/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1982-2012 AT&T Intellectual Property *
* and is licensed under the *
* Eclipse Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.eclipse.org/org/documents/epl-v10.html *
* (with md5 checksum b35adb5213ca9657e911e9befb180842) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* David Korn <dgk@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* David Korn
* AT&T Labs
*
*/
#include "defs.h"
#include <fcin.h>
#include <ls.h>
#include <nval.h>
#include "variables.h"
#include "path.h"
#include "io.h"
#include "jobs.h"
#include "history.h"
#include "test.h"
#include "FEATURE/dynamic"
#include "FEATURE/externs"
#if SHOPT_PFSH
# ifdef _hdr_exec_attr
# include <exec_attr.h>
# endif
# if _lib_vfork
# include <ast_vfork.h>
# else
# define vfork() fork()
# endif
#endif
#define RW_ALL (S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR|S_IWGRP|S_IWOTH)
#define LIBCMD "cmd"
static int canexecute(Shell_t*,char*,int);
static void funload(Shell_t*,int,const char*);
static void exscript(Shell_t*,char*, char*[], char**);
static int path_chkpaths(Shell_t*,Pathcomp_t*,Pathcomp_t*,Pathcomp_t*,int);
static void path_checkdup(Shell_t *shp,register Pathcomp_t*);
static const char *std_path;
static int onstdpath(const char *name)
{
register const char *cp = std_path, *sp;
if(cp)
while(*cp)
{
for(sp=name; *sp && (*cp == *sp); sp++,cp++);
if(*sp==0 && (*cp==0 || *cp==':'))
return(1);
while(*cp && *cp++!=':');
}
return(0);
}
#if SHOPT_PFSH
int path_xattr(Shell_t *shp, const char *path, char *rpath)
{
char resolvedpath[PATH_MAX + 1];
if (shp->gd->user && *shp->gd->user)
{
execattr_t *pf;
if(!rpath)
rpath = resolvedpath;
if (!realpath(path, resolvedpath))
return -1;
if(pf=getexecuser(shp->gd->user, KV_COMMAND, resolvedpath, GET_ONE))
{
if (!pf->attr || pf->attr->length == 0)
{
free_execattr(pf);
return(0);
}
free_execattr(pf);
return(1);
}
}
errno = ENOENT;
return(-1);
}
#endif /* SHOPT_PFSH */
static pid_t path_pfexecve(Shell_t *shp,const char *path, char *argv[],char *const envp[],int spawn)
{
#if SHOPT_PFSH
char resolvedpath[PATH_MAX + 1];
pid_t pid;
if(spawn)
{
while((pid = vfork()) < 0)
_sh_fork(shp,pid, 0, (int*)0);
if(pid)
return(pid);
}
if(!sh_isoption(SH_PFSH))
return(execve(path, argv, envp));
/* Solaris implements realpath(3C) using the resolvepath(2) */
/* system call so we can save us to call access(2) first */
/* we can exec the command directly instead of via pfexec(1) if */
/* there is a matching entry without attributes in exec_attr(4) */
if(!path_xattr(shp,path,resolvedpath))
return(execve(path, argv, envp));
--argv;
argv[0] = argv[1];
argv[1] = resolvedpath;
return(execve("/usr/bin/pfexec", argv, envp));
#else
return(execve(path, argv, envp));
#endif
}
static pid_t _spawnveg(Shell_t *shp,const char *path, char* const argv[], char* const envp[], pid_t pgid)
{
pid_t pid;
while(1)
{
sh_stats(STAT_SPAWN);
pid = spawnveg(path,argv,envp,pgid);
if(pid>=0 || errno!=EAGAIN)
break;
}
return(pid);
}
/*
* used with command -x to run the command in multiple passes
* spawn is non-zero when invoked via spawn
* the exitval is set to the maximum for each execution
*/
static pid_t path_xargs(Shell_t *shp,const char *path, char *argv[],char *const envp[], int spawn)
{
register char *cp, **av, **xv;
char **avlast= &argv[shp->xargmax], **saveargs=0;
char *const *ev;
long size, left;
int nlast=1,n,exitval=0;
pid_t pid;
if(shp->xargmin < 0)
return((pid_t)-1);
size = shp->gd->lim.arg_max-1024;
for(ev=envp; cp= *ev; ev++)
size -= strlen(cp)-1;
for(av=argv; (cp= *av) && av< &argv[shp->xargmin]; av++)
size -= strlen(cp)-1;
for(av=avlast; cp= *av; av++,nlast++)
size -= strlen(cp)-1;
av = &argv[shp->xargmin];
if(!spawn)
job_clear();
shp->exitval = 0;
while(av<avlast)
{
for(xv=av,left=size; left>0 && av<avlast;)
left -= strlen(*av++)+1;
/* leave at least two for last */
if(left<0 && (avlast-av)<2)
av--;
if(xv==&argv[shp->xargmin])
{
n = nlast*sizeof(char*);
saveargs = (char**)malloc(n);
memcpy((void*)saveargs, (void*)av, n);
memcpy((void*)av,(void*)avlast,n);
}
else
{
for(n=shp->xargmin; xv < av; xv++)
argv[n++] = *xv;
for(xv=avlast; cp= *xv; xv++)
argv[n++] = cp;
argv[n] = 0;
}
if(saveargs || av<avlast || (exitval && !spawn))
{
if((pid=_spawnveg(shp,path,argv,envp,0)) < 0)
return(-1);
job_post(shp,pid,0);
job_wait(pid);
if(shp->exitval>exitval)
exitval = shp->exitval;
if(saveargs)
{
memcpy((void*)av,saveargs,n);
free((void*)saveargs);
saveargs = 0;
}
}
else if(spawn && !sh_isoption(SH_PFSH))
{
shp->xargexit = exitval;
if(saveargs)
free((void*)saveargs);
return(_spawnveg(shp,path,argv,envp,spawn>>1));
}
else
{
if(saveargs)
free((void*)saveargs);
return(path_pfexecve(shp,path,argv,envp,spawn));
}
}
if(!spawn)
exit(exitval);
return((pid_t)-1);
}
/*
* make sure PWD is set up correctly
* Return the present working directory
* Invokes getcwd() if necessary
* Sets the PWD variable to this value
*/
char *path_pwd(Shell_t *shp,int flag)
{
register char *cp;
register int count = 0;
if(shp->pwd)
return((char*)shp->pwd);
while(1)
{
/* try from lowest to highest */
switch(count++)
{
case 0:
cp = nv_getval(PWDNOD);
break;
case 1:
cp = nv_getval(HOME);
break;
case 2:
cp = "/";
break;
case 3:
{
if(cp=getcwd(NIL(char*),0))
{
nv_offattr(PWDNOD,NV_NOFREE);
_nv_unset(PWDNOD,0);
PWDNOD->nvalue.cp = cp;
goto skip;
}
break;
}
case 4:
return((char*)e_dot);
}
if(cp && *cp=='/' && test_inode(cp,e_dot))
break;
}
if(count>1)
{
nv_offattr(PWDNOD,NV_NOFREE);
nv_putval(PWDNOD,cp,NV_RDONLY);
}
skip:
nv_onattr(PWDNOD,NV_NOFREE|NV_EXPORT);
shp->pwd = (char*)(PWDNOD->nvalue.cp);
return(cp);
}
/*
* delete current Pathcomp_t structure
*/
void path_delete(Pathcomp_t *first)
{
register Pathcomp_t *pp=first, *old=0, *ppnext;
while(pp)
{
ppnext = pp->next;
if(--pp->refcount<=0)
{
if(pp->lib)
free((void*)pp->lib);
if(pp->bbuf)
free((void*)pp->bbuf);
free((void*)pp);
if(old)
old->next = ppnext;
}
else
old = pp;
pp = ppnext;
}
}
/*
* returns library variable from .paths
* The value might be returned on the stack overwriting path
*/
static char *path_lib(Shell_t *shp,Pathcomp_t *pp, char *path)
{
register char *last = strrchr(path,'/');
register int r;
struct stat statb;
if(last)
*last = 0;
else
path = ".";
r = stat(path,&statb);
if(last)
*last = '/';
if(r>=0)
{
Pathcomp_t pcomp;
char save[8];
for( ;pp; pp=pp->next)
{
path_checkdup(shp,pp);
if(pp->ino==statb.st_ino && pp->dev==statb.st_dev && pp->mtime==statb.st_mtime)
return(pp->lib);
}
pcomp.len = 0;
if(last)
pcomp.len = last-path;
memcpy((void*)save, (void*)stakptr(PATH_OFFSET+pcomp.len),sizeof(save));
if(path_chkpaths(shp,(Pathcomp_t*)0,(Pathcomp_t*)0,&pcomp,PATH_OFFSET))
return(stakfreeze(1));
memcpy((void*)stakptr(PATH_OFFSET+pcomp.len),(void*)save,sizeof(save));
}
return(0);
}
#if 0
void path_dump(register Pathcomp_t *pp)
{
sfprintf(sfstderr,"dump\n");
while(pp)
{
sfprintf(sfstderr,"pp=%x dev=%d ino=%d len=%d flags=%o name=%.*s\n",
pp,pp->dev,pp->ino,pp->len,pp->flags,pp->len,pp->name);
pp = pp->next;
}
}
#endif
/*
* check for duplicate directories on PATH
*/
static void path_checkdup(Shell_t *shp,register Pathcomp_t *pp)
{
register char *name = pp->name;
register Pathcomp_t *oldpp,*first;
register int flag=0;
struct stat statb;
if(stat(name,&statb)<0 || !S_ISDIR(statb.st_mode))
{
pp->flags |= PATH_SKIP;
pp->dev = *name=='/';
return;
}
pp->mtime = statb.st_mtime;
pp->ino = statb.st_ino;
pp->dev = statb.st_dev;
if(*name=='/' && onstdpath(name))
flag = PATH_STD_DIR;
first = (pp->flags&PATH_CDPATH)?(Pathcomp_t*)shp->cdpathlist:path_get(shp,"");
for(oldpp=first; oldpp && oldpp!=pp; oldpp=oldpp->next)
{
if(pp->ino==oldpp->ino && pp->dev==oldpp->dev && pp->mtime==oldpp->mtime)
{
flag |= PATH_SKIP;
break;
}
}
pp->flags |= flag;
if(((pp->flags&(PATH_PATH|PATH_SKIP))==PATH_PATH))
{
int offset = staktell();
stakputs(name);
path_chkpaths(shp,first,0,pp,offset);
stakseek(offset);
}
}
/*
* write the next path to search on the current stack
* if last is given, all paths that come before <last> are skipped
* the next pathcomp is returned.
*/
Pathcomp_t *path_nextcomp(Shell_t *shp,register Pathcomp_t *pp, const char *name, Pathcomp_t *last)
{
Pathcomp_t *ppnext;
stakseek(PATH_OFFSET);
if(*name=='/')
pp = 0;
else
{
for(;pp && pp!=last;pp=ppnext)
{
ppnext = pp->next;
if(!pp->dev && !pp->ino)
path_checkdup(shp,pp);
if(pp->flags&PATH_SKIP)
return(ppnext);
if(!last || *pp->name!='/')
break;
}
if(!pp) /* this should not happen */
pp = last;
}
if(pp && (pp->name[0]!='.' || pp->name[1]))
{
if(*pp->name!='/')
{
stakputs(path_pwd(shp,1));
if(*stakptr(staktell()-1)!='/')
stakputc('/');
}
stakwrite(pp->name,pp->len);
if(pp->name[pp->len-1]!='/')
stakputc('/');
}
stakputs(name);
stakputc(0);
while(pp && pp!=last && (pp=pp->next))
{
if(!(pp->flags&PATH_SKIP))
return(pp);
}
return((Pathcomp_t*)0);
}
static Pathcomp_t* defpath_init(Shell_t *shp)
{
Pathcomp_t *pp = (void*)path_addpath(shp,(Pathcomp_t*)0,(std_path),PATH_PATH);
return(pp);
}
static void path_init(Shell_t *shp)
{
const char *val;
Pathcomp_t *pp;
if(!std_path && !(std_path=astconf("PATH",NIL(char*),NIL(char*))))
std_path = e_defpath;
if(val=sh_scoped(shp,(PATHNOD))->nvalue.cp)
{
shp->pathlist = pp = (void*)path_addpath(shp,(Pathcomp_t*)shp->pathlist,val,PATH_PATH);
}
else
{
if(!(pp=(Pathcomp_t*)shp->defpathlist))
pp = defpath_init(shp);
shp->pathlist = (void*)path_dup(pp);
}
if(val=sh_scoped(shp,(FPATHNOD))->nvalue.cp)
{
pp = (void*)path_addpath(shp,(Pathcomp_t*)shp->pathlist,val,PATH_FPATH);
}
}
/*
* returns that pathlist to search
*/
Pathcomp_t *path_get(register Shell_t *shp,register const char *name)
{
register Pathcomp_t *pp=0;
if(*name && strchr(name,'/'))
return(0);
if(!sh_isstate(SH_DEFPATH))
{
if(!shp->pathlist)
path_init(shp);
pp = (Pathcomp_t*)shp->pathlist;
}
if(!pp && (!(sh_scoped(shp,PATHNOD)->nvalue.cp)) || sh_isstate(SH_DEFPATH))
{
if(!(pp=(Pathcomp_t*)shp->defpathlist))
pp = defpath_init(shp);
}
return(pp);
}
/*
* open file corresponding to name using path give by <pp>
*/
static int path_opentype(Shell_t *shp,const char *name, register Pathcomp_t *pp, int fun)
{
register int fd= -1;
struct stat statb;
Pathcomp_t *oldpp;
if(!pp && !shp->pathlist)
path_init(shp);
if(!fun && strchr(name,'/'))
{
if(sh_isoption(SH_RESTRICTED))
errormsg(SH_DICT,ERROR_exit(1),e_restricted,name);
}
do
{
pp = path_nextcomp(shp,oldpp=pp,name,0);
while(oldpp && (oldpp->flags&PATH_SKIP))
oldpp = oldpp->next;
if(fun && (!oldpp || !(oldpp->flags&PATH_FPATH)))
continue;
if((fd = sh_open(path_relative(shp,stakptr(PATH_OFFSET)),O_RDONLY,0)) >= 0)
{
if(fstat(fd,&statb)<0 || S_ISDIR(statb.st_mode))
{
errno = EISDIR;
sh_close(fd);
fd = -1;
}
}
}
while( fd<0 && pp);
if(fd>=0 && (fd = sh_iomovefd(fd)) > 0)
{
fcntl(fd,F_SETFD,FD_CLOEXEC);
shp->fdstatus[fd] |= IOCLEX;
}
return(fd);
}
/*
* open file corresponding to name using path give by <pp>
*/
int path_open(Shell_t *shp,const char *name, register Pathcomp_t *pp)
{
return(path_opentype(shp,name,pp,0));
}
/*
* given a pathname return the base name
*/
char *path_basename(register const char *name)
{
register const char *start = name;
while (*name)
if ((*name++ == '/') && *name) /* don't trim trailing / */
start = name;
return ((char*)start);
}
char *path_fullname(Shell_t *shp,const char *name)
{
int len=strlen(name)+1,dirlen=0;
char *path,*pwd;
if(*name!='/')
{
pwd = path_pwd(shp,1);
dirlen = strlen(pwd)+1;
}
path = (char*)malloc(len+dirlen);
if(dirlen)
{
memcpy((void*)path,(void*)pwd,dirlen);
path[dirlen-1] = '/';
}
memcpy((void*)&path[dirlen],(void*)name,len);
pathcanon(path,0);
return(path);
}
/*
* load functions from file <fno>
*/
static void funload(Shell_t *shp,int fno, const char *name)
{
char *pname,*oldname=shp->st.filename, buff[IOBSIZE+1];
Namval_t *np;
struct Ufunction *rp,*rpfirst;
int savestates = sh_getstate(), oldload=shp->funload;
pname = path_fullname(shp,stakptr(PATH_OFFSET));
if(shp->fpathdict && (rp = dtmatch(shp->fpathdict,(void*)pname)))
{
Dt_t *funtree = sh_subfuntree(1);
while(1)
{
rpfirst = dtprev(shp->fpathdict,rp);
if(!rpfirst || strcmp(pname,rpfirst->fname))
break;
rp = rpfirst;
}
do
{
if((np = dtsearch(funtree,rp->np)) && is_afunction(np))
{
if(np->nvalue.rp)
np->nvalue.rp->fdict = 0;
nv_delete(np,funtree,NV_NOFREE);
}
dtinsert(funtree,rp->np);
rp->fdict = funtree;
}
while((rp=dtnext(shp->fpathdict,rp)) && strcmp(pname,rp->fname)==0);
sh_close(fno);
free((void*)pname);
return;
}
sh_onstate(SH_NOLOG);
sh_onstate(SH_NOALIAS);
shp->readscript = (char*)name;
shp->st.filename = pname;
shp->funload = 1;
error_info.line = 0;
sh_eval(sfnew(NIL(Sfio_t*),buff,IOBSIZE,fno,SF_READ),SH_FUNEVAL);
sh_close(fno);
shp->readscript = 0;
#if SHOPT_NAMESPACE
if(shp->namespace)
np = sh_fsearch(shp,name,0);
else
#endif /* SHOPT_NAMESPACE */
np = nv_search(name,shp->fun_tree,0);
if(!np || !np->nvalue.ip)
pname = stakcopy(shp->st.filename);
else
pname = 0;
free((void*)shp->st.filename);
shp->funload = oldload;
shp->st.filename = oldname;
sh_setstate(savestates);
if(pname)
errormsg(SH_DICT,ERROR_exit(ERROR_NOEXEC),e_funload,name,pname);
}
/*
* do a path search and track alias if requested
* if flag is 0, or if name not found, then try autoloading function
* if flag==2 or 3, returns 1 if name found on FPATH
* if flag==3 no tracked alias will be set
* returns 1, if function was autoloaded.
* If oldpp is not NULL, it will contain a pointer to the path component
* where it was found.
*/
int path_search(Shell_t *shp,register const char *name,Pathcomp_t **oldpp, int flag)
{
register Namval_t *np;
register int fno;
Pathcomp_t *pp=0;
if(name && strchr(name,'/'))
{
stakseek(PATH_OFFSET);
stakputs(name);
if(canexecute(shp,stakptr(PATH_OFFSET),0)<0)
{
*stakptr(PATH_OFFSET) = 0;
return(0);
}
if(*name=='/')
return(1);
stakseek(PATH_OFFSET);
stakputs(path_pwd(shp,1));
stakputc('/');
stakputs(name);
stakputc(0);
return(0);
}
if(sh_isstate(SH_DEFPATH))
{
if(!shp->defpathlist)
defpath_init(shp);
}
else if(!shp->pathlist)
path_init(shp);
if(flag)
{
if(!(flag&1) && (np=nv_search(name,shp->track_tree,0)) && !nv_isattr(np,NV_NOALIAS) && (pp=(Pathcomp_t*)np->nvalue.cp))
{
stakseek(PATH_OFFSET);
path_nextcomp(shp,pp,name,pp);
if(oldpp)
*oldpp = pp;
stakputc(0);
return(0);
}
pp = path_absolute(shp,name,oldpp?*oldpp:NIL(Pathcomp_t*));
if(oldpp)
*oldpp = pp;
if(!pp && (np=nv_search(name,shp->fun_tree,0))&&np->nvalue.ip)
return(1);
if(!pp)
*stakptr(PATH_OFFSET) = 0;
}
if(flag==0 || !pp || (pp->flags&PATH_FPATH))
{
if(!pp)
pp=sh_isstate(SH_DEFPATH)?shp->defpathlist:shp->pathlist;
if(pp && strmatch(name,e_alphanum) && (fno=path_opentype(shp,name,pp,1))>=0)
{
if(flag==2)
{
sh_close(fno);
return(1);
}
funload(shp,fno,name);
return(1);
}
*stakptr(PATH_OFFSET) = 0;
return(0);
}
else if(pp && !sh_isstate(SH_DEFPATH) && *name!='/' && flag<3)
{
if(np=nv_search(name,shp->track_tree,NV_ADD))
path_alias(np,pp);
}
return(0);
}
/*
* do a path search and find the full pathname of file name
*/
Pathcomp_t *path_absolute(Shell_t *shp,register const char *name, Pathcomp_t *pp)
{
register int f,isfun;
int noexec=0;
Pathcomp_t *oldpp;
Namval_t *np;
char *cp;
char *bp;
shp->path_err = ENOENT;
if(!pp && !(pp=path_get(shp,"")))
return(0);
shp->path_err = 0;
while(1)
{
sh_sigcheck(shp);
shp->bltin_dir = 0;
while(oldpp=pp)
{
pp = path_nextcomp(shp,pp,name,0);
if(!(oldpp->flags&PATH_SKIP))
break;
}
if(!oldpp)
{
shp->path_err = ENOENT;
return(0);
}
isfun = (oldpp->flags&PATH_FPATH);
if(!isfun && !sh_isoption(SH_RESTRICTED))
{
#if SHOPT_DYNAMIC
Shbltin_f addr;
int n;
#endif
if(*stakptr(PATH_OFFSET)=='/' && nv_search(stakptr(PATH_OFFSET),shp->bltin_tree,0))
return(oldpp);
#if SHOPT_DYNAMIC
n = staktell();
stakputs("b_");
stakputs(name);
stakputc(0);
if((addr = sh_getlib(shp, stakptr(n), oldpp)) &&
(np = sh_addbuiltin(stakptr(PATH_OFFSET),addr,NiL)) &&
nv_isattr(np,NV_BLTINOPT))
{
shp->bltin_dir = 0;
return(oldpp);
}
stakseek(n);
while(bp = oldpp->blib)
{
char *fp;
void *dll;
int m;
if(fp = strchr(bp, ':'))
{
*fp++ = 0;
oldpp->blib = fp;
fp = 0;
}
else
{
fp = oldpp->bbuf;
oldpp->blib = oldpp->bbuf = 0;
}
n = staktell();
stakputs("b_");
stakputs(name);
stakputc(0);
m = staktell();
shp->bltin_dir = oldpp->name;
if(*bp!='/')
{
stakputs(oldpp->name);
stakputc('/');
}
stakputs(bp);
stakputc(0);
if(cp = strrchr(stakptr(m),'/'))
cp++;
else
cp = stakptr(m);
if(!strcmp(cp,LIBCMD) &&
(addr=(Shbltin_f)dlllook((void*)0,stakptr(n))) &&
(np = sh_addbuiltin(stakptr(PATH_OFFSET),addr,NiL)) &&
nv_isattr(np,NV_BLTINOPT))
{
found:
if(fp)
free(fp);
shp->bltin_dir = 0;
return(oldpp);
}
#ifdef SH_PLUGIN_VERSION
if (dll = dllplugin(SH_ID, stakptr(m), NiL, SH_PLUGIN_VERSION, NiL, RTLD_LAZY, NiL, 0))
sh_addlib(shp,dll,stakptr(m),oldpp);
#else
#if (_AST_VERSION>=20040404)
if (dll = dllplug(SH_ID, stakptr(m), NiL, RTLD_LAZY, NiL, 0))
#else
if (dll = dllfind(stakptr(m), NiL, RTLD_LAZY, NiL, 0))
#endif
{
/*
* this detects the 2007-05-11 builtin context change and also
* the 2008-03-30 opt_info.num change that hit libcmd::b_head
*/
if (libcmd && !dlllook(dll, "b_pids"))
{
dlclose(dll);
dll = 0;
}
else
sh_addlib(shp,dll,stakptr(m),oldpp);
}
#endif
if(dll &&
(addr=(Shbltin_f)dlllook(dll,stakptr(n))) &&
(!(np = sh_addbuiltin(stakptr(PATH_OFFSET),NiL,NiL)) || np->nvalue.bfp!=(Nambfp_f)addr) &&
(np = sh_addbuiltin(stakptr(PATH_OFFSET),addr,NiL)))
{
np->nvenv = dll;
goto found;
}
if(*stakptr(PATH_OFFSET)=='/' && nv_search(stakptr(PATH_OFFSET),shp->bltin_tree,0))
goto found;
if(fp)
free(fp);
stakseek(n);
}
#endif /* SHOPT_DYNAMIC */
}
shp->bltin_dir = 0;
sh_stats(STAT_PATHS);
f = canexecute(shp,stakptr(PATH_OFFSET),isfun);
if(isfun && f>=0 && (cp = strrchr(name,'.')))
{
*cp = 0;
if(nv_open(name,sh_subfuntree(1),NV_NOARRAY|NV_IDENT|NV_NOSCOPE))
f = -1;
*cp = '.';
}
if(isfun && f>=0)
{
nv_onattr(nv_open(name,sh_subfuntree(1),NV_NOARRAY|NV_IDENT|NV_NOSCOPE),NV_LTOU|NV_FUNCTION);
funload(shp,f,name);
close(f);
f = -1;
return(0);
}
else if(f>=0 && (oldpp->flags & PATH_STD_DIR))
{
int n = staktell();
stakputs("/bin/");
stakputs(name);
stakputc(0);
np = nv_search(stakptr(n),shp->bltin_tree,0);
stakseek(n);
if(np)
{
n = np->nvflag;
np = sh_addbuiltin(stakptr(PATH_OFFSET),(Shbltin_f)np->nvalue.bfp,nv_context(np));
np->nvflag = n;
}
}
if(!pp || f>=0)
break;
if(errno!=ENOENT)
noexec = errno;
}
if(f<0)
{
shp->path_err = (noexec?noexec:ENOENT);
return(0);
}
stakputc(0);
return(oldpp);
}
/*
* returns 0 if path can execute
* sets exec_err if file is found but can't be executable
*/
#undef S_IXALL
#ifdef S_IXUSR
# define S_IXALL (S_IXUSR|S_IXGRP|S_IXOTH)
#else
# ifdef S_IEXEC
# define S_IXALL (S_IEXEC|(S_IEXEC>>3)|(S_IEXEC>>6))
# else
# define S_IXALL 0111
# endif /*S_EXEC */
#endif /* S_IXUSR */
static int canexecute(Shell_t *shp,register char *path, int isfun)
{
struct stat statb;
register int fd=0;
path = path_relative(shp,path);
if(isfun)
{
if((fd=open(path,O_RDONLY,0))<0 || fstat(fd,&statb)<0)
goto err;
}
else if(stat(path,&statb) < 0)
{
#if _WINIX
/* check for .exe or .bat suffix */
char *cp;
if(errno==ENOENT && (!(cp=strrchr(path,'.')) || strlen(cp)>4 || strchr(cp,'/')))
{
int offset = staktell()-1;
stakseek(offset);
stakputs(".bat");
path = stakptr(PATH_OFFSET);
if(stat(path,&statb) < 0)
{
if(errno!=ENOENT)
goto err;
memcpy(stakptr(offset),".sh",4);
if(stat(path,&statb) < 0)
goto err;
}
}
else
#endif /* _WINIX */
goto err;
}
errno = EPERM;
if(S_ISDIR(statb.st_mode))
errno = EISDIR;
else if((statb.st_mode&S_IXALL)==S_IXALL || sh_access(path,X_OK)>=0)
return(fd);
if(isfun && fd>=0)
sh_close(fd);
err:
return(-1);
}
/*
* Return path relative to present working directory
*/
char *path_relative(Shell_t *shp,register const char* file)
{
register const char *pwd;
register const char *fp = file;
/* can't relpath when shp->pwd not set */
if(!(pwd=shp->pwd))
return((char*)fp);
while(*pwd==*fp)
{
if(*pwd++==0)
return((char*)e_dot);
fp++;
}
if(*pwd==0 && *fp == '/')
{
while(*++fp=='/');
if(*fp)
return((char*)fp);
return((char*)e_dot);
}
return((char*)file);
}
void path_exec(Shell_t *shp,register const char *arg0,register char *argv[],struct argnod *local)
{
char **envp;
const char *opath;
Pathcomp_t *libpath, *pp=0;
int slash=0;
nv_setlist(local,NV_EXPORT|NV_IDENT|NV_ASSIGN,0);
envp = sh_envgen();
if(strchr(arg0,'/'))
{
slash=1;
/* name containing / not allowed for restricted shell */
if(sh_isoption(SH_RESTRICTED))
errormsg(SH_DICT,ERROR_exit(1),e_restricted,arg0);
}
else
pp=path_get(shp,arg0);
shp->path_err= ENOENT;
sfsync(NIL(Sfio_t*));
timerdel(NIL(void*));
/* find first path that has a library component */
while(pp && (pp->flags&PATH_SKIP))
pp = pp->next;
if(pp || slash) do
{
sh_sigcheck(shp);
if(libpath=pp)
{
pp = path_nextcomp(shp,pp,arg0,0);
opath = stakfreeze(1)+PATH_OFFSET;
}
else
opath = arg0;
path_spawn(shp,opath,argv,envp,libpath,0);
while(pp && (pp->flags&PATH_FPATH))
pp = path_nextcomp(shp,pp,arg0,0);
}
while(pp);
/* force an exit */
((struct checkpt*)shp->jmplist)->mode = SH_JMPEXIT;
if((errno=shp->path_err)==ENOENT)
errormsg(SH_DICT,ERROR_exit(ERROR_NOENT),e_found,arg0);
else
errormsg(SH_DICT,ERROR_system(ERROR_NOEXEC),e_exec,arg0);
}
pid_t path_spawn(Shell_t *shp,const char *opath,register char **argv, char **envp, Pathcomp_t *libpath, int spawn)
{
register char *path;
char **xp=0, *xval, *libenv = (libpath?libpath->lib:0);
Namval_t* np;
char *s, *v;
int r, n, pidsize;
pid_t pid= -1;
/* leave room for inserting _= pathname in environment */
envp--;
#if _lib_readlink
/* save original pathname */
stakseek(PATH_OFFSET);
pidsize = sfprintf(stkstd,"*%d*",spawn?getpid():getppid());
stakputs(opath);
opath = stakfreeze(1)+PATH_OFFSET+pidsize;
np=nv_search(argv[0],shp->track_tree,0);
while(libpath && !libpath->lib)
libpath=libpath->next;
if(libpath && (!np || nv_size(np)>0))
{
/* check for symlink and use symlink name */
char buff[PATH_MAX+1];
char save[PATH_MAX+1];
stakseek(PATH_OFFSET);
stakputs(opath);
path = stakptr(PATH_OFFSET);
while((n=readlink(path,buff,PATH_MAX))>0)
{
buff[n] = 0;
n = PATH_OFFSET;
r = 0;
if((v=strrchr(path,'/')) && *buff!='/')
{
if(buff[0]=='.' && buff[1]=='.' && (r = strlen(path) + 1) <= PATH_MAX)
memcpy(save, path, r);
else
r = 0;
n += (v+1-path);
}
stakseek(n);
stakputs(buff);
stakputc(0);
path = stakptr(PATH_OFFSET);
if(v && buff[0]=='.' && buff[1]=='.')
{
pathcanon(path, 0);
if(r && access(path,X_OK))
{
memcpy(path, save, r);
break;
}
}
if(libenv = path_lib(shp,libpath,path))
break;
}
stakseek(0);
}
#endif
if(libenv && (v = strchr(libenv,'=')))
{
n = v - libenv;
*v = 0;
np = nv_open(libenv,shp->var_tree,0);
*v = '=';
s = nv_getval(np);
stakputs(libenv);
if(s)
{
stakputc(':');
stakputs(s);
}
v = stakfreeze(1);
r = 1;
xp = envp + 1;
while (s = *xp++)
{
if (strneq(s, v, n) && s[n] == '=')
{
xval = *--xp;
*xp = v;
r = 0;
break;
}
}
if (r)
{
*envp-- = v;
xp = 0;
}
}
if(!opath)
opath = stakptr(PATH_OFFSET);
envp[0] = (char*)opath-(PATH_OFFSET+pidsize);
envp[0][0] = '_';
envp[0][1] = '=';
sfsync(sfstderr);
sh_sigcheck(shp);
path = path_relative(shp,opath);
#ifdef SHELLMAGIC
if(*path!='/' && path!=opath)
{
/*
* The following code because execv(foo,) and execv(./foo,)
* may not yield the same results
*/
char *sp = (char*)malloc(strlen(path)+3);
sp[0] = '.';
sp[1] = '/';
strcpy(sp+2,path);
path = sp;
}
#endif /* SHELLMAGIC */
if(spawn && !sh_isoption(SH_PFSH))
pid = _spawnveg(shp,opath, &argv[0],envp, spawn>>1);
else
pid = path_pfexecve(shp,opath, &argv[0] ,envp,spawn);
if(xp)
*xp = xval;
#ifdef SHELLMAGIC
if(*path=='.' && path!=opath)
{
free(path);
path = path_relative(shp,opath);
}
#endif /* SHELLMAGIC */
if(pid>0)
return(pid);
retry:
switch(shp->path_err = errno)
{
#ifdef apollo
/*
* On apollo's execve will fail with eacces when
* file has execute but not read permissions. So,
* for now we will pretend that EACCES and ENOEXEC
* mean the same thing.
*/
case EACCES:
#endif /* apollo */
case ENOEXEC:
#if SHOPT_SUID_EXEC
case EPERM:
/* some systems return EPERM if setuid bit is on */
#endif
errno = ENOEXEC;
if(spawn)
{
#ifdef _lib_fork
if(shp->subshell)
return(-1);
do
{
if((pid=fork())>0)
return(pid);
}
while(_sh_fork(shp,pid,0,(int*)0) < 0);
((struct checkpt*)shp->jmplist)->mode = SH_JMPEXIT;
#else
return(-1);
#endif
}
exscript(shp,path,argv,envp);
#ifndef apollo
case EACCES:
{
struct stat statb;
if(stat(path,&statb)>=0)
{
if(S_ISDIR(statb.st_mode))
errno = EISDIR;
#ifdef S_ISSOCK
if(S_ISSOCK(statb.st_mode))
exscript(shp,path,argv,envp);
#endif
}
}
/* FALL THROUGH */
#endif /* !apollo */
#ifdef ENAMETOOLONG
case ENAMETOOLONG:
#endif /* ENAMETOOLONG */
#if !SHOPT_SUID_EXEC
case EPERM:
#endif
shp->path_err = errno;
return(-1);
case ENOTDIR:
case ENOENT:
case EINTR:
#ifdef EMLINK
case EMLINK:
#endif /* EMLINK */
return(-1);
case E2BIG:
if(shp->xargmin)
{
pid = path_xargs(shp,opath, &argv[0] ,envp,spawn);
if(pid<0)
goto retry;
return(pid);
}
default:
errormsg(SH_DICT,ERROR_system(ERROR_NOEXEC),e_exec,path);
}
return 0;
}
/*
* File is executable but not machine code.
* Assume file is a Shell script and execute it.
*/
static void exscript(Shell_t *shp,register char *path,register char *argv[],char **envp)
{
register Sfio_t *sp;
path = path_relative(shp,path);
shp->comdiv=0;
shp->bckpid = 0;
shp->coshell = 0;
shp->st.ioset=0;
/* clean up any cooperating processes */
if(shp->cpipe[0]>0)
sh_pclose(shp->cpipe);
if(shp->cpid && shp->outpipe)
sh_close(*shp->outpipe);
shp->cpid = 0;
if(sp=fcfile())
while(sfstack(sp,SF_POPSTACK));
job_clear();
if(shp->infd>0 && (shp->fdstatus[shp->infd]&IOCLEX))
sh_close(shp->infd);
sh_setstate(sh_state(SH_FORKED));
sfsync(sfstderr);
#if SHOPT_SUID_EXEC && !SHOPT_PFSH
/* check if file cannot open for read or script is setuid/setgid */
{
static char name[] = "/tmp/euidXXXXXXXXXX";
register int n;
register uid_t euserid;
char *savet=0;
struct stat statb;
if((n=sh_open(path,O_RDONLY,0)) >= 0)
{
/* move <n> if n=0,1,2 */
n = sh_iomovefd(n);
if(fstat(n,&statb)>=0 && !(statb.st_mode&(S_ISUID|S_ISGID)))
goto openok;
sh_close(n);
}
if((euserid=geteuid()) != shp->gd->userid)
{
strncpy(name+9,fmtbase((long)getpid(),10,0),sizeof(name)-10);
/* create a suid open file with owner equal effective uid */
if((n=open(name,O_CREAT|O_TRUNC|O_WRONLY,S_ISUID|S_IXUSR)) < 0)
goto fail;
unlink(name);
/* make sure that file has right owner */
if(fstat(n,&statb)<0 || statb.st_uid != euserid)
goto fail;
if(n!=10)
{
sh_close(10);
fcntl(n, F_DUPFD, 10);
sh_close(n);
n=10;
}
}
savet = *--argv;
*argv = path;
path_pfexecve(shp,e_suidexec,argv,envp,0);
fail:
/*
* The following code is just for compatibility
*/
if((n=open(path,O_RDONLY,0)) < 0)
errormsg(SH_DICT,ERROR_system(ERROR_NOEXEC),e_exec,path);
if(savet)
*argv++ = savet;
openok:
shp->infd = n;
}
#else
if((shp->infd = sh_open(path,O_RDONLY,0)) < 0)
errormsg(SH_DICT,ERROR_system(ERROR_NOEXEC),e_exec,path);
#endif
shp->infd = sh_iomovefd(shp->infd);
#if SHOPT_ACCT
sh_accbegin(path) ; /* reset accounting */
#endif /* SHOPT_ACCT */
shp->arglist = sh_argcreate(argv);
shp->lastarg = strdup(path);
/* save name of calling command */
shp->readscript = error_info.id;
/* close history file if name has changed */
if(shp->gd->hist_ptr && (path=nv_getval(HISTFILE)) && strcmp(path,shp->gd->hist_ptr->histname))
{
hist_close(shp->gd->hist_ptr);
(HISTCUR)->nvalue.lp = 0;
}
sh_offstate(SH_FORKED);
if(shp->sigflag[SIGCHLD]==SH_SIGOFF)
shp->sigflag[SIGCHLD] = SH_SIGFAULT;
siglongjmp(*shp->jmplist,SH_JMPSCRIPT);
}
#if SHOPT_ACCT
# include <sys/acct.h>
# include "FEATURE/time"
static struct acct sabuf;
static struct tms buffer;
static clock_t before;
static char *SHACCT; /* set to value of SHACCT environment variable */
static shaccton; /* non-zero causes accounting record to be written */
static int compress(time_t);
/*
* initialize accounting, i.e., see if SHACCT variable set
*/
void sh_accinit(void)
{
SHACCT = getenv("SHACCT");
}
/*
* suspend accounting until turned on by sh_accbegin()
*/
void sh_accsusp(void)
{
shaccton=0;
#ifdef AEXPAND
sabuf.ac_flag |= AEXPND;
#endif /* AEXPAND */
}
/*
* begin an accounting record by recording start time
*/
void sh_accbegin(const char *cmdname)
{
if(SHACCT)
{
sabuf.ac_btime = time(NIL(time_t *));
before = times(&buffer);
sabuf.ac_uid = getuid();
sabuf.ac_gid = getgid();
strncpy(sabuf.ac_comm, (char*)path_basename(cmdname),
sizeof(sabuf.ac_comm));
shaccton = 1;
}
}
/*
* terminate an accounting record and append to accounting file
*/
void sh_accend(void)
{
int fd;
clock_t after;
if(shaccton)
{
after = times(&buffer);
sabuf.ac_utime = compress(buffer.tms_utime + buffer.tms_cutime);
sabuf.ac_stime = compress(buffer.tms_stime + buffer.tms_cstime);
sabuf.ac_etime = compress( (time_t)(after-before));
fd = open( SHACCT , O_WRONLY | O_APPEND | O_CREAT,RW_ALL);
write(fd, (const char*)&sabuf, sizeof( sabuf ));
close( fd);
}
}
/*
* Produce a pseudo-floating point representation
* with 3 bits base-8 exponent, 13 bits fraction.
*/
static int compress(register time_t t)
{
register int exp = 0, rund = 0;
while (t >= 8192)
{
exp++;
rund = t&04;
t >>= 3;
}
if (rund)
{
t++;
if (t >= 8192)
{
t >>= 3;
exp++;
}
}
return((exp<<13) + t);
}
#endif /* SHOPT_ACCT */
/*
* add a pathcomponent to the path search list and eliminate duplicates
* and non-existing absolute paths.
*/
static Pathcomp_t *path_addcomp(Shell_t *shp,Pathcomp_t *first, Pathcomp_t *old,const char *name, int flag)
{
register Pathcomp_t *pp, *oldpp;
int len, offset=staktell();
if(!(flag&PATH_BFPATH))
{
register const char *cp = name;
while(*cp && *cp!=':')
stakputc(*cp++);
len = staktell()-offset;
stakputc(0);
stakseek(offset);
name = (const char*)stakptr(offset);
}
else
len = strlen(name);
for(pp=first; pp; pp=pp->next)
{
if(len == pp->len && memcmp(name,pp->name,len)==0)
{
pp->flags |= flag;
return(first);
}
}
for(pp=first, oldpp=0; pp; oldpp=pp, pp=pp->next);
pp = newof((Pathcomp_t*)0,Pathcomp_t,1,len+1);
pp->shp = shp;
pp->refcount = 1;
memcpy((char*)(pp+1),name,len+1);
pp->name = (char*)(pp+1);
pp->len = len;
if(oldpp)
oldpp->next = pp;
else
first = pp;
pp->flags = flag;
if(strcmp(name,SH_CMDLIB_DIR)==0)
{
pp->dev = 1;
pp->flags |= PATH_BUILTIN_LIB;
pp->blib = pp->bbuf = malloc(sizeof(LIBCMD));
strcpy(pp->blib,LIBCMD);
return(first);
}
if((old||shp->pathinit) && ((flag&(PATH_PATH|PATH_SKIP))==PATH_PATH))
path_chkpaths(shp,first,old,pp,offset);
return(first);
}
/*
* This function checks for the .paths file in directory in <pp>
* it assumes that the directory is on the stack at <offset>
*/
static int path_chkpaths(Shell_t *shp,Pathcomp_t *first, Pathcomp_t* old,Pathcomp_t *pp, int offset)
{
struct stat statb;
int k,m,n,fd;
char *sp,*cp,*ep;
stakseek(offset+pp->len);
if(pp->len==1 && *stakptr(offset)=='/')
stakseek(offset);
stakputs("/.paths");
if((fd=open(stakptr(offset),O_RDONLY))>=0)
{
fstat(fd,&statb);
n = statb.st_size;
stakseek(offset+pp->len+n+2);
sp = stakptr(offset+pp->len);
*sp++ = '/';
n=read(fd,cp=sp,n);
sp[n] = 0;
close(fd);
for(ep=0; n--; cp++)
{
if(*cp=='=')
{
ep = cp+1;
continue;
}
else if(*cp!='\r' && *cp!='\n')
continue;
if(*sp=='#' || sp==cp)
{
sp = cp+1;
continue;
}
*cp = 0;
m = ep ? (ep-sp) : 0;
if(m==0 || m==6 && memcmp((void*)sp,(void*)"FPATH=",m)==0)
{
if(first)
{
char *ptr = stakptr(offset+pp->len+1);
if(ep)
strcpy(ptr,ep);
path_addcomp(shp,first,old,stakptr(offset),PATH_FPATH|PATH_BFPATH);
}
}
else if(m==11 && memcmp((void*)sp,(void*)"PLUGIN_LIB=",m)==0)
{
if(pp->bbuf)
free(pp->bbuf);
pp->blib = pp->bbuf = strdup(ep);
}
else if(m)
{
pp->lib = (char*)malloc(cp-sp+pp->len+2);
memcpy((void*)pp->lib,(void*)sp,m);
memcpy((void*)&pp->lib[m],stakptr(offset),pp->len);
pp->lib[k=m+pp->len] = '/';
strcpy((void*)&pp->lib[k+1],ep);
pathcanon(&pp->lib[m],0);
if(!first)
{
stakseek(0);
stakputs(pp->lib);
free((void*)pp->lib);
return(1);
}
}
sp = cp+1;
ep = 0;
}
}
return(0);
}
Pathcomp_t *path_addpath(Shell_t *shp,Pathcomp_t *first, register const char *path,int type)
{
register const char *cp;
Pathcomp_t *old=0;
int offset = staktell();
char *savptr;
if(!path && type!=PATH_PATH)
return(first);
if(type!=PATH_FPATH)
{
old = first;
first = 0;
}
if(offset)
savptr = stakfreeze(0);
if(path) while(*(cp=path))
{
if(*cp==':')
{
if(type!=PATH_FPATH)
first = path_addcomp(shp,first,old,".",type);
while(*++path == ':');
}
else
{
int c;
while(*path && *path!=':')
path++;
c = *path++;
first = path_addcomp(shp,first,old,cp,type);
if(c==0)
break;
if(*path==0)
path--;
}
}
if(old)
{
if(!first && !path)
{
Pathcomp_t *pp = (Pathcomp_t*)shp->defpathlist;
if(!pp)
pp = defpath_init(shp);
first = path_dup(pp);
}
if(cp=(sh_scoped(shp,FPATHNOD))->nvalue.cp)
first = (void*)path_addpath(shp,(Pathcomp_t*)first,cp,PATH_FPATH);
path_delete(old);
}
if(offset)
stakset(savptr,offset);
else
stakseek(0);
return(first);
}
/*
* duplicate the path give by <first> by incremented reference counts
*/
Pathcomp_t *path_dup(Pathcomp_t *first)
{
register Pathcomp_t *pp=first;
while(pp)
{
pp->refcount++;
pp = pp->next;
}
return(first);
}
/*
* called whenever the directory is changed
*/
void path_newdir(Shell_t *shp,Pathcomp_t *first)
{
register Pathcomp_t *pp=first, *next, *pq;
struct stat statb;
for(pp=first; pp; pp=pp->next)
{
pp->flags &= ~PATH_SKIP;
if(*pp->name=='/')
continue;
/* delete .paths component */
if((next=pp->next) && (next->flags&PATH_BFPATH))
{
pp->next = next->next;
if(--next->refcount<=0)
free((void*)next);
}
if(stat(pp->name,&statb)<0 || !S_ISDIR(statb.st_mode))
{
pp->dev = 0;
pp->ino = 0;
continue;
}
pp->dev = statb.st_dev;
pp->ino = statb.st_ino;
pp->mtime = statb.st_mtime;
for(pq=first;pq!=pp;pq=pq->next)
{
if(pp->ino==pq->ino && pp->dev==pq->dev)
pp->flags |= PATH_SKIP;
}
for(pq=pp;pq=pq->next;)
{
if(pp->ino==pq->ino && pp->dev==pq->dev)
pq->flags |= PATH_SKIP;
}
if((pp->flags&(PATH_PATH|PATH_SKIP))==PATH_PATH)
{
/* try to insert .paths component */
int offset = staktell();
stakputs(pp->name);
stakseek(offset);
next = pp->next;
pp->next = 0;
path_chkpaths(shp,first,(Pathcomp_t*)0,pp,offset);
if(pp->next)
pp = pp->next;
pp->next = next;
}
}
#if 0
path_dump(first);
#endif
}
Pathcomp_t *path_unsetfpath(Shell_t *shp)
{
Pathcomp_t *first = (Pathcomp_t*)shp->pathlist;
register Pathcomp_t *pp=first, *old=0;
if(shp->fpathdict)
{
struct Ufunction *rp, *rpnext;
for(rp=(struct Ufunction*)dtfirst(shp->fpathdict);rp;rp=rpnext)
{
rpnext = (struct Ufunction*)dtnext(shp->fpathdict,rp);
if(rp->fdict)
nv_delete(rp->np,rp->fdict,NV_NOFREE);
rp->fdict = 0;
}
}
while(pp)
{
if((pp->flags&PATH_FPATH) && !(pp->flags&PATH_BFPATH))
{
if(pp->flags&PATH_PATH)
pp->flags &= ~PATH_FPATH;
else
{
Pathcomp_t *ppsave=pp;
if(old)
old->next = pp->next;
else
first = pp->next;
pp = pp->next;
if(--ppsave->refcount<=0)
{
if(ppsave->lib)
free((void*)ppsave->lib);
free((void*)ppsave);
}
continue;
}
}
old = pp;
pp = pp->next;
}
return(first);
}
Pathcomp_t *path_dirfind(Pathcomp_t *first,const char *name,int c)
{
register Pathcomp_t *pp=first;
while(pp)
{
if(memcmp(name,pp->name,pp->len)==0 && name[pp->len]==c)
return(pp);
pp = pp->next;
}
return(0);
}
/*
* get discipline for tracked alias
*/
static char *talias_get(Namval_t *np, Namfun_t *nvp)
{
Pathcomp_t *pp = (Pathcomp_t*)np->nvalue.cp;
char *ptr;
if(!pp)
return(NULL);
pp->shp->last_table = 0;
path_nextcomp(pp->shp,pp,nv_name(np),pp);
ptr = stakfreeze(0);
return(ptr+PATH_OFFSET);
}
static void talias_put(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
if(!val && np->nvalue.cp)
{
Pathcomp_t *pp = (Pathcomp_t*)np->nvalue.cp;
if(--pp->refcount<=0)
free((void*)pp);
}
nv_putv(np,val,flags,fp);
}
static const Namdisc_t talias_disc = { 0, talias_put, talias_get };
static Namfun_t talias_init = { &talias_disc, 1 };
/*
* set tracked alias node <np> to value <pp>
*/
void path_alias(register Namval_t *np,register Pathcomp_t *pp)
{
if(pp)
{
struct stat statb;
char *sp;
Pathcomp_t *old = 0;
nv_offattr(np,NV_NOPRINT);
nv_stack(np,&talias_init);
old = (Pathcomp_t*)np->nvalue.cp;
if (old && (--old->refcount <= 0))
free((void*)old);
np->nvalue.cp = (char*)pp;
pp->refcount++;
nv_setattr(np,NV_TAGGED|NV_NOFREE);
path_nextcomp(pp->shp,pp,nv_name(np),pp);
sp = stakptr(PATH_OFFSET);
if(sp && lstat(sp,&statb)>=0 && S_ISLNK(statb.st_mode))
nv_setsize(np,statb.st_size+1);
else
nv_setsize(np,0);
}
else
_nv_unset(np,0);
}