/* * function system() - slightly modified from sources dLibs 1.2 * - a freely distributable C library for Atari ST. * Authors: Dale Schumacher and John Stanley, I believe. * Changes for gcc compiler and gnulib.olb - Michal Jaegermann */#include <osbind.h>#include <stdio.h>#include <string.h>#include <basepage.h>#ifdef __GNUC__#include <process.h>#define ERROR 2#endif/* #define DEBUG  */#ifdef DEBUG#define _COOKIE(x) puts(x);putchar('\n')#endifvoid staticparse_args(char *cmdln, register char **argv){	register char *p;	static char delim[] = " \t\r\n";	if(p = strtok(cmdln, delim)) {		do {			*argv++ = p;		} while(p = strtok(NULL, delim));	}}#ifdef __GNUC__/* this is used by assembler statement to keep a copy of registers */static volatile long savearea[16];#endifintsystem(const char *command){	register char *p;	register int (*shell)();#ifndef __GNUC__	char rv[2];#endif	char cmdln[1024];	char *args[64];	char *getenv(const char *);	if(!command)		return(ERROR);	/* get _shell_p value */	p = (char *) Super(0L);  /* supervisor mode */	shell = (int (*)()) *((long *) 0x4F6L);	(void) Super(p);	 /* restore user mode */	/* validate _shell_p */	if((shell) &&				/* Shell available. */	   (((long) shell) < ((long) _base)) &&	/* Reasonable shell pointer. */	   (strncmp((char *)shell, "PATH", 4)))	/* Not corrupted */		{#ifdef __GNUC__		int ret;#endif		/* execute the command */#ifdef DEBUG_COOKIE("system: using _shell_p");printf("'shell' got value 0x%08lx\n", (long)shell);#endif/* a bit of paranoia caused by some misbehaving programs */#ifdef __GNUC__asm("moveml d1-d7/a0-a7,_savearea");			ret = (*shell)(command);asm("moveml _savearea,d1-d7/a0-a7");		return (ret);#else		return ((*shell)(command));#endif		}	strcpy(cmdln, command);	/* copy the command line for parsing */	if((p = getenv("SHELL")) && (*p))	/* SHELL= variable? */		{		args[0] = p;		parse_args(cmdln, (args + 1));#ifdef DEBUG_COOKIE("system: executing SHELL");_COOKIE(p);#endif		}	else	/* attempt to find first token as a program on the path */		{		parse_args(cmdln, args);		p = args[0];#ifdef DEBUG_COOKIE("system: directly executing program");_COOKIE(p);#endif		}#ifdef __GNUC__	return(spawnvp(0, p, args));#else   /* original from dLibs */	forkvpe(p, args, NULL);	wait(rv);	return((rv[1] == 0) ? rv[0] : rv[1]);#endif}