common/sh/init.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1982-2011 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                  David Korn <dgk@research.att.com>                   *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 *
 * Shell initialization
 *
 *   David Korn
 *   AT&T Labs
 *
 */

#include        "defs.h"
#include        <stak.h>
#include        <ccode.h>
#include        <pwd.h>
#include        <tmx.h>
#include        "variables.h"
#include        "path.h"
#include        "fault.h"
#include        "name.h"
#include    "edit.h"
#include    "jobs.h"
#include    "io.h"
#include    "shlex.h"
#include    "builtins.h"
#include    "FEATURE/time"
#include    "FEATURE/dynamic"
#include    "FEATURE/externs"
#include    "lexstates.h"
#include    "version.h"

#if _hdr_wctype
#include    <ast_wchar.h>
#include    <wctype.h>
#endif
#if !_typ_wctrans_t
#undef  wctrans_t
#define wctrans_t   sh_wctrans_t
typedef long wctrans_t;
#endif
#if !_lib_wctrans
#undef  wctrans
#define wctrans     sh_wctrans
static wctrans_t wctrans(const char *name)
{
    if(strcmp(name,e_tolower)==0)
        return(1);
    else if(strcmp(name,e_toupper)==0)
        return(2);
    return(0);
}
#endif
#if !_lib_towctrans
#undef  towctrans
#define towctrans   sh_towctrans
static int towctrans(int c, wctrans_t t)
{
    if(t==1 && isupper(c))
        c = tolower(c);
    else if(t==2 && isupper(c))
        c = toupper(c);
    return(c);
}
#endif

char e_version[]    = "\n@(#)$Id: Version "
#if SHOPT_AUDIT
#define ATTRS       1
            "A"
#endif
#if SHOPT_BASH
#define ATTRS       1
            "B"
#endif
#if SHOPT_COSHELL
#define ATTRS       1
            "J"
#else
#if SHOPT_BGX
#define ATTRS       1
            "j"
#endif
#endif
#if SHOPT_ACCT
#define ATTRS       1
            "L"
#endif
#if SHOPT_MULTIBYTE
#define ATTRS       1
            "M"
#endif
#if SHOPT_PFSH && _hdr_exec_attr
#define ATTRS       1
            "P"
#endif
#if SHOPT_REGRESS
#define ATTRS       1
            "R"
#endif
#if ATTRS
            " "
#endif
            SH_RELEASE " $\0\n";

#if SHOPT_BASH
    extern void bash_init(Shell_t*,int);
#endif

#define RANDMASK    0x7fff

#ifndef ARG_MAX
#   define ARG_MAX  (1*1024*1024)
#endif
#ifndef CHILD_MAX
#   define CHILD_MAX    (1*1024)
#endif
#ifndef CLK_TCK
#   define CLK_TCK  60
#endif /* CLK_TCK */

#ifndef environ
    extern char **environ;
#endif

#undef  getconf
#define getconf(x)  strtol(astconf(x,NiL,NiL),NiL,0)

struct seconds
{
    Namfun_t    hdr;
    Shell_t     *sh;
};

struct rand
{
    Namfun_t    hdr;
    Shell_t     *sh;
    int32_t     rand_last;
};

struct ifs
{
    Namfun_t    hdr;
    Namval_t    *ifsnp;
};

struct match
{
    Namfun_t    hdr;
    char        *val;
    char        *rval;
    int     vsize;
    int     nmatch;
    int     lastsub;
    int     match[2*(MATCH_MAX+1)];
};

typedef struct _init_
{
    Shell_t     *sh;
#if SHOPT_FS_3D
    Namfun_t    VPATH_init;
#endif /* SHOPT_FS_3D */
    struct ifs  IFS_init;
    Namfun_t    PATH_init;
    Namfun_t    FPATH_init;
    Namfun_t    CDPATH_init;
    Namfun_t    SHELL_init;
    Namfun_t    ENV_init;
    Namfun_t    VISUAL_init;
    Namfun_t    EDITOR_init;
    Namfun_t    HISTFILE_init;
    Namfun_t    HISTSIZE_init;
    Namfun_t    OPTINDEX_init;
    struct seconds  SECONDS_init;
    struct rand RAND_init;
    Namfun_t    LINENO_init;
    Namfun_t    L_ARG_init;
    Namfun_t    SH_VERSION_init;
    struct match    SH_MATCH_init;
    Namfun_t    SH_MATH_init;
#if SHOPT_COSHELL
    Namfun_t    SH_JOBPOOL_init;
#endif /* SHOPT_COSHELL */
#ifdef _hdr_locale
    Namfun_t    LC_TYPE_init;
    Namfun_t    LC_NUM_init;
    Namfun_t    LC_COLL_init;
    Namfun_t    LC_MSG_init;
    Namfun_t    LC_ALL_init;
    Namfun_t    LANG_init;
#endif /* _hdr_locale */
} Init_t;

static int      lctype;
static int      nbltins;
static void     env_init(Shell_t*);
static Init_t       *nv_init(Shell_t*);
static Dt_t     *inittree(Shell_t*,const struct shtable2*);
static int      shlvl;

#ifdef _WINIX
#   define EXE  "?(.exe)"
#else
#   define EXE
#endif

static int      rand_shift;


/*
 * Invalidate all path name bindings
 */
static void rehash(register Namval_t *np,void *data)
{
    NOT_USED(data);
    nv_onattr(np,NV_NOALIAS);
}

/*
 * out of memory routine for stak routines
 */
static char *nospace(int unused)
{
    NOT_USED(unused);
    errormsg(SH_DICT,ERROR_exit(3),e_nospace);
    return(NIL(char*));
}

/* Trap for VISUAL and EDITOR variables */
static void put_ed(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    register const char *cp, *name=nv_name(np);
    register int    newopt=0;
    Shell_t *shp = nv_shell(np);
    if(*name=='E' && nv_getval(sh_scoped(shp,VISINOD)))
        goto done;
    if(!(cp=val) && (*name=='E' || !(cp=nv_getval(sh_scoped(shp,EDITNOD)))))
        goto done;
    /* turn on vi or emacs option if editor name is either*/
    cp = path_basename(cp);
    if(strmatch(cp,"*[Vv][Ii]*"))
        newopt=SH_VI;
    else if(strmatch(cp,"*gmacs*"))
        newopt=SH_GMACS;
    else if(strmatch(cp,"*macs*"))
        newopt=SH_EMACS;
    if(newopt)
    {
        sh_offoption(SH_VI);
        sh_offoption(SH_EMACS);
        sh_offoption(SH_GMACS);
        sh_onoption(newopt);
    }
done:
    nv_putv(np, val, flags, fp);
}

/* Trap for HISTFILE and HISTSIZE variables */
static void put_history(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    Shell_t *shp = nv_shell(np);
    void    *histopen = shp->gd->hist_ptr;
    char    *cp;
    if(val && histopen)
    {
        if(np==HISTFILE && (cp=nv_getval(np)) && strcmp(val,cp)==0)
            return;
        if(np==HISTSIZE && sh_arith(shp,val)==nv_getnum(HISTSIZE))
            return;
        hist_close(shp->gd->hist_ptr);
    }
    nv_putv(np, val, flags, fp);
    if(histopen)
    {
        if(val)
            sh_histinit(shp);
        else
            hist_close(histopen);
    }
}

/* Trap for OPTINDEX */
static void put_optindex(Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    Shell_t *shp = nv_shell(np);
    shp->st.opterror = shp->st.optchar = 0;
    nv_putv(np, val, flags, fp);
    if(!val)
        nv_disc(np,fp,NV_POP);
}

static Sfdouble_t nget_optindex(register Namval_t* np, Namfun_t *fp)
{
    return((Sfdouble_t)*np->nvalue.lp);
}

static Namfun_t *clone_optindex(Namval_t* np, Namval_t *mp, int flags, Namfun_t *fp)
{
    Namfun_t *dp = (Namfun_t*)malloc(sizeof(Namfun_t));
    memcpy((void*)dp,(void*)fp,sizeof(Namfun_t));
    mp->nvalue.lp = np->nvalue.lp;
    dp->nofree = 0;
    return(dp);
}


/* Trap for restricted variables FPATH, PATH, SHELL, ENV */
static void put_restricted(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    Shell_t *shp = nv_shell(np);
    int path_scoped = 0, fpath_scoped=0;
    Pathcomp_t *pp;
    char *name = nv_name(np);
    if(!(flags&NV_RDONLY) && sh_isoption(SH_RESTRICTED))
        errormsg(SH_DICT,ERROR_exit(1),e_restricted,nv_name(np));
    if(np==PATHNOD  || (path_scoped=(strcmp(name,PATHNOD->nvname)==0)))
    {
        nv_scan(shp->track_tree,rehash,(void*)0,NV_TAGGED,NV_TAGGED);
        if(path_scoped && !val)
            val = PATHNOD->nvalue.cp;
    }
    if(val && !(flags&NV_RDONLY) && np->nvalue.cp && strcmp(val,np->nvalue.cp)==0)
         return;
    if(np==FPATHNOD || (fpath_scoped=(strcmp(name,FPATHNOD->nvname)==0)))
        shp->pathlist = (void*)path_unsetfpath(shp);
    nv_putv(np, val, flags, fp);
    shp->universe = 0;
    if(shp->pathlist)
    {
        val = np->nvalue.cp;
        if(np==PATHNOD || path_scoped)
            pp = (void*)path_addpath(shp,(Pathcomp_t*)shp->pathlist,val,PATH_PATH);
        else if(val && (np==FPATHNOD || fpath_scoped))
            pp = (void*)path_addpath(shp,(Pathcomp_t*)shp->pathlist,val,PATH_FPATH);
        else
            return;
        if(shp->pathlist = (void*)pp)
            pp->shp = shp;
        if(!val && (flags&NV_NOSCOPE))
        {
            Namval_t *mp = dtsearch(shp->var_tree,np);
            if(mp && (val=nv_getval(mp)))
                nv_putval(mp,val,NV_RDONLY);
        }
#if 0
sfprintf(sfstderr,"%d: name=%s val=%s\n",getpid(),name,val);
path_dump((Pathcomp_t*)shp->pathlist);
#endif
    }
}

static void put_cdpath(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    Pathcomp_t *pp;
    Shell_t *shp = nv_shell(np);
    nv_putv(np, val, flags, fp);
    if(!shp->cdpathlist)
        return;
    val = np->nvalue.cp;
    pp = (void*)path_addpath(shp,(Pathcomp_t*)shp->cdpathlist,val,PATH_CDPATH);
    if(shp->cdpathlist = (void*)pp)
        pp->shp = shp;
}

#ifdef _hdr_locale
    /*
     * This function needs to be modified to handle international
     * error message translations
     */
#if ERROR_VERSION >= 20000101L
    static char* msg_translate(const char* catalog, const char* message)
    {
    NOT_USED(catalog);
    return((char*)message);
    }
#else
    static char* msg_translate(const char* message, int type)
    {
    NOT_USED(type);
    return((char*)message);
    }
#endif

    /* Trap for LC_ALL, LC_CTYPE, LC_MESSAGES, LC_COLLATE and LANG */
    static void put_lang(Namval_t* np,const char *val,int flags,Namfun_t *fp)
    {
    Shell_t *shp = nv_shell(np);
    int type;
    char *name = nv_name(np);
    if(name==(LCALLNOD)->nvname)
        type = LC_ALL;
    else if(name==(LCTYPENOD)->nvname)
        type = LC_CTYPE;
    else if(name==(LCMSGNOD)->nvname)
        type = LC_MESSAGES;
    else if(name==(LCCOLLNOD)->nvname)
        type = LC_COLLATE;
    else if(name==(LCNUMNOD)->nvname)
        type = LC_NUMERIC;
#ifdef LC_LANG
    else if(name==(LANGNOD)->nvname)
        type = LC_LANG;
#else
#define LC_LANG     LC_ALL
    else if(name==(LANGNOD)->nvname && (!(name=nv_getval(LCALLNOD)) || !*name))
        type = LC_LANG;
#endif
    else
        type= -1;
    if(!sh_isstate(SH_INIT) && (type>=0 || type==LC_ALL || type==LC_LANG))
    {
        char*       r;
#ifdef AST_LC_setenv
        ast.locale.set |= AST_LC_setenv;
#endif
        r = setlocale(type,val?val:"");
#ifdef AST_LC_setenv
        ast.locale.set ^= AST_LC_setenv;
#endif
        if(!r && val)
        {
            if(!sh_isstate(SH_INIT) || shp->login_sh==0)
                errormsg(SH_DICT,0,e_badlocale,val);
            return;
        }
    }
    nv_putv(np, val, flags, fp);
    if(CC_NATIVE!=CC_ASCII && (type==LC_ALL || type==LC_LANG || type==LC_CTYPE))
    {
        if(sh_lexstates[ST_BEGIN]!=sh_lexrstates[ST_BEGIN])
            free((void*)sh_lexstates[ST_BEGIN]);
        lctype++;
        if(ast.locale.set&(1<<AST_LC_CTYPE))
        {
            register int c;
            char *state[4];
            sh_lexstates[ST_BEGIN] = state[0] = (char*)malloc(4*(1<<CHAR_BIT));
            memcpy(state[0],sh_lexrstates[ST_BEGIN],(1<<CHAR_BIT));
            sh_lexstates[ST_NAME] = state[1] = state[0] + (1<<CHAR_BIT);
            memcpy(state[1],sh_lexrstates[ST_NAME],(1<<CHAR_BIT));
            sh_lexstates[ST_DOL] = state[2] = state[1] + (1<<CHAR_BIT);
            memcpy(state[2],sh_lexrstates[ST_DOL],(1<<CHAR_BIT));
            sh_lexstates[ST_BRACE] = state[3] = state[2] + (1<<CHAR_BIT);
            memcpy(state[3],sh_lexrstates[ST_BRACE],(1<<CHAR_BIT));
            for(c=0; c<(1<<CHAR_BIT); c++)
            {
                if(state[0][c]!=S_REG)
                    continue;
                if(state[2][c]!=S_ERR)
                    continue;
                if(isblank(c))
                {
                    state[0][c]=0;
                    state[1][c]=S_BREAK;
                    state[2][c]=S_BREAK;
                    continue;
                }
                if(!isalpha(c))
                    continue;
                state[0][c]=S_NAME;
                if(state[1][c]==S_REG)
                    state[1][c]=0;
                state[2][c]=S_ALP;
                if(state[3][c]==S_ERR)
                    state[3][c]=0;
            }
        }
        else
        {
            sh_lexstates[ST_BEGIN]=(char*)sh_lexrstates[ST_BEGIN];
            sh_lexstates[ST_NAME]=(char*)sh_lexrstates[ST_NAME];
            sh_lexstates[ST_DOL]=(char*)sh_lexrstates[ST_DOL];
            sh_lexstates[ST_BRACE]=(char*)sh_lexrstates[ST_BRACE];
        }
    }
#if ERROR_VERSION < 20000101L
    if(type==LC_ALL || type==LC_MESSAGES)
        error_info.translate = msg_translate;
#endif
    }
#endif /* _hdr_locale */

/* Trap for IFS assignment and invalidates state table */
static void put_ifs(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    register struct ifs *ip = (struct ifs*)fp;
    Shell_t     *shp;
    ip->ifsnp = 0;
    if(!val)
    {
        fp = nv_stack(np, NIL(Namfun_t*));
        if(fp && !fp->nofree)
            free((void*)fp);
    }
    if(val != np->nvalue.cp)
        nv_putv(np, val, flags, fp);
    if(!val && !(flags&NV_CLONE) && (fp=np->nvfun) && !fp->disc && (shp=(Shell_t*)(fp->last)))
        nv_stack(np,&((Init_t*)shp->init_context)->IFS_init.hdr);
}

/*
 * This is the lookup function for IFS
 * It keeps the sh.ifstable up to date
 */
static char* get_ifs(register Namval_t* np, Namfun_t *fp)
{
    register struct ifs *ip = (struct ifs*)fp;
    register char *cp, *value;
    register int c,n;
    register Shell_t *shp = nv_shell(np);
    value = nv_getv(np,fp);
    if(np!=ip->ifsnp)
    {
        ip->ifsnp = np;
        memset(shp->ifstable,0,(1<<CHAR_BIT));
        if(cp=value)
        {
#if SHOPT_MULTIBYTE
            while(n=mbsize(cp),c= *(unsigned char*)cp)
#else
            while(c= *(unsigned char*)cp++)
#endif /* SHOPT_MULTIBYTE */
            {
#if SHOPT_MULTIBYTE
                cp++;
                if(n>1)
                {
                    cp += (n-1);
                    shp->ifstable[c] = S_MBYTE;
                    continue;
                }
#endif /* SHOPT_MULTIBYTE */
                n = S_DELIM;
                if(c== *cp)
                    cp++;
                else if(c=='\n')
                    n = S_NL;
                else if(isspace(c))
                    n = S_SPACE;
                shp->ifstable[c] = n;
            }
        }
        else
        {
            shp->ifstable[' '] = shp->ifstable['\t'] = S_SPACE;
            shp->ifstable['\n'] = S_NL;
        }
    }
    return(value);
}

/*
 * these functions are used to get and set the SECONDS variable
 */
#ifdef timeofday
#   define dtime(tp) ((double)((tp)->tv_sec)+1e-6*((double)((tp)->tv_usec)))
#   define tms  timeval
#else
#   define dtime(tp)    (((double)times(tp))/shgd->lim.clk_tck)
#   define timeofday(a)
#endif

static void put_seconds(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    double d;
    struct tms tp;
    if(!val)
    {
        fp = nv_stack(np, NIL(Namfun_t*));
        if(fp && !fp->nofree)
            free((void*)fp);
        nv_putv(np, val, flags, fp);
        return;
    }
    if(!np->nvalue.dp)
    {
        nv_setsize(np,3);
        nv_onattr(np,NV_DOUBLE);
        np->nvalue.dp = new_of(double,0);
    }
    nv_putv(np, val, flags, fp);
    d = *np->nvalue.dp;
    timeofday(&tp);
    *np->nvalue.dp = dtime(&tp)-d;
}

static char* get_seconds(register Namval_t* np, Namfun_t *fp)
{
    Shell_t *shp = nv_shell(np);
    register int places = nv_size(np);
    struct tms tp;
    double d, offset = (np->nvalue.dp?*np->nvalue.dp:0);
    NOT_USED(fp);
    timeofday(&tp);
    d = dtime(&tp)- offset;
    sfprintf(shp->strbuf,"%.*f",places,d);
    return(sfstruse(shp->strbuf));
}

static Sfdouble_t nget_seconds(register Namval_t* np, Namfun_t *fp)
{
    struct tms tp;
    double offset = (np->nvalue.dp?*np->nvalue.dp:0);
    NOT_USED(fp);
    timeofday(&tp);
    return(dtime(&tp)- offset);
}

/*
 * These three functions are used to get and set the RANDOM variable
 */
static void put_rand(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    struct rand *rp = (struct rand*)fp;
    register long n;
    if(!val)
    {
        fp = nv_stack(np, NIL(Namfun_t*));
        if(fp && !fp->nofree)
            free((void*)fp);
        _nv_unset(np,0);
        return;
    }
    if(flags&NV_INTEGER)
        n = *(double*)val;
    else
        n = sh_arith(rp->sh,val);
    srand((int)(n&RANDMASK));
    rp->rand_last = -1;
    if(!np->nvalue.lp)
        np->nvalue.lp = &rp->rand_last;
}

/*
 * get random number in range of 0 - 2**15
 * never pick same number twice in a row
 */
static Sfdouble_t nget_rand(register Namval_t* np, Namfun_t *fp)
{
    register long cur, last= *np->nvalue.lp;
    NOT_USED(fp);
    do
        cur = (rand()>>rand_shift)&RANDMASK;
    while(cur==last);
    *np->nvalue.lp = cur;
    return((Sfdouble_t)cur);
}

static char* get_rand(register Namval_t* np, Namfun_t *fp)
{
    register long n = nget_rand(np,fp);
    return(fmtbase(n, 10, 0));
}

/*
 * These three routines are for LINENO
 */
static Sfdouble_t nget_lineno(Namval_t* np, Namfun_t *fp)
{
    double d=1;
    if(error_info.line >0)
        d = error_info.line;
    else if(error_info.context && error_info.context->line>0)
        d = error_info.context->line;
    NOT_USED(np);
    NOT_USED(fp);
    return(d);
}

static void put_lineno(Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    register long n;
    Shell_t *shp = nv_shell(np);
    if(!val)
    {
        fp = nv_stack(np, NIL(Namfun_t*));
        if(fp && !fp->nofree)
            free((void*)fp);
        _nv_unset(np,0);
        return;
    }
    if(flags&NV_INTEGER)
        n = *(double*)val;
    else
        n = sh_arith(shp,val);
    shp->st.firstline += nget_lineno(np,fp)+1-n;
}

static char* get_lineno(register Namval_t* np, Namfun_t *fp)
{
    register long n = nget_lineno(np,fp);
    return(fmtbase(n, 10, 0));
}

static char* get_lastarg(Namval_t* np, Namfun_t *fp)
{
    Shell_t *shp = nv_shell(np);
    char    *cp;
    int pid;
        if(sh_isstate(SH_INIT) && (cp=shp->lastarg) && *cp=='*' && (pid=strtol(cp+1,&cp,10)) && *cp=='*')
        nv_putval(np,(pid==shp->gd->ppid?cp+1:0),0);
    return(shp->lastarg);
}

static void put_lastarg(Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    Shell_t *shp = nv_shell(np);
    if(flags&NV_INTEGER)
    {
        sfprintf(shp->strbuf,"%.*g",12,*((double*)val));
        val = sfstruse(shp->strbuf);
    }
    if(val)
        val = strdup(val);
    if(shp->lastarg && !nv_isattr(np,NV_NOFREE))
        free((void*)shp->lastarg);
    else
        nv_offattr(np,NV_NOFREE);
    shp->lastarg = (char*)val;
    nv_offattr(np,NV_EXPORT);
    np->nvenv = 0;
}

static int hasgetdisc(register Namfun_t *fp)
{
        while(fp && !fp->disc->getnum && !fp->disc->getval)
                fp = fp->next;
    return(fp!=0);
}

/*
 * store the most recent value for use in .sh.match
 */
void sh_setmatch(const char *v, int vsize, int nmatch, int match[])
{
    struct match *mp = (struct match*)(SH_MATCHNOD->nvfun->next);
    register int i,n;
    if(mp->nmatch = nmatch)
    {
        memcpy(mp->match,match,nmatch*2*sizeof(match[0]));
        for(n=match[0],vsize=0,i=0; i < 2*nmatch; i++)
        {
            if(mp->match[i]>=0 && (mp->match[i] -= n) > vsize)
                vsize = mp->match[i];
        }
        v += n;
        if(vsize >= mp->vsize)
        {
            if(mp->vsize)
                mp->val = (char*)realloc(mp->val,vsize+1);
            else
                mp->val = (char*)malloc(vsize+1);
            mp->vsize = vsize;
        }
        memcpy(mp->val,v,vsize);
        mp->val[vsize] = 0;
        nv_putsub(SH_MATCHNOD, NIL(char*), (nmatch-1)|ARRAY_FILL|ARRAY_SETSUB);
        for(n=match[0],i=1; i < nmatch; i++)
        {
            if(mp->match[2*i] < 0)
            {
                nv_putsub(SH_MATCHNOD,NIL(char*),i);
                _nv_unset(SH_MATCHNOD,NV_RDONLY);
            }
        }
        mp->lastsub = -1;
    }
}

#define array_scan(np)  ((nv_arrayptr(np)->nelem&ARRAY_SCAN))

static char* get_match(register Namval_t* np, Namfun_t *fp)
{
    struct match *mp = (struct match*)fp;
    int sub,n;
    char *val;
    sub = nv_aindex(np);
    if(sub>=mp->nmatch)
        return(0);
    if(sub==mp->lastsub)
        return(mp->rval);
    if(mp->rval)
    {
        free((void*)mp->rval);
        mp->rval = 0;
    }
    n = mp->match[2*sub+1]-mp->match[2*sub];
    if(n<=0)
        return("");
    val = mp->val+mp->match[2*sub];
    if(mp->val[mp->match[2*sub+1]]==0)
        return(val);
    mp->rval = (char*)malloc(n+1);
    mp->lastsub = sub;
    memcpy(mp->rval,val,n);
    mp->rval[n] = 0;
    return(mp->rval);
}

static const Namdisc_t SH_MATCH_disc  = { sizeof(struct match), 0, get_match };

static char* get_version(register Namval_t* np, Namfun_t *fp)
{
    return(nv_getv(np,fp));
}

static Sfdouble_t nget_version(register Namval_t* np, Namfun_t *fp)
{
    register const char *cp = e_version + strlen(e_version)-10;
    register int        c;
    Sflong_t        t = 0;
    NOT_USED(fp);

    while (c = *cp++)
        if (c >= '0' && c <= '9')
        {
            t *= 10;
            t += c - '0';
        }
    return((Sfdouble_t)t);
}

static const Namdisc_t SH_VERSION_disc  = {  0, 0, get_version, nget_version };

#if SHOPT_FS_3D
    /*
     * set or unset the mappings given a colon separated list of directories
     */
    static void vpath_set(char *str, int mode)
    {
    register char *lastp, *oldp=str, *newp=strchr(oldp,':');
    if(!shgd->lim.fs3d)
        return;
    while(newp)
    {
        *newp++ = 0;
        if(lastp=strchr(newp,':'))
            *lastp = 0;
        mount((mode?newp:""),oldp,FS3D_VIEW,0);
        newp[-1] = ':';
        oldp = newp;
        newp=lastp;
    }
    }

    /* catch vpath assignments */
    static void put_vpath(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
    {
    register char *cp;
    if(cp = nv_getval(np))
        vpath_set(cp,0);
    if(val)
        vpath_set((char*)val,1);
    nv_putv(np,val,flags,fp);
    }
    static const Namdisc_t VPATH_disc   = { 0, put_vpath  };
    static Namfun_t VPATH_init  = { &VPATH_disc, 1  };
#endif /* SHOPT_FS_3D */


static const Namdisc_t IFS_disc     = {  sizeof(struct ifs), put_ifs, get_ifs };
const Namdisc_t RESTRICTED_disc = {  sizeof(Namfun_t), put_restricted };
static const Namdisc_t CDPATH_disc  = {  sizeof(Namfun_t), put_cdpath };
static const Namdisc_t EDITOR_disc  = {  sizeof(Namfun_t), put_ed };
static const Namdisc_t HISTFILE_disc    = {  sizeof(Namfun_t), put_history };
static const Namdisc_t OPTINDEX_disc    = {  sizeof(Namfun_t), put_optindex, 0, nget_optindex, 0, 0, clone_optindex };
static const Namdisc_t SECONDS_disc = {  sizeof(struct seconds), put_seconds, get_seconds, nget_seconds };
static const Namdisc_t RAND_disc    = {  sizeof(struct rand), put_rand, get_rand, nget_rand };
static const Namdisc_t LINENO_disc  = {  sizeof(Namfun_t), put_lineno, get_lineno, nget_lineno };
static const Namdisc_t L_ARG_disc   = {  sizeof(Namfun_t), put_lastarg, get_lastarg };


#define MAX_MATH_ARGS   3

static char *name_math(Namval_t *np, Namfun_t *fp)
{
    Shell_t     *shp = sh_getinterp();
    sfprintf(shp->strbuf,".sh.math.%s",np->nvname);
    return(sfstruse(shp->strbuf));
}

static const Namdisc_t  math_child_disc =
{
    0,0,0,0,0,0,0,
    name_math
};

static Namfun_t  math_child_fun =
{
    &math_child_disc, 1, 0, sizeof(Namfun_t)
};

static void math_init(Shell_t *shp)
{
    Namval_t    *np;
    char        *name;
    int     i;
    shp->mathnodes = (char*)calloc(1,MAX_MATH_ARGS*(NV_MINSZ+5));
    name = shp->mathnodes+MAX_MATH_ARGS*NV_MINSZ;
    for(i=0; i < MAX_MATH_ARGS; i++)
    {
        np = nv_namptr(shp->mathnodes,i);
        np->nvfun = &math_child_fun;
        memcpy(name,"arg",3);
        name[3] = '1'+i;
        np->nvname = name;
        name+=5;
        nv_onattr(np,NV_MINIMAL|NV_NOFREE|NV_LDOUBLE|NV_RDONLY);
    }
}

static Namval_t *create_math(Namval_t *np,const char *name,int flag,Namfun_t *fp)
{
    Shell_t     *shp = nv_shell(np);
    if(!name)
        return(SH_MATHNOD);
    if(name[0]!='a' || name[1]!='r' || name[2]!='g' || name[4] || !isdigit(name[3]) || (name[3]=='0' || (name[3]-'0')>MAX_MATH_ARGS))
        return(0);
    fp->last = (char*)&name[4];
    return(nv_namptr(shp->mathnodes,name[3]-'1'));
}

static char* get_math(register Namval_t* np, Namfun_t *fp)
{
    Shell_t     *shp = nv_shell(np);
    Namval_t    *mp,fake;
    char        *val;
    int     first=0;
    fake.nvname = ".sh.math.";
    mp = (Namval_t*)dtprev(shp->fun_tree,&fake);
    while(mp=(Namval_t*)dtnext(shp->fun_tree,mp))
    {
        if(memcmp(mp->nvname,".sh.math.",9))
            break;
        if(first++)
            sfputc(shp->strbuf,' ');
        sfputr(shp->strbuf,mp->nvname+9,-1);
    }
    val = sfstruse(shp->strbuf);
    return(val);

}

static char *setdisc_any(Namval_t *np, const char *event, Namval_t *action, Namfun_t *fp)
{
    Shell_t     *shp=nv_shell(np);
    Namval_t    *mp,fake;
    char        *name;
    int     getname=0, off=staktell();
    fake.nvname = nv_name(np);
    if(!event)
    {
        if(!action)
        {
            mp = (Namval_t*)dtprev(shp->fun_tree,&fake);
            return((char*)dtnext(shp->fun_tree,mp));
        }
        getname = 1;
    }
    stakputs(fake.nvname);
    stakputc('.');
    stakputs(event);
    stakputc(0);
    name  = stakptr(off);
    mp = nv_search(name, shp->fun_tree, action?NV_ADD:0);
    stakseek(off);
    if(getname)
        return(mp?(char*)dtnext(shp->fun_tree,mp):0);
    if(action==np)
        action = mp;
    return(action?(char*)action:"");
}

static const Namdisc_t SH_MATH_disc  = { 0, 0, get_math, 0, setdisc_any, create_math, };

#if SHOPT_COSHELL
static const Namdisc_t SH_JOBPOOL_disc  = { 0, 0, 0, 0, setdisc_any, 0, };
#endif /*  SHOPT_COSHELL */

#if SHOPT_NAMESPACE
    static char* get_nspace(Namval_t* np, Namfun_t *fp)
    {
    if(sh.namespace)
        return(nv_name(sh.namespace));
    return((char*)np->nvalue.cp);
    }
    static const Namdisc_t NSPACE_disc  = {  0, 0, get_nspace };
    static Namfun_t NSPACE_init = {  &NSPACE_disc, 1};
#endif /* SHOPT_NAMESPACE */

#ifdef _hdr_locale
    static const Namdisc_t LC_disc  = {  sizeof(Namfun_t), put_lang };
#endif /* _hdr_locale */

/*
 * This function will get called whenever a configuration parameter changes
 */
static int newconf(const char *name, const char *path, const char *value)
{
    Shell_t *shp = sh_getinterp();
    register char *arg;
    if(!name)
        setenviron(value);
    else if(strcmp(name,"UNIVERSE")==0 && strcmp(astconf(name,0,0),value))
    {
        shp->universe = 0;
        /* set directory in new universe */
        if(*(arg = path_pwd(shp,0))=='/')
            chdir(arg);
        /* clear out old tracked alias */
        stakseek(0);
        stakputs(nv_getval(PATHNOD));
        stakputc(0);
        nv_putval(PATHNOD,stakseek(0),NV_RDONLY);
    }
    return(1);
}

#if (CC_NATIVE != CC_ASCII)
    static void a2e(char *d, const char *s)
    {
    register const unsigned char *t;
    register int i;
    t = CCMAP(CC_ASCII, CC_NATIVE);
    for(i=0; i<(1<<CHAR_BIT); i++)
        d[t[i]] = s[i];
    }

    static void init_ebcdic(void)
    {
    int i;
    char *cp = (char*)malloc(ST_NONE*(1<<CHAR_BIT));
    for(i=0; i < ST_NONE; i++)
    {
        a2e(cp,sh_lexrstates[i]);
        sh_lexstates[i] = cp;
        cp += (1<<CHAR_BIT);
    }
    }
#endif

/*
 * return SH_TYPE_* bitmask for path
 * 0 for "not a shell"
 */
int sh_type(register const char *path)
{
    register const char*    s;
    register int        t = 0;

    if (s = (const char*)strrchr(path, '/'))
    {
        if (*path == '-')
            t |= SH_TYPE_LOGIN;
        s++;
    }
    else
        s = path;
    if (*s == '-')
    {
        s++;
        t |= SH_TYPE_LOGIN;
    }
    for (;;)
    {
        if (!(t & (SH_TYPE_KSH|SH_TYPE_BASH)))
        {
            if (*s == 'k')
            {
                s++;
                t |= SH_TYPE_KSH;
                continue;
            }
#if SHOPT_BASH
            if (*s == 'b' && *(s+1) == 'a')
            {
                s += 2;
                t |= SH_TYPE_BASH;
                continue;
            }
#endif
        }
        if (!(t & (SH_TYPE_PROFILE|SH_TYPE_RESTRICTED)))
        {
#if SHOPT_PFSH
            if (*s == 'p' && *(s+1) == 'f')
            {
                s += 2;
                t |= SH_TYPE_PROFILE;
                continue;
            }
#endif
            if (*s == 'r')
            {
                s++;
                t |= SH_TYPE_RESTRICTED;
                continue;
            }
        }
        break;
    }
    if (*s++ == 's' && (*s == 'h' || *s == 'u'))
    {
        s++;
        t |= SH_TYPE_SH;
        if ((t & SH_TYPE_KSH) && *s == '9' && *(s+1) == '3')
            s += 2;
#if _WINIX
        if (*s == '.' && *(s+1) == 'e' && *(s+2) == 'x' && *(s+3) == 'e')
            s += 4;
#endif
        if (!isalnum(*s))
            return t;
    }
    return t & ~(SH_TYPE_BASH|SH_TYPE_KSH|SH_TYPE_PROFILE|SH_TYPE_RESTRICTED);
}


static char *get_mode(Namval_t* np, Namfun_t* nfp)
{
    mode_t mode = nv_getn(np,nfp);
    return(fmtperm(mode));
}

static void put_mode(Namval_t* np, const char* val, int flag, Namfun_t* nfp)
{
    if(val)
    {
        mode_t mode;
        char *last;
        if(flag&NV_INTEGER)
        {
            if(flag&NV_LONG)
                mode = *(Sfdouble_t*)val;
            else
                mode = *(double*)val;
        }
        else
            mode = strperm(val, &last,0);
        if(*last)
            errormsg(SH_DICT,ERROR_exit(1),"%s: invalid mode string",val);
        nv_putv(np,(char*)&mode,NV_INTEGER,nfp);
    }
    else
        nv_putv(np,val,flag,nfp);
}

static const Namdisc_t modedisc =
{
    0,
        put_mode,
        get_mode,
};


/*
 * initialize the shell
 */
Shell_t *sh_init(register int argc,register char *argv[], Shinit_f userinit)
{
    static int beenhere;
    Shell_t *shp;
    register int n;
    int type;
    static char *login_files[3];
    memfatal();
    n = strlen(e_version);
    if(e_version[n-1]=='$' && e_version[n-2]==' ')
        e_version[n-2]=0;
#if (CC_NATIVE == CC_ASCII)
    memcpy(sh_lexstates,sh_lexrstates,ST_NONE*sizeof(char*));
#else
    init_ebcdic();
#endif
    if(!beenhere)
    {
        beenhere = 1;
        shp = &sh;
        shgd = newof(0,struct shared,1,0);
        shgd->pid = getpid();
        shgd->ppid = getppid();
        shgd->userid=getuid();
        shgd->euserid=geteuid();
        shgd->groupid=getgid();
        shgd->egroupid=getegid();
        shgd->lim.clk_tck = getconf("CLK_TCK");
        shgd->lim.arg_max = getconf("ARG_MAX");
        shgd->lim.child_max = getconf("CHILD_MAX");
        shgd->lim.ngroups_max = getconf("NGROUPS_MAX");
        shgd->lim.posix_version = getconf("VERSION");
        shgd->lim.posix_jobcontrol = getconf("JOB_CONTROL");
        if(shgd->lim.arg_max <=0)
            shgd->lim.arg_max = ARG_MAX;
        if(shgd->lim.child_max <=0)
            shgd->lim.child_max = CHILD_MAX;
        if(shgd->lim.clk_tck <=0)
            shgd->lim.clk_tck = CLK_TCK;
#if SHOPT_FS_3D
        if(fs3d(FS3D_TEST))
            shgd->lim.fs3d = 1;
#endif /* SHOPT_FS_3D */
        shgd->ed_context = (void*)ed_open(shp);
        error_info.exit = sh_exit;
        error_info.id = path_basename(argv[0]);
    }
    else
        newof(0,Shell_t,1,0);
    umask(shp->mask=umask(0));
    shp->gd = shgd;
    shp->mac_context = sh_macopen(shp);
    shp->arg_context = sh_argopen(shp);
    shp->lex_context = (void*)sh_lexopen(0,shp,1);
    shp->strbuf = sfstropen();
    shp->stk = stkstd;
    sfsetbuf(shp->strbuf,(char*)0,64);
    sh_onstate(SH_INIT);
#if ERROR_VERSION >= 20000102L
    error_info.catalog = e_dict;
#endif
#if SHOPT_REGRESS
    {
        Opt_t*  nopt;
        Opt_t*  oopt;
        char*   a;
        char**  av = argv;
        char*   regress[3];

        sh_regress_init(shp);
        regress[0] = "__regress__";
        regress[2] = 0;
        /* NOTE: only shp is used by __regress__ at this point */
        shp->bltindata.shp = shp;
        while ((a = *++av) && a[0] == '-' && (a[1] == 'I' || a[1] == '-' && a[2] == 'r'))
        {
            if (a[1] == 'I')
            {
                if (a[2])
                    regress[1] = a + 2;
                else if (!(regress[1] = *++av))
                    break;
            }
            else if (strncmp(a+2, "regress", 7))
                break;
            else if (a[9] == '=')
                regress[1] = a + 10;
            else if (!(regress[1] = *++av))
                break;
            nopt = optctx(0, 0);
            oopt = optctx(nopt, 0);
            b___regress__(2, regress, &shp->bltindata);
            optctx(oopt, nopt);
        }
    }
#endif
    shp->cpipe[0] = -1;
    shp->coutpipe = -1;
    for(n=0;n < 10; n++)
    {
        /* don't use lower bits when rand() generates large numbers */
        if(rand() > RANDMASK)
        {
            rand_shift = 3;
            break;
        }
    }
    sh_ioinit(shp);
    /* initialize signal handling */
    sh_siginit(shp);
    stakinstall(NIL(Stak_t*),nospace);
    /* set up memory for name-value pairs */
    shp->init_context =  nv_init(shp);
    /* read the environment */
    if(argc>0)
    {
        type = sh_type(*argv);
        if(type&SH_TYPE_LOGIN)
            shp->login_sh = 2;
    }
    env_init(shp);
    if(!ENVNOD->nvalue.cp)
    {
        sfprintf(shp->strbuf,"%s/.kshrc",nv_getval(HOME));
        nv_putval(ENVNOD,sfstruse(shp->strbuf),NV_RDONLY);
    }
    *SHLVL->nvalue.ip +=1;
    nv_offattr(SHLVL,NV_IMPORT);
#if SHOPT_SPAWN
    {
        /*
         * try to find the pathname for this interpreter
         * try using environment variable _ or argv[0]
         */
        char *cp=nv_getval(L_ARGNOD);
        char buff[PATH_MAX+1];
        shp->gd->shpath = 0;
#if _AST_VERSION >= 20090202L
        if((n = pathprog(NiL, buff, sizeof(buff))) > 0 && n <= sizeof(buff))
            shp->gd->shpath = strdup(buff);
#else
        sfprintf(shp->strbuf,"/proc/%d/exe",getpid());
        if((n=readlink(sfstruse(shp->strbuf),buff,sizeof(buff)-1))>0)
        {
            buff[n] = 0;
            shp->gd->shpath = strdup(buff);
        }
#endif
        else if((cp && (sh_type(cp)&SH_TYPE_SH)) || (argc>0 && strchr(cp= *argv,'/')))
        {
            if(*cp=='/')
                shp->gd->shpath = strdup(cp);
            else if(cp = nv_getval(PWDNOD))
            {
                int offset = staktell();
                stakputs(cp);
                stakputc('/');
                stakputs(argv[0]);
                pathcanon(stakptr(offset),PATH_DOTDOT);
                shp->gd->shpath = strdup(stakptr(offset));
                stakseek(offset);
            }
        }
    }
#endif
    nv_putval(IFSNOD,(char*)e_sptbnl,NV_RDONLY);
#if SHOPT_FS_3D
    nv_stack(VPATHNOD, &VPATH_init);
#endif /* SHOPT_FS_3D */
    astconfdisc(newconf);
#if SHOPT_TIMEOUT
    shp->st.tmout = SHOPT_TIMEOUT;
#endif /* SHOPT_TIMEOUT */
    /* initialize jobs table */
    job_clear();
    if(argc>0)
    {
        int dolv_index = -1;
        /* check for restricted shell */
        if(type&SH_TYPE_RESTRICTED)
            sh_onoption(SH_RESTRICTED);
#if SHOPT_PFSH
        /* check for profile shell */
        else if(type&SH_TYPE_PROFILE)
            sh_onoption(SH_PFSH);
#endif
#if SHOPT_BASH
        /* check for invocation as bash */
        if(type&SH_TYPE_BASH)
        {
                shp>userinit = userinit = bash_init;
            sh_onoption(SH_BASH);
            sh_onstate(SH_PREINIT);
            (*userinit)(shp, 0);
            sh_offstate(SH_PREINIT);
        }
#endif
        /* look for options */
        /* shp->st.dolc is $#   */
        if((shp->st.dolc = sh_argopts(-argc,argv,shp)) < 0)
        {
            shp->exitval = 2;
            sh_done(shp,0);
        }
        opt_info.disc = 0;
        dolv_index = (argc-1)-shp->st.dolc;
        shp->st.dolv=argv+dolv_index;
        shp->st.repl_index = dolv_index;
        shp->st.repl_arg = argv[dolv_index];
        shp->st.dolv[0] = argv[0];
        if(shp->st.dolc < 1)
            sh_onoption(SH_SFLAG);
        if(!sh_isoption(SH_SFLAG))
        {
            shp->st.dolc--;
            shp->st.dolv++;
#if _WINIX
            {
                char*   name;
                name = shp->st.dolv[0];
                if(name[1]==':' && (name[2]=='/' || name[2]=='\\'))
                {
#if _lib_pathposix
                    char*   p;

                    if((n = pathposix(name, NIL(char*), 0)) > 0 && (p = (char*)malloc(++n)))
                    {
                        pathposix(name, p, n);
                        name = p;
                    }
                    else
#endif
                    {
                        name[1] = name[0];
                        name[0] = name[2] = '/';
                    }
                }
            }
#endif /* _WINIX */
        }
        if(beenhere==1)
        {
            struct lconv*   lc;
            shp->decomma = (lc=localeconv()) && lc->decimal_point && *lc->decimal_point==',';
            beenhere = 2;
        }
    }
#if SHOPT_PFSH
    if (sh_isoption(SH_PFSH))
    {
        struct passwd *pw = getpwuid(shp->gd->userid);
        if(pw)
            shp->gd->user = strdup(pw->pw_name);

    }
#endif
    /* set[ug]id scripts require the -p flag */
    if(shp->gd->userid!=shp->gd->euserid || shp->gd->groupid!=shp->gd->egroupid)
    {
#ifdef SHOPT_P_SUID
        /* require sh -p to run setuid and/or setgid */
        if(!sh_isoption(SH_PRIVILEGED) && shp->gd->userid >= SHOPT_P_SUID)
        {
            setuid(shp->gd->euserid=shp->gd->userid);
            setgid(shp->gd->egroupid=shp->gd->groupid);
        }
        else
#endif /* SHOPT_P_SUID */
            sh_onoption(SH_PRIVILEGED);
#ifdef SHELLMAGIC
        /* careful of #! setuid scripts with name beginning with - */
        if(shp->login_sh && argv[1] && strcmp(argv[0],argv[1])==0)
            errormsg(SH_DICT,ERROR_exit(1),e_prohibited);
#endif /*SHELLMAGIC*/
    }
    else
        sh_offoption(SH_PRIVILEGED);
    /* shname for $0 in profiles and . scripts */
    if(sh_isdevfd(argv[1]))
        shp->shname = strdup(argv[0]);
    else
        shp->shname = strdup(shp->st.dolv[0]);
    /*
     * return here for shell script execution
     * but not for parenthesis subshells
     */
    error_info.id = strdup(shp->st.dolv[0]); /* error_info.id is $0 */
    shp->jmpbuffer = (void*)&shp->checkbase;
    sh_pushcontext(shp,&shp->checkbase,SH_JMPSCRIPT);
    shp->st.self = &shp->global;
        shp->topscope = (Shscope_t*)shp->st.self;
    sh_offstate(SH_INIT);
    login_files[0] = (char*)e_profile;
    login_files[1] = ".profile";
    shp->gd->login_files = login_files;
    shp->bltindata.version = SH_VERSION;
    shp->bltindata.shp = shp;
    shp->bltindata.shrun = sh_run;
    shp->bltindata.shtrap = sh_trap;
    shp->bltindata.shexit = sh_exit;
    shp->bltindata.shbltin = sh_addbuiltin;
#if _AST_VERSION >= 20080617L
    shp->bltindata.shgetenv = sh_getenv;
    shp->bltindata.shsetenv = sh_setenviron;
    astintercept(&shp->bltindata,1);
#endif
#if 0
#define NV_MKINTTYPE(x,y,z) nv_mkinttype(#x,sizeof(x),(x)-1<0,(y),(Namdisc_t*)z);
    NV_MKINTTYPE(pid_t,"process id",0);
    NV_MKINTTYPE(gid_t,"group id",0);
    NV_MKINTTYPE(uid_t,"user id",0);
    NV_MKINTTYPE(size_t,(const char*)0,0);
    NV_MKINTTYPE(ssize_t,(const char*)0,0);
    NV_MKINTTYPE(off_t,"offset in bytes",0);
    NV_MKINTTYPE(ino_t,"\ai-\anode number",0);
    NV_MKINTTYPE(mode_t,(const char*)0,&modedisc);
    NV_MKINTTYPE(dev_t,"device id",0);
    NV_MKINTTYPE(nlink_t,"hard link count",0);
    NV_MKINTTYPE(blkcnt_t,"block count",0);
    NV_MKINTTYPE(time_t,"seconds since the epoch",0);
    nv_mkstat();
#endif
    if(shp->userinit=userinit)
        (*userinit)(shp, 0);
    return(shp);
}

Shell_t *sh_getinterp(void)
{
    return(&sh);
}

/*
 * reinitialize before executing a script
 */
int sh_reinit(char *argv[])
{
    Shell_t *shp = sh_getinterp();
    Shopt_t opt;
    Namval_t *np,*npnext;
    Dt_t    *dp;
    struct adata
    {
        Shell_t     *sh;
        void        *extra[2];
    } data;
    for(np=dtfirst(shp->fun_tree);np;np=npnext)
    {
        if((dp=shp->fun_tree)->walk)
            dp = dp->walk;
        npnext = (Namval_t*)dtnext(shp->fun_tree,np);
        if(np>= shgd->bltin_cmds && np < &shgd->bltin_cmds[nbltins])
            continue;
        if(is_abuiltin(np) && nv_isattr(np,NV_EXPORT))
            continue;
        if(*np->nvname=='/')
            continue;
        nv_delete(np,dp,NV_NOFREE);
    }
    dtclose(shp->alias_tree);
    shp->alias_tree = inittree(shp,shtab_aliases);
    shp->last_root = shp->var_tree;
    shp->inuse_bits = 0;
    if(shp->userinit)
        (*shp->userinit)(shp, 1);
    if(shp->heredocs)
    {
        sfclose(shp->heredocs);
        shp->heredocs = 0;
    }
    /* remove locals */
    sh_onstate(SH_INIT);
    memset(&data,0,sizeof(data));
    data.sh = shp;
    nv_scan(shp->var_tree,sh_envnolocal,(void*)&data,NV_EXPORT,0);
    nv_scan(shp->var_tree,sh_envnolocal,(void*)&data,NV_ARRAY,NV_ARRAY);
    sh_offstate(SH_INIT);
    memset(shp->st.trapcom,0,(shp->st.trapmax+1)*sizeof(char*));
    memset((void*)&opt,0,sizeof(opt));
#if SHOPT_NAMESPACE
    if(shp->namespace)
    {
        dp=nv_dict(shp->namespace);
        if(dp==shp->var_tree)
            shp->var_tree = dtview(dp,0);
        _nv_unset(shp->namespace,NV_RDONLY);
        shp->namespace = 0;
    }
#endif /* SHOPT_NAMESPACE */
    if(sh_isoption(SH_TRACKALL))
        on_option(&opt,SH_TRACKALL);
    if(sh_isoption(SH_EMACS))
        on_option(&opt,SH_EMACS);
    if(sh_isoption(SH_GMACS))
        on_option(&opt,SH_GMACS);
    if(sh_isoption(SH_VI))
        on_option(&opt,SH_VI);
    if(sh_isoption(SH_VIRAW))
        on_option(&opt,SH_VIRAW);
    shp->options = opt;
    /* set up new args */
    if(argv)
        shp->arglist = sh_argcreate(argv);
    if(shp->arglist)
        sh_argreset(shp,shp->arglist,NIL(struct dolnod*));
    shp->envlist=0;
    shp->curenv = 0;
    shp->shname = error_info.id = strdup(shp->st.dolv[0]);
    sh_offstate(SH_FORKED);
    shp->fn_depth = shp->dot_depth = 0;
    sh_sigreset(0);
    if(!(SHLVL->nvalue.ip))
    {
        shlvl = 0;
        SHLVL->nvalue.ip = &shlvl;
        nv_onattr(SHLVL,NV_INTEGER|NV_EXPORT|NV_NOFREE);
    }
    *SHLVL->nvalue.ip +=1;
    nv_offattr(SHLVL,NV_IMPORT);
    shp->st.filename = strdup(shp->lastarg);
    return(1);
}

/*
 * set when creating a local variable of this name
 */
Namfun_t *nv_cover(register Namval_t *np)
{
    if(np==IFSNOD || np==PATHNOD || np==SHELLNOD || np==FPATHNOD || np==CDPNOD || np==SECONDS || np==ENVNOD || np==LINENO)
        return(np->nvfun);
#ifdef _hdr_locale
    if(np==LCALLNOD || np==LCTYPENOD || np==LCMSGNOD || np==LCCOLLNOD || np==LCNUMNOD || np==LANGNOD)
        return(np->nvfun);
#endif
     return(0);
}

static const char *shdiscnames[] = { "tilde", 0};

#ifdef SHOPT_STATS
struct Stats
{
    Namfun_t    hdr;
    Shell_t     *sh;
    char        *nodes;
    int     numnodes;
    int     current;
};

static Namval_t *next_stat(register Namval_t* np, Dt_t *root,Namfun_t *fp)
{
    struct Stats *sp = (struct Stats*)fp;
    if(!root)
        sp->current = 0;
    else if(++sp->current>=sp->numnodes)
        return(0);
    return(nv_namptr(sp->nodes,sp->current));
}

static Namval_t *create_stat(Namval_t *np,const char *name,int flag,Namfun_t *fp)
{
    struct Stats        *sp = (struct Stats*)fp;
    register const char *cp=name;
    register int        i=0,n;
    Namval_t        *nq=0;
    Shell_t         *shp = sp->sh;
    if(!name)
        return(SH_STATS);
    while((i=*cp++) && i != '=' && i != '+' && i!='[');
    n = (cp-1) -name;
    for(i=0; i < sp->numnodes; i++)
    {
        nq = nv_namptr(sp->nodes,i);
        if((n==0||memcmp(name,nq->nvname,n)==0) && nq->nvname[n]==0)
            goto found;
    }
    nq = 0;
found:
    if(nq)
    {
        fp->last = (char*)&name[n];
        shp->last_table = SH_STATS;
    }
    else
        errormsg(SH_DICT,ERROR_exit(1),e_notelem,n,name,nv_name(np));
    return(nq);
}

static const Namdisc_t stat_disc =
{
    0, 0, 0, 0, 0,
    create_stat,
    0, 0,
    next_stat
};

static char *name_stat(Namval_t *np, Namfun_t *fp)
{
    Shell_t *shp = sh_getinterp();
    sfprintf(shp->strbuf,".sh.stats.%s",np->nvname);
    return(sfstruse(shp->strbuf));
}

static const Namdisc_t  stat_child_disc =
{
    0,0,0,0,0,0,0,
    name_stat
};

static Namfun_t  stat_child_fun =
{
    &stat_child_disc, 1, 0, sizeof(Namfun_t)
};

static void stat_init(Shell_t *shp)
{
    int     i,nstat = STAT_SUBSHELL+1;
    struct Stats    *sp = newof(0,struct Stats,1,nstat*NV_MINSZ);
    Namval_t    *np;
    sp->numnodes = nstat;
    sp->nodes = (char*)(sp+1);
    shgd->stats = (int*)calloc(sizeof(int*),nstat);
    sp->sh = shp;
    for(i=0; i < nstat; i++)
    {
        np = nv_namptr(sp->nodes,i);
        np->nvfun = &stat_child_fun;
        np->nvname = (char*)shtab_stats[i].sh_name;
        nv_onattr(np,NV_RDONLY|NV_MINIMAL|NV_NOFREE|NV_INTEGER);
        nv_setsize(np,10);
        np->nvalue.ip = &shgd->stats[i];
    }
    sp->hdr.dsize = sizeof(struct Stats) + nstat*(sizeof(int)+NV_MINSZ);
    sp->hdr.disc = &stat_disc;
    nv_stack(SH_STATS,&sp->hdr);
    sp->hdr.nofree = 1;
    nv_setvtree(SH_STATS);
}
#else
#   define stat_init(x)
#endif /* SHOPT_STATS */

/*
 * Initialize the shell name and alias table
 */
static Init_t *nv_init(Shell_t *shp)
{
    register Init_t *ip;
    double d=0;
    ip = newof(0,Init_t,1,0);
    if(!ip)
        return(0);
    shp->nvfun.last = (char*)shp;
    shp->nvfun.nofree = 1;
    ip->sh = shp;
    shp->var_base = shp->var_tree = inittree(shp,shtab_variables);
    SHLVL->nvalue.ip = &shlvl;
    ip->IFS_init.hdr.disc = &IFS_disc;
    ip->PATH_init.disc = &RESTRICTED_disc;
    ip->PATH_init.nofree = 1;
    ip->FPATH_init.disc = &RESTRICTED_disc;
    ip->FPATH_init.nofree = 1;
    ip->CDPATH_init.disc = &CDPATH_disc;
    ip->CDPATH_init.nofree = 1;
    ip->SHELL_init.disc = &RESTRICTED_disc;
    ip->SHELL_init.nofree = 1;
    ip->ENV_init.disc = &RESTRICTED_disc;
    ip->ENV_init.nofree = 1;
    ip->VISUAL_init.disc = &EDITOR_disc;
    ip->VISUAL_init.nofree = 1;
    ip->EDITOR_init.disc = &EDITOR_disc;
    ip->EDITOR_init.nofree = 1;
    ip->HISTFILE_init.disc = &HISTFILE_disc;
    ip->HISTFILE_init.nofree = 1;
    ip->HISTSIZE_init.disc = &HISTFILE_disc;
    ip->HISTSIZE_init.nofree = 1;
    ip->OPTINDEX_init.disc = &OPTINDEX_disc;
    ip->OPTINDEX_init.nofree = 1;
    ip->SECONDS_init.hdr.disc = &SECONDS_disc;
    ip->SECONDS_init.hdr.nofree = 1;
    ip->RAND_init.hdr.disc = &RAND_disc;
    ip->RAND_init.hdr.nofree = 1;
    ip->RAND_init.sh = shp;
    ip->SH_MATCH_init.hdr.disc = &SH_MATCH_disc;
    ip->SH_MATCH_init.hdr.nofree = 1;
    ip->SH_MATH_init.disc = &SH_MATH_disc;
    ip->SH_MATH_init.nofree = 1;
#if SHOPT_COSHELL
    ip->SH_JOBPOOL_init.disc = &SH_JOBPOOL_disc;
    ip->SH_JOBPOOL_init.nofree = 1;
    nv_stack(SH_JOBPOOL, &ip->SH_JOBPOOL_init);
#endif /* SHOPT_COSHELL */
    ip->SH_VERSION_init.disc = &SH_VERSION_disc;
    ip->SH_VERSION_init.nofree = 1;
    ip->LINENO_init.disc = &LINENO_disc;
    ip->LINENO_init.nofree = 1;
    ip->L_ARG_init.disc = &L_ARG_disc;
    ip->L_ARG_init.nofree = 1;
#ifdef _hdr_locale
    ip->LC_TYPE_init.disc = &LC_disc;
    ip->LC_TYPE_init.nofree = 1;
    ip->LC_NUM_init.disc = &LC_disc;
    ip->LC_NUM_init.nofree = 1;
    ip->LC_COLL_init.disc = &LC_disc;
    ip->LC_COLL_init.nofree = 1;
    ip->LC_MSG_init.disc = &LC_disc;
    ip->LC_MSG_init.nofree = 1;
    ip->LC_ALL_init.disc = &LC_disc;
    ip->LC_ALL_init.nofree = 1;
    ip->LANG_init.disc = &LC_disc;
    ip->LANG_init.nofree = 1;
#endif /* _hdr_locale */
    nv_stack(IFSNOD, &ip->IFS_init.hdr);
    ip->IFS_init.hdr.nofree = 1;
    nv_stack(PATHNOD, &ip->PATH_init);
    nv_stack(FPATHNOD, &ip->FPATH_init);
    nv_stack(CDPNOD, &ip->CDPATH_init);
    nv_stack(SHELLNOD, &ip->SHELL_init);
    nv_stack(ENVNOD, &ip->ENV_init);
    nv_stack(VISINOD, &ip->VISUAL_init);
    nv_stack(EDITNOD, &ip->EDITOR_init);
    nv_stack(HISTFILE, &ip->HISTFILE_init);
    nv_stack(HISTSIZE, &ip->HISTSIZE_init);
    nv_stack(OPTINDNOD, &ip->OPTINDEX_init);
    nv_stack(SECONDS, &ip->SECONDS_init.hdr);
    nv_stack(L_ARGNOD, &ip->L_ARG_init);
    nv_putval(SECONDS, (char*)&d, NV_DOUBLE);
    nv_stack(RANDNOD, &ip->RAND_init.hdr);
    d = (shp->gd->pid&RANDMASK);
    nv_putval(RANDNOD, (char*)&d, NV_DOUBLE);
    nv_stack(LINENO, &ip->LINENO_init);
    nv_stack(SH_MATCHNOD, &ip->SH_MATCH_init.hdr);
    nv_putsub(SH_MATCHNOD,(char*)0,10);
    nv_stack(SH_MATHNOD, &ip->SH_MATH_init);
    nv_stack(SH_VERSIONNOD, &ip->SH_VERSION_init);
#ifdef _hdr_locale
    nv_stack(LCTYPENOD, &ip->LC_TYPE_init);
    nv_stack(LCALLNOD, &ip->LC_ALL_init);
    nv_stack(LCMSGNOD, &ip->LC_MSG_init);
    nv_stack(LCCOLLNOD, &ip->LC_COLL_init);
    nv_stack(LCNUMNOD, &ip->LC_NUM_init);
    nv_stack(LANGNOD, &ip->LANG_init);
#endif /* _hdr_locale */
    (PPIDNOD)->nvalue.lp = (&shp->gd->ppid);
    (TMOUTNOD)->nvalue.lp = (&shp->st.tmout);
    (MCHKNOD)->nvalue.lp = (&sh_mailchk);
    (OPTINDNOD)->nvalue.lp = (&shp->st.optindex);
    /* set up the seconds clock */
    shp->alias_tree = inittree(shp,shtab_aliases);
    shp->track_tree = dtopen(&_Nvdisc,Dtset);
    shp->bltin_tree = inittree(shp,(const struct shtable2*)shtab_builtins);
    shp->fun_tree = dtopen(&_Nvdisc,Dtoset);
    dtview(shp->fun_tree,shp->bltin_tree);
    nv_mount(DOTSHNOD, "type", shp->typedict=dtopen(&_Nvdisc,Dtoset));
    nv_adddisc(DOTSHNOD, shdiscnames, (Namval_t**)0);
    DOTSHNOD->nvalue.cp = Empty;
    SH_LINENO->nvalue.ip = &shp->st.lineno;
    VERSIONNOD->nvalue.nrp = newof(0,struct Namref,1,0);
        VERSIONNOD->nvalue.nrp->np = SH_VERSIONNOD;
        VERSIONNOD->nvalue.nrp->root = nv_dict(DOTSHNOD);
        VERSIONNOD->nvalue.nrp->table = DOTSHNOD;
    nv_onattr(VERSIONNOD,NV_REF);
    math_init(shp);
    if(!shgd->stats)
        stat_init(shp);
    return(ip);
}

/*
 * initialize name-value pairs
 */

static Dt_t *inittree(Shell_t *shp,const struct shtable2 *name_vals)
{
    register Namval_t *np;
    register const struct shtable2 *tp;
    register unsigned n = 0;
    register Dt_t *treep;
    Dt_t *base_treep, *dict;
    for(tp=name_vals;*tp->sh_name;tp++)
        n++;
    np = (Namval_t*)calloc(n,sizeof(Namval_t));
    if(!shgd->bltin_nodes)
    {
        shgd->bltin_nodes = np;
        shgd->bltin_nnodes = n;
    }
    else if(name_vals==(const struct shtable2*)shtab_builtins)
    {
        shgd->bltin_cmds = np;
        nbltins = n;
    }
    base_treep = treep = dtopen(&_Nvdisc,Dtoset);
    treep->user = (void*)shp;
    for(tp=name_vals;*tp->sh_name;tp++,np++)
    {
        if((np->nvname = strrchr(tp->sh_name,'.')) && np->nvname!=((char*)tp->sh_name))
            np->nvname++;
        else
        {
            np->nvname = (char*)tp->sh_name;
            treep = base_treep;
        }
        np->nvenv = 0;
        if(name_vals==(const struct shtable2*)shtab_builtins)
            np->nvalue.bfp = ((struct shtable3*)tp)->sh_value;
        else
        {
            if(name_vals == shtab_variables)
                np->nvfun = &shp->nvfun;
            np->nvalue.cp = (char*)tp->sh_value;
        }
        nv_setattr(np,tp->sh_number);
        if(nv_isattr(np,NV_TABLE))
            nv_mount(np,(const char*)0,dict=dtopen(&_Nvdisc,Dtoset));
        if(nv_isattr(np,NV_INTEGER))
            nv_setsize(np,10);
        else
            nv_setsize(np,0);
        dtinsert(treep,np);
        if(nv_istable(np))
            treep = dict;
    }
    return(treep);
}

/*
 * read in the process environment and set up name-value pairs
 * skip over items that are not name-value pairs
 */

static void env_init(Shell_t *shp)
{
    register char       *cp;
    register Namval_t   *np,*mp;
    register char       **ep=environ;
    char            *dp,*next=0;
    int         nenv=0,k=0,size=0;
    Namval_t        *np0;
#ifdef _ENV_H
    shp->env = env_open(environ,3);
    env_delete(shp->env,"_");
#endif
    if(!ep)
        goto skip;
    while(*ep++)
        nenv++;
    np = newof(0,Namval_t,nenv,0);
    for(np0=np,ep=environ;cp= *ep; ep++)
    {
        dp = strchr(cp,'=');
        if(!dp)
            continue;
        *dp++ = 0;
        if(mp = dtmatch(shp->var_base,cp))
        {
            mp->nvenv = (char*)cp;
            dp[-1] = '=';
        }
        else if(*cp=='A' && cp[1]=='_' && cp[2]=='_' && cp[3]=='z' && cp[4]==0)
        {
            dp[-1] = '=';
            next = cp+4;
            continue;
        }
        else
        {
            k++;
            mp = np++;
            mp->nvname = cp;
            size += strlen(cp);
        }
            nv_onattr(mp,NV_IMPORT);
        if(mp->nvfun || nv_isattr(mp,NV_INTEGER))
            nv_putval(mp,dp,0);
        else
        {
            mp->nvalue.cp = dp;
            nv_onattr(mp,NV_NOFREE);
        }
        nv_onattr(mp,NV_EXPORT|NV_IMPORT);
    }
    np =  (Namval_t*)realloc((void*)np0,k*sizeof(Namval_t));
    dp = (char*)malloc(size+k);
    while(k-->0)
    {
        size = strlen(np->nvname);
        memcpy(dp,np->nvname,size+1);
        np->nvname[size] = '=';
        np->nvenv = np->nvname;
        np->nvname = dp;
        dp += size+1;
        dtinsert(shp->var_base,np++);
    }
    while(cp=next)
    {
        if(next = strchr(++cp,'='))
            *next = 0;
        np = nv_search(cp+2,shp->var_tree,NV_ADD);
        if(np!=SHLVL && nv_isattr(np,NV_IMPORT|NV_EXPORT))
        {
            int flag = *(unsigned char*)cp-' ';
            int size = *(unsigned char*)(cp+1)-' ';
            if((flag&NV_INTEGER) && size==0)
            {
                /* check for floating*/
                char *val = nv_getval(np);
                strtol(val,&dp,10);
                if(*dp=='.' || *dp=='e' || *dp=='E')
                {
                    char *lp;
                    flag |= NV_DOUBLE;
                    if(*dp=='.')
                    {
                        strtol(dp+1,&lp,10);
                        if(*lp)
                            dp = lp;
                    }
                    if(*dp && *dp!='.')
                    {
                        flag |= NV_EXPNOTE;
                        size = dp-val;
                    }
                    else
                        size = strlen(dp);
                    size--;
                }
            }
            nv_newattr(np,flag|NV_IMPORT|NV_EXPORT,size);
            if((flag&(NV_INTEGER|NV_UTOL|NV_LTOU))==(NV_UTOL|NV_LTOU))
                nv_mapchar(np,(flag&NV_UTOL)?e_tolower:e_toupper);
        }
        else
            cp += 2;
    }
skip:
#ifdef _ENV_H
    env_delete(shp->env,e_envmarker);
#endif
    if(nv_isnull(PWDNOD) || nv_isattr(PWDNOD,NV_TAGGED))
    {
        nv_offattr(PWDNOD,NV_TAGGED);
        path_pwd(shp,0);
    }
    if((cp = nv_getval(SHELLNOD)) && (sh_type(cp)&SH_TYPE_RESTRICTED))
        sh_onoption(SH_RESTRICTED); /* restricted shell */
    return;
}

/*
 * terminate shell and free up the space
 */
int sh_term(void)
{
    sfdisc(sfstdin,SF_POPDISC);
    free((char*)sh.outbuff);
    stakset(NIL(char*),0);
    return(0);
}

/* function versions of these */

#define DISABLE /* proto workaround */

unsigned long sh_isoption DISABLE (int opt)
{
    return(sh_isoption(opt));
}

unsigned long sh_onoption DISABLE (int opt)
{
    return(sh_onoption(opt));
}

unsigned long sh_offoption DISABLE (int opt)
{
    return(sh_offoption(opt));
}

void    sh_sigcheck DISABLE (void)
{
    Shell_t *shp = sh_getinterp();
    sh_sigcheck(shp);
}

Dt_t*   sh_bltin_tree DISABLE (void)
{
    return(sh.bltin_tree);
}

/*
 * This code is for character mapped variables with wctrans()
 */
struct Mapchar
{
    Namfun_t    hdr;
    const char  *name;
    wctrans_t   trans;
    int     lctype;
};

static void put_trans(register Namval_t* np,const char *val,int flags,Namfun_t *fp)
{
    struct Mapchar *mp = (struct Mapchar*)fp;
    int c,offset = staktell(),off=offset;
    if(val)
    {
        if(mp->lctype!=lctype)
        {
            mp->lctype = lctype;
            mp->trans = wctrans(mp->name);
        }
        if(!mp->trans || (flags&NV_INTEGER))
            goto skip;
        while(c = mbchar(val))
        {
            c = towctrans(c,mp->trans);
            stakseek(off+c);
            stakseek(off);
            c  = mbconv(stakptr(off),c);
            off += c;
            stakseek(off);
        }
        stakputc(0);
        val = stakptr(offset);
    }
    else
    {
        nv_disc(np,fp,NV_POP);
        if(!(fp->nofree&1))
            free((void*)fp);
    }
skip:
    nv_putv(np,val,flags,fp);
    stakseek(offset);
}

static const Namdisc_t TRANS_disc      = {  sizeof(struct Mapchar), put_trans };

Namfun_t    *nv_mapchar(Namval_t *np,const char *name)
{
    wctrans_t   trans = name?wctrans(name):0;
    struct Mapchar  *mp=0;
    int     n=0,low;
    if(np)
        mp = (struct Mapchar*)nv_hasdisc(np,&TRANS_disc);
    if(!name)
        return(mp?(Namfun_t*)mp->name:0);
    if(!trans)
        return(0);
    if(!np)
        return(((Namfun_t*)0)+1);
    if((low=strcmp(name,e_tolower)) && strcmp(name,e_toupper))
        n += strlen(name)+1;
    if(mp)
    {
        if(strcmp(name,mp->name)==0)
            return(&mp->hdr);
        nv_disc(np,&mp->hdr,NV_POP);
        if(!(mp->hdr.nofree&1))
            free((void*)mp);
    }
    mp = newof(0,struct Mapchar,1,n);
    mp->trans = trans;
    mp->lctype = lctype;
    if(low==0)
        mp->name = e_tolower;
    else if(n==0)
        mp->name = e_toupper;
    else
    {
        mp->name = (char*)(mp+1);
        strcpy((char*)mp->name,name);
    }
    mp->hdr.disc =  &TRANS_disc;
    return(&mp->hdr);
}