/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include "lib.h"#include <stdlib.h>#include <sys/stat.h>#include <fcntl.h>#include <dirent.h>#include <unistd.h>#include <string.h>#include <signal.h>#include "sys9.h"#include "dir.h" /* * Called before main to initialize environ. * Some plan9 environment variables * have 0 bytes in them (notably $path); * we change them to 1's (and execve changes back) * * Also, register the note handler. */ char **environ;int errno;unsigned long _clock; static void fdsetup(char *, char *);static void sigsetup(char *, char *); enum {	Envhunk=7000,}; void_envsetup(void){	int dfd, fdinited, n, nd, m, i, j, f, nohandle, psize, cnt;	char *ps, *p;	char **pp;	char name[NAME_MAX+5];	Dir *d9, *d9a;	static char **emptyenvp = 0; 	environ = emptyenvp;		/* pessimism */	nohandle = 0;	fdinited = 0;	cnt = 0;	strcpy(name, "#e");	dfd = _OPEN(name, 0);	if(dfd < 0)		return;	name[2] = '/';	ps = p = malloc(Envhunk);	if(p == 0)		return;	psize = Envhunk;	nd = _dirreadall(dfd, &d9a);	_CLOSE(dfd);	for(j=0; j<nd; j++){		d9 = &d9a[j];		n = strlen(d9->name);		if(n >= sizeof name - 4)			continue;	/* shouldn't be possible */		m = d9->length;		i = p - ps;		if(i+n+1+m+1 > psize) {			psize += (n+m+2 < Envhunk)? Envhunk : n+m+2;			ps = realloc(ps, psize);			if (ps == 0) {				free(d9a);				return;			}			p = ps + i;		}		memcpy(p, d9->name, n);		p[n] = '=';		strcpy(name+3, d9->name);		f = _OPEN(name, O_RDONLY);		if(f < 0 || _READ(f, p+n+1, m) != m)			m = 0;		_CLOSE(f);		if(p[n+m] == 0)			m--;		for(i=0; i<m; i++)			if(p[n+1+i] == 0)				p[n+1+i] = 1;		p[n+1+m] = 0;		if(strcmp(d9->name, "_fdinfo") == 0) {			_fdinit(p+n+1, p+n+1+m);			fdinited = 1;		} else if(strcmp(d9->name, "_sighdlr") == 0)			sigsetup(p+n+1, p+n+1+m);		else if(strcmp(d9->name, "nohandle") == 0)			nohandle = 1;		p += n+m+2;		cnt++;	}	free(d9a);	if(!fdinited)		_fdinit(0, 0);	pp = malloc((1+cnt)*sizeof(char *));	if (pp == 0)		return;	environ = pp;	p = ps;	for(i = 0; i < cnt; i++) {		*pp++ = p;		p = memchr(p, 0, ps+psize-p);		if (!p)			break;		p++;	}	*pp = 0;	if(!nohandle)		_NOTIFY(_notehandler);} static voidsigsetup(char *s, char *se){	int sig;	char *e; 	while(s < se){		sig = strtoul(s, &e, 10);		if(s == e)			break;		s = e;		if(sig <= MAXSIG)			_sighdlr[sig] = SIG_IGN;	}}