#include <grass/gis.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
/**********************************************************
 * G_gets (buf)
 *    char *buf      buffer to receive data
 *
 *  does a gets() from stdin. exits upon EOF.
 *  if stdin is a tty (ie, not a pipe or redirected)
 *  then ctrl-z is detected
 *
 * returns
 *  1 read ok
 *  0 ctrl-z entered. calling routine should re-print a prompt
 *    and call G_gets() again
 *
 * note: This is very useful for allowing a program to 
 *       reprompt after the program is restarted after
 *       being stopped with a ctrl-Z.
 *
 * sample use:
 *   do {
 *      fprintf (stderr, "Enter some input:  ") ;
 *   } while ( ! G_gets(buff) )  ;
 *
 *   If the user suspends the process at this prompt G_gets will return
 *   "0" causing the reprompting.
 ***********************************************************/

static int ctrlz = 0;
static void catch_ctrlz (int);
static void catch_int (int);


int G_gets (char *buf)
  {
#ifdef SIGTSTP
  	RETSIGTYPE (*sigtstp)();
  	int tty;
#endif
	char p[128];
	char *eof;
  
  	ctrlz = 0;
#ifdef SIGTSTP
  	if ((tty = isatty(0)))
  	{
		sigtstp = signal (SIGTSTP, catch_ctrlz);
		if (sigtstp != (RETSIGTYPE (*)()) SIG_DFL)
  		    signal (SIGTSTP, sigtstp);
  	}
#endif
      eof = fgets(p,100,stdin);
      /* strip the EOL character      */
      if( strlen(p) > 1 && p[strlen(p)-1] == '\n' && p[strlen(p)-2] == '\r' )
           p[strlen(p)-2]='\0'; /* Handles DOS/Windows "\r\n" */
      else
           p[strlen(p)-1]='\0'; /* Handles Unix "\n" or old Mac "\r" */
      /*      buf could be any length.  Any overflow will occur here. */
      strcpy(buf,p);

#ifdef SIGTSTP
  	if (tty)
  		signal (SIGTSTP, sigtstp);
#endif
	if (eof)
  		return 1;
  	if (ctrlz)
  		return 0;

  	exit(EXIT_SUCCESS);
  }
  
static void catch_ctrlz (int n)
  {
#ifdef __MINGW32__
      G_warning ( "catch_ctrlz: ignored Ctrl-z" );
#else
      
  	RETSIGTYPE (*sigint)();
  
  /* having caught ctrlz - effect a ctrl-z using kill */
  	ctrlz = 1;
	signal (n, SIG_DFL);
	kill (0, n);

/* for berkley systems, ctrlz will not cause eof on read */
	sigint = signal (SIGINT, catch_int);
	kill (getpid(), SIGINT);
	signal (SIGINT, sigint);
#endif
}

static void catch_int (int n)
{
}
