef  __DJGPP__

/* Make so our start-up code is minimal: disable filename
   globbing, and don't load environment file.  */
#include <crt0.h>

char ** __crt0_glob_function(char *arg) { return (char **)0; }
void   __crt0_load_environment_file(char *app_name) {}

#else

/* Some Unix boxes don't have functon prototypes on the header files.
   -Wall will complain about this, so here are the prototypes:  */

void perror (const char *);
int  fgetc  (FILE *);
int  fputs  (const char *, FILE *);
int  fprintf(FILE *, const char *, ...);
int  fclose (FILE *);

#endif  /* __DJGPP__ */

static char chapter[] = "@chapter";
static char section[] = "@section";

int
main(int argc, char *argv[])
{
  if (argc == 3)
    {
      size_t maxline = 100;     /* not necessarily a limit, see below */
      char *linebuf = (char *)malloc(maxline);
      int chap_no  = 0, sec_no = 0;
      FILE *fp_in  = fopen(argv[1], "r");
      FILE *fp_out = fopen(argv[2], "w");

      if (linebuf == (char *)0)
        {
          errno = ENOMEM;
          perror("line storage allocation");
          return 2;
        }
      if (fp_in == (FILE *)0)
        {
          perror(argv[1]);
          return 2;
        }
      if (fp_out == (FILE *)0)
        {
          perror(argv[2]);
          return 2;
        }

      while (fgets(linebuf, maxline, fp_in))
        {
          size_t linelen = strlen(linebuf);

          /* If this line is longer than linebuf[], enlarge the
             buffer and read until end of this line.  */
          while (linebuf[linelen - 1] != '\n')
            {
              maxline *= 2;
              linebuf = (char *)realloc(linebuf, maxline);
              if (linebuf == (char *)0)
                {
                  errno = ENOMEM;
                  perror("line storage re-allocation");
                  return 2;
                }

              while (linelen < maxline && linebuf[linelen - 1] != '\n')
                {
                  linebuf[linelen++] = fgetc(fp_in);

                  if (feof(fp_in))
                    linebuf[linelen-1] = '\n';
                }

              linebuf[linelen] = '\0';
            }

          if (memcmp(linebuf, chapter, sizeof(chapter) - 1) == 0)
            {
              chap_no++;
              sec_no = 0;
              fputs(chapter, fp_out);
              fprintf(fp_out, " %d.", chap_no);
              fputs(linebuf + sizeof(chapter) - 1, fp_out);
            }
          else if (memcmp(linebuf, section, sizeof(section) - 1) == 0)
            {
              sec_no++;
              fputs(section, fp_out);
              fprintf(fp_out, " %d.%d", chap_no, sec_no);
              fputs(linebuf + sizeof(section) - 1, fp_out);
            }
          else
            fputs(linebuf, fp_out);
        }

      if (feof(fp_in))
        {
          fprintf(stderr, "%s has %d chapters\n", argv[1], chap_no);
          fclose(fp_in);
          fclose(fp_out);
          return 0;
        }
      if (ferror(fp_in))
        {
          perror(argv[1]);
          return 2;
        }

      fprintf(stderr, "Not EOF and not Error???\n");
      return 2;
    }
  else
    {
      fprintf(stderr, "Usage: %s infile outfile\n", *argv);
      return 1;
    }
}