5.8.4/distrib/mg.c

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*    mg.c
 *
 *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
 *    2000, 2001, 2002, 2003, 2004, by Larry Wall and others
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 *
 */

/*
 * "Sam sat on the ground and put his head in his hands.  'I wish I had never
 * come here, and I don't want to see no more magic,' he said, and fell silent."
 */

/*
=head1 Magical Functions
*/

#include "EXTERN.h"
#define PERL_IN_MG_C
#include "perl.h"

#if defined(HAS_GETGROUPS) || defined(HAS_SETGROUPS)
#  ifndef NGROUPS
#    define NGROUPS 32
#  endif
#  ifdef I_GRP
#    include <grp.h>
#  endif
#ifdef __sun
#include <alloca.h>
#include <unistd.h>
#endif
#endif

#ifdef __hpux
#  include <sys/pstat.h>
#endif

Signal_t Perl_csighandler(int sig);

/* if you only have signal() and it resets on each signal, FAKE_PERSISTENT_SIGNAL_HANDLERS fixes */
#if !defined(HAS_SIGACTION) && defined(VMS)
#  define  FAKE_PERSISTENT_SIGNAL_HANDLERS
#endif
/* if we're doing kill() with sys$sigprc on VMS, FAKE_DEFAULT_SIGNAL_HANDLERS */
#if defined(KILL_BY_SIGPRC)
#  define  FAKE_DEFAULT_SIGNAL_HANDLERS
#endif

static void restore_magic(pTHX_ void *p);
static void unwind_handler_stack(pTHX_ void *p);

#ifdef __Lynx__
/* Missing protos on LynxOS */
void setruid(uid_t id);
void seteuid(uid_t id);
void setrgid(uid_t id);
void setegid(uid_t id);
#endif

/*
 * Use the "DESTRUCTOR" scope cleanup to reinstate magic.
 */

struct magic_state {
    SV* mgs_sv;
    U32 mgs_flags;
    I32 mgs_ss_ix;
};
/* MGS is typedef'ed to struct magic_state in perl.h */

STATIC void
S_save_magic(pTHX_ I32 mgs_ix, SV *sv)
{
    MGS* mgs;
    assert(SvMAGICAL(sv));

    SAVEDESTRUCTOR_X(restore_magic, INT2PTR(void*, (IV)mgs_ix));

    mgs = SSPTR(mgs_ix, MGS*);
    mgs->mgs_sv = sv;
    mgs->mgs_flags = SvMAGICAL(sv) | SvREADONLY(sv);
    mgs->mgs_ss_ix = PL_savestack_ix;   /* points after the saved destructor */

    SvMAGICAL_off(sv);
    SvREADONLY_off(sv);
    SvFLAGS(sv) |= (SvFLAGS(sv) & (SVp_NOK|SVp_POK)) >> PRIVSHIFT;
}

/*
=for apidoc mg_magical

Turns on the magical status of an SV.  See C<sv_magic>.

=cut
*/

void
Perl_mg_magical(pTHX_ SV *sv)
{
    MAGIC* mg;
    for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
    MGVTBL* vtbl = mg->mg_virtual;
    if (vtbl) {
        if (vtbl->svt_get && !(mg->mg_flags & MGf_GSKIP))
        SvGMAGICAL_on(sv);
        if (vtbl->svt_set)
        SvSMAGICAL_on(sv);
        if (!(SvFLAGS(sv) & (SVs_GMG|SVs_SMG)) || vtbl->svt_clear)
        SvRMAGICAL_on(sv);
    }
    }
}

/*
=for apidoc mg_get

Do magic after a value is retrieved from the SV.  See C<sv_magic>.

=cut
*/

int
Perl_mg_get(pTHX_ SV *sv)
{
    int new = 0;
    MAGIC *newmg, *head, *cur, *mg;
    I32 mgs_ix = SSNEW(sizeof(MGS));

    save_magic(mgs_ix, sv);

    /* We must call svt_get(sv, mg) for each valid entry in the linked
       list of magic. svt_get() may delete the current entry, add new
       magic to the head of the list, or upgrade the SV. AMS 20010810 */

    newmg = cur = head = mg = SvMAGIC(sv);
    while (mg) {
    MGVTBL *vtbl = mg->mg_virtual;

    if (!(mg->mg_flags & MGf_GSKIP) && vtbl && vtbl->svt_get) {
        CALL_FPTR(vtbl->svt_get)(aTHX_ sv, mg);

        /* guard against sv having been freed */
        if (SvTYPE(sv) == SVTYPEMASK) {
        Perl_croak(aTHX_ "Tied variable freed while still in use");
        }
        /* guard against magic having been deleted - eg FETCH calling
         * untie */
        if (!SvMAGIC(sv))
        break;

        /* Don't restore the flags for this entry if it was deleted. */
        if (mg->mg_flags & MGf_GSKIP)
        (SSPTR(mgs_ix, MGS *))->mgs_flags = 0;
    }

    mg = mg->mg_moremagic;

    if (new) {
        /* Have we finished with the new entries we saw? Start again
           where we left off (unless there are more new entries). */
        if (mg == head) {
        new  = 0;
        mg   = cur;
        head = newmg;
        }
    }

    /* Were any new entries added? */
    if (!new && (newmg = SvMAGIC(sv)) != head) {
        new = 1;
        cur = mg;
        mg  = newmg;
    }
    }

    restore_magic(aTHX_ INT2PTR(void *, (IV)mgs_ix));
    return 0;
}

/*
=for apidoc mg_set

Do magic after a value is assigned to the SV.  See C<sv_magic>.

=cut
*/

int
Perl_mg_set(pTHX_ SV *sv)
{
    I32 mgs_ix;
    MAGIC* mg;
    MAGIC* nextmg;

    mgs_ix = SSNEW(sizeof(MGS));
    save_magic(mgs_ix, sv);

    for (mg = SvMAGIC(sv); mg; mg = nextmg) {
    MGVTBL* vtbl = mg->mg_virtual;
    nextmg = mg->mg_moremagic;  /* it may delete itself */
    if (mg->mg_flags & MGf_GSKIP) {
        mg->mg_flags &= ~MGf_GSKIP; /* setting requires another read */
        (SSPTR(mgs_ix, MGS*))->mgs_flags = 0;
    }
    if (vtbl && vtbl->svt_set)
        CALL_FPTR(vtbl->svt_set)(aTHX_ sv, mg);
    }

    restore_magic(aTHX_ INT2PTR(void*, (IV)mgs_ix));
    return 0;
}

/*
=for apidoc mg_length

Report on the SV's length.  See C<sv_magic>.

=cut
*/

U32
Perl_mg_length(pTHX_ SV *sv)
{
    MAGIC* mg;
    STRLEN len;

    for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
    MGVTBL* vtbl = mg->mg_virtual;
    if (vtbl && vtbl->svt_len) {
            I32 mgs_ix;

        mgs_ix = SSNEW(sizeof(MGS));
        save_magic(mgs_ix, sv);
        /* omit MGf_GSKIP -- not changed here */
        len = CALL_FPTR(vtbl->svt_len)(aTHX_ sv, mg);
        restore_magic(aTHX_ INT2PTR(void*, (IV)mgs_ix));
        return len;
    }
    }

    if (DO_UTF8(sv))
    {
        U8 *s = (U8*)SvPV(sv, len);
        len = Perl_utf8_length(aTHX_ s, s + len);
    }
    else
        (void)SvPV(sv, len);
    return len;
}

I32
Perl_mg_size(pTHX_ SV *sv)
{
    MAGIC* mg;
    I32 len;

    for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
    MGVTBL* vtbl = mg->mg_virtual;
    if (vtbl && vtbl->svt_len) {
            I32 mgs_ix;

        mgs_ix = SSNEW(sizeof(MGS));
        save_magic(mgs_ix, sv);
        /* omit MGf_GSKIP -- not changed here */
        len = CALL_FPTR(vtbl->svt_len)(aTHX_ sv, mg);
        restore_magic(aTHX_ INT2PTR(void*, (IV)mgs_ix));
        return len;
    }
    }

    switch(SvTYPE(sv)) {
    case SVt_PVAV:
        len = AvFILLp((AV *) sv); /* Fallback to non-tied array */
        return len;
    case SVt_PVHV:
        /* FIXME */
    default:
        Perl_croak(aTHX_ "Size magic not implemented");
        break;
    }
    return 0;
}

/*
=for apidoc mg_clear

Clear something magical that the SV represents.  See C<sv_magic>.

=cut
*/

int
Perl_mg_clear(pTHX_ SV *sv)
{
    I32 mgs_ix;
    MAGIC* mg;

    mgs_ix = SSNEW(sizeof(MGS));
    save_magic(mgs_ix, sv);

    for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
    MGVTBL* vtbl = mg->mg_virtual;
    /* omit GSKIP -- never set here */

    if (vtbl && vtbl->svt_clear)
        CALL_FPTR(vtbl->svt_clear)(aTHX_ sv, mg);
    }

    restore_magic(aTHX_ INT2PTR(void*, (IV)mgs_ix));
    return 0;
}

/*
=for apidoc mg_find

Finds the magic pointer for type matching the SV.  See C<sv_magic>.

=cut
*/

MAGIC*
Perl_mg_find(pTHX_ SV *sv, int type)
{
    MAGIC* mg;
    if (!sv)
        return 0;
    for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
    if (mg->mg_type == type)
        return mg;
    }
    return 0;
}

/*
=for apidoc mg_copy

Copies the magic from one SV to another.  See C<sv_magic>.

=cut
*/

int
Perl_mg_copy(pTHX_ SV *sv, SV *nsv, const char *key, I32 klen)
{
    int count = 0;
    MAGIC* mg;
    for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
    MGVTBL* vtbl = mg->mg_virtual;
    if ((mg->mg_flags & MGf_COPY) && vtbl->svt_copy){
        count += CALL_FPTR(vtbl->svt_copy)(aTHX_ sv, mg, nsv, key, klen);
    }
    else if (isUPPER(mg->mg_type)) {
        sv_magic(nsv,
             mg->mg_type == PERL_MAGIC_tied ? SvTIED_obj(sv, mg) :
             (mg->mg_type == PERL_MAGIC_regdata && mg->mg_obj)
                            ? sv : mg->mg_obj,
             toLOWER(mg->mg_type), key, klen);
        count++;
    }
    }
    return count;
}

/*
=for apidoc mg_free

Free any magic storage used by the SV.  See C<sv_magic>.

=cut
*/

int
Perl_mg_free(pTHX_ SV *sv)
{
    MAGIC* mg;
    MAGIC* moremagic;
    for (mg = SvMAGIC(sv); mg; mg = moremagic) {
    MGVTBL* vtbl = mg->mg_virtual;
    moremagic = mg->mg_moremagic;
    if (vtbl && vtbl->svt_free)
        CALL_FPTR(vtbl->svt_free)(aTHX_ sv, mg);
    if (mg->mg_ptr && mg->mg_type != PERL_MAGIC_regex_global) {
        if (mg->mg_len > 0 || mg->mg_type == PERL_MAGIC_utf8)
        Safefree(mg->mg_ptr);
        else if (mg->mg_len == HEf_SVKEY)
        SvREFCNT_dec((SV*)mg->mg_ptr);
    }
    if (mg->mg_flags & MGf_REFCOUNTED)
        SvREFCNT_dec(mg->mg_obj);
    Safefree(mg);
    }
    SvMAGIC(sv) = 0;
    return 0;
}

#include <signal.h>

U32
Perl_magic_regdata_cnt(pTHX_ SV *sv, MAGIC *mg)
{
    register REGEXP *rx;

    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
    if (mg->mg_obj)     /* @+ */
        return rx->nparens;
    else            /* @- */
        return rx->lastparen;
    }

    return (U32)-1;
}

int
Perl_magic_regdatum_get(pTHX_ SV *sv, MAGIC *mg)
{
    register I32 paren;
    register I32 s;
    register I32 i;
    register REGEXP *rx;
    I32 t;

    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
    paren = mg->mg_len;
    if (paren < 0)
        return 0;
    if (paren <= (I32)rx->nparens &&
        (s = rx->startp[paren]) != -1 &&
        (t = rx->endp[paren]) != -1)
        {
        if (mg->mg_obj)     /* @+ */
            i = t;
        else            /* @- */
            i = s;

        if (i > 0 && RX_MATCH_UTF8(rx)) {
            char *b = rx->subbeg;
            if (b)
                i = Perl_utf8_length(aTHX_ (U8*)b, (U8*)(b+i));
        }

        sv_setiv(sv, i);
        }
    }
    return 0;
}

int
Perl_magic_regdatum_set(pTHX_ SV *sv, MAGIC *mg)
{
    Perl_croak(aTHX_ PL_no_modify);
    /* NOT REACHED */
    return 0;
}

U32
Perl_magic_len(pTHX_ SV *sv, MAGIC *mg)
{
    register I32 paren;
    register I32 i;
    register REGEXP *rx;
    I32 s1, t1;

    switch (*mg->mg_ptr) {
    case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9': case '&':
    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {

        paren = atoi(mg->mg_ptr); /* $& is in [0] */
      getparen:
        if (paren <= (I32)rx->nparens &&
        (s1 = rx->startp[paren]) != -1 &&
        (t1 = rx->endp[paren]) != -1)
        {
        i = t1 - s1;
          getlen:
        if (i > 0 && RX_MATCH_UTF8(rx)) {
            char *s    = rx->subbeg + s1;
            char *send = rx->subbeg + t1;

                    i = t1 - s1;
            if (is_utf8_string((U8*)s, i))
            i = Perl_utf8_length(aTHX_ (U8*)s, (U8*)send);
        }
        if (i < 0)
            Perl_croak(aTHX_ "panic: magic_len: %"IVdf, (IV)i);
        return i;
        }
        else {
        if (ckWARN(WARN_UNINITIALIZED))
            report_uninit();
        }
    }
    else {
        if (ckWARN(WARN_UNINITIALIZED))
        report_uninit();
    }
    return 0;
    case '+':
    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
        paren = rx->lastparen;
        if (paren)
        goto getparen;
    }
    return 0;
    case '\016': /* ^N */
    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
        paren = rx->lastcloseparen;
        if (paren)
        goto getparen;
    }
    return 0;
    case '`':
    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
        if (rx->startp[0] != -1) {
        i = rx->startp[0];
        if (i > 0) {
            s1 = 0;
            t1 = i;
            goto getlen;
        }
        }
    }
    return 0;
    case '\'':
    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
        if (rx->endp[0] != -1) {
        i = rx->sublen - rx->endp[0];
        if (i > 0) {
            s1 = rx->endp[0];
            t1 = rx->sublen;
            goto getlen;
        }
        }
    }
    return 0;
    }
    magic_get(sv,mg);
    if (!SvPOK(sv) && SvNIOK(sv)) {
    STRLEN n_a;
    sv_2pv(sv, &n_a);
    }
    if (SvPOK(sv))
    return SvCUR(sv);
    return 0;
}

int
Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
{
    register I32 paren;
    register char *s = NULL;
    register I32 i;
    register REGEXP *rx;

    switch (*mg->mg_ptr) {
    case '\001':        /* ^A */
    sv_setsv(sv, PL_bodytarget);
    break;
    case '\003':        /* ^C */
    sv_setiv(sv, (IV)PL_minus_c);
    break;

    case '\004':        /* ^D */
    sv_setiv(sv, (IV)(PL_debug & DEBUG_MASK));
#if defined(YYDEBUG) && defined(DEBUGGING)
    PL_yydebug = DEBUG_p_TEST;
#endif
    break;
    case '\005':  /* ^E */
     if (*(mg->mg_ptr+1) == '\0') {
#ifdef MACOS_TRADITIONAL
         {
          char msg[256];

          sv_setnv(sv,(double)gMacPerl_OSErr);
          sv_setpv(sv, gMacPerl_OSErr ? GetSysErrText(gMacPerl_OSErr, msg) : "");
         }
#else
#ifdef VMS
         {
#             include <descrip.h>
#             include <starlet.h>
          char msg[255];
          $DESCRIPTOR(msgdsc,msg);
          sv_setnv(sv,(NV) vaxc$errno);
          if (sys$getmsg(vaxc$errno,&msgdsc.dsc$w_length,&msgdsc,0,0) & 1)
               sv_setpvn(sv,msgdsc.dsc$a_pointer,msgdsc.dsc$w_length);
          else
               sv_setpv(sv,"");
         }
#else
#ifdef OS2
         if (!(_emx_env & 0x200)) { /* Under DOS */
          sv_setnv(sv, (NV)errno);
          sv_setpv(sv, errno ? Strerror(errno) : "");
         } else {
          if (errno != errno_isOS2) {
               int tmp = _syserrno();
               if (tmp) /* 2nd call to _syserrno() makes it 0 */
                Perl_rc = tmp;
          }
          sv_setnv(sv, (NV)Perl_rc);
          sv_setpv(sv, os2error(Perl_rc));
         }
#else
#ifdef WIN32
         {
          DWORD dwErr = GetLastError();
          sv_setnv(sv, (NV)dwErr);
          if (dwErr)
          {
               PerlProc_GetOSError(sv, dwErr);
          }
          else
               sv_setpv(sv, "");
          SetLastError(dwErr);
         }
#else
         {
         int saveerrno = errno;
         sv_setnv(sv, (NV)errno);
         sv_setpv(sv, errno ? Strerror(errno) : "");
         errno = saveerrno;
         }
#endif
#endif
#endif
#endif
         SvNOK_on(sv);  /* what a wonderful hack! */
     }
     else if (strEQ(mg->mg_ptr+1, "NCODING"))
          sv_setsv(sv, PL_encoding);
     break;
    case '\006':        /* ^F */
    sv_setiv(sv, (IV)PL_maxsysfd);
    break;
    case '\010':        /* ^H */
    sv_setiv(sv, (IV)PL_hints);
    break;
    case '\011':        /* ^I */ /* NOT \t in EBCDIC */
    if (PL_inplace)
        sv_setpv(sv, PL_inplace);
    else
        sv_setsv(sv, &PL_sv_undef);
    break;
    case '\017':        /* ^O & ^OPEN */
    if (*(mg->mg_ptr+1) == '\0') {
        sv_setpv(sv, PL_osname);
        SvTAINTED_off(sv);
    }
    else if (strEQ(mg->mg_ptr, "\017PEN")) {
        if (!PL_compiling.cop_io)
        sv_setsv(sv, &PL_sv_undef);
            else {
            sv_setsv(sv, PL_compiling.cop_io);
        }
    }
    break;
    case '\020':        /* ^P */
    sv_setiv(sv, (IV)PL_perldb);
    break;
    case '\023':        /* ^S */
        if (*(mg->mg_ptr+1) == '\0') {
        if (PL_lex_state != LEX_NOTPARSING)
        (void)SvOK_off(sv);
        else if (PL_in_eval)
        sv_setiv(sv, PL_in_eval & ~(EVAL_INREQUIRE));
        else
        sv_setiv(sv, 0);
    }
    break;
    case '\024':        /* ^T */
        if (*(mg->mg_ptr+1) == '\0') {
#ifdef BIG_TIME
            sv_setnv(sv, PL_basetime);
#else
            sv_setiv(sv, (IV)PL_basetime);
#endif
        }
        else if (strEQ(mg->mg_ptr, "\024AINT"))
            sv_setiv(sv, PL_tainting
            ? (PL_taint_warn || PL_unsafe ? -1 : 1)
            : 0);
        break;
    case '\025':        /* $^UNICODE */
        if (strEQ(mg->mg_ptr, "\025NICODE"))
        sv_setuv(sv, (UV) PL_unicode);
        break;
    case '\027':        /* ^W  & $^WARNING_BITS */
    if (*(mg->mg_ptr+1) == '\0')
        sv_setiv(sv, (IV)((PL_dowarn & G_WARN_ON) ? TRUE : FALSE));
    else if (strEQ(mg->mg_ptr+1, "ARNING_BITS")) {
        if (PL_compiling.cop_warnings == pWARN_NONE ||
            PL_compiling.cop_warnings == pWARN_STD)
        {
            sv_setpvn(sv, WARN_NONEstring, WARNsize) ;
            }
            else if (PL_compiling.cop_warnings == pWARN_ALL) {
            sv_setpvn(sv, WARN_ALLstring, WARNsize) ;
        }
            else {
            sv_setsv(sv, PL_compiling.cop_warnings);
        }
        SvPOK_only(sv);
    }
    break;
    case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9': case '&':
    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
        I32 s1, t1;

        /*
         * Pre-threads, this was paren = atoi(GvENAME((GV*)mg->mg_obj));
         * XXX Does the new way break anything?
         */
        paren = atoi(mg->mg_ptr); /* $& is in [0] */
      getparen:
        if (paren <= (I32)rx->nparens &&
        (s1 = rx->startp[paren]) != -1 &&
        (t1 = rx->endp[paren]) != -1)
        {
        i = t1 - s1;
        s = rx->subbeg + s1;
        if (!rx->subbeg)
            break;

          getrx:
        if (i >= 0) {
            sv_setpvn(sv, s, i);
            if (RX_MATCH_UTF8(rx) && is_utf8_string((U8*)s, i))
            SvUTF8_on(sv);
            else
            SvUTF8_off(sv);
            if (PL_tainting) {
            if (RX_MATCH_TAINTED(rx)) {
                MAGIC* mg = SvMAGIC(sv);
                MAGIC* mgt;
                PL_tainted = 1;
                SvMAGIC(sv) = mg->mg_moremagic;
                SvTAINT(sv);
                if ((mgt = SvMAGIC(sv))) {
                mg->mg_moremagic = mgt;
                SvMAGIC(sv) = mg;
                }
            } else
                SvTAINTED_off(sv);
            }
            break;
        }
        }
    }
    sv_setsv(sv,&PL_sv_undef);
    break;
    case '+':
    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
        paren = rx->lastparen;
        if (paren)
        goto getparen;
    }
    sv_setsv(sv,&PL_sv_undef);
    break;
    case '\016':        /* ^N */
    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
        paren = rx->lastcloseparen;
        if (paren)
        goto getparen;
    }
    sv_setsv(sv,&PL_sv_undef);
    break;
    case '`':
    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
        if ((s = rx->subbeg) && rx->startp[0] != -1) {
        i = rx->startp[0];
        goto getrx;
        }
    }
    sv_setsv(sv,&PL_sv_undef);
    break;
    case '\'':
    if (PL_curpm && (rx = PM_GETRE(PL_curpm))) {
        if (rx->subbeg && rx->endp[0] != -1) {
        s = rx->subbeg + rx->endp[0];
        i = rx->sublen - rx->endp[0];
        goto getrx;
        }
    }
    sv_setsv(sv,&PL_sv_undef);
    break;
    case '.':
#ifndef lint
    if (GvIO(PL_last_in_gv)) {
        sv_setiv(sv, (IV)IoLINES(GvIOp(PL_last_in_gv)));
    }
#endif
    break;
    case '?':
    {
        sv_setiv(sv, (IV)STATUS_CURRENT);
#ifdef COMPLEX_STATUS
        LvTARGOFF(sv) = PL_statusvalue;
        LvTARGLEN(sv) = PL_statusvalue_vms;
#endif
    }
    break;
    case '^':
    if (GvIOp(PL_defoutgv))
        s = IoTOP_NAME(GvIOp(PL_defoutgv));
    if (s)
        sv_setpv(sv,s);
    else {
        sv_setpv(sv,GvENAME(PL_defoutgv));
        sv_catpv(sv,"_TOP");
    }
    break;
    case '~':
    if (GvIOp(PL_defoutgv))
        s = IoFMT_NAME(GvIOp(PL_defoutgv));
    if (!s)
        s = GvENAME(PL_defoutgv);
    sv_setpv(sv,s);
    break;
#ifndef lint
    case '=':
    if (GvIOp(PL_defoutgv))
        sv_setiv(sv, (IV)IoPAGE_LEN(GvIOp(PL_defoutgv)));
    break;
    case '-':
    if (GvIOp(PL_defoutgv))
        sv_setiv(sv, (IV)IoLINES_LEFT(GvIOp(PL_defoutgv)));
    break;
    case '%':
    if (GvIOp(PL_defoutgv))
        sv_setiv(sv, (IV)IoPAGE(GvIOp(PL_defoutgv)));
    break;
#endif
    case ':':
    break;
    case '/':
    break;
    case '[':
    WITH_THR(sv_setiv(sv, (IV)PL_curcop->cop_arybase));
    break;
    case '|':
    if (GvIOp(PL_defoutgv))
        sv_setiv(sv, (IV)(IoFLAGS(GvIOp(PL_defoutgv)) & IOf_FLUSH) != 0 );
    break;
    case ',':
    break;
    case '\\':
    if (PL_ors_sv)
        sv_copypv(sv, PL_ors_sv);
    break;
    case '#':
    sv_setpv(sv,PL_ofmt);
    break;
    case '!':
#ifdef VMS
    sv_setnv(sv, (NV)((errno == EVMSERR) ? vaxc$errno : errno));
    sv_setpv(sv, errno ? Strerror(errno) : "");
#else
    {
    int saveerrno = errno;
    sv_setnv(sv, (NV)errno);
#ifdef OS2
    if (errno == errno_isOS2 || errno == errno_isOS2_set)
        sv_setpv(sv, os2error(Perl_rc));
    else
#endif
    sv_setpv(sv, errno ? Strerror(errno) : "");
    errno = saveerrno;
    }
#endif
    SvNOK_on(sv);   /* what a wonderful hack! */
    break;
    case '<':
    sv_setiv(sv, (IV)PL_uid);
    break;
    case '>':
    sv_setiv(sv, (IV)PL_euid);
    break;
    case '(':
    sv_setiv(sv, (IV)PL_gid);
#ifdef HAS_GETGROUPS
    Perl_sv_setpvf(aTHX_ sv, "%"Gid_t_f, PL_gid);
#endif
    goto add_groups;
    case ')':
    sv_setiv(sv, (IV)PL_egid);
#ifdef HAS_GETGROUPS
    Perl_sv_setpvf(aTHX_ sv, "%"Gid_t_f, PL_egid);
#endif
      add_groups:
#ifdef HAS_GETGROUPS
    {
#ifdef __sun
        int maxgrp = getgroups(0, NULL);
        Groups_t *gary = alloca(maxgrp * sizeof (Groups_t));
        i = getgroups(maxgrp,gary);
#else
        Groups_t gary[NGROUPS];
        i = getgroups(NGROUPS,gary);
#endif
        while (--i >= 0)
        Perl_sv_catpvf(aTHX_ sv, " %"Gid_t_f, gary[i]);
    }
#endif
    (void)SvIOK_on(sv); /* what a wonderful hack! */
    break;
    case '*':
    break;
#ifndef MACOS_TRADITIONAL
    case '0':
    break;
#endif
#ifdef USE_5005THREADS
    case '@':
    sv_setsv(sv, thr->errsv);
    break;
#endif /* USE_5005THREADS */
    }
    return 0;
}

int
Perl_magic_getuvar(pTHX_ SV *sv, MAGIC *mg)
{
    struct ufuncs *uf = (struct ufuncs *)mg->mg_ptr;

    if (uf && uf->uf_val)
    (*uf->uf_val)(aTHX_ uf->uf_index, sv);
    return 0;
}

int
Perl_magic_setenv(pTHX_ SV *sv, MAGIC *mg)
{
    register char *s;
    char *ptr;
    STRLEN len, klen;

    s = SvPV(sv,len);
    ptr = MgPV(mg,klen);
    my_setenv(ptr, s);

#ifdef DYNAMIC_ENV_FETCH
     /* We just undefd an environment var.  Is a replacement */
     /* waiting in the wings? */
    if (!len) {
    SV **valp;
    if ((valp = hv_fetch(GvHVn(PL_envgv), ptr, klen, FALSE)))
        s = SvPV(*valp, len);
    }
#endif

#if !defined(OS2) && !defined(AMIGAOS) && !defined(WIN32) && !defined(MSDOS)
                /* And you'll never guess what the dog had */
                /*   in its mouth... */
    if (PL_tainting) {
    MgTAINTEDDIR_off(mg);
#ifdef VMS
    if (s && klen == 8 && strEQ(ptr, "DCL$PATH")) {
        char pathbuf[256], eltbuf[256], *cp, *elt = s;
        Stat_t sbuf;
        int i = 0, j = 0;

        do {          /* DCL$PATH may be a search list */
        while (1) {   /* as may dev portion of any element */
            if ( ((cp = strchr(elt,'[')) || (cp = strchr(elt,'<'))) ) {
            if ( *(cp+1) == '.' || *(cp+1) == '-' ||
                 cando_by_name(S_IWUSR,0,elt) ) {
                MgTAINTEDDIR_on(mg);
                return 0;
            }
            }
            if ((cp = strchr(elt, ':')) != Nullch)
            *cp = '\0';
            if (my_trnlnm(elt, eltbuf, j++))
            elt = eltbuf;
            else
            break;
        }
        j = 0;
        } while (my_trnlnm(s, pathbuf, i++) && (elt = pathbuf));
    }
#endif /* VMS */
    if (s && klen == 4 && strEQ(ptr,"PATH")) {
        char *strend = s + len;

        while (s < strend) {
        char tmpbuf[256];
        Stat_t st;
        I32 i;
        s = delimcpy(tmpbuf, tmpbuf + sizeof tmpbuf,
                 s, strend, ':', &i);
        s++;
        if (i >= sizeof tmpbuf   /* too long -- assume the worst */
              || *tmpbuf != '/'
              || (PerlLIO_stat(tmpbuf, &st) == 0 && (st.st_mode & 2)) ) {
            MgTAINTEDDIR_on(mg);
            return 0;
        }
        }
    }
    }
#endif /* neither OS2 nor AMIGAOS nor WIN32 nor MSDOS */

    return 0;
}

int
Perl_magic_clearenv(pTHX_ SV *sv, MAGIC *mg)
{
    STRLEN n_a;
    my_setenv(MgPV(mg,n_a),Nullch);
    return 0;
}

int
Perl_magic_set_all_env(pTHX_ SV *sv, MAGIC *mg)
{
#if defined(VMS)
    Perl_die(aTHX_ "Can't make list assignment to %%ENV on this system");
#else
    if (PL_localizing) {
    HE* entry;
    STRLEN n_a;
    magic_clear_all_env(sv,mg);
    hv_iterinit((HV*)sv);
    while ((entry = hv_iternext((HV*)sv))) {
        I32 keylen;
        my_setenv(hv_iterkey(entry, &keylen),
              SvPV(hv_iterval((HV*)sv, entry), n_a));
    }
    }
#endif
    return 0;
}

int
Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
{
#ifndef PERL_MICRO
#if defined(VMS) || defined(EPOC)
    Perl_die(aTHX_ "Can't make list assignment to %%ENV on this system");
#else
#  if defined(PERL_IMPLICIT_SYS) || defined(WIN32)
    PerlEnv_clearenv();
#  else
#    ifdef USE_ENVIRON_ARRAY
#      if defined(USE_ITHREADS)
    /* only the parent thread can clobber the process environment */
    if (PL_curinterp == aTHX)
#      endif
    {
#      ifndef PERL_USE_SAFE_PUTENV
    I32 i;

    if (environ == PL_origenviron)
    environ = (char**)safesysmalloc(sizeof(char*));
    else
    for (i = 0; environ[i]; i++)
        safesysfree(environ[i]);
#      endif /* PERL_USE_SAFE_PUTENV */

    environ[0] = Nullch;
    }
#    endif /* USE_ENVIRON_ARRAY */
#   endif /* PERL_IMPLICIT_SYS || WIN32 */
#endif /* VMS || EPOC */
#endif /* !PERL_MICRO */
    return 0;
}

#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
static int sig_handlers_initted = 0;
#endif
#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
static int sig_ignoring[SIG_SIZE];      /* which signals we are ignoring */
#endif
#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
static int sig_defaulting[SIG_SIZE];
#endif

#ifndef PERL_MICRO
#ifdef HAS_SIGPROCMASK
static void
restore_sigmask(pTHX_ SV *save_sv)
{
    sigset_t *ossetp = (sigset_t *) SvPV_nolen( save_sv );
    (void)sigprocmask(SIG_SETMASK, ossetp, (sigset_t *)0);
}
#endif
int
Perl_magic_getsig(pTHX_ SV *sv, MAGIC *mg)
{
    I32 i;
    STRLEN n_a;
    /* Are we fetching a signal entry? */
    i = whichsig(MgPV(mg,n_a));
    if (i > 0) {
        if(PL_psig_ptr[i])
            sv_setsv(sv,PL_psig_ptr[i]);
        else {
            Sighandler_t sigstate;
            sigstate = rsignal_state(i);
#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
            if (sig_handlers_initted && sig_ignoring[i]) sigstate = SIG_IGN;
#endif
#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
            if (sig_handlers_initted && sig_defaulting[i]) sigstate = SIG_DFL;
#endif
            /* cache state so we don't fetch it again */
            if(sigstate == SIG_IGN)
                sv_setpv(sv,"IGNORE");
            else
                sv_setsv(sv,&PL_sv_undef);
            PL_psig_ptr[i] = SvREFCNT_inc(sv);
            SvTEMP_off(sv);
        }
    }
    return 0;
}
int
Perl_magic_clearsig(pTHX_ SV *sv, MAGIC *mg)
{
    /* XXX Some of this code was copied from Perl_magic_setsig. A little
     * refactoring might be in order.
     */
    register char *s;
    STRLEN n_a;
    SV* to_dec;
    s = MgPV(mg,n_a);
    if (*s == '_') {
    SV** svp;
    if (strEQ(s,"__DIE__"))
        svp = &PL_diehook;
    else if (strEQ(s,"__WARN__"))
        svp = &PL_warnhook;
    else
        Perl_croak(aTHX_ "No such hook: %s", s);
    if (*svp) {
        to_dec = *svp;
        *svp = 0;
            SvREFCNT_dec(to_dec);
    }
    }
    else {
    I32 i;
    /* Are we clearing a signal entry? */
    i = whichsig(s);
    if (i > 0) {
#ifdef HAS_SIGPROCMASK
        sigset_t set, save;
        SV* save_sv;
        /* Avoid having the signal arrive at a bad time, if possible. */
        sigemptyset(&set);
        sigaddset(&set,i);
        sigprocmask(SIG_BLOCK, &set, &save);
        ENTER;
        save_sv = newSVpv((char *)(&save), sizeof(sigset_t));
        SAVEFREESV(save_sv);
        SAVEDESTRUCTOR_X(restore_sigmask, save_sv);
#endif
        PERL_ASYNC_CHECK();
#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS) || defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
        if (!sig_handlers_initted) Perl_csighandler_init();
#endif
#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
        sig_defaulting[i] = 1;
        (void)rsignal(i, PL_csighandlerp);
#else
        (void)rsignal(i, SIG_DFL);
#endif
            if(PL_psig_name[i]) {
            SvREFCNT_dec(PL_psig_name[i]);
            PL_psig_name[i]=0;
            }
            if(PL_psig_ptr[i]) {
        to_dec=PL_psig_ptr[i];
            PL_psig_ptr[i]=0;
        LEAVE;
            SvREFCNT_dec(to_dec);
            }
        else
        LEAVE;
    }
    }
    return 0;
}

void
Perl_raise_signal(pTHX_ int sig)
{
    /* Set a flag to say this signal is pending */
    PL_psig_pend[sig]++;
    /* And one to say _a_ signal is pending */
    PL_sig_pending = 1;
}

Signal_t
Perl_csighandler(int sig)
{
#ifdef PERL_GET_SIG_CONTEXT
    dTHXa(PERL_GET_SIG_CONTEXT);
#else
    dTHX;
#endif
#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
    (void) rsignal(sig, PL_csighandlerp);
    if (sig_ignoring[sig]) return;
#endif
#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
    if (sig_defaulting[sig])
#ifdef KILL_BY_SIGPRC
            exit((Perl_sig_to_vmscondition(sig)&STS$M_COND_ID)|STS$K_SEVERE|STS$M_INHIB_MSG);
#else
            exit(1);
#endif
#endif
   if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
    /* Call the perl level handler now--
     * with risk we may be in malloc() etc. */
    (*PL_sighandlerp)(sig);
   else
    Perl_raise_signal(aTHX_ sig);
}

#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS) || defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
void
Perl_csighandler_init(void)
{
    int sig;
    if (sig_handlers_initted) return;

    for (sig = 1; sig < SIG_SIZE; sig++) {
#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
        dTHX;
        sig_defaulting[sig] = 1;
        (void) rsignal(sig, PL_csighandlerp);
#endif
#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
        sig_ignoring[sig] = 0;
#endif
    }
    sig_handlers_initted = 1;
}
#endif

void
Perl_despatch_signals(pTHX)
{
    int sig;
    PL_sig_pending = 0;
    for (sig = 1; sig < SIG_SIZE; sig++) {
    if (PL_psig_pend[sig]) {
        PERL_BLOCKSIG_ADD(set, sig);
        PL_psig_pend[sig] = 0;
        PERL_BLOCKSIG_BLOCK(set);
        (*PL_sighandlerp)(sig);
        PERL_BLOCKSIG_UNBLOCK(set);
    }
    }
}

int
Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
{
    register char *s;
    I32 i;
    SV** svp = 0;
    /* Need to be careful with SvREFCNT_dec(), because that can have side
     * effects (due to closures). We must make sure that the new disposition
     * is in place before it is called.
     */
    SV* to_dec = 0;
    STRLEN len;
#ifdef HAS_SIGPROCMASK
    sigset_t set, save;
    SV* save_sv;
#endif

    s = MgPV(mg,len);
    if (*s == '_') {
    if (strEQ(s,"__DIE__"))
        svp = &PL_diehook;
    else if (strEQ(s,"__WARN__"))
        svp = &PL_warnhook;
    else
        Perl_croak(aTHX_ "No such hook: %s", s);
    i = 0;
    if (*svp) {
        to_dec = *svp;
        *svp = 0;
    }
    }
    else {
    i = whichsig(s);    /* ...no, a brick */
    if (i < 0) {
        if (ckWARN(WARN_SIGNAL))
        Perl_warner(aTHX_ packWARN(WARN_SIGNAL), "No such signal: SIG%s", s);
        return 0;
    }
#ifdef HAS_SIGPROCMASK
    /* Avoid having the signal arrive at a bad time, if possible. */
    sigemptyset(&set);
    sigaddset(&set,i);
    sigprocmask(SIG_BLOCK, &set, &save);
    ENTER;
    save_sv = newSVpv((char *)(&save), sizeof(sigset_t));
    SAVEFREESV(save_sv);
    SAVEDESTRUCTOR_X(restore_sigmask, save_sv);
#endif
    PERL_ASYNC_CHECK();
#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS) || defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
    if (!sig_handlers_initted) Perl_csighandler_init();
#endif
#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
    sig_ignoring[i] = 0;
#endif
#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
    sig_defaulting[i] = 0;
#endif
    SvREFCNT_dec(PL_psig_name[i]);
    to_dec = PL_psig_ptr[i];
    PL_psig_ptr[i] = SvREFCNT_inc(sv);
    SvTEMP_off(sv); /* Make sure it doesn't go away on us */
    PL_psig_name[i] = newSVpvn(s, len);
    SvREADONLY_on(PL_psig_name[i]);
    }
    if (SvTYPE(sv) == SVt_PVGV || SvROK(sv)) {
    if (i) {
        (void)rsignal(i, PL_csighandlerp);
#ifdef HAS_SIGPROCMASK
        LEAVE;
#endif
    }
    else
        *svp = SvREFCNT_inc(sv);
    if(to_dec)
        SvREFCNT_dec(to_dec);
    return 0;
    }
    s = SvPV_force(sv,len);
    if (strEQ(s,"IGNORE")) {
    if (i) {
#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
        sig_ignoring[i] = 1;
        (void)rsignal(i, PL_csighandlerp);
#else
        (void)rsignal(i, SIG_IGN);
#endif
    }
    }
    else if (strEQ(s,"DEFAULT") || !*s) {
    if (i)
#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
      {
        sig_defaulting[i] = 1;
        (void)rsignal(i, PL_csighandlerp);
      }
#else
        (void)rsignal(i, SIG_DFL);
#endif
    }
    else {
    /*
     * We should warn if HINT_STRICT_REFS, but without
     * access to a known hint bit in a known OP, we can't
     * tell whether HINT_STRICT_REFS is in force or not.
     */
    if (!strchr(s,':') && !strchr(s,'\''))
        sv_insert(sv, 0, 0, "main::", 6);
    if (i)
        (void)rsignal(i, PL_csighandlerp);
    else
        *svp = SvREFCNT_inc(sv);
    }
#ifdef HAS_SIGPROCMASK
    if(i)
    LEAVE;
#endif
    if(to_dec)
    SvREFCNT_dec(to_dec);
    return 0;
}
#endif /* !PERL_MICRO */

int
Perl_magic_setisa(pTHX_ SV *sv, MAGIC *mg)
{
    PL_sub_generation++;
    return 0;
}

int
Perl_magic_setamagic(pTHX_ SV *sv, MAGIC *mg)
{
    /* HV_badAMAGIC_on(Sv_STASH(sv)); */
    PL_amagic_generation++;

    return 0;
}

int
Perl_magic_getnkeys(pTHX_ SV *sv, MAGIC *mg)
{
    HV *hv = (HV*)LvTARG(sv);
    I32 i = 0;

    if (hv) {
         (void) hv_iterinit(hv);
         if (! SvTIED_mg((SV*)hv, PERL_MAGIC_tied))
         i = HvKEYS(hv);
         else {
         while (hv_iternext(hv))
             i++;
         }
    }

    sv_setiv(sv, (IV)i);
    return 0;
}

int
Perl_magic_setnkeys(pTHX_ SV *sv, MAGIC *mg)
{
    if (LvTARG(sv)) {
    hv_ksplit((HV*)LvTARG(sv), SvIV(sv));
    }
    return 0;
}

/* caller is responsible for stack switching/cleanup */
STATIC int
S_magic_methcall(pTHX_ SV *sv, MAGIC *mg, char *meth, I32 flags, int n, SV *val)
{
    dSP;

    PUSHMARK(SP);
    EXTEND(SP, n);
    PUSHs(SvTIED_obj(sv, mg));
    if (n > 1) {
    if (mg->mg_ptr) {
        if (mg->mg_len >= 0)
        PUSHs(sv_2mortal(newSVpvn(mg->mg_ptr, mg->mg_len)));
        else if (mg->mg_len == HEf_SVKEY)
        PUSHs((SV*)mg->mg_ptr);
    }
    else if (mg->mg_type == PERL_MAGIC_tiedelem) {
        PUSHs(sv_2mortal(newSViv(mg->mg_len)));
    }
    }
    if (n > 2) {
    PUSHs(val);
    }
    PUTBACK;

    return call_method(meth, flags);
}

STATIC int
S_magic_methpack(pTHX_ SV *sv, MAGIC *mg, char *meth)
{
    dSP;

    ENTER;
    SAVETMPS;
    PUSHSTACKi(PERLSI_MAGIC);

    if (magic_methcall(sv, mg, meth, G_SCALAR, 2, NULL)) {
    sv_setsv(sv, *PL_stack_sp--);
    }

    POPSTACK;
    FREETMPS;
    LEAVE;
    return 0;
}

int
Perl_magic_getpack(pTHX_ SV *sv, MAGIC *mg)
{
    if (mg->mg_ptr)
    mg->mg_flags |= MGf_GSKIP;
    magic_methpack(sv,mg,"FETCH");
    return 0;
}

int
Perl_magic_setpack(pTHX_ SV *sv, MAGIC *mg)
{
    dSP;
    ENTER;
    PUSHSTACKi(PERLSI_MAGIC);
    magic_methcall(sv, mg, "STORE", G_SCALAR|G_DISCARD, 3, sv);
    POPSTACK;
    LEAVE;
    return 0;
}

int
Perl_magic_clearpack(pTHX_ SV *sv, MAGIC *mg)
{
    return magic_methpack(sv,mg,"DELETE");
}


U32
Perl_magic_sizepack(pTHX_ SV *sv, MAGIC *mg)
{
    dSP;
    U32 retval = 0;

    ENTER;
    SAVETMPS;
    PUSHSTACKi(PERLSI_MAGIC);
    if (magic_methcall(sv, mg, "FETCHSIZE", G_SCALAR, 2, NULL)) {
    sv = *PL_stack_sp--;
    retval = (U32) SvIV(sv)-1;
    }
    POPSTACK;
    FREETMPS;
    LEAVE;
    return retval;
}

int
Perl_magic_wipepack(pTHX_ SV *sv, MAGIC *mg)
{
    dSP;

    ENTER;
    PUSHSTACKi(PERLSI_MAGIC);
    PUSHMARK(SP);
    XPUSHs(SvTIED_obj(sv, mg));
    PUTBACK;
    call_method("CLEAR", G_SCALAR|G_DISCARD);
    POPSTACK;
    LEAVE;

    return 0;
}

int
Perl_magic_nextpack(pTHX_ SV *sv, MAGIC *mg, SV *key)
{
    dSP;
    const char *meth = SvOK(key) ? "NEXTKEY" : "FIRSTKEY";

    ENTER;
    SAVETMPS;
    PUSHSTACKi(PERLSI_MAGIC);
    PUSHMARK(SP);
    EXTEND(SP, 2);
    PUSHs(SvTIED_obj(sv, mg));
    if (SvOK(key))
    PUSHs(key);
    PUTBACK;

    if (call_method(meth, G_SCALAR))
    sv_setsv(key, *PL_stack_sp--);

    POPSTACK;
    FREETMPS;
    LEAVE;
    return 0;
}

int
Perl_magic_existspack(pTHX_ SV *sv, MAGIC *mg)
{
    return magic_methpack(sv,mg,"EXISTS");
}

SV *
Perl_magic_scalarpack(pTHX_ HV *hv, MAGIC *mg)
{
    dSP;
    SV *retval = &PL_sv_undef;
    SV *tied = SvTIED_obj((SV*)hv, mg);
    HV *pkg = SvSTASH((SV*)SvRV(tied));

    if (!gv_fetchmethod_autoload(pkg, "SCALAR", FALSE)) {
        SV *key;
        if (HvEITER(hv))
            /* we are in an iteration so the hash cannot be empty */
            return &PL_sv_yes;
        /* no xhv_eiter so now use FIRSTKEY */
        key = sv_newmortal();
        magic_nextpack((SV*)hv, mg, key);
        HvEITER(hv) = NULL;     /* need to reset iterator */
        return SvOK(key) ? &PL_sv_yes : &PL_sv_no;
    }

    /* there is a SCALAR method that we can call */
    ENTER;
    PUSHSTACKi(PERLSI_MAGIC);
    PUSHMARK(SP);
    EXTEND(SP, 1);
    PUSHs(tied);
    PUTBACK;

    if (call_method("SCALAR", G_SCALAR))
        retval = *PL_stack_sp--;
    POPSTACK;
    LEAVE;
    return retval;
}

int
Perl_magic_setdbline(pTHX_ SV *sv, MAGIC *mg)
{
    OP *o;
    I32 i;
    GV* gv;
    SV** svp;
    STRLEN n_a;

    gv = PL_DBline;
    i = SvTRUE(sv);
    svp = av_fetch(GvAV(gv),
             atoi(MgPV(mg,n_a)), FALSE);
    if (svp && SvIOKp(*svp) && (o = INT2PTR(OP*,SvIVX(*svp)))) {
    /* set or clear breakpoint in the relevant control op */
    if (i)
        o->op_flags |= OPf_SPECIAL;
    else
        o->op_flags &= ~OPf_SPECIAL;
    }
    return 0;
}

int
Perl_magic_getarylen(pTHX_ SV *sv, MAGIC *mg)
{
    sv_setiv(sv, AvFILL((AV*)mg->mg_obj) + PL_curcop->cop_arybase);
    return 0;
}

int
Perl_magic_setarylen(pTHX_ SV *sv, MAGIC *mg)
{
    av_fill((AV*)mg->mg_obj, SvIV(sv) - PL_curcop->cop_arybase);
    return 0;
}

int
Perl_magic_getpos(pTHX_ SV *sv, MAGIC *mg)
{
    SV* lsv = LvTARG(sv);

    if (SvTYPE(lsv) >= SVt_PVMG && SvMAGIC(lsv)) {
    mg = mg_find(lsv, PERL_MAGIC_regex_global);
    if (mg && mg->mg_len >= 0) {
        I32 i = mg->mg_len;
        if (DO_UTF8(lsv))
        sv_pos_b2u(lsv, &i);
        sv_setiv(sv, i + PL_curcop->cop_arybase);
        return 0;
    }
    }
    (void)SvOK_off(sv);
    return 0;
}

int
Perl_magic_setpos(pTHX_ SV *sv, MAGIC *mg)
{
    SV* lsv = LvTARG(sv);
    SSize_t pos;
    STRLEN len;
    STRLEN ulen = 0;

    mg = 0;

    if (SvTYPE(lsv) >= SVt_PVMG && SvMAGIC(lsv))
    mg = mg_find(lsv, PERL_MAGIC_regex_global);
    if (!mg) {
    if (!SvOK(sv))
        return 0;
    sv_magic(lsv, (SV*)0, PERL_MAGIC_regex_global, Nullch, 0);
    mg = mg_find(lsv, PERL_MAGIC_regex_global);
    }
    else if (!SvOK(sv)) {
    mg->mg_len = -1;
    return 0;
    }
    len = SvPOK(lsv) ? SvCUR(lsv) : sv_len(lsv);

    pos = SvIV(sv) - PL_curcop->cop_arybase;

    if (DO_UTF8(lsv)) {
    ulen = sv_len_utf8(lsv);
    if (ulen)
        len = ulen;
    }

    if (pos < 0) {
    pos += len;
    if (pos < 0)
        pos = 0;
    }
    else if (pos > (SSize_t)len)
    pos = len;

    if (ulen) {
    I32 p = pos;
    sv_pos_u2b(lsv, &p, 0);
    pos = p;
    }

    mg->mg_len = pos;
    mg->mg_flags &= ~MGf_MINMATCH;

    return 0;
}

int
Perl_magic_getglob(pTHX_ SV *sv, MAGIC *mg)
{
    if (SvFAKE(sv)) {           /* FAKE globs can get coerced */
    SvFAKE_off(sv);
    gv_efullname3(sv,((GV*)sv), "*");
    SvFAKE_on(sv);
    }
    else
    gv_efullname3(sv,((GV*)sv), "*");   /* a gv value, be nice */
    return 0;
}

int
Perl_magic_setglob(pTHX_ SV *sv, MAGIC *mg)
{
    register char *s;
    GV* gv;
    STRLEN n_a;

    if (!SvOK(sv))
    return 0;
    s = SvPV(sv, n_a);
    if (*s == '*' && s[1])
    s++;
    gv = gv_fetchpv(s,TRUE, SVt_PVGV);
    if (sv == (SV*)gv)
    return 0;
    if (GvGP(sv))
    gp_free((GV*)sv);
    GvGP(sv) = gp_ref(GvGP(gv));
    return 0;
}

int
Perl_magic_getsubstr(pTHX_ SV *sv, MAGIC *mg)
{
    STRLEN len;
    SV *lsv = LvTARG(sv);
    char *tmps = SvPV(lsv,len);
    I32 offs = LvTARGOFF(sv);
    I32 rem = LvTARGLEN(sv);

    if (SvUTF8(lsv))
    sv_pos_u2b(lsv, &offs, &rem);
    if (offs > (I32)len)
    offs = len;
    if (rem + offs > (I32)len)
    rem = len - offs;
    sv_setpvn(sv, tmps + offs, (STRLEN)rem);
    if (SvUTF8(lsv))
        SvUTF8_on(sv);
    return 0;
}

int
Perl_magic_setsubstr(pTHX_ SV *sv, MAGIC *mg)
{
    STRLEN len;
    char *tmps = SvPV(sv, len);
    SV *lsv = LvTARG(sv);
    I32 lvoff = LvTARGOFF(sv);
    I32 lvlen = LvTARGLEN(sv);

    if (DO_UTF8(sv)) {
    sv_utf8_upgrade(lsv);
    sv_pos_u2b(lsv, &lvoff, &lvlen);
    sv_insert(lsv, lvoff, lvlen, tmps, len);
    SvUTF8_on(lsv);
    }
    else if (lsv && SvUTF8(lsv)) {
    sv_pos_u2b(lsv, &lvoff, &lvlen);
    tmps = (char*)bytes_to_utf8((U8*)tmps, &len);
    sv_insert(lsv, lvoff, lvlen, tmps, len);
    Safefree(tmps);
    }
    else
        sv_insert(lsv, lvoff, lvlen, tmps, len);

    return 0;
}

int
Perl_magic_gettaint(pTHX_ SV *sv, MAGIC *mg)
{
    TAINT_IF((mg->mg_len & 1) ||
         ((mg->mg_len & 2) && mg->mg_obj == sv));   /* kludge */
    return 0;
}

int
Perl_magic_settaint(pTHX_ SV *sv, MAGIC *mg)
{
    if (PL_localizing) {
    if (PL_localizing == 1)
        mg->mg_len <<= 1;
    else
        mg->mg_len >>= 1;
    }
    else if (PL_tainted)
    mg->mg_len |= 1;
    else
    mg->mg_len &= ~1;
    return 0;
}

int
Perl_magic_getvec(pTHX_ SV *sv, MAGIC *mg)
{
    SV *lsv = LvTARG(sv);

    if (!lsv) {
    (void)SvOK_off(sv);
    return 0;
    }

    sv_setuv(sv, do_vecget(lsv, LvTARGOFF(sv), LvTARGLEN(sv)));
    return 0;
}

int
Perl_magic_setvec(pTHX_ SV *sv, MAGIC *mg)
{
    do_vecset(sv);  /* XXX slurp this routine */
    return 0;
}

int
Perl_magic_getdefelem(pTHX_ SV *sv, MAGIC *mg)
{
    SV *targ = Nullsv;
    if (LvTARGLEN(sv)) {
    if (mg->mg_obj) {
        SV *ahv = LvTARG(sv);
        if (SvTYPE(ahv) == SVt_PVHV) {
        HE *he = hv_fetch_ent((HV*)ahv, mg->mg_obj, FALSE, 0);
        if (he)
            targ = HeVAL(he);
        }
        else {
        SV **svp = avhv_fetch_ent((AV*)ahv, mg->mg_obj, FALSE, 0);
        if (svp)
            targ = *svp;
        }
    }
    else {
        AV* av = (AV*)LvTARG(sv);
        if ((I32)LvTARGOFF(sv) <= AvFILL(av))
        targ = AvARRAY(av)[LvTARGOFF(sv)];
    }
    if (targ && targ != &PL_sv_undef) {
        /* somebody else defined it for us */
        SvREFCNT_dec(LvTARG(sv));
        LvTARG(sv) = SvREFCNT_inc(targ);
        LvTARGLEN(sv) = 0;
        SvREFCNT_dec(mg->mg_obj);
        mg->mg_obj = Nullsv;
        mg->mg_flags &= ~MGf_REFCOUNTED;
    }
    }
    else
    targ = LvTARG(sv);
    sv_setsv(sv, targ ? targ : &PL_sv_undef);
    return 0;
}

int
Perl_magic_setdefelem(pTHX_ SV *sv, MAGIC *mg)
{
    if (LvTARGLEN(sv))
    vivify_defelem(sv);
    if (LvTARG(sv)) {
    sv_setsv(LvTARG(sv), sv);
    SvSETMAGIC(LvTARG(sv));
    }
    return 0;
}

void
Perl_vivify_defelem(pTHX_ SV *sv)
{
    MAGIC *mg;
    SV *value = Nullsv;

    if (!LvTARGLEN(sv) || !(mg = mg_find(sv, PERL_MAGIC_defelem)))
    return;
    if (mg->mg_obj) {
    SV *ahv = LvTARG(sv);
    STRLEN n_a;
    if (SvTYPE(ahv) == SVt_PVHV) {
        HE *he = hv_fetch_ent((HV*)ahv, mg->mg_obj, TRUE, 0);
        if (he)
        value = HeVAL(he);
    }
    else {
        SV **svp = avhv_fetch_ent((AV*)ahv, mg->mg_obj, TRUE, 0);
        if (svp)
        value = *svp;
    }
    if (!value || value == &PL_sv_undef)
        Perl_croak(aTHX_ PL_no_helem, SvPV(mg->mg_obj, n_a));
    }
    else {
    AV* av = (AV*)LvTARG(sv);
    if ((I32)LvTARGLEN(sv) < 0 && (I32)LvTARGOFF(sv) > AvFILL(av))
        LvTARG(sv) = Nullsv;    /* array can't be extended */
    else {
        SV** svp = av_fetch(av, LvTARGOFF(sv), TRUE);
        if (!svp || (value = *svp) == &PL_sv_undef)
        Perl_croak(aTHX_ PL_no_aelem, (I32)LvTARGOFF(sv));
    }
    }
    (void)SvREFCNT_inc(value);
    SvREFCNT_dec(LvTARG(sv));
    LvTARG(sv) = value;
    LvTARGLEN(sv) = 0;
    SvREFCNT_dec(mg->mg_obj);
    mg->mg_obj = Nullsv;
    mg->mg_flags &= ~MGf_REFCOUNTED;
}

int
Perl_magic_killbackrefs(pTHX_ SV *sv, MAGIC *mg)
{
    AV *av = (AV*)mg->mg_obj;
    SV **svp = AvARRAY(av);
    I32 i = AvFILLp(av);
    while (i >= 0) {
    if (svp[i] && svp[i] != &PL_sv_undef) {
        if (!SvWEAKREF(svp[i]))
        Perl_croak(aTHX_ "panic: magic_killbackrefs");
        /* XXX Should we check that it hasn't changed? */
        SvRV(svp[i]) = 0;
        (void)SvOK_off(svp[i]);
        SvWEAKREF_off(svp[i]);
        svp[i] = &PL_sv_undef;
    }
    i--;
    }
    SvREFCNT_dec(av); /* remove extra count added by sv_add_backref() */
    return 0;
}

int
Perl_magic_setmglob(pTHX_ SV *sv, MAGIC *mg)
{
    mg->mg_len = -1;
    SvSCREAM_off(sv);
    return 0;
}

int
Perl_magic_setbm(pTHX_ SV *sv, MAGIC *mg)
{
    sv_unmagic(sv, PERL_MAGIC_bm);
    SvVALID_off(sv);
    return 0;
}

int
Perl_magic_setfm(pTHX_ SV *sv, MAGIC *mg)
{
    sv_unmagic(sv, PERL_MAGIC_fm);
    SvCOMPILED_off(sv);
    return 0;
}

int
Perl_magic_setuvar(pTHX_ SV *sv, MAGIC *mg)
{
    struct ufuncs *uf = (struct ufuncs *)mg->mg_ptr;

    if (uf && uf->uf_set)
    (*uf->uf_set)(aTHX_ uf->uf_index, sv);
    return 0;
}

int
Perl_magic_setregexp(pTHX_ SV *sv, MAGIC *mg)
{
    sv_unmagic(sv, PERL_MAGIC_qr);
    return 0;
}

int
Perl_magic_freeregexp(pTHX_ SV *sv, MAGIC *mg)
{
    regexp *re = (regexp *)mg->mg_obj;
    ReREFCNT_dec(re);
    return 0;
}

#ifdef USE_LOCALE_COLLATE
int
Perl_magic_setcollxfrm(pTHX_ SV *sv, MAGIC *mg)
{
    /*
     * RenE<eacute> Descartes said "I think not."
     * and vanished with a faint plop.
     */
    if (mg->mg_ptr) {
    Safefree(mg->mg_ptr);
    mg->mg_ptr = NULL;
    mg->mg_len = -1;
    }
    return 0;
}
#endif /* USE_LOCALE_COLLATE */

/* Just clear the UTF-8 cache data. */
int
Perl_magic_setutf8(pTHX_ SV *sv, MAGIC *mg)
{
     Safefree(mg->mg_ptr);  /* The mg_ptr holds the pos cache. */
     mg->mg_ptr = 0;
     mg->mg_len = -1;       /* The mg_len holds the len cache. */
     return 0;
}

int
Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
{
    register char *s;
    I32 i;
    STRLEN len;
    switch (*mg->mg_ptr) {
    case '\001':    /* ^A */
    sv_setsv(PL_bodytarget, sv);
    break;
    case '\003':    /* ^C */
    PL_minus_c = (bool)(SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv));
    break;

    case '\004':    /* ^D */
#ifdef DEBUGGING
    s = SvPV_nolen(sv);
    PL_debug = get_debug_opts(&s) | DEBUG_TOP_FLAG;
    DEBUG_x(dump_all());
#else
    PL_debug = (SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv)) | DEBUG_TOP_FLAG;
#endif
    break;
    case '\005':  /* ^E */
    if (*(mg->mg_ptr+1) == '\0') {
#ifdef MACOS_TRADITIONAL
        gMacPerl_OSErr = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
#else
#  ifdef VMS
        set_vaxc_errno(SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv));
#  else
#    ifdef WIN32
        SetLastError( SvIV(sv) );
#    else
#      ifdef OS2
        os2_setsyserrno(SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv));
#      else
        /* will anyone ever use this? */
        SETERRNO(SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv), 4);
#      endif
#    endif
#  endif
#endif
    }
    else if (strEQ(mg->mg_ptr+1, "NCODING")) {
        if (PL_encoding)
        SvREFCNT_dec(PL_encoding);
        if (SvOK(sv) || SvGMAGICAL(sv)) {
        PL_encoding = newSVsv(sv);
        }
        else {
        PL_encoding = Nullsv;
        }
    }
    break;
    case '\006':    /* ^F */
    PL_maxsysfd = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
    break;
    case '\010':    /* ^H */
    PL_hints = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
    break;
    case '\011':    /* ^I */ /* NOT \t in EBCDIC */
    if (PL_inplace)
        Safefree(PL_inplace);
    if (SvOK(sv))
        PL_inplace = savepv(SvPV(sv,len));
    else
        PL_inplace = Nullch;
    break;
    case '\017':    /* ^O */
    if (*(mg->mg_ptr+1) == '\0') {
        if (PL_osname) {
        Safefree(PL_osname);
        PL_osname = Nullch;
        }
        if (SvOK(sv)) {
        TAINT_PROPER("assigning to $^O");
        PL_osname = savepv(SvPV(sv,len));
        }
    }
    else if (strEQ(mg->mg_ptr, "\017PEN")) {
        if (!PL_compiling.cop_io)
        PL_compiling.cop_io = newSVsv(sv);
        else
        sv_setsv(PL_compiling.cop_io,sv);
    }
    break;
    case '\020':    /* ^P */
    PL_perldb = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
    if ((PERLDB_SUB || PERLDB_LINE || PERLDB_SUBLINE)
        && !PL_DBsingle)
        init_debugger();
    break;
    case '\024':    /* ^T */
#ifdef BIG_TIME
    PL_basetime = (Time_t)(SvNOK(sv) ? SvNVX(sv) : sv_2nv(sv));
#else
    PL_basetime = (Time_t)(SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv));
#endif
    break;
    case '\027':    /* ^W & $^WARNING_BITS */
    if (*(mg->mg_ptr+1) == '\0') {
        if ( ! (PL_dowarn & G_WARN_ALL_MASK)) {
            i = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
            PL_dowarn = (PL_dowarn & ~G_WARN_ON)
                    | (i ? G_WARN_ON : G_WARN_OFF) ;
        }
    }
    else if (strEQ(mg->mg_ptr+1, "ARNING_BITS")) {
        if ( ! (PL_dowarn & G_WARN_ALL_MASK)) {
        if (!SvPOK(sv) && PL_localizing) {
                sv_setpvn(sv, WARN_NONEstring, WARNsize);
                PL_compiling.cop_warnings = pWARN_NONE;
            break;
        }
        {
            STRLEN len, i;
            int accumulate = 0 ;
            int any_fatals = 0 ;
            char * ptr = (char*)SvPV(sv, len) ;
            for (i = 0 ; i < len ; ++i) {
                accumulate |= ptr[i] ;
                any_fatals |= (ptr[i] & 0xAA) ;
            }
            if (!accumulate)
                    PL_compiling.cop_warnings = pWARN_NONE;
            else if (isWARN_on(sv, WARN_ALL) && !any_fatals) {
                    PL_compiling.cop_warnings = pWARN_ALL;
                    PL_dowarn |= G_WARN_ONCE ;
                }
                    else {
                    if (specialWARN(PL_compiling.cop_warnings))
                    PL_compiling.cop_warnings = newSVsv(sv) ;
                    else
                        sv_setsv(PL_compiling.cop_warnings, sv);
                    if (isWARN_on(PL_compiling.cop_warnings, WARN_ONCE))
                        PL_dowarn |= G_WARN_ONCE ;
                }

        }
        }
    }
    break;
    case '.':
    if (PL_localizing) {
        if (PL_localizing == 1)
        SAVESPTR(PL_last_in_gv);
    }
    else if (SvOK(sv) && GvIO(PL_last_in_gv))
        IoLINES(GvIOp(PL_last_in_gv)) = SvIV(sv);
    break;
    case '^':
    Safefree(IoTOP_NAME(GvIOp(PL_defoutgv)));
    IoTOP_NAME(GvIOp(PL_defoutgv)) = s = savepv(SvPV(sv,len));
    IoTOP_GV(GvIOp(PL_defoutgv)) = gv_fetchpv(s,TRUE, SVt_PVIO);
    break;
    case '~':
    Safefree(IoFMT_NAME(GvIOp(PL_defoutgv)));
    IoFMT_NAME(GvIOp(PL_defoutgv)) = s = savepv(SvPV(sv,len));
    IoFMT_GV(GvIOp(PL_defoutgv)) = gv_fetchpv(s,TRUE, SVt_PVIO);
    break;
    case '=':
    IoPAGE_LEN(GvIOp(PL_defoutgv)) = (SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv));
    break;
    case '-':
    IoLINES_LEFT(GvIOp(PL_defoutgv)) = (SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv));
    if (IoLINES_LEFT(GvIOp(PL_defoutgv)) < 0L)
        IoLINES_LEFT(GvIOp(PL_defoutgv)) = 0L;
    break;
    case '%':
    IoPAGE(GvIOp(PL_defoutgv)) = (SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv));
    break;
    case '|':
    {
        IO *io = GvIOp(PL_defoutgv);
        if(!io)
          break;
        if ((SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv)) == 0)
        IoFLAGS(io) &= ~IOf_FLUSH;
        else {
        if (!(IoFLAGS(io) & IOf_FLUSH)) {
            PerlIO *ofp = IoOFP(io);
            if (ofp)
            (void)PerlIO_flush(ofp);
            IoFLAGS(io) |= IOf_FLUSH;
        }
        }
    }
    break;
    case '*':
    i = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
    PL_multiline = (i != 0);
    break;
    case '/':
    SvREFCNT_dec(PL_rs);
    PL_rs = newSVsv(sv);
    break;
    case '\\':
    if (PL_ors_sv)
        SvREFCNT_dec(PL_ors_sv);
    if (SvOK(sv) || SvGMAGICAL(sv)) {
        PL_ors_sv = newSVsv(sv);
    }
    else {
        PL_ors_sv = Nullsv;
    }
    break;
    case ',':
    if (PL_ofs_sv)
        SvREFCNT_dec(PL_ofs_sv);
    if (SvOK(sv) || SvGMAGICAL(sv)) {
        PL_ofs_sv = newSVsv(sv);
    }
    else {
        PL_ofs_sv = Nullsv;
    }
    break;
    case '#':
    if (PL_ofmt)
        Safefree(PL_ofmt);
    PL_ofmt = savepv(SvPV(sv,len));
    break;
    case '[':
    PL_compiling.cop_arybase = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
    break;
    case '?':
#ifdef COMPLEX_STATUS
    if (PL_localizing == 2) {
        PL_statusvalue = LvTARGOFF(sv);
        PL_statusvalue_vms = LvTARGLEN(sv);
    }
    else
#endif
#ifdef VMSISH_STATUS
    if (VMSISH_STATUS)
        STATUS_NATIVE_SET((U32)(SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv)));
    else
#endif
        STATUS_POSIX_SET(SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv));
    break;
    case '!':
        {
#ifdef VMS
#   define PERL_VMS_BANG vaxc$errno
#else
#   define PERL_VMS_BANG 0
#endif
    SETERRNO(SvIOK(sv) ? SvIVX(sv) : SvOK(sv) ? sv_2iv(sv) : 0,
         (SvIV(sv) == EVMSERR) ? 4 : PERL_VMS_BANG);
    }
    break;
    case '<':
    PL_uid = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
    if (PL_delaymagic) {
        PL_delaymagic |= DM_RUID;
        break;              /* don't do magic till later */
    }
#ifdef HAS_SETRUID
    (void)setruid((Uid_t)PL_uid);
#else
#ifdef HAS_SETREUID
    (void)setreuid((Uid_t)PL_uid, (Uid_t)-1);
#else
#ifdef HAS_SETRESUID
      (void)setresuid((Uid_t)PL_uid, (Uid_t)-1, (Uid_t)-1);
#else
    if (PL_uid == PL_euid) {        /* special case $< = $> */
#ifdef PERL_DARWIN
        /* workaround for Darwin's setuid peculiarity, cf [perl #24122] */
        if (PL_uid != 0 && PerlProc_getuid() == 0)
        (void)PerlProc_setuid(0);
#endif
        (void)PerlProc_setuid(PL_uid);
    } else {
        PL_uid = PerlProc_getuid();
        Perl_croak(aTHX_ "setruid() not implemented");
    }
#endif
#endif
#endif
    PL_uid = PerlProc_getuid();
    PL_tainting |= (PL_uid && (PL_euid != PL_uid || PL_egid != PL_gid));
    break;
    case '>':
    PL_euid = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
    if (PL_delaymagic) {
        PL_delaymagic |= DM_EUID;
        break;              /* don't do magic till later */
    }
#ifdef HAS_SETEUID
    (void)seteuid((Uid_t)PL_euid);
#else
#ifdef HAS_SETREUID
    (void)setreuid((Uid_t)-1, (Uid_t)PL_euid);
#else
#ifdef HAS_SETRESUID
    (void)setresuid((Uid_t)-1, (Uid_t)PL_euid, (Uid_t)-1);
#else
    if (PL_euid == PL_uid)      /* special case $> = $< */
        PerlProc_setuid(PL_euid);
    else {
        PL_euid = PerlProc_geteuid();
        Perl_croak(aTHX_ "seteuid() not implemented");
    }
#endif
#endif
#endif
    PL_euid = PerlProc_geteuid();
    PL_tainting |= (PL_uid && (PL_euid != PL_uid || PL_egid != PL_gid));
    break;
    case '(':
    PL_gid = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
    if (PL_delaymagic) {
        PL_delaymagic |= DM_RGID;
        break;              /* don't do magic till later */
    }
#ifdef HAS_SETRGID
    (void)setrgid((Gid_t)PL_gid);
#else
#ifdef HAS_SETREGID
    (void)setregid((Gid_t)PL_gid, (Gid_t)-1);
#else
#ifdef HAS_SETRESGID
      (void)setresgid((Gid_t)PL_gid, (Gid_t)-1, (Gid_t) 1);
#else
    if (PL_gid == PL_egid)          /* special case $( = $) */
        (void)PerlProc_setgid(PL_gid);
    else {
        PL_gid = PerlProc_getgid();
        Perl_croak(aTHX_ "setrgid() not implemented");
    }
#endif
#endif
#endif
    PL_gid = PerlProc_getgid();
    PL_tainting |= (PL_uid && (PL_euid != PL_uid || PL_egid != PL_gid));
    break;
    case ')':
#ifdef HAS_SETGROUPS
    {
        char *p = SvPV(sv, len);
#ifdef _SC_NGROUPS_MAX
        int maxgrp = sysconf(_SC_NGROUPS_MAX);
        Groups_t *gary = alloca(maxgrp * sizeof (Groups_t));
#else
        int maxgrp = NGROUPS;
        Groups_t gary[NGROUPS];
#endif

        while (isSPACE(*p))
        ++p;
        PL_egid = Atol(p);
        for (i = 0; i < maxgrp; ++i) {
        while (*p && !isSPACE(*p))
            ++p;
        while (isSPACE(*p))
            ++p;
        if (!*p)
            break;
        gary[i] = Atol(p);
        }
        if (i)
        (void)setgroups(i, gary);
    }
#else  /* HAS_SETGROUPS */
    PL_egid = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
#endif /* HAS_SETGROUPS */
    if (PL_delaymagic) {
        PL_delaymagic |= DM_EGID;
        break;              /* don't do magic till later */
    }
#ifdef HAS_SETEGID
    (void)setegid((Gid_t)PL_egid);
#else
#ifdef HAS_SETREGID
    (void)setregid((Gid_t)-1, (Gid_t)PL_egid);
#else
#ifdef HAS_SETRESGID
    (void)setresgid((Gid_t)-1, (Gid_t)PL_egid, (Gid_t)-1);
#else
    if (PL_egid == PL_gid)          /* special case $) = $( */
        (void)PerlProc_setgid(PL_egid);
    else {
        PL_egid = PerlProc_getegid();
        Perl_croak(aTHX_ "setegid() not implemented");
    }
#endif
#endif
#endif
    PL_egid = PerlProc_getegid();
    PL_tainting |= (PL_uid && (PL_euid != PL_uid || PL_egid != PL_gid));
    break;
    case ':':
    PL_chopset = SvPV_force(sv,len);
    break;
#ifndef MACOS_TRADITIONAL
    case '0':
    LOCK_DOLLARZERO_MUTEX;
#ifdef HAS_SETPROCTITLE
    /* The BSDs don't show the argv[] in ps(1) output, they
     * show a string from the process struct and provide
     * the setproctitle() routine to manipulate that. */
    {
        s = SvPV(sv, len);
#   if __FreeBSD_version > 410001
        /* The leading "-" removes the "perl: " prefix,
         * but not the "(perl) suffix from the ps(1)
         * output, because that's what ps(1) shows if the
         * argv[] is modified. */
        setproctitle("-%s", s);
#   else    /* old FreeBSDs, NetBSD, OpenBSD, anyBSD */
        /* This doesn't really work if you assume that
         * $0 = 'foobar'; will wipe out 'perl' from the $0
         * because in ps(1) output the result will be like
         * sprintf("perl: %s (perl)", s)
         * I guess this is a security feature:
         * one (a user process) cannot get rid of the original name.
         * --jhi */
        setproctitle("%s", s);
#   endif
    }
#endif
#if defined(__hpux) && defined(PSTAT_SETCMD)
    {
         union pstun un;
         s = SvPV(sv, len);
         un.pst_command = s;
         pstat(PSTAT_SETCMD, un, len, 0, 0);
    }
#endif
    /* PL_origalen is set in perl_parse(). */
    s = SvPV_force(sv,len);
    if (len >= (STRLEN)PL_origalen) {
        /* Longer than original, will be truncated. */
        Copy(s, PL_origargv[0], PL_origalen, char);
        PL_origargv[0][PL_origalen - 1] = 0;
    }
    else {
        /* Shorter than original, will be padded. */
        Copy(s, PL_origargv[0], len, char);
        PL_origargv[0][len] = 0;
        memset(PL_origargv[0] + len + 1,
           /* Is the space counterintuitive?  Yes.
            * (You were expecting \0?)
            * Does it work?  Seems to.  (In Linux 2.4.20 at least.)
            * --jhi */
           (int)' ',
           PL_origalen - len - 1);
        for (i = 1; i < PL_origargc; i++)
         PL_origargv[i] = 0;
    }
    UNLOCK_DOLLARZERO_MUTEX;
    break;
#endif
#ifdef USE_5005THREADS
    case '@':
    sv_setsv(thr->errsv, sv);
    break;
#endif /* USE_5005THREADS */
    }
    return 0;
}

#ifdef USE_5005THREADS
int
Perl_magic_mutexfree(pTHX_ SV *sv, MAGIC *mg)
{
    DEBUG_S(PerlIO_printf(Perl_debug_log,
              "0x%"UVxf": magic_mutexfree 0x%"UVxf"\n",
              PTR2UV(thr), PTR2UV(sv)));
    if (MgOWNER(mg))
    Perl_croak(aTHX_ "panic: magic_mutexfree");
    MUTEX_DESTROY(MgMUTEXP(mg));
    COND_DESTROY(MgCONDP(mg));
    return 0;
}
#endif /* USE_5005THREADS */

I32
Perl_whichsig(pTHX_ char *sig)
{
    register char **sigv;

    for (sigv = PL_sig_name; *sigv; sigv++)
    if (strEQ(sig,*sigv))
        return PL_sig_num[sigv - PL_sig_name];
#ifdef SIGCLD
    if (strEQ(sig,"CHLD"))
    return SIGCLD;
#endif
#ifdef SIGCHLD
    if (strEQ(sig,"CLD"))
    return SIGCHLD;
#endif
    return -1;
}

#if !defined(PERL_IMPLICIT_CONTEXT)
static SV* sig_sv;
#endif

Signal_t
Perl_sighandler(int sig)
{
#ifdef PERL_GET_SIG_CONTEXT
    dTHXa(PERL_GET_SIG_CONTEXT);
#else
    dTHX;
#endif
    dSP;
    GV *gv = Nullgv;
    HV *st;
    SV *sv = Nullsv, *tSv = PL_Sv;
    CV *cv = Nullcv;
    OP *myop = PL_op;
    U32 flags = 0;
    XPV *tXpv = PL_Xpv;

    if (PL_savestack_ix + 15 <= PL_savestack_max)
    flags |= 1;
    if (PL_markstack_ptr < PL_markstack_max - 2)
    flags |= 4;
    if (PL_retstack_ix < PL_retstack_max - 2)
    flags |= 8;
    if (PL_scopestack_ix < PL_scopestack_max - 3)
    flags |= 16;

    if (!PL_psig_ptr[sig]) {
        PerlIO_printf(Perl_error_log, "Signal SIG%s received, but no signal handler set.\n",
                 PL_sig_name[sig]);
        exit(sig);
    }

    /* Max number of items pushed there is 3*n or 4. We cannot fix
       infinity, so we fix 4 (in fact 5): */
    if (flags & 1) {
    PL_savestack_ix += 5;       /* Protect save in progress. */
    SAVEDESTRUCTOR_X(unwind_handler_stack, (void*)&flags);
    }
    if (flags & 4)
    PL_markstack_ptr++;     /* Protect mark. */
    if (flags & 8) {
    PL_retstack_ix++;
    PL_retstack[PL_retstack_ix] = NULL;
    }
    if (flags & 16)
    PL_scopestack_ix += 1;
    /* sv_2cv is too complicated, try a simpler variant first: */
    if (!SvROK(PL_psig_ptr[sig]) || !(cv = (CV*)SvRV(PL_psig_ptr[sig]))
    || SvTYPE(cv) != SVt_PVCV)
    cv = sv_2cv(PL_psig_ptr[sig],&st,&gv,TRUE);

    if (!cv || !CvROOT(cv)) {
    if (ckWARN(WARN_SIGNAL))
        Perl_warner(aTHX_ packWARN(WARN_SIGNAL), "SIG%s handler \"%s\" not defined.\n",
        PL_sig_name[sig], (gv ? GvENAME(gv)
                : ((cv && CvGV(cv))
                   ? GvENAME(CvGV(cv))
                   : "__ANON__")));
    goto cleanup;
    }

    if(PL_psig_name[sig]) {
        sv = SvREFCNT_inc(PL_psig_name[sig]);
    flags |= 64;
#if !defined(PERL_IMPLICIT_CONTEXT)
    sig_sv = sv;
#endif
    } else {
    sv = sv_newmortal();
    sv_setpv(sv,PL_sig_name[sig]);
    }

    PUSHSTACKi(PERLSI_SIGNAL);
    PUSHMARK(SP);
    PUSHs(sv);
    PUTBACK;

    call_sv((SV*)cv, G_DISCARD|G_EVAL);

    POPSTACK;
    if (SvTRUE(ERRSV)) {
#ifndef PERL_MICRO
#ifdef HAS_SIGPROCMASK
    /* Handler "died", for example to get out of a restart-able read().
     * Before we re-do that on its behalf re-enable the signal which was
     * blocked by the system when we entered.
     */
    sigset_t set;
    sigemptyset(&set);
    sigaddset(&set,sig);
    sigprocmask(SIG_UNBLOCK, &set, NULL);
#else
    /* Not clear if this will work */
    (void)rsignal(sig, SIG_IGN);
    (void)rsignal(sig, PL_csighandlerp);
#endif
#endif /* !PERL_MICRO */
    Perl_die(aTHX_ Nullformat);
    }
cleanup:
    if (flags & 1)
    PL_savestack_ix -= 8; /* Unprotect save in progress. */
    if (flags & 4)
    PL_markstack_ptr--;
    if (flags & 8)
    PL_retstack_ix--;
    if (flags & 16)
    PL_scopestack_ix -= 1;
    if (flags & 64)
    SvREFCNT_dec(sv);
    PL_op = myop;           /* Apparently not needed... */

    PL_Sv = tSv;            /* Restore global temporaries. */
    PL_Xpv = tXpv;
    return;
}


static void
restore_magic(pTHX_ void *p)
{
    MGS* mgs = SSPTR(PTR2IV(p), MGS*);
    SV* sv = mgs->mgs_sv;

    if (!sv)
        return;

    if (SvTYPE(sv) >= SVt_PVMG && SvMAGIC(sv))
    {
    if (mgs->mgs_flags)
        SvFLAGS(sv) |= mgs->mgs_flags;
    else
        mg_magical(sv);
    if (SvGMAGICAL(sv))
        SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK|SVf_POK);
    }

    mgs->mgs_sv = NULL;  /* mark the MGS structure as restored */

    /* If we're still on top of the stack, pop us off.  (That condition
     * will be satisfied if restore_magic was called explicitly, but *not*
     * if it's being called via leave_scope.)
     * The reason for doing this is that otherwise, things like sv_2cv()
     * may leave alloc gunk on the savestack, and some code
     * (e.g. sighandler) doesn't expect that...
     */
    if (PL_savestack_ix == mgs->mgs_ss_ix)
    {
    I32 popval = SSPOPINT;
        assert(popval == SAVEt_DESTRUCTOR_X);
        PL_savestack_ix -= 2;
    popval = SSPOPINT;
        assert(popval == SAVEt_ALLOC);
    popval = SSPOPINT;
        PL_savestack_ix -= popval;
    }

}

static void
unwind_handler_stack(pTHX_ void *p)
{
    U32 flags = *(U32*)p;

    if (flags & 1)
    PL_savestack_ix -= 5; /* Unprotect save in progress. */
    /* cxstack_ix-- Not needed, die already unwound it. */
#if !defined(PERL_IMPLICIT_CONTEXT)
    if (flags & 64)
    SvREFCNT_dec(sig_sv);
#endif
}