#include <u.h>#include <libc.h> char*getenv(char *name){	int r, f;	long s;	char *ans;	char *p, *ep, ename[100]; 	if(strchr(name, '/') != nil)		return nil;	snprint(ename, sizeof ename, "/env/%s", name);	if(strcmp(ename+5, name) != 0)		return nil;	f = open(ename, OREAD);	if(f < 0)		return 0;	s = seek(f, 0, 2);	ans = malloc(s+1);	if(ans) {		seek(f, 0, 0);		r = read(f, ans, s);		if(r >= 0) {			ep = ans + s - 1;			for(p = ans; p < ep; p++)				if(*p == '\0')					*p = ' ';			ans[s] = '\0';		}	}	close(f);	return ans;}