/*
 * getpid.c --
 *	Binary package for UNIX getpid(2) and friends.
 *
 * $Id: getpid.c,v 1.4 2001-06-15 17:32:46+09 kabe Exp $
 */

#include <tcl.h>
#include <unistd.h>	/*getpid()*/

static int Getpid_PpidObjCmd(ClientData cd, Tcl_Interp *interp, int objc, 
    Tcl_Obj *CONST objv[]);
/* shorthand of the above */
static Tcl_ObjCmdProc	Getpid_fObjCmd;

int
Getpid_Init(Tcl_Interp *interp)
{
	Tcl_CmdInfo	cinfo;

	/* Don't overwrite existing commands (especially "pid") */

	if (!Tcl_GetCommandInfo(interp, "ppid", &cinfo))
	    Tcl_CreateObjCommand(interp, "ppid", Getpid_PpidObjCmd, NULL, NULL);
	if (!Tcl_GetCommandInfo(interp, "pid", &cinfo))
	    Tcl_CreateObjCommand(interp, "pid" , Getpid_fObjCmd, getpid , NULL);
	if (!Tcl_GetCommandInfo(interp, "pgrp", &cinfo))
	    Tcl_CreateObjCommand(interp, "pgrp", Getpid_fObjCmd, getpgrp, NULL);
	if (!Tcl_GetCommandInfo(interp, "pgid", &cinfo))
	    Tcl_CreateObjCommand(interp, "pgid", Getpid_fObjCmd, getpgid, NULL);
	
	/* TODO: rather than defining raw commands, subcommanding like
	 * "process parentpid" "process group" (cf.file,fconfigure)
	 * is more Tcl-ish.
	 * Better is pushing into new namespace.
	 */
	
	Tcl_PkgProvide(interp, "getpid", "1.0");

	return TCL_OK;
}

/*
 *-------------------------------------------------
 * Getpid_PpidObjCmd --
 *	This procedure returns getppid(2) value.
 *-------------------------------------------------
 */
static int 
Getpid_PpidObjCmd(cd, interp, objc, objv)
    ClientData cd;		/* Not used. */
    Tcl_Interp *interp;		/* Current interpreter. */
    int objc;			/* # of arguments. */
    Tcl_Obj *CONST objv[];	/* Arguments. */
{
#ifndef EDUCATIONAL
	Tcl_SetLongObj(Tcl_GetObjResult(interp), (long)getppid());
#else
	Tcl_Obj	*result;
	result = Tcl_NewLongObj((long)getppid());
	Tcl_SetObjResult(interp, result);
#endif
	return TCL_OK;
}

/*
 *-------------------------------------------------
 * Getpid_fObjCmd --
 *	This procedure returns whatever returned by pid_t func(void).
 *	(Well, you rarely need these for Tcl..)
 *-------------------------------------------------
 */
static int
Getpid_fObjCmd(func, interp, objc, objv)
    ClientData func;		/* int func(void) to call. */
    Tcl_Interp *interp;		/* Current interpreter. */
    int objc;			/* # of arguments. */
    Tcl_Obj *CONST objv[];	/* Arguments. */
{
	Tcl_SetLongObj(Tcl_GetObjResult(interp), (long)((pid_t (*)(void))func)());

	/* -1 return from getpgid() is an error,
	 * but will pass on anyway for now (doesn't throw error).
	 */
	
	/* TODO: Original "pid" command takes an argument for
	 * command pipe.
	 */
	return TCL_OK;
}