// $Header$#include "system.h"#include <stdio.h>#include <string.h>#include <osfcn.h>#include <sys/file.h>#include "Executable.h"#ifdef HAVE_UNISTD_H#include <unistd.h>#endifextern "C" {char* getenv( const char* );char* strdup( const char* );}Executable::Executable( const char* arg_executable )	{	executable = strdup( arg_executable );	exec_error = has_exited = 0;	}Executable::~Executable()	{	delete executable;	}char* which_executable( const char* exec_name )	{	char* path = getenv( "PATH" );	if ( ! path || exec_name[0] == '/' || exec_name[0] == '.' )		{		if ( access( exec_name, X_OK ) == 0 )			return strdup( exec_name );		else			return 0;		}	char directory[1024];	char* dir_beginning = path;	char* dir_ending = path;	while ( *dir_beginning )		{		while ( *dir_ending && *dir_ending != ':' )			++dir_ending;		int hold_char = *dir_ending;		if ( hold_char )			*dir_ending = '\0';		sprintf( directory, "%s/%s", dir_beginning, exec_name );		if ( hold_char )			*(dir_ending++) = hold_char;		if ( access( directory, X_OK ) == 0 )			return strdup( directory );		dir_beginning = dir_ending;		}	return 0;	}