/* Copyright (C) 1989, 1995, 1996, 1997, 1998 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU Ghostscript is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
  to anyone for the consequences of using it or for whether it serves any
  particular purpose or works at all, unless he says so in writing.  Refer
  to the GNU General Public License for full details.
  
  Everyone is granted permission to copy, modify and redistribute GNU
  Ghostscript, but only under the conditions described in the GNU General
  Public License.  A copy of this license is supposed to have been given
  to you along with GNU Ghostscript so you can know your rights and
  responsibilities.  It should be in a file named COPYING.  Among other
  things, the copyright notice and this notice must be preserved on all
  copies.
  
  Aladdin Enterprises supports the work of the GNU Project, but is not
  affiliated with the Free Software Foundation or the GNU Project.  GNU
  Ghostscript, as distributed by Aladdin Enterprises, does not require any
  GNU software to build or run it.
*/

/*$Id: gp_unix.c $ */
/* Unix-specific routines for Ghostscript */
#include "pipe_.h"
#include "string_.h"
#include "time_.h"
#include "gx.h"
#include "gsexit.h"
#include "gp.h"

/*
 * This is the only place in Ghostscript that calls 'exit'.  Including
 * <stdlib.h> is overkill, but that's where it's declared on ANSI systems.
 * We don't have any way of detecting whether we have a standard library
 * (some GNU compilers perversely define __STDC__ but don't provide
 * an ANSI-compliant library), so we check __PROTOTYPES__ and
 * hope for the best.  We pick up getenv at the same time.
 */
#ifdef __PROTOTYPES__
#  include <stdlib.h>		/* for exit and getenv */
#else
extern void exit(P1(int));
extern char *getenv(P1(const char *));

#endif

/* Do platform-dependent initialization. */
void
gp_init(void)
{
}

/* Do platform-dependent cleanup. */
void
gp_exit(int exit_status, int code)
{
}

/* Exit the program. */
void
gp_do_exit(int exit_status)
{
    exit(exit_status);
}

/* ------ Miscellaneous ------ */

/* Get the string corresponding to an OS error number. */
/* Unix systems support this so inconsistently that we don't attempt */
/* to figure out whether it's available. */
const char *
gp_strerror(int errnum)
{
    return NULL;
}

/* ------ Date and time ------ */

/* Read the current time (in seconds since Jan. 1, 1970) */
/* and fraction (in nanoseconds). */
void
gp_get_realtime(long *pdt)
{
    struct timeval tp;

#if gettimeofday_no_timezone	/* older versions of SVR4 */
    {
	if (gettimeofday(&tp) == -1) {
	    lprintf("Ghostscript: gettimeofday failed!\n");
	    gs_exit(1);
	}
    }
#else /* All other systems */
    {
	struct timezone tzp;

	if (gettimeofday(&tp, &tzp) == -1) {
	    lprintf("Ghostscript: gettimeofday failed!\n");
	    gs_exit(1);
	}
    }
#endif

    /* tp.tv_sec is #secs since Jan 1, 1970 */
    pdt[0] = tp.tv_sec;

    /* Some Unix systems (e.g., Interactive 3.2 r3.0) return garbage */
    /* in tp.tv_usec.  Try to filter out the worst of it here. */
    pdt[1] = tp.tv_usec >= 0 && tp.tv_usec < 1000000 ? tp.tv_usec * 1000 : 0;

#ifdef DEBUG_CLOCK
    printf("tp.tv_sec = %d  tp.tv_usec = %d  pdt[0] = %ld  pdt[1] = %ld\n",
	   tp.tv_sec, tp.tv_usec, pdt[0], pdt[1]);
#endif
}

/* Read the current user CPU time (in seconds) */
/* and fraction (in nanoseconds).  */
void
gp_get_usertime(long *pdt)
{
#if use_times_for_usertime
    struct tms tms;
    long ticks;
    const long ticks_per_sec = CLK_TCK;

    times(&tms);
    ticks = tms.tms_utime + tms.tms_stime + tms.tms_cutime + tms.tms_cstime;
    pdt[0] = ticks / ticks_per_sec;
    pdt[1] = (ticks % ticks_per_sec) * (1000000000 / ticks_per_sec);
#else
    gp_get_realtime(pdt);	/* Use an approximation on other hosts.  */
#endif
}

/* ------ Screen management ------ */

/* Get the environment variable that specifies the display to use. */
const char *
gp_getenv_display(void)
{
    return getenv("DISPLAY");
}

/* ------ Printer accessing ------ */

/* Open a connection to a printer.  A null file name means use the */
/* standard printer connected to the machine, if any. */
/* "|command" opens an output pipe. */
/* Return NULL if the connection could not be opened. */
FILE *
gp_open_printer(char fname[gp_file_name_sizeof], int binary_mode)
{
    return
	(strlen(fname) == 0 ?
	 gp_open_scratch_file(gp_scratch_file_name_prefix, fname, "w") :
	 fname[0] == '|' ?
	 popen(fname + 1, "w") :
	 fopen(fname, "w"));
}

/* Close the connection to the printer. */
void
gp_close_printer(FILE * pfile, const char *fname)
{
    if (fname[0] == '|')
	pclose(pfile);
    else
	fclose(pfile);
}
