xref: /openbsd/gnu/usr.bin/perl/doio.c (revision c0dd97bf)
1 /*    doio.c
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  */
10 
11 /*
12  *  Far below them they saw the white waters pour into a foaming bowl, and
13  *  then swirl darkly about a deep oval basin in the rocks, until they found
14  *  their way out again through a narrow gate, and flowed away, fuming and
15  *  chattering, into calmer and more level reaches.
16  *
17  *     [p.684 of _The Lord of the Rings_, IV/vi: "The Forbidden Pool"]
18  */
19 
20 /* This file contains functions that do the actual I/O on behalf of ops.
21  * For example, pp_print() calls the do_print() function in this file for
22  * each argument needing printing.
23  */
24 
25 #include "EXTERN.h"
26 #define PERL_IN_DOIO_C
27 #include "perl.h"
28 
29 #if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
30 #ifndef HAS_SEM
31 #include <sys/ipc.h>
32 #endif
33 #ifdef HAS_MSG
34 #include <sys/msg.h>
35 #endif
36 #ifdef HAS_SHM
37 #include <sys/shm.h>
38 # ifndef HAS_SHMAT_PROTOTYPE
39     extern Shmat_t shmat (int, char *, int);
40 # endif
41 #endif
42 #endif
43 
44 #ifdef I_UTIME
45 #  if defined(_MSC_VER) || defined(__MINGW32__)
46 #    include <sys/utime.h>
47 #  else
48 #    include <utime.h>
49 #  endif
50 #endif
51 
52 #ifdef O_EXCL
53 #  define OPEN_EXCL O_EXCL
54 #else
55 #  define OPEN_EXCL 0
56 #endif
57 
58 #define PERL_MODE_MAX 8
59 #define PERL_FLAGS_MAX 10
60 
61 #include <signal.h>
62 
63 static IO *
64 S_openn_setup(pTHX_ GV *gv, char *mode, PerlIO **saveifp, PerlIO **saveofp,
65               int *savefd,  char *savetype)
66 {
67     IO * const io = GvIOn(gv);
68 
69     PERL_ARGS_ASSERT_OPENN_SETUP;
70 
71     *saveifp = NULL;
72     *saveofp = NULL;
73     *savefd = -1;
74     *savetype = IoTYPE_CLOSED;
75 
76     Zero(mode,sizeof(mode),char);
77     PL_forkprocess = 1;		/* assume true if no fork */
78 
79     /* If currently open - close before we re-open */
80     if (IoIFP(io)) {
81 	if (IoTYPE(io) == IoTYPE_STD) {
82 	    /* This is a clone of one of STD* handles */
83 	}
84 	else {
85             const int old_fd = PerlIO_fileno(IoIFP(io));
86 
87             if (old_fd >= 0 && old_fd <= PL_maxsysfd) {
88                 /* This is one of the original STD* handles */
89                 *saveifp  = IoIFP(io);
90                 *saveofp  = IoOFP(io);
91                 *savetype = IoTYPE(io);
92                 *savefd   = old_fd;
93             }
94             else {
95                 int result;
96 
97                 if (IoTYPE(io) == IoTYPE_PIPE)
98                     result = PerlProc_pclose(IoIFP(io));
99                 else if (IoIFP(io) != IoOFP(io)) {
100                     if (IoOFP(io)) {
101                         result = PerlIO_close(IoOFP(io));
102                         PerlIO_close(IoIFP(io)); /* clear stdio, fd already closed */
103                     }
104                     else
105                         result = PerlIO_close(IoIFP(io));
106                 }
107                 else
108                     result = PerlIO_close(IoIFP(io));
109 
110                 if (result == EOF && old_fd > PL_maxsysfd) {
111                     /* Why is this not Perl_warn*() call ? */
112                     PerlIO_printf(Perl_error_log,
113                                   "Warning: unable to close filehandle %"HEKf" properly.\n",
114                                   HEKfARG(GvENAME_HEK(gv))
115                         );
116                 }
117             }
118         }
119 	IoOFP(io) = IoIFP(io) = NULL;
120     }
121     return io;
122 }
123 
124 bool
125 Perl_do_openn(pTHX_ GV *gv, const char *oname, I32 len, int as_raw,
126 	      int rawmode, int rawperm, PerlIO *supplied_fp, SV **svp,
127 	      I32 num_svs)
128 {
129     PERL_ARGS_ASSERT_DO_OPENN;
130 
131     if (as_raw) {
132         /* sysopen style args, i.e. integer mode and permissions */
133 
134 	if (num_svs != 0) {
135 	    Perl_croak(aTHX_ "panic: sysopen with multiple args, num_svs=%ld",
136 		       (long) num_svs);
137 	}
138         return do_open_raw(gv, oname, len, rawmode, rawperm);
139     }
140     return do_open6(gv, oname, len, supplied_fp, svp, num_svs);
141 }
142 
143 bool
144 Perl_do_open_raw(pTHX_ GV *gv, const char *oname, STRLEN len,
145                  int rawmode, int rawperm)
146 {
147     PerlIO *saveifp;
148     PerlIO *saveofp;
149     int savefd;
150     char savetype;
151     char mode[PERL_MODE_MAX];	/* file mode ("r\0", "rb\0", "ab\0" etc.) */
152     IO * const io = openn_setup(gv, mode, &saveifp, &saveofp, &savefd, &savetype);
153     int writing = 0;
154     PerlIO *fp;
155 
156     PERL_ARGS_ASSERT_DO_OPEN_RAW;
157 
158     /* For ease of blame back to 5.000, keep the existing indenting. */
159     {
160         /* sysopen style args, i.e. integer mode and permissions */
161 	STRLEN ix = 0;
162 	const int appendtrunc =
163 	     0
164 #ifdef O_APPEND	/* Not fully portable. */
165 	     |O_APPEND
166 #endif
167 #ifdef O_TRUNC	/* Not fully portable. */
168 	     |O_TRUNC
169 #endif
170 	     ;
171 	const int modifyingmode = O_WRONLY|O_RDWR|O_CREAT|appendtrunc;
172 	int ismodifying;
173         SV *namesv;
174 
175 	/* It's not always
176 
177 	   O_RDONLY 0
178 	   O_WRONLY 1
179 	   O_RDWR   2
180 
181 	   It might be (in OS/390 and Mac OS Classic it is)
182 
183 	   O_WRONLY 1
184 	   O_RDONLY 2
185 	   O_RDWR   3
186 
187 	   This means that simple & with O_RDWR would look
188 	   like O_RDONLY is present.  Therefore we have to
189 	   be more careful.
190 	*/
191 	if ((ismodifying = (rawmode & modifyingmode))) {
192 	     if ((ismodifying & O_WRONLY) == O_WRONLY ||
193 		 (ismodifying & O_RDWR)   == O_RDWR   ||
194 		 (ismodifying & (O_CREAT|appendtrunc)))
195 		  TAINT_PROPER("sysopen");
196 	}
197 	mode[ix++] = IoTYPE_NUMERIC; /* Marker to openn to use numeric "sysopen" */
198 
199 #if defined(USE_64_BIT_RAWIO) && defined(O_LARGEFILE)
200 	rawmode |= O_LARGEFILE;	/* Transparently largefiley. */
201 #endif
202 
203         IoTYPE(io) = PerlIO_intmode2str(rawmode, &mode[ix], &writing);
204 
205 	namesv = newSVpvn_flags(oname, len, SVs_TEMP);
206 	fp = PerlIO_openn(aTHX_ NULL, mode, -1, rawmode, rawperm, NULL, 1, &namesv);
207     }
208     return openn_cleanup(gv, io, fp, mode, oname, saveifp, saveofp, savefd,
209                          savetype, writing, 0, NULL);
210 }
211 
212 bool
213 Perl_do_open6(pTHX_ GV *gv, const char *oname, STRLEN len,
214               PerlIO *supplied_fp, SV **svp, U32 num_svs)
215 {
216     PerlIO *saveifp;
217     PerlIO *saveofp;
218     int savefd;
219     char savetype;
220     char mode[PERL_MODE_MAX];	/* file mode ("r\0", "rb\0", "ab\0" etc.) */
221     IO * const io = openn_setup(gv, mode, &saveifp, &saveofp, &savefd, &savetype);
222     int writing = 0;
223     PerlIO *fp;
224     bool was_fdopen = FALSE;
225     char *type  = NULL;
226 
227     PERL_ARGS_ASSERT_DO_OPEN6;
228 
229     /* For ease of blame back to 5.000, keep the existing indenting. */
230     {
231 	/* Regular (non-sys) open */
232 	char *name;
233 	STRLEN olen = len;
234 	char *tend;
235 	int dodup = 0;
236         bool in_raw = 0, in_crlf = 0, out_raw = 0, out_crlf = 0;
237 
238         /* Collect default raw/crlf info from the op */
239         if (PL_op && PL_op->op_type == OP_OPEN) {
240             /* set up IO layers */
241             const U8 flags = PL_op->op_private;
242             in_raw = (flags & OPpOPEN_IN_RAW);
243             in_crlf = (flags & OPpOPEN_IN_CRLF);
244             out_raw = (flags & OPpOPEN_OUT_RAW);
245             out_crlf = (flags & OPpOPEN_OUT_CRLF);
246         }
247 
248 	type = savepvn(oname, len);
249 	tend = type+len;
250 	SAVEFREEPV(type);
251 
252         /* Lose leading and trailing white space */
253 	while (isSPACE(*type))
254 	    type++;
255         while (tend > type && isSPACE(tend[-1]))
256 	    *--tend = '\0';
257 
258 	if (num_svs) {
259             const char *p;
260             STRLEN nlen = 0;
261 	    /* New style explicit name, type is just mode and layer info */
262 #ifdef USE_STDIO
263 	    if (SvROK(*svp) && !strchr(oname,'&')) {
264 		if (ckWARN(WARN_IO))
265 		    Perl_warner(aTHX_ packWARN(WARN_IO),
266 			    "Can't open a reference");
267 		SETERRNO(EINVAL, LIB_INVARG);
268                 fp = NULL;
269 		goto say_false;
270 	    }
271 #endif /* USE_STDIO */
272             p = (SvOK(*svp) || SvGMAGICAL(*svp)) ? SvPV(*svp, nlen) : NULL;
273 
274             if (p && !IS_SAFE_PATHNAME(p, nlen, "open")) {
275                 fp = NULL;
276                 goto say_false;
277             }
278 
279 	    name = p ? savepvn(p, nlen) : savepvs("");
280 
281 	    SAVEFREEPV(name);
282 	}
283 	else {
284 	    name = type;
285 	    len  = tend-type;
286 	}
287 	IoTYPE(io) = *type;
288 	if ((*type == IoTYPE_RDWR) && /* scary */
289            (*(type+1) == IoTYPE_RDONLY || *(type+1) == IoTYPE_WRONLY) &&
290 	    ((!num_svs || (tend > type+1 && tend[-1] != IoTYPE_PIPE)))) {
291 	    TAINT_PROPER("open");
292 	    mode[1] = *type++;
293 	    writing = 1;
294 	}
295 
296 	if (*type == IoTYPE_PIPE) {
297 	    if (num_svs) {
298 		if (type[1] != IoTYPE_STD) {
299 	          unknown_open_mode:
300 		    Perl_croak(aTHX_ "Unknown open() mode '%.*s'", (int)olen, oname);
301 		}
302 		type++;
303 	    }
304 	    do {
305 		type++;
306 	    } while (isSPACE(*type));
307 	    if (!num_svs) {
308 		name = type;
309 		len = tend-type;
310 	    }
311 	    if (*name == '\0') {
312 		/* command is missing 19990114 */
313 		if (ckWARN(WARN_PIPE))
314 		    Perl_warner(aTHX_ packWARN(WARN_PIPE), "Missing command in piped open");
315 		errno = EPIPE;
316                 fp = NULL;
317 		goto say_false;
318 	    }
319 	    if (!(*name == '-' && name[1] == '\0') || num_svs)
320 		TAINT_ENV();
321 	    TAINT_PROPER("piped open");
322 	    if (!num_svs && name[len-1] == '|') {
323 		name[--len] = '\0' ;
324 		if (ckWARN(WARN_PIPE))
325 		    Perl_warner(aTHX_ packWARN(WARN_PIPE), "Can't open bidirectional pipe");
326 	    }
327 	    mode[0] = 'w';
328 	    writing = 1;
329             if (out_raw)
330 		mode[1] = 'b';
331             else if (out_crlf)
332 		mode[1] = 't';
333 	    if (num_svs > 1) {
334 		fp = PerlProc_popen_list(mode, num_svs, svp);
335 	    }
336 	    else {
337 		fp = PerlProc_popen(name,mode);
338 	    }
339 	    if (num_svs) {
340 		if (*type) {
341 		    if (PerlIO_apply_layers(aTHX_ fp, mode, type) != 0) {
342                         fp = NULL;
343 			goto say_false;
344 		    }
345 		}
346 	    }
347 	} /* IoTYPE_PIPE */
348 	else if (*type == IoTYPE_WRONLY) {
349 	    TAINT_PROPER("open");
350 	    type++;
351 	    if (*type == IoTYPE_WRONLY) {
352 		/* Two IoTYPE_WRONLYs in a row make for an IoTYPE_APPEND. */
353 		mode[0] = IoTYPE(io) = IoTYPE_APPEND;
354 		type++;
355 	    }
356 	    else {
357 		mode[0] = 'w';
358 	    }
359 	    writing = 1;
360 
361             if (out_raw)
362 		mode[1] = 'b';
363             else if (out_crlf)
364 		mode[1] = 't';
365 	    if (*type == '&') {
366 	      duplicity:
367 		dodup = PERLIO_DUP_FD;
368 		type++;
369 		if (*type == '=') {
370 		    dodup = 0;
371 		    type++;
372 		}
373 		if (!num_svs && !*type && supplied_fp) {
374 		    /* "<+&" etc. is used by typemaps */
375 		    fp = supplied_fp;
376 		}
377 		else {
378 		    PerlIO *that_fp = NULL;
379                     int wanted_fd;
380                     UV uv;
381 		    if (num_svs > 1) {
382 			/* diag_listed_as: More than one argument to '%s' open */
383 			Perl_croak(aTHX_ "More than one argument to '%c&' open",IoTYPE(io));
384 		    }
385 		    while (isSPACE(*type))
386 			type++;
387 		    if (num_svs && (
388 			     SvIOK(*svp)
389 			  || (SvPOKp(*svp) && looks_like_number(*svp))
390 		       )) {
391                         wanted_fd = SvUV(*svp);
392 			num_svs = 0;
393 		    }
394 		    else if (isDIGIT(*type)
395                         && grok_atoUV(type, &uv, NULL)
396                         && uv <= INT_MAX
397                     ) {
398                         wanted_fd = (int)uv;
399 		    }
400 		    else {
401 			const IO* thatio;
402 			if (num_svs) {
403 			    thatio = sv_2io(*svp);
404 			}
405 			else {
406 			    GV * const thatgv = gv_fetchpvn_flags(type, tend - type,
407 						       0, SVt_PVIO);
408 			    thatio = GvIO(thatgv);
409 			}
410 			if (!thatio) {
411 #ifdef EINVAL
412 			    SETERRNO(EINVAL,SS_IVCHAN);
413 #endif
414                             fp = NULL;
415 			    goto say_false;
416 			}
417 			if ((that_fp = IoIFP(thatio))) {
418 			    /* Flush stdio buffer before dup. --mjd
419 			     * Unfortunately SEEK_CURing 0 seems to
420 			     * be optimized away on most platforms;
421 			     * only Solaris and Linux seem to flush
422 			     * on that. --jhi */
423 			    /* On the other hand, do all platforms
424 			     * take gracefully to flushing a read-only
425 			     * filehandle?  Perhaps we should do
426 			     * fsetpos(src)+fgetpos(dst)?  --nik */
427 			    PerlIO_flush(that_fp);
428 			    wanted_fd = PerlIO_fileno(that_fp);
429 			    /* When dup()ing STDIN, STDOUT or STDERR
430 			     * explicitly set appropriate access mode */
431 			    if (that_fp == PerlIO_stdout()
432 				|| that_fp == PerlIO_stderr())
433 			        IoTYPE(io) = IoTYPE_WRONLY;
434 			    else if (that_fp == PerlIO_stdin())
435                                 IoTYPE(io) = IoTYPE_RDONLY;
436 			    /* When dup()ing a socket, say result is
437 			     * one as well */
438 			    else if (IoTYPE(thatio) == IoTYPE_SOCKET)
439 				IoTYPE(io) = IoTYPE_SOCKET;
440 			}
441                         else {
442                             SETERRNO(EBADF, RMS_IFI);
443                             fp = NULL;
444                             goto say_false;
445                         }
446 		    }
447 		    if (!num_svs)
448 			type = NULL;
449 		    if (that_fp) {
450 			fp = PerlIO_fdupopen(aTHX_ that_fp, NULL, dodup);
451 		    }
452 		    else {
453 			if (dodup)
454                             wanted_fd = PerlLIO_dup(wanted_fd);
455 			else
456 			    was_fdopen = TRUE;
457                         if (!(fp = PerlIO_openn(aTHX_ type,mode,wanted_fd,0,0,NULL,num_svs,svp))) {
458                             if (dodup && wanted_fd >= 0)
459                                 PerlLIO_close(wanted_fd);
460 			}
461 		    }
462 		}
463 	    } /* & */
464 	    else {
465 		while (isSPACE(*type))
466 		    type++;
467 		if (*type == IoTYPE_STD && (!type[1] || isSPACE(type[1]) || type[1] == ':')) {
468 		    type++;
469 		    fp = PerlIO_stdout();
470 		    IoTYPE(io) = IoTYPE_STD;
471 		    if (num_svs > 1) {
472 			/* diag_listed_as: More than one argument to '%s' open */
473 			Perl_croak(aTHX_ "More than one argument to '>%c' open",IoTYPE_STD);
474 		    }
475 		}
476 		else  {
477 		    if (num_svs) {
478                         fp = PerlIO_openn(aTHX_ type,mode,-1,0,0,NULL,num_svs,svp);
479                     }
480                     else {
481                         SV *namesv = newSVpvn_flags(type, tend - type, SVs_TEMP);
482 		        type = NULL;
483                         fp = PerlIO_openn(aTHX_ type,mode,-1,0,0,NULL,1,&namesv);
484 		    }
485 		}
486 	    } /* !& */
487 	    if (!fp && type && *type && *type != ':' && !isIDFIRST(*type))
488 	       goto unknown_open_mode;
489 	} /* IoTYPE_WRONLY */
490 	else if (*type == IoTYPE_RDONLY) {
491 	    do {
492 		type++;
493 	    } while (isSPACE(*type));
494 	    mode[0] = 'r';
495             if (in_raw)
496 		mode[1] = 'b';
497             else if (in_crlf)
498 		mode[1] = 't';
499 	    if (*type == '&') {
500 		goto duplicity;
501 	    }
502 	    if (*type == IoTYPE_STD && (!type[1] || isSPACE(type[1]) || type[1] == ':')) {
503 		type++;
504 		fp = PerlIO_stdin();
505 		IoTYPE(io) = IoTYPE_STD;
506 		if (num_svs > 1) {
507 		    /* diag_listed_as: More than one argument to '%s' open */
508 		    Perl_croak(aTHX_ "More than one argument to '<%c' open",IoTYPE_STD);
509 		}
510 	    }
511 	    else {
512 		if (num_svs) {
513                     fp = PerlIO_openn(aTHX_ type,mode,-1,0,0,NULL,num_svs,svp);
514                 }
515                 else {
516                     SV *namesv  = newSVpvn_flags(type, tend - type, SVs_TEMP);
517 		    type = NULL;
518                     fp = PerlIO_openn(aTHX_ type,mode,-1,0,0,NULL,1,&namesv);
519 		}
520 	    }
521 	    if (!fp && type && *type && *type != ':' && !isIDFIRST(*type))
522 	       goto unknown_open_mode;
523 	} /* IoTYPE_RDONLY */
524 	else if ((num_svs && /* '-|...' or '...|' */
525 		  type[0] == IoTYPE_STD && type[1] == IoTYPE_PIPE) ||
526 	         (!num_svs && tend > type+1 && tend[-1] == IoTYPE_PIPE)) {
527 	    if (num_svs) {
528 		type += 2;   /* skip over '-|' */
529 	    }
530 	    else {
531 		*--tend = '\0';
532 		while (tend > type && isSPACE(tend[-1]))
533 		    *--tend = '\0';
534 		for (; isSPACE(*type); type++)
535 		    ;
536 		name = type;
537 	        len  = tend-type;
538 	    }
539 	    if (*name == '\0') {
540 		/* command is missing 19990114 */
541 		if (ckWARN(WARN_PIPE))
542 		    Perl_warner(aTHX_ packWARN(WARN_PIPE), "Missing command in piped open");
543 		errno = EPIPE;
544                 fp = NULL;
545 		goto say_false;
546 	    }
547 	    if (!(*name == '-' && name[1] == '\0') || num_svs)
548 		TAINT_ENV();
549 	    TAINT_PROPER("piped open");
550 	    mode[0] = 'r';
551 
552             if (in_raw)
553 		mode[1] = 'b';
554             else if (in_crlf)
555 		mode[1] = 't';
556 
557 	    if (num_svs > 1) {
558 		fp = PerlProc_popen_list(mode,num_svs,svp);
559 	    }
560 	    else {
561 		fp = PerlProc_popen(name,mode);
562 	    }
563 	    IoTYPE(io) = IoTYPE_PIPE;
564 	    if (num_svs) {
565 		while (isSPACE(*type))
566 		    type++;
567 		if (*type) {
568 		    if (PerlIO_apply_layers(aTHX_ fp, mode, type) != 0) {
569                         fp = NULL;
570 			goto say_false;
571 		    }
572 		}
573 	    }
574 	}
575 	else { /* layer(Args) */
576 	    if (num_svs)
577 		goto unknown_open_mode;
578 	    name = type;
579 	    IoTYPE(io) = IoTYPE_RDONLY;
580 	    for (; isSPACE(*name); name++)
581 		;
582 	    mode[0] = 'r';
583 
584             if (in_raw)
585 		mode[1] = 'b';
586             else if (in_crlf)
587 		mode[1] = 't';
588 
589 	    if (*name == '-' && name[1] == '\0') {
590 		fp = PerlIO_stdin();
591 		IoTYPE(io) = IoTYPE_STD;
592 	    }
593 	    else {
594 		if (num_svs) {
595                     fp = PerlIO_openn(aTHX_ type,mode,-1,0,0,NULL,num_svs,svp);
596                 }
597                 else {
598 		    SV *namesv = newSVpvn_flags(type, tend - type, SVs_TEMP);
599 		    type = NULL;
600                     fp = PerlIO_openn(aTHX_ type,mode,-1,0,0,NULL,1,&namesv);
601 		}
602 	    }
603 	}
604     }
605 
606   say_false:
607     return openn_cleanup(gv, io, fp, mode, oname, saveifp, saveofp, savefd,
608                          savetype, writing, was_fdopen, type);
609 }
610 
611 /* Yes, this is ugly, but it's private, and I don't see a cleaner way to
612    simplify the two-headed public interface of do_openn. */
613 static bool
614 S_openn_cleanup(pTHX_ GV *gv, IO *io, PerlIO *fp, char *mode, const char *oname,
615                 PerlIO *saveifp, PerlIO *saveofp, int savefd, char savetype,
616                 int writing, bool was_fdopen, const char *type)
617 {
618     int fd;
619 
620     PERL_ARGS_ASSERT_OPENN_CLEANUP;
621 
622     if (!fp) {
623 	if (IoTYPE(io) == IoTYPE_RDONLY && ckWARN(WARN_NEWLINE)
624 	    && should_warn_nl(oname)
625 
626 	)
627         {
628             GCC_DIAG_IGNORE(-Wformat-nonliteral); /* PL_warn_nl is constant */
629 	    Perl_warner(aTHX_ packWARN(WARN_NEWLINE), PL_warn_nl, "open");
630             GCC_DIAG_RESTORE;
631         }
632 	goto say_false;
633     }
634 
635     if (ckWARN(WARN_IO)) {
636 	if ((IoTYPE(io) == IoTYPE_RDONLY) &&
637 	    (fp == PerlIO_stdout() || fp == PerlIO_stderr())) {
638 		Perl_warner(aTHX_ packWARN(WARN_IO),
639 			    "Filehandle STD%s reopened as %"HEKf
640 			    " only for input",
641 			    ((fp == PerlIO_stdout()) ? "OUT" : "ERR"),
642 			    HEKfARG(GvENAME_HEK(gv)));
643 	}
644 	else if ((IoTYPE(io) == IoTYPE_WRONLY) && fp == PerlIO_stdin()) {
645 		Perl_warner(aTHX_ packWARN(WARN_IO),
646 		    "Filehandle STDIN reopened as %"HEKf" only for output",
647 		     HEKfARG(GvENAME_HEK(gv))
648 		);
649 	}
650     }
651 
652     fd = PerlIO_fileno(fp);
653     /* Do NOT do: "if (fd < 0) goto say_false;" here.  If there is no
654      * fd assume it isn't a socket - this covers PerlIO::scalar -
655      * otherwise unless we "know" the type probe for socket-ness.
656      */
657     if (IoTYPE(io) && IoTYPE(io) != IoTYPE_PIPE && IoTYPE(io) != IoTYPE_STD && fd >= 0) {
658 	if (PerlLIO_fstat(fd,&PL_statbuf) < 0) {
659 	    /* If PerlIO claims to have fd we had better be able to fstat() it. */
660 	    (void) PerlIO_close(fp);
661 	    goto say_false;
662 	}
663 #ifndef PERL_MICRO
664 	if (S_ISSOCK(PL_statbuf.st_mode))
665 	    IoTYPE(io) = IoTYPE_SOCKET;	/* in case a socket was passed in to us */
666 #ifdef HAS_SOCKET
667 	else if (
668 	    !(PL_statbuf.st_mode & S_IFMT)
669 	    && IoTYPE(io) != IoTYPE_WRONLY  /* Dups of STD* filehandles already have */
670 	    && IoTYPE(io) != IoTYPE_RDONLY  /* type so they aren't marked as sockets */
671 	) {				    /* on OS's that return 0 on fstat()ed pipe */
672 	     char tmpbuf[256];
673 	     Sock_size_t buflen = sizeof tmpbuf;
674 	     if (PerlSock_getsockname(fd, (struct sockaddr *)tmpbuf, &buflen) >= 0
675 		      || errno != ENOTSOCK)
676 		    IoTYPE(io) = IoTYPE_SOCKET; /* some OS's return 0 on fstat()ed socket */
677 				                /* but some return 0 for streams too, sigh */
678 	}
679 #endif /* HAS_SOCKET */
680 #endif /* !PERL_MICRO */
681     }
682 
683     /* Eeek - FIXME !!!
684      * If this is a standard handle we discard all the layer stuff
685      * and just dup the fd into whatever was on the handle before !
686      */
687 
688     if (saveifp) {		/* must use old fp? */
689         /* If fd is less that PL_maxsysfd i.e. STDIN..STDERR
690            then dup the new fileno down
691          */
692 	if (saveofp) {
693 	    PerlIO_flush(saveofp);	/* emulate PerlIO_close() */
694 	    if (saveofp != saveifp) {	/* was a socket? */
695 		PerlIO_close(saveofp);
696 	    }
697 	}
698 	if (savefd != fd) {
699 	    /* Still a small can-of-worms here if (say) PerlIO::scalar
700 	       is assigned to (say) STDOUT - for now let dup2() fail
701 	       and provide the error
702 	     */
703 	    if (fd < 0) {
704                 SETERRNO(EBADF,RMS_IFI);
705 		goto say_false;
706             } else if (PerlLIO_dup2(fd, savefd) < 0) {
707 		(void)PerlIO_close(fp);
708 		goto say_false;
709 	    }
710 #ifdef VMS
711 	    if (savefd != PerlIO_fileno(PerlIO_stdin())) {
712                 char newname[FILENAME_MAX+1];
713                 if (PerlIO_getname(fp, newname)) {
714                     if (fd == PerlIO_fileno(PerlIO_stdout()))
715                         vmssetuserlnm("SYS$OUTPUT", newname);
716                     if (fd == PerlIO_fileno(PerlIO_stderr()))
717                         vmssetuserlnm("SYS$ERROR", newname);
718                 }
719 	    }
720 #endif
721 
722 #if !defined(WIN32)
723            /* PL_fdpid isn't used on Windows, so avoid this useless work.
724             * XXX Probably the same for a lot of other places. */
725             {
726                 Pid_t pid;
727                 SV *sv;
728 
729                 sv = *av_fetch(PL_fdpid,fd,TRUE);
730                 SvUPGRADE(sv, SVt_IV);
731                 pid = SvIVX(sv);
732                 SvIV_set(sv, 0);
733                 sv = *av_fetch(PL_fdpid,savefd,TRUE);
734                 SvUPGRADE(sv, SVt_IV);
735                 SvIV_set(sv, pid);
736             }
737 #endif
738 
739 	    if (was_fdopen) {
740                 /* need to close fp without closing underlying fd */
741                 int ofd = PerlIO_fileno(fp);
742                 int dupfd = ofd >= 0 ? PerlLIO_dup(ofd) : -1;
743 #if defined(HAS_FCNTL) && defined(F_SETFD)
744 		/* Assume if we have F_SETFD we have F_GETFD. */
745                 /* Get a copy of all the fd flags. */
746                 int fd_flags = ofd >= 0 ? fcntl(ofd, F_GETFD) : -1;
747                 if (fd_flags < 0) {
748                     if (dupfd >= 0)
749                         PerlLIO_close(dupfd);
750                     goto say_false;
751                 }
752 #endif
753                 if (ofd < 0 || dupfd < 0) {
754                     if (dupfd >= 0)
755                         PerlLIO_close(dupfd);
756                     goto say_false;
757                 }
758                 PerlIO_close(fp);
759                 PerlLIO_dup2(dupfd, ofd);
760 #if defined(HAS_FCNTL) && defined(F_SETFD)
761 		/* The dup trick has lost close-on-exec on ofd,
762                  * and possibly any other flags, so restore them. */
763 		fcntl(ofd,F_SETFD, fd_flags);
764 #endif
765                 PerlLIO_close(dupfd);
766 	    }
767             else
768 		PerlIO_close(fp);
769 	}
770 	fp = saveifp;
771 	PerlIO_clearerr(fp);
772 	fd = PerlIO_fileno(fp);
773     }
774 #if defined(HAS_FCNTL) && defined(F_SETFD) && defined(FD_CLOEXEC)
775     if (fd >= 0 && fd > PL_maxsysfd && fcntl(fd, F_SETFD, FD_CLOEXEC) < 0) {
776         PerlLIO_close(fd);
777         goto say_false;
778     }
779 #endif
780     IoIFP(io) = fp;
781 
782     IoFLAGS(io) &= ~IOf_NOLINE;
783     if (writing) {
784 	if (IoTYPE(io) == IoTYPE_SOCKET
785 	    || (IoTYPE(io) == IoTYPE_WRONLY && fd >= 0 && S_ISCHR(PL_statbuf.st_mode)) ) {
786 	    char *s = mode;
787 	    if (*s == IoTYPE_IMPLICIT || *s == IoTYPE_NUMERIC)
788 	      s++;
789 	    *s = 'w';
790 	    if (!(IoOFP(io) = PerlIO_openn(aTHX_ type,s,fd,0,0,NULL,0,NULL))) {
791 		PerlIO_close(fp);
792 		goto say_false;
793 	    }
794 	}
795 	else
796 	    IoOFP(io) = fp;
797     }
798     return TRUE;
799 
800   say_false:
801     IoIFP(io) = saveifp;
802     IoOFP(io) = saveofp;
803     IoTYPE(io) = savetype;
804     return FALSE;
805 }
806 
807 PerlIO *
808 Perl_nextargv(pTHX_ GV *gv, bool nomagicopen)
809 {
810     IO * const io = GvIOp(gv);
811     SV *const old_out_name = PL_inplace ? newSVsv(GvSV(gv)) : NULL;
812 
813     PERL_ARGS_ASSERT_NEXTARGV;
814 
815     if (old_out_name)
816         SAVEFREESV(old_out_name);
817 
818     if (!PL_argvoutgv)
819 	PL_argvoutgv = gv_fetchpvs("ARGVOUT", GV_ADD|GV_NOTQUAL, SVt_PVIO);
820     if (io && (IoFLAGS(io) & (IOf_ARGV|IOf_START)) == (IOf_ARGV|IOf_START)) {
821 	IoFLAGS(io) &= ~IOf_START;
822 	if (PL_inplace) {
823 	    assert(PL_defoutgv);
824 	    Perl_av_create_and_push(aTHX_ &PL_argvout_stack,
825 				    SvREFCNT_inc_simple_NN(PL_defoutgv));
826 	}
827     }
828     if (PL_filemode & (S_ISUID|S_ISGID)) {
829 	PerlIO_flush(IoIFP(GvIOn(PL_argvoutgv)));  /* chmod must follow last write */
830 #ifdef HAS_FCHMOD
831 	if (PL_lastfd != -1)
832 	    (void)fchmod(PL_lastfd,PL_filemode);
833 #else
834 	(void)PerlLIO_chmod(PL_oldname,PL_filemode);
835 #endif
836     }
837     PL_lastfd = -1;
838     PL_filemode = 0;
839     if (!GvAV(gv))
840 	return NULL;
841     while (av_tindex(GvAV(gv)) >= 0) {
842 	Stat_t statbuf;
843 	STRLEN oldlen;
844         SV *const sv = av_shift(GvAV(gv));
845 	SAVEFREESV(sv);
846 	SvTAINTED_off(GvSVn(gv)); /* previous tainting irrelevant */
847 	sv_setsv(GvSVn(gv),sv);
848 	SvSETMAGIC(GvSV(gv));
849 	PL_oldname = SvPVx(GvSV(gv), oldlen);
850         if (LIKELY(!PL_inplace)) {
851             if (nomagicopen
852                     ? do_open6(gv, "<", 1, NULL, &GvSV(gv), 1)
853                     : do_open6(gv, PL_oldname, oldlen, NULL, NULL, 0)
854                ) {
855                 return IoIFP(GvIOp(gv));
856             }
857         }
858         else {
859             {
860                 IO * const io = GvIOp(PL_argvoutgv);
861                 if (io && IoIFP(io) && old_out_name && !io_close(io, PL_argvoutgv, FALSE, FALSE)) {
862                     Perl_croak(aTHX_ "Failed to close in-place edit file %"SVf": %s\n",
863                                old_out_name, Strerror(errno));
864                 }
865             }
866             /* This very long block ends with return IoIFP(GvIOp(gv));
867                Both this block and the block above fall through on open
868                failure to the warning code, and then the while loop above tries
869                the next entry. */
870             if (do_open_raw(gv, PL_oldname, oldlen, O_RDONLY, 0)) {
871 #ifndef FLEXFILENAMES
872                 int filedev;
873                 int fileino;
874 #endif
875                 Uid_t fileuid;
876                 Gid_t filegid;
877 
878 		TAINT_PROPER("inplace open");
879 		if (oldlen == 1 && *PL_oldname == '-') {
880 		    setdefout(gv_fetchpvs("STDOUT", GV_ADD|GV_NOTQUAL,
881 					  SVt_PVIO));
882 		    return IoIFP(GvIOp(gv));
883 		}
884 #ifndef FLEXFILENAMES
885 		filedev = PL_statbuf.st_dev;
886 		fileino = PL_statbuf.st_ino;
887 #endif
888 		PL_filemode = PL_statbuf.st_mode;
889 		fileuid = PL_statbuf.st_uid;
890 		filegid = PL_statbuf.st_gid;
891 		if (!S_ISREG(PL_filemode)) {
892 		    Perl_ck_warner_d(aTHX_ packWARN(WARN_INPLACE),
893 				     "Can't do inplace edit: %s is not a regular file",
894 				     PL_oldname );
895 		    do_close(gv,FALSE);
896 		    continue;
897 		}
898 		if (*PL_inplace && strNE(PL_inplace, "*")) {
899 		    const char *star = strchr(PL_inplace, '*');
900 		    if (star) {
901 			const char *begin = PL_inplace;
902 			sv_setpvs(sv, "");
903 			do {
904 			    sv_catpvn(sv, begin, star - begin);
905 			    sv_catpvn(sv, PL_oldname, oldlen);
906 			    begin = ++star;
907 			} while ((star = strchr(begin, '*')));
908 			if (*begin)
909 			    sv_catpv(sv,begin);
910 		    }
911 		    else {
912 			sv_catpv(sv,PL_inplace);
913 		    }
914 #ifndef FLEXFILENAMES
915 		    if ((PerlLIO_stat(SvPVX_const(sv),&PL_statbuf) >= 0
916 			 && PL_statbuf.st_dev == filedev
917 			 && PL_statbuf.st_ino == fileino)
918 #ifdef DJGPP
919 			|| ((_djstat_fail_bits & _STFAIL_TRUENAME)!=0)
920 #endif
921                       )
922 		    {
923 			Perl_ck_warner_d(aTHX_ packWARN(WARN_INPLACE),
924 					 "Can't do inplace edit: %"SVf" would not be unique",
925 					 SVfARG(sv));
926 			do_close(gv,FALSE);
927 			continue;
928 		    }
929 #endif
930 #ifdef HAS_RENAME
931 #if !defined(DOSISH) && !defined(__CYGWIN__)
932 		    if (PerlLIO_rename(PL_oldname,SvPVX_const(sv)) < 0) {
933 			Perl_ck_warner_d(aTHX_ packWARN(WARN_INPLACE),
934 					 "Can't rename %s to %"SVf": %s, skipping file",
935 					 PL_oldname, SVfARG(sv), Strerror(errno));
936 			do_close(gv,FALSE);
937 			continue;
938 		    }
939 #else
940 		    do_close(gv,FALSE);
941 		    (void)PerlLIO_unlink(SvPVX_const(sv));
942 		    (void)PerlLIO_rename(PL_oldname,SvPVX_const(sv));
943 		    do_open_raw(gv, SvPVX_const(sv), SvCUR(sv), O_RDONLY, 0);
944 #endif /* DOSISH */
945 #else
946 		    (void)UNLINK(SvPVX_const(sv));
947 		    if (link(PL_oldname,SvPVX_const(sv)) < 0) {
948 			Perl_ck_warner_d(aTHX_ packWARN(WARN_INPLACE),
949 					 "Can't rename %s to %"SVf": %s, skipping file",
950 					 PL_oldname, SVfARG(sv), Strerror(errno) );
951 			do_close(gv,FALSE);
952 			continue;
953 		    }
954 		    (void)UNLINK(PL_oldname);
955 #endif
956 		}
957 		else {
958 #if !defined(DOSISH) && !defined(__amigaos4__)
959 #  ifndef VMS  /* Don't delete; use automatic file versioning */
960 		    if (UNLINK(PL_oldname) < 0) {
961 			Perl_ck_warner_d(aTHX_ packWARN(WARN_INPLACE),
962 					 "Can't remove %s: %s, skipping file",
963 					 PL_oldname, Strerror(errno) );
964 			do_close(gv,FALSE);
965 			continue;
966 		    }
967 #  endif
968 #else
969 		    Perl_croak(aTHX_ "Can't do inplace edit without backup");
970 #endif
971 		}
972 
973 		sv_setpvn(sv,PL_oldname,oldlen);
974 		SETERRNO(0,0);		/* in case sprintf set errno */
975 		if (!Perl_do_open_raw(aTHX_ PL_argvoutgv, SvPVX_const(sv),
976                                       SvCUR(sv),
977 #ifdef VMS
978                                       O_WRONLY|O_CREAT|O_TRUNC, 0
979 #else
980                                       O_WRONLY|O_CREAT|OPEN_EXCL, 0600
981 #endif
982                         )) {
983 		    Perl_ck_warner_d(aTHX_ packWARN(WARN_INPLACE), "Can't do inplace edit on %s: %s",
984 				     PL_oldname, Strerror(errno) );
985 		    do_close(gv,FALSE);
986 		    continue;
987 		}
988 		setdefout(PL_argvoutgv);
989 		PL_lastfd = PerlIO_fileno(IoIFP(GvIOp(PL_argvoutgv)));
990                 if (PL_lastfd >= 0) {
991                     (void)PerlLIO_fstat(PL_lastfd,&statbuf);
992 #ifdef HAS_FCHMOD
993                     (void)fchmod(PL_lastfd,PL_filemode);
994 #else
995                     (void)PerlLIO_chmod(PL_oldname,PL_filemode);
996 #endif
997                     if (fileuid != statbuf.st_uid || filegid != statbuf.st_gid) {
998                         /* XXX silently ignore failures */
999 #ifdef HAS_FCHOWN
1000                         PERL_UNUSED_RESULT(fchown(PL_lastfd,fileuid,filegid));
1001 #else
1002 #ifdef HAS_CHOWN
1003                         PERL_UNUSED_RESULT(PerlLIO_chown(PL_oldname,fileuid,filegid));
1004 #endif
1005 #endif
1006                     }
1007 		}
1008                 return IoIFP(GvIOp(gv));
1009 	    }
1010 	} /* successful do_open_raw(), PL_inplace non-NULL */
1011 
1012         if (ckWARN_d(WARN_INPLACE)) {
1013             const int eno = errno;
1014             if (PerlLIO_stat(PL_oldname, &statbuf) >= 0
1015                 && !S_ISREG(statbuf.st_mode)) {
1016                 Perl_warner(aTHX_ packWARN(WARN_INPLACE),
1017                             "Can't do inplace edit: %s is not a regular file",
1018                             PL_oldname);
1019             }
1020             else {
1021                 Perl_warner(aTHX_ packWARN(WARN_INPLACE), "Can't open %s: %s",
1022                             PL_oldname, Strerror(eno));
1023             }
1024 	}
1025     }
1026     if (io && (IoFLAGS(io) & IOf_ARGV))
1027 	IoFLAGS(io) |= IOf_START;
1028     if (PL_inplace) {
1029         if (old_out_name) {
1030             IO * const io = GvIOp(PL_argvoutgv);
1031             if (io && IoIFP(io) && !io_close(io, PL_argvoutgv, FALSE, FALSE)) {
1032                 Perl_croak(aTHX_ "Failed to close in-place edit file %"SVf": %s\n",
1033                            old_out_name, Strerror(errno));
1034             }
1035         }
1036         else {
1037             /* maybe this is no longer wanted */
1038             (void)do_close(PL_argvoutgv,FALSE);
1039         }
1040 	if (io && (IoFLAGS(io) & IOf_ARGV)
1041 	    && PL_argvout_stack && AvFILLp(PL_argvout_stack) >= 0)
1042 	{
1043 	    GV * const oldout = MUTABLE_GV(av_pop(PL_argvout_stack));
1044 	    setdefout(oldout);
1045 	    SvREFCNT_dec_NN(oldout);
1046 	    return NULL;
1047 	}
1048 	setdefout(gv_fetchpvs("STDOUT", GV_ADD|GV_NOTQUAL, SVt_PVIO));
1049     }
1050     return NULL;
1051 }
1052 
1053 /* explicit renamed to avoid C++ conflict    -- kja */
1054 bool
1055 Perl_do_close(pTHX_ GV *gv, bool not_implicit)
1056 {
1057     bool retval;
1058     IO *io;
1059 
1060     if (!gv)
1061 	gv = PL_argvgv;
1062     if (!gv || !isGV_with_GP(gv)) {
1063 	if (not_implicit)
1064 	    SETERRNO(EBADF,SS_IVCHAN);
1065 	return FALSE;
1066     }
1067     io = GvIO(gv);
1068     if (!io) {		/* never opened */
1069 	if (not_implicit) {
1070 	    report_evil_fh(gv);
1071 	    SETERRNO(EBADF,SS_IVCHAN);
1072 	}
1073 	return FALSE;
1074     }
1075     retval = io_close(io, NULL, not_implicit, FALSE);
1076     if (not_implicit) {
1077 	IoLINES(io) = 0;
1078 	IoPAGE(io) = 0;
1079 	IoLINES_LEFT(io) = IoPAGE_LEN(io);
1080     }
1081     IoTYPE(io) = IoTYPE_CLOSED;
1082     return retval;
1083 }
1084 
1085 bool
1086 Perl_io_close(pTHX_ IO *io, GV *gv, bool not_implicit, bool warn_on_fail)
1087 {
1088     bool retval = FALSE;
1089 
1090     PERL_ARGS_ASSERT_IO_CLOSE;
1091 
1092     if (IoIFP(io)) {
1093 	if (IoTYPE(io) == IoTYPE_PIPE) {
1094 	    const int status = PerlProc_pclose(IoIFP(io));
1095 	    if (not_implicit) {
1096 		STATUS_NATIVE_CHILD_SET(status);
1097 		retval = (STATUS_UNIX == 0);
1098 	    }
1099 	    else {
1100 		retval = (status != -1);
1101 	    }
1102 	}
1103 	else if (IoTYPE(io) == IoTYPE_STD)
1104 	    retval = TRUE;
1105 	else {
1106 	    if (IoOFP(io) && IoOFP(io) != IoIFP(io)) {		/* a socket */
1107 		const bool prev_err = PerlIO_error(IoOFP(io));
1108 #ifdef USE_PERLIO
1109 		if (prev_err)
1110 		    PerlIO_restore_errno(IoOFP(io));
1111 #endif
1112 		retval = (PerlIO_close(IoOFP(io)) != EOF && !prev_err);
1113 		PerlIO_close(IoIFP(io));	/* clear stdio, fd already closed */
1114 	    }
1115 	    else {
1116 		const bool prev_err = PerlIO_error(IoIFP(io));
1117 #ifdef USE_PERLIO
1118 		if (prev_err)
1119 		    PerlIO_restore_errno(IoIFP(io));
1120 #endif
1121 		retval = (PerlIO_close(IoIFP(io)) != EOF && !prev_err);
1122 	    }
1123 	}
1124 	IoOFP(io) = IoIFP(io) = NULL;
1125 
1126 	if (warn_on_fail && !retval) {
1127 	    if (gv)
1128 		Perl_ck_warner_d(aTHX_ packWARN(WARN_IO),
1129 				"Warning: unable to close filehandle %"
1130 				 HEKf" properly: %"SVf,
1131 				 HEKfARG(GvNAME_HEK(gv)),
1132                                  SVfARG(get_sv("!",GV_ADD)));
1133 	    else
1134 		Perl_ck_warner_d(aTHX_ packWARN(WARN_IO),
1135 				"Warning: unable to close filehandle "
1136 				"properly: %"SVf,
1137 				 SVfARG(get_sv("!",GV_ADD)));
1138 	}
1139     }
1140     else if (not_implicit) {
1141 	SETERRNO(EBADF,SS_IVCHAN);
1142     }
1143 
1144     return retval;
1145 }
1146 
1147 bool
1148 Perl_do_eof(pTHX_ GV *gv)
1149 {
1150     IO * const io = GvIO(gv);
1151 
1152     PERL_ARGS_ASSERT_DO_EOF;
1153 
1154     if (!io)
1155 	return TRUE;
1156     else if (IoTYPE(io) == IoTYPE_WRONLY)
1157 	report_wrongway_fh(gv, '>');
1158 
1159     while (IoIFP(io)) {
1160         if (PerlIO_has_cntptr(IoIFP(io))) {	/* (the code works without this) */
1161 	    if (PerlIO_get_cnt(IoIFP(io)) > 0)	/* cheat a little, since */
1162 		return FALSE;			/* this is the most usual case */
1163         }
1164 
1165 	{
1166 	     /* getc and ungetc can stomp on errno */
1167 	    dSAVE_ERRNO;
1168 	    const int ch = PerlIO_getc(IoIFP(io));
1169 	    if (ch != EOF) {
1170 		(void)PerlIO_ungetc(IoIFP(io),ch);
1171 		RESTORE_ERRNO;
1172 		return FALSE;
1173 	    }
1174 	    RESTORE_ERRNO;
1175 	}
1176 
1177         if (PerlIO_has_cntptr(IoIFP(io)) && PerlIO_canset_cnt(IoIFP(io))) {
1178 	    if (PerlIO_get_cnt(IoIFP(io)) < -1)
1179 		PerlIO_set_cnt(IoIFP(io),-1);
1180 	}
1181 	if (PL_op->op_flags & OPf_SPECIAL) { /* not necessarily a real EOF yet? */
1182 	    if (gv != PL_argvgv || !nextargv(gv, FALSE))	/* get another fp handy */
1183 		return TRUE;
1184 	}
1185 	else
1186 	    return TRUE;		/* normal fp, definitely end of file */
1187     }
1188     return TRUE;
1189 }
1190 
1191 Off_t
1192 Perl_do_tell(pTHX_ GV *gv)
1193 {
1194     IO *const io = GvIO(gv);
1195     PerlIO *fp;
1196 
1197     PERL_ARGS_ASSERT_DO_TELL;
1198 
1199     if (io && (fp = IoIFP(io))) {
1200 	return PerlIO_tell(fp);
1201     }
1202     report_evil_fh(gv);
1203     SETERRNO(EBADF,RMS_IFI);
1204     return (Off_t)-1;
1205 }
1206 
1207 bool
1208 Perl_do_seek(pTHX_ GV *gv, Off_t pos, int whence)
1209 {
1210     IO *const io = GvIO(gv);
1211     PerlIO *fp;
1212 
1213     if (io && (fp = IoIFP(io))) {
1214 	return PerlIO_seek(fp, pos, whence) >= 0;
1215     }
1216     report_evil_fh(gv);
1217     SETERRNO(EBADF,RMS_IFI);
1218     return FALSE;
1219 }
1220 
1221 Off_t
1222 Perl_do_sysseek(pTHX_ GV *gv, Off_t pos, int whence)
1223 {
1224     IO *const io = GvIO(gv);
1225     PerlIO *fp;
1226 
1227     PERL_ARGS_ASSERT_DO_SYSSEEK;
1228 
1229     if (io && (fp = IoIFP(io))) {
1230         int fd = PerlIO_fileno(fp);
1231         if (fd < 0 || (whence == SEEK_SET && pos < 0)) {
1232             SETERRNO(EINVAL,LIB_INVARG);
1233             return -1;
1234         } else {
1235             return PerlLIO_lseek(fd, pos, whence);
1236         }
1237     }
1238     report_evil_fh(gv);
1239     SETERRNO(EBADF,RMS_IFI);
1240     return (Off_t)-1;
1241 }
1242 
1243 int
1244 Perl_mode_from_discipline(pTHX_ const char *s, STRLEN len)
1245 {
1246     int mode = O_BINARY;
1247     PERL_UNUSED_CONTEXT;
1248     if (s) {
1249 	while (*s) {
1250 	    if (*s == ':') {
1251 		switch (s[1]) {
1252 		case 'r':
1253 		    if (s[2] == 'a' && s[3] == 'w'
1254 			&& (!s[4] || s[4] == ':' || isSPACE(s[4])))
1255 		    {
1256 			mode = O_BINARY;
1257 			s += 4;
1258 			len -= 4;
1259 			break;
1260 		    }
1261 		    /* FALLTHROUGH */
1262 		case 'c':
1263 		    if (s[2] == 'r' && s[3] == 'l' && s[4] == 'f'
1264 			&& (!s[5] || s[5] == ':' || isSPACE(s[5])))
1265 		    {
1266 			mode = O_TEXT;
1267 			s += 5;
1268 			len -= 5;
1269 			break;
1270 		    }
1271 		    /* FALLTHROUGH */
1272 		default:
1273 		    goto fail_discipline;
1274 		}
1275 	    }
1276 	    else if (isSPACE(*s)) {
1277 		++s;
1278 		--len;
1279 	    }
1280 	    else {
1281 		const char *end;
1282   fail_discipline:
1283 		end = strchr(s+1, ':');
1284 		if (!end)
1285 		    end = s+len;
1286 #ifndef PERLIO_LAYERS
1287 		Perl_croak(aTHX_ "IO layers (like '%.*s') unavailable", end-s, s);
1288 #else
1289 		len -= end-s;
1290 		s = end;
1291 #endif
1292 	    }
1293 	}
1294     }
1295     return mode;
1296 }
1297 
1298 #if !defined(HAS_TRUNCATE) && !defined(HAS_CHSIZE)
1299 I32
1300 my_chsize(int fd, Off_t length)
1301 {
1302 #ifdef F_FREESP
1303 	/* code courtesy of William Kucharski */
1304 #define HAS_CHSIZE
1305 
1306     Stat_t filebuf;
1307 
1308     if (PerlLIO_fstat(fd, &filebuf) < 0)
1309 	return -1;
1310 
1311     if (filebuf.st_size < length) {
1312 
1313 	/* extend file length */
1314 
1315 	if ((PerlLIO_lseek(fd, (length - 1), 0)) < 0)
1316 	    return -1;
1317 
1318 	/* write a "0" byte */
1319 
1320 	if ((PerlLIO_write(fd, "", 1)) != 1)
1321 	    return -1;
1322     }
1323     else {
1324 	/* truncate length */
1325 	struct flock fl;
1326 	fl.l_whence = 0;
1327 	fl.l_len = 0;
1328 	fl.l_start = length;
1329 	fl.l_type = F_WRLCK;    /* write lock on file space */
1330 
1331 	/*
1332 	* This relies on the UNDOCUMENTED F_FREESP argument to
1333 	* fcntl(2), which truncates the file so that it ends at the
1334 	* position indicated by fl.l_start.
1335 	*
1336 	* Will minor miracles never cease?
1337 	*/
1338 
1339 	if (fcntl(fd, F_FREESP, &fl) < 0)
1340 	    return -1;
1341 
1342     }
1343     return 0;
1344 #else
1345     Perl_croak_nocontext("truncate not implemented");
1346 #endif /* F_FREESP */
1347     return -1;
1348 }
1349 #endif /* !HAS_TRUNCATE && !HAS_CHSIZE */
1350 
1351 bool
1352 Perl_do_print(pTHX_ SV *sv, PerlIO *fp)
1353 {
1354     PERL_ARGS_ASSERT_DO_PRINT;
1355 
1356     /* assuming fp is checked earlier */
1357     if (!sv)
1358 	return TRUE;
1359     if (SvTYPE(sv) == SVt_IV && SvIOK(sv)) {
1360 	assert(!SvGMAGICAL(sv));
1361 	if (SvIsUV(sv))
1362 	    PerlIO_printf(fp, "%"UVuf, (UV)SvUVX(sv));
1363 	else
1364 	    PerlIO_printf(fp, "%"IVdf, (IV)SvIVX(sv));
1365 	return !PerlIO_error(fp);
1366     }
1367     else {
1368 	STRLEN len;
1369 	/* Do this first to trigger any overloading.  */
1370 	const char *tmps = SvPV_const(sv, len);
1371 	U8 *tmpbuf = NULL;
1372 	bool happy = TRUE;
1373 
1374 	if (PerlIO_isutf8(fp)) { /* If the stream is utf8 ... */
1375 	    if (!SvUTF8(sv)) {	/* Convert to utf8 if necessary */
1376 		/* We don't modify the original scalar.  */
1377 		tmpbuf = bytes_to_utf8((const U8*) tmps, &len);
1378 		tmps = (char *) tmpbuf;
1379 	    }
1380 	    else if (ckWARN4_d(WARN_UTF8, WARN_SURROGATE, WARN_NON_UNICODE, WARN_NONCHAR)) {
1381 		(void) check_utf8_print((const U8*) tmps, len);
1382 	    }
1383 	} /* else stream isn't utf8 */
1384 	else if (DO_UTF8(sv)) { /* But if is utf8 internally, attempt to
1385 				   convert to bytes */
1386 	    STRLEN tmplen = len;
1387 	    bool utf8 = TRUE;
1388 	    U8 * const result = bytes_from_utf8((const U8*) tmps, &tmplen, &utf8);
1389 	    if (!utf8) {
1390 
1391 		/* Here, succeeded in downgrading from utf8.  Set up to below
1392 		 * output the converted value */
1393 		tmpbuf = result;
1394 		tmps = (char *) tmpbuf;
1395 		len = tmplen;
1396 	    }
1397 	    else {  /* Non-utf8 output stream, but string only representable in
1398 		       utf8 */
1399 		assert((char *)result == tmps);
1400 		Perl_ck_warner_d(aTHX_ packWARN(WARN_UTF8),
1401 				 "Wide character in %s",
1402 				   PL_op ? OP_DESC(PL_op) : "print"
1403 				);
1404 		    /* Could also check that isn't one of the things to avoid
1405 		     * in utf8 by using check_utf8_print(), but not doing so,
1406 		     * since the stream isn't a UTF8 stream */
1407 	    }
1408 	}
1409 	/* To detect whether the process is about to overstep its
1410 	 * filesize limit we would need getrlimit().  We could then
1411 	 * also transparently raise the limit with setrlimit() --
1412 	 * but only until the system hard limit/the filesystem limit,
1413 	 * at which we would get EPERM.  Note that when using buffered
1414 	 * io the write failure can be delayed until the flush/close. --jhi */
1415 	if (len && (PerlIO_write(fp,tmps,len) == 0))
1416 	    happy = FALSE;
1417 	Safefree(tmpbuf);
1418 	return happy ? !PerlIO_error(fp) : FALSE;
1419     }
1420 }
1421 
1422 I32
1423 Perl_my_stat_flags(pTHX_ const U32 flags)
1424 {
1425     dSP;
1426     IO *io;
1427     GV* gv;
1428 
1429     if (PL_op->op_flags & OPf_REF) {
1430 	gv = cGVOP_gv;
1431       do_fstat:
1432         if (gv == PL_defgv)
1433             return PL_laststatval;
1434 	io = GvIO(gv);
1435         do_fstat_have_io:
1436         PL_laststype = OP_STAT;
1437         PL_statgv = gv ? gv : (GV *)io;
1438         sv_setpvs(PL_statname, "");
1439         if (io) {
1440 	    if (IoIFP(io)) {
1441                 int fd = PerlIO_fileno(IoIFP(io));
1442                 if (fd < 0) {
1443                     /* E.g. PerlIO::scalar has no real fd. */
1444                     return (PL_laststatval = -1);
1445                 } else {
1446                     return (PL_laststatval = PerlLIO_fstat(fd, &PL_statcache));
1447                 }
1448             } else if (IoDIRP(io)) {
1449                 return (PL_laststatval = PerlLIO_fstat(my_dirfd(IoDIRP(io)), &PL_statcache));
1450             }
1451         }
1452 	PL_laststatval = -1;
1453 	report_evil_fh(gv);
1454 	return -1;
1455     }
1456     else if ((PL_op->op_private & (OPpFT_STACKED|OPpFT_AFTER_t))
1457 	     == OPpFT_STACKED)
1458 	return PL_laststatval;
1459     else {
1460 	SV* const sv = TOPs;
1461 	const char *s;
1462 	STRLEN len;
1463 	if ((gv = MAYBE_DEREF_GV_flags(sv,flags))) {
1464 	    goto do_fstat;
1465 	}
1466         else if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PVIO) {
1467             io = MUTABLE_IO(SvRV(sv));
1468 	    gv = NULL;
1469             goto do_fstat_have_io;
1470         }
1471 
1472 	s = SvPV_flags_const(sv, len, flags);
1473 	PL_statgv = NULL;
1474 	sv_setpvn(PL_statname, s, len);
1475 	s = SvPVX_const(PL_statname);		/* s now NUL-terminated */
1476 	PL_laststype = OP_STAT;
1477 	PL_laststatval = PerlLIO_stat(s, &PL_statcache);
1478 	if (PL_laststatval < 0 && ckWARN(WARN_NEWLINE) && should_warn_nl(s)) {
1479             GCC_DIAG_IGNORE(-Wformat-nonliteral); /* PL_warn_nl is constant */
1480 	    Perl_warner(aTHX_ packWARN(WARN_NEWLINE), PL_warn_nl, "stat");
1481             GCC_DIAG_RESTORE;
1482         }
1483 	return PL_laststatval;
1484     }
1485 }
1486 
1487 
1488 I32
1489 Perl_my_lstat_flags(pTHX_ const U32 flags)
1490 {
1491     static const char* const no_prev_lstat = "The stat preceding -l _ wasn't an lstat";
1492     dSP;
1493     const char *file;
1494     SV* const sv = TOPs;
1495     bool isio = FALSE;
1496     if (PL_op->op_flags & OPf_REF) {
1497 	if (cGVOP_gv == PL_defgv) {
1498 	    if (PL_laststype != OP_LSTAT)
1499 		Perl_croak(aTHX_ "%s", no_prev_lstat);
1500 	    return PL_laststatval;
1501 	}
1502 	PL_laststatval = -1;
1503 	if (ckWARN(WARN_IO)) {
1504 	    /* diag_listed_as: Use of -l on filehandle%s */
1505 	    Perl_warner(aTHX_ packWARN(WARN_IO),
1506 		 	     "Use of -l on filehandle %"HEKf,
1507 			      HEKfARG(GvENAME_HEK(cGVOP_gv)));
1508 	}
1509 	return -1;
1510     }
1511     if ((PL_op->op_private & (OPpFT_STACKED|OPpFT_AFTER_t))
1512 	     == OPpFT_STACKED) {
1513       if (PL_laststype != OP_LSTAT)
1514 	Perl_croak(aTHX_ "%s", no_prev_lstat);
1515       return PL_laststatval;
1516     }
1517 
1518     PL_laststype = OP_LSTAT;
1519     PL_statgv = NULL;
1520     if ( (  (SvROK(sv) && (  isGV_with_GP(SvRV(sv))
1521                           || (isio = SvTYPE(SvRV(sv)) == SVt_PVIO)  )
1522             )
1523          || isGV_with_GP(sv)
1524          )
1525       && ckWARN(WARN_IO)) {
1526         if (isio)
1527 	    /* diag_listed_as: Use of -l on filehandle%s */
1528             Perl_warner(aTHX_ packWARN(WARN_IO),
1529                              "Use of -l on filehandle");
1530         else
1531 	    /* diag_listed_as: Use of -l on filehandle%s */
1532             Perl_warner(aTHX_ packWARN(WARN_IO),
1533                              "Use of -l on filehandle %"HEKf,
1534                               HEKfARG(GvENAME_HEK((const GV *)
1535                                           (SvROK(sv) ? SvRV(sv) : sv))));
1536     }
1537     file = SvPV_flags_const_nolen(sv, flags);
1538     sv_setpv(PL_statname,file);
1539     PL_laststatval = PerlLIO_lstat(file,&PL_statcache);
1540     if (PL_laststatval < 0 && ckWARN(WARN_NEWLINE) && should_warn_nl(file)) {
1541         GCC_DIAG_IGNORE(-Wformat-nonliteral); /* PL_warn_nl is constant */
1542         Perl_warner(aTHX_ packWARN(WARN_NEWLINE), PL_warn_nl, "lstat");
1543         GCC_DIAG_RESTORE;
1544     }
1545     return PL_laststatval;
1546 }
1547 
1548 static void
1549 S_exec_failed(pTHX_ const char *cmd, int fd, int do_report)
1550 {
1551     const int e = errno;
1552     PERL_ARGS_ASSERT_EXEC_FAILED;
1553 
1554     if (ckWARN(WARN_EXEC))
1555         Perl_warner(aTHX_ packWARN(WARN_EXEC), "Can't exec \"%s\": %s",
1556                     cmd, Strerror(e));
1557     if (do_report) {
1558         /* XXX silently ignore failures */
1559         PERL_UNUSED_RESULT(PerlLIO_write(fd, (void*)&e, sizeof(int)));
1560 	PerlLIO_close(fd);
1561     }
1562 }
1563 
1564 bool
1565 Perl_do_aexec5(pTHX_ SV *really, SV **mark, SV **sp,
1566 	       int fd, int do_report)
1567 {
1568     dVAR;
1569     PERL_ARGS_ASSERT_DO_AEXEC5;
1570 #if defined(__SYMBIAN32__) || defined(__LIBCATAMOUNT__)
1571     Perl_croak(aTHX_ "exec? I'm not *that* kind of operating system");
1572 #else
1573     if (sp > mark) {
1574 	const char **a;
1575 	const char *tmps = NULL;
1576 	Newx(PL_Argv, sp - mark + 1, const char*);
1577 	a = PL_Argv;
1578 
1579 	while (++mark <= sp) {
1580 	    if (*mark)
1581 		*a++ = SvPV_nolen_const(*mark);
1582 	    else
1583 		*a++ = "";
1584 	}
1585 	*a = NULL;
1586 	if (really)
1587 	    tmps = SvPV_nolen_const(really);
1588 	if ((!really && *PL_Argv[0] != '/') ||
1589 	    (really && *tmps != '/'))		/* will execvp use PATH? */
1590 	    TAINT_ENV();		/* testing IFS here is overkill, probably */
1591 	PERL_FPU_PRE_EXEC
1592 	if (really && *tmps) {
1593             PerlProc_execvp(tmps,EXEC_ARGV_CAST(PL_Argv));
1594 	} else {
1595             PerlProc_execvp(PL_Argv[0],EXEC_ARGV_CAST(PL_Argv));
1596 	}
1597 	PERL_FPU_POST_EXEC
1598  	S_exec_failed(aTHX_ (really ? tmps : PL_Argv[0]), fd, do_report);
1599     }
1600     do_execfree();
1601 #endif
1602     return FALSE;
1603 }
1604 
1605 void
1606 Perl_do_execfree(pTHX)
1607 {
1608     Safefree(PL_Argv);
1609     PL_Argv = NULL;
1610     Safefree(PL_Cmd);
1611     PL_Cmd = NULL;
1612 }
1613 
1614 #ifdef PERL_DEFAULT_DO_EXEC3_IMPLEMENTATION
1615 
1616 bool
1617 Perl_do_exec3(pTHX_ const char *incmd, int fd, int do_report)
1618 {
1619     dVAR;
1620     const char **a;
1621     char *s;
1622     char *buf;
1623     char *cmd;
1624     /* Make a copy so we can change it */
1625     const Size_t cmdlen = strlen(incmd) + 1;
1626 
1627     PERL_ARGS_ASSERT_DO_EXEC3;
1628 
1629     Newx(buf, cmdlen, char);
1630     cmd = buf;
1631     memcpy(cmd, incmd, cmdlen);
1632 
1633     while (*cmd && isSPACE(*cmd))
1634 	cmd++;
1635 
1636     /* save an extra exec if possible */
1637 
1638 #ifdef CSH
1639     {
1640         char flags[PERL_FLAGS_MAX];
1641 	if (strnEQ(cmd,PL_cshname,PL_cshlen) &&
1642 	    strnEQ(cmd+PL_cshlen," -c",3)) {
1643           my_strlcpy(flags, "-c", PERL_FLAGS_MAX);
1644 	  s = cmd+PL_cshlen+3;
1645 	  if (*s == 'f') {
1646 	      s++;
1647               my_strlcat(flags, "f", PERL_FLAGS_MAX - 2);
1648 	  }
1649 	  if (*s == ' ')
1650 	      s++;
1651 	  if (*s++ == '\'') {
1652 	      char * const ncmd = s;
1653 
1654 	      while (*s)
1655 		  s++;
1656 	      if (s[-1] == '\n')
1657 		  *--s = '\0';
1658 	      if (s[-1] == '\'') {
1659 		  *--s = '\0';
1660 		  PERL_FPU_PRE_EXEC
1661 		  PerlProc_execl(PL_cshname, "csh", flags, ncmd, (char*)NULL);
1662 		  PERL_FPU_POST_EXEC
1663 		  *s = '\'';
1664  		  S_exec_failed(aTHX_ PL_cshname, fd, do_report);
1665 		  Safefree(buf);
1666 		  return FALSE;
1667 	      }
1668 	  }
1669 	}
1670     }
1671 #endif /* CSH */
1672 
1673     /* see if there are shell metacharacters in it */
1674 
1675     if (*cmd == '.' && isSPACE(cmd[1]))
1676 	goto doshell;
1677 
1678     if (strnEQ(cmd,"exec",4) && isSPACE(cmd[4]))
1679 	goto doshell;
1680 
1681     s = cmd;
1682     while (isWORDCHAR(*s))
1683 	s++;	/* catch VAR=val gizmo */
1684     if (*s == '=')
1685 	goto doshell;
1686 
1687     for (s = cmd; *s; s++) {
1688 	if (*s != ' ' && !isALPHA(*s) &&
1689 	    strchr("$&*(){}[]'\";\\|?<>~`\n",*s)) {
1690 	    if (*s == '\n' && !s[1]) {
1691 		*s = '\0';
1692 		break;
1693 	    }
1694 	    /* handle the 2>&1 construct at the end */
1695 	    if (*s == '>' && s[1] == '&' && s[2] == '1'
1696 		&& s > cmd + 1 && s[-1] == '2' && isSPACE(s[-2])
1697 		&& (!s[3] || isSPACE(s[3])))
1698 	    {
1699                 const char *t = s + 3;
1700 
1701 		while (*t && isSPACE(*t))
1702 		    ++t;
1703 		if (!*t && (PerlLIO_dup2(1,2) != -1)) {
1704 		    s[-2] = '\0';
1705 		    break;
1706 		}
1707 	    }
1708 	  doshell:
1709 	    PERL_FPU_PRE_EXEC
1710             PerlProc_execl(PL_sh_path, "sh", "-c", cmd, (char *)NULL);
1711 	    PERL_FPU_POST_EXEC
1712  	    S_exec_failed(aTHX_ PL_sh_path, fd, do_report);
1713 	    Safefree(buf);
1714 	    return FALSE;
1715 	}
1716     }
1717 
1718     Newx(PL_Argv, (s - cmd) / 2 + 2, const char*);
1719     PL_Cmd = savepvn(cmd, s-cmd);
1720     a = PL_Argv;
1721     for (s = PL_Cmd; *s;) {
1722 	while (isSPACE(*s))
1723 	    s++;
1724 	if (*s)
1725 	    *(a++) = s;
1726 	while (*s && !isSPACE(*s))
1727 	    s++;
1728 	if (*s)
1729 	    *s++ = '\0';
1730     }
1731     *a = NULL;
1732     if (PL_Argv[0]) {
1733 	PERL_FPU_PRE_EXEC
1734         PerlProc_execvp(PL_Argv[0],EXEC_ARGV_CAST(PL_Argv));
1735 	PERL_FPU_POST_EXEC
1736 	if (errno == ENOEXEC) {		/* for system V NIH syndrome */
1737 	    do_execfree();
1738 	    goto doshell;
1739 	}
1740  	S_exec_failed(aTHX_ PL_Argv[0], fd, do_report);
1741     }
1742     do_execfree();
1743     Safefree(buf);
1744     return FALSE;
1745 }
1746 
1747 #endif /* OS2 || WIN32 */
1748 
1749 I32
1750 Perl_apply(pTHX_ I32 type, SV **mark, SV **sp)
1751 {
1752     I32 val;
1753     I32 tot = 0;
1754     const char *const what = PL_op_name[type];
1755     const char *s;
1756     STRLEN len;
1757     SV ** const oldmark = mark;
1758     bool killgp = FALSE;
1759 
1760     PERL_ARGS_ASSERT_APPLY;
1761 
1762     PERL_UNUSED_VAR(what); /* may not be used depending on compile options */
1763 
1764     /* Doing this ahead of the switch statement preserves the old behaviour,
1765        where attempting to use kill as a taint test test would fail on
1766        platforms where kill was not defined.  */
1767 #ifndef HAS_KILL
1768     if (type == OP_KILL)
1769 	Perl_die(aTHX_ PL_no_func, what);
1770 #endif
1771 #ifndef HAS_CHOWN
1772     if (type == OP_CHOWN)
1773 	Perl_die(aTHX_ PL_no_func, what);
1774 #endif
1775 
1776 
1777 #define APPLY_TAINT_PROPER() \
1778     STMT_START {							\
1779 	if (TAINT_get) { TAINT_PROPER(what); }				\
1780     } STMT_END
1781 
1782     /* This is a first heuristic; it doesn't catch tainting magic. */
1783     if (TAINTING_get) {
1784 	while (++mark <= sp) {
1785 	    if (SvTAINTED(*mark)) {
1786 		TAINT;
1787 		break;
1788 	    }
1789 	}
1790 	mark = oldmark;
1791     }
1792     switch (type) {
1793     case OP_CHMOD:
1794 	APPLY_TAINT_PROPER();
1795 	if (++mark <= sp) {
1796 	    val = SvIV(*mark);
1797 	    APPLY_TAINT_PROPER();
1798 	    tot = sp - mark;
1799 	    while (++mark <= sp) {
1800                 GV* gv;
1801                 if ((gv = MAYBE_DEREF_GV(*mark))) {
1802 		    if (GvIO(gv) && IoIFP(GvIOp(gv))) {
1803 #ifdef HAS_FCHMOD
1804                         int fd = PerlIO_fileno(IoIFP(GvIOn(gv)));
1805 			APPLY_TAINT_PROPER();
1806                         if (fd < 0) {
1807                             SETERRNO(EBADF,RMS_IFI);
1808                             tot--;
1809                         } else if (fchmod(fd, val))
1810                             tot--;
1811 #else
1812 			Perl_die(aTHX_ PL_no_func, "fchmod");
1813 #endif
1814 		    }
1815 		    else {
1816                         SETERRNO(EBADF,RMS_IFI);
1817 			tot--;
1818 		    }
1819 		}
1820 		else {
1821 		    const char *name = SvPV_nomg_const(*mark, len);
1822 		    APPLY_TAINT_PROPER();
1823                     if (!IS_SAFE_PATHNAME(name, len, "chmod") ||
1824                         PerlLIO_chmod(name, val)) {
1825                         tot--;
1826                     }
1827 		}
1828 	    }
1829 	}
1830 	break;
1831 #ifdef HAS_CHOWN
1832     case OP_CHOWN:
1833 	APPLY_TAINT_PROPER();
1834 	if (sp - mark > 2) {
1835             I32 val2;
1836 	    val = SvIVx(*++mark);
1837 	    val2 = SvIVx(*++mark);
1838 	    APPLY_TAINT_PROPER();
1839 	    tot = sp - mark;
1840 	    while (++mark <= sp) {
1841                 GV* gv;
1842 		if ((gv = MAYBE_DEREF_GV(*mark))) {
1843 		    if (GvIO(gv) && IoIFP(GvIOp(gv))) {
1844 #ifdef HAS_FCHOWN
1845                         int fd = PerlIO_fileno(IoIFP(GvIOn(gv)));
1846 			APPLY_TAINT_PROPER();
1847                         if (fd < 0) {
1848                             SETERRNO(EBADF,RMS_IFI);
1849 			    tot--;
1850                         } else if (fchown(fd, val, val2))
1851 			    tot--;
1852 #else
1853 			Perl_die(aTHX_ PL_no_func, "fchown");
1854 #endif
1855 		    }
1856 		    else {
1857                         SETERRNO(EBADF,RMS_IFI);
1858 			tot--;
1859 		    }
1860 		}
1861 		else {
1862 		    const char *name = SvPV_nomg_const(*mark, len);
1863 		    APPLY_TAINT_PROPER();
1864                     if (!IS_SAFE_PATHNAME(name, len, "chown") ||
1865                         PerlLIO_chown(name, val, val2)) {
1866 			tot--;
1867                     }
1868 		}
1869 	    }
1870 	}
1871 	break;
1872 #endif
1873 /*
1874 XXX Should we make lchown() directly available from perl?
1875 For now, we'll let Configure test for HAS_LCHOWN, but do
1876 nothing in the core.
1877     --AD  5/1998
1878 */
1879 #ifdef HAS_KILL
1880     case OP_KILL:
1881 	APPLY_TAINT_PROPER();
1882 	if (mark == sp)
1883 	    break;
1884 	s = SvPVx_const(*++mark, len);
1885 	if (*s == '-' && isALPHA(s[1]))
1886 	{
1887 	    s++;
1888 	    len--;
1889             killgp = TRUE;
1890 	}
1891 	if (isALPHA(*s)) {
1892 	    if (*s == 'S' && s[1] == 'I' && s[2] == 'G') {
1893 		s += 3;
1894                 len -= 3;
1895             }
1896            if ((val = whichsig_pvn(s, len)) < 0)
1897                Perl_croak(aTHX_ "Unrecognized signal name \"%"SVf"\"", SVfARG(*mark));
1898 	}
1899 	else
1900 	{
1901 	    val = SvIV(*mark);
1902 	    if (val < 0)
1903 	    {
1904 		killgp = TRUE;
1905                 val = -val;
1906 	    }
1907 	}
1908 	APPLY_TAINT_PROPER();
1909 	tot = sp - mark;
1910 
1911 	while (++mark <= sp) {
1912 	    Pid_t proc;
1913 	    SvGETMAGIC(*mark);
1914 	    if (!(SvNIOK(*mark) || looks_like_number(*mark)))
1915 		Perl_croak(aTHX_ "Can't kill a non-numeric process ID");
1916 	    proc = SvIV_nomg(*mark);
1917 	    APPLY_TAINT_PROPER();
1918 #ifdef HAS_KILLPG
1919             /* use killpg in preference, as the killpg() wrapper for Win32
1920              * understands process groups, but the kill() wrapper doesn't */
1921             if (killgp ? PerlProc_killpg(proc, val)
1922                        : PerlProc_kill(proc, val))
1923 #else
1924             if (PerlProc_kill(killgp ? -proc: proc, val))
1925 #endif
1926 		tot--;
1927 	}
1928 	PERL_ASYNC_CHECK();
1929 	break;
1930 #endif
1931     case OP_UNLINK:
1932 	APPLY_TAINT_PROPER();
1933 	tot = sp - mark;
1934 	while (++mark <= sp) {
1935 	    s = SvPV_const(*mark, len);
1936 	    APPLY_TAINT_PROPER();
1937 	    if (!IS_SAFE_PATHNAME(s, len, "unlink")) {
1938                 tot--;
1939             }
1940 	    else if (PL_unsafe) {
1941 		if (UNLINK(s))
1942 		{
1943 		    tot--;
1944 		}
1945 #if defined(__amigaos4__) && defined(NEWLIB)
1946 		else
1947 		{
1948                   /* Under AmigaOS4 unlink only 'fails' if the
1949                    * filename is invalid.  It may not remove the file
1950                    * if it's locked, so check if it's still around. */
1951                   if ((access(s,F_OK) != -1))
1952                   {
1953                     tot--;
1954                   }
1955 		}
1956 #endif
1957 	    }
1958 	    else {	/* don't let root wipe out directories without -U */
1959 		Stat_t statbuf;
1960 		if (PerlLIO_lstat(s, &statbuf) < 0)
1961 		    tot--;
1962 		else if (S_ISDIR(statbuf.st_mode)) {
1963 		    SETERRNO(EISDIR, SS_NOPRIV);
1964 		    tot--;
1965 		}
1966 		else {
1967 		    if (UNLINK(s))
1968 		    {
1969 				tot--;
1970 			}
1971 #if defined(__amigaos4__) && defined(NEWLIB)
1972 			else
1973 			{
1974 				/* Under AmigaOS4 unlink only 'fails' if the filename is invalid */
1975 				/* It may not remove the file if it's Locked, so check if it's still */
1976 				/* arround */
1977 				if((access(s,F_OK) != -1))
1978 				{
1979 					tot--;
1980 				}
1981 			}
1982 #endif
1983 		}
1984 	    }
1985 	}
1986 	break;
1987 #if defined(HAS_UTIME) || defined(HAS_FUTIMES)
1988     case OP_UTIME:
1989 	APPLY_TAINT_PROPER();
1990 	if (sp - mark > 2) {
1991 #if defined(HAS_FUTIMES)
1992 	    struct timeval utbuf[2];
1993 	    void *utbufp = utbuf;
1994 #elif defined(I_UTIME) || defined(VMS)
1995 	    struct utimbuf utbuf;
1996 	    struct utimbuf *utbufp = &utbuf;
1997 #else
1998 	    struct {
1999 		Time_t	actime;
2000 		Time_t	modtime;
2001 	    } utbuf;
2002 	    void *utbufp = &utbuf;
2003 #endif
2004 
2005 	   SV* const accessed = *++mark;
2006 	   SV* const modified = *++mark;
2007 
2008            /* Be like C, and if both times are undefined, let the C
2009             * library figure out what to do.  This usually means
2010             * "current time". */
2011 
2012            if ( accessed == &PL_sv_undef && modified == &PL_sv_undef )
2013                 utbufp = NULL;
2014            else {
2015                 Zero(&utbuf, sizeof utbuf, char);
2016 #ifdef HAS_FUTIMES
2017 		utbuf[0].tv_sec = (long)SvIV(accessed);  /* time accessed */
2018 		utbuf[0].tv_usec = 0;
2019 		utbuf[1].tv_sec = (long)SvIV(modified);  /* time modified */
2020 		utbuf[1].tv_usec = 0;
2021 #elif defined(BIG_TIME)
2022                 utbuf.actime = (Time_t)SvNV(accessed);  /* time accessed */
2023                 utbuf.modtime = (Time_t)SvNV(modified); /* time modified */
2024 #else
2025                 utbuf.actime = (Time_t)SvIV(accessed);  /* time accessed */
2026                 utbuf.modtime = (Time_t)SvIV(modified); /* time modified */
2027 #endif
2028             }
2029 	    APPLY_TAINT_PROPER();
2030 	    tot = sp - mark;
2031 	    while (++mark <= sp) {
2032                 GV* gv;
2033                 if ((gv = MAYBE_DEREF_GV(*mark))) {
2034 		    if (GvIO(gv) && IoIFP(GvIOp(gv))) {
2035 #ifdef HAS_FUTIMES
2036                         int fd =  PerlIO_fileno(IoIFP(GvIOn(gv)));
2037 			APPLY_TAINT_PROPER();
2038                         if (fd < 0) {
2039                             SETERRNO(EBADF,RMS_IFI);
2040                             tot--;
2041 			} else if (futimes(fd, (struct timeval *) utbufp))
2042 			    tot--;
2043 #else
2044 			Perl_die(aTHX_ PL_no_func, "futimes");
2045 #endif
2046 		    }
2047 		    else {
2048 			tot--;
2049 		    }
2050 		}
2051 		else {
2052 		    const char * const name = SvPV_nomg_const(*mark, len);
2053 		    APPLY_TAINT_PROPER();
2054 		    if (!IS_SAFE_PATHNAME(name, len, "utime")) {
2055                         tot--;
2056                     }
2057                     else
2058 #ifdef HAS_FUTIMES
2059 		    if (utimes(name, (struct timeval *)utbufp))
2060 #else
2061 		    if (PerlLIO_utime(name, utbufp))
2062 #endif
2063 			tot--;
2064 		}
2065 
2066 	    }
2067 	}
2068 	else
2069 	    tot = 0;
2070 	break;
2071 #endif
2072     }
2073     return tot;
2074 
2075 #undef APPLY_TAINT_PROPER
2076 }
2077 
2078 /* Do the permissions allow some operation?  Assumes statcache already set. */
2079 #ifndef VMS /* VMS' cando is in vms.c */
2080 bool
2081 Perl_cando(pTHX_ Mode_t mode, bool effective, const Stat_t *statbufp)
2082 /* effective is a flag, true for EUID, or for checking if the effective gid
2083  *  is in the list of groups returned from getgroups().
2084  */
2085 {
2086     PERL_ARGS_ASSERT_CANDO;
2087     PERL_UNUSED_CONTEXT;
2088 
2089 #ifdef DOSISH
2090     /* [Comments and code from Len Reed]
2091      * MS-DOS "user" is similar to UNIX's "superuser," but can't write
2092      * to write-protected files.  The execute permission bit is set
2093      * by the Microsoft C library stat() function for the following:
2094      *		.exe files
2095      *		.com files
2096      *		.bat files
2097      *		directories
2098      * All files and directories are readable.
2099      * Directories and special files, e.g. "CON", cannot be
2100      * write-protected.
2101      * [Comment by Tom Dinger -- a directory can have the write-protect
2102      *		bit set in the file system, but DOS permits changes to
2103      *		the directory anyway.  In addition, all bets are off
2104      *		here for networked software, such as Novell and
2105      *		Sun's PC-NFS.]
2106      */
2107 
2108      /* Atari stat() does pretty much the same thing. we set x_bit_set_in_stat
2109       * too so it will actually look into the files for magic numbers
2110       */
2111      return (mode & statbufp->st_mode) ? TRUE : FALSE;
2112 
2113 #else /* ! DOSISH */
2114 # ifdef __CYGWIN__
2115     if (ingroup(544,effective)) {     /* member of Administrators */
2116 # else
2117     if ((effective ? PerlProc_geteuid() : PerlProc_getuid()) == 0) {	/* root is special */
2118 # endif
2119 	if (mode == S_IXUSR) {
2120 	    if (statbufp->st_mode & 0111 || S_ISDIR(statbufp->st_mode))
2121 		return TRUE;
2122 	}
2123 	else
2124 	    return TRUE;		/* root reads and writes anything */
2125 	return FALSE;
2126     }
2127     if (statbufp->st_uid == (effective ? PerlProc_geteuid() : PerlProc_getuid()) ) {
2128 	if (statbufp->st_mode & mode)
2129 	    return TRUE;	/* ok as "user" */
2130     }
2131     else if (ingroup(statbufp->st_gid,effective)) {
2132 	if (statbufp->st_mode & mode >> 3)
2133 	    return TRUE;	/* ok as "group" */
2134     }
2135     else if (statbufp->st_mode & mode >> 6)
2136 	return TRUE;	/* ok as "other" */
2137     return FALSE;
2138 #endif /* ! DOSISH */
2139 }
2140 #endif /* ! VMS */
2141 
2142 static bool
2143 S_ingroup(pTHX_ Gid_t testgid, bool effective)
2144 {
2145 #ifndef PERL_IMPLICIT_SYS
2146     /* PERL_IMPLICIT_SYS like Win32: getegid() etc. require the context. */
2147     PERL_UNUSED_CONTEXT;
2148 #endif
2149     if (testgid == (effective ? PerlProc_getegid() : PerlProc_getgid()))
2150 	return TRUE;
2151 #ifdef HAS_GETGROUPS
2152     {
2153 	Groups_t *gary = NULL;
2154 	I32 anum;
2155         bool rc = FALSE;
2156 
2157 	anum = getgroups(0, gary);
2158         if (anum > 0) {
2159             Newx(gary, anum, Groups_t);
2160             anum = getgroups(anum, gary);
2161             while (--anum >= 0)
2162                 if (gary[anum] == testgid) {
2163                     rc = TRUE;
2164                     break;
2165                 }
2166 
2167             Safefree(gary);
2168         }
2169         return rc;
2170     }
2171 #else
2172     return FALSE;
2173 #endif
2174 }
2175 
2176 #if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
2177 
2178 I32
2179 Perl_do_ipcget(pTHX_ I32 optype, SV **mark, SV **sp)
2180 {
2181     const key_t key = (key_t)SvNVx(*++mark);
2182     SV *nsv = optype == OP_MSGGET ? NULL : *++mark;
2183     const I32 flags = SvIVx(*++mark);
2184 
2185     PERL_ARGS_ASSERT_DO_IPCGET;
2186     PERL_UNUSED_ARG(sp);
2187 
2188     SETERRNO(0,0);
2189     switch (optype)
2190     {
2191 #ifdef HAS_MSG
2192     case OP_MSGGET:
2193 	return msgget(key, flags);
2194 #endif
2195 #ifdef HAS_SEM
2196     case OP_SEMGET:
2197 	return semget(key, (int) SvIV(nsv), flags);
2198 #endif
2199 #ifdef HAS_SHM
2200     case OP_SHMGET:
2201 	return shmget(key, (size_t) SvUV(nsv), flags);
2202 #endif
2203 #if !defined(HAS_MSG) || !defined(HAS_SEM) || !defined(HAS_SHM)
2204     default:
2205         /* diag_listed_as: msg%s not implemented */
2206 	Perl_croak(aTHX_ "%s not implemented", PL_op_desc[optype]);
2207 #endif
2208     }
2209     return -1;			/* should never happen */
2210 }
2211 
2212 I32
2213 Perl_do_ipcctl(pTHX_ I32 optype, SV **mark, SV **sp)
2214 {
2215     char *a;
2216     I32 ret = -1;
2217     const I32 id  = SvIVx(*++mark);
2218 #ifdef Semctl
2219     const I32 n   = (optype == OP_SEMCTL) ? SvIVx(*++mark) : 0;
2220 #endif
2221     const I32 cmd = SvIVx(*++mark);
2222     SV * const astr = *++mark;
2223     STRLEN infosize = 0;
2224     I32 getinfo = (cmd == IPC_STAT);
2225 
2226     PERL_ARGS_ASSERT_DO_IPCCTL;
2227     PERL_UNUSED_ARG(sp);
2228 
2229     switch (optype)
2230     {
2231 #ifdef HAS_MSG
2232     case OP_MSGCTL:
2233 	if (cmd == IPC_STAT || cmd == IPC_SET)
2234 	    infosize = sizeof(struct msqid_ds);
2235 	break;
2236 #endif
2237 #ifdef HAS_SHM
2238     case OP_SHMCTL:
2239 	if (cmd == IPC_STAT || cmd == IPC_SET)
2240 	    infosize = sizeof(struct shmid_ds);
2241 	break;
2242 #endif
2243 #ifdef HAS_SEM
2244     case OP_SEMCTL:
2245 #ifdef Semctl
2246 	if (cmd == IPC_STAT || cmd == IPC_SET)
2247 	    infosize = sizeof(struct semid_ds);
2248 	else if (cmd == GETALL || cmd == SETALL)
2249 	{
2250 	    struct semid_ds semds;
2251 	    union semun semun;
2252 #ifdef EXTRA_F_IN_SEMUN_BUF
2253             semun.buff = &semds;
2254 #else
2255             semun.buf = &semds;
2256 #endif
2257 	    getinfo = (cmd == GETALL);
2258 	    if (Semctl(id, 0, IPC_STAT, semun) == -1)
2259 		return -1;
2260 	    infosize = semds.sem_nsems * sizeof(short);
2261 		/* "short" is technically wrong but much more portable
2262 		   than guessing about u_?short(_t)? */
2263 	}
2264 #else
2265         /* diag_listed_as: sem%s not implemented */
2266 	Perl_croak(aTHX_ "%s not implemented", PL_op_desc[optype]);
2267 #endif
2268 	break;
2269 #endif
2270 #if !defined(HAS_MSG) || !defined(HAS_SEM) || !defined(HAS_SHM)
2271     default:
2272         /* diag_listed_as: shm%s not implemented */
2273 	Perl_croak(aTHX_ "%s not implemented", PL_op_desc[optype]);
2274 #endif
2275     }
2276 
2277     if (infosize)
2278     {
2279 	if (getinfo)
2280 	{
2281 	    SvPV_force_nolen(astr);
2282 	    a = SvGROW(astr, infosize+1);
2283 	}
2284 	else
2285 	{
2286 	    STRLEN len;
2287 	    a = SvPV(astr, len);
2288 	    if (len != infosize)
2289 		Perl_croak(aTHX_ "Bad arg length for %s, is %lu, should be %ld",
2290 		      PL_op_desc[optype],
2291 		      (unsigned long)len,
2292 		      (long)infosize);
2293 	}
2294     }
2295     else
2296     {
2297 	const IV i = SvIV(astr);
2298 	a = INT2PTR(char *,i);		/* ouch */
2299     }
2300     SETERRNO(0,0);
2301     switch (optype)
2302     {
2303 #ifdef HAS_MSG
2304     case OP_MSGCTL:
2305 	ret = msgctl(id, cmd, (struct msqid_ds *)a);
2306 	break;
2307 #endif
2308 #ifdef HAS_SEM
2309     case OP_SEMCTL: {
2310 #ifdef Semctl
2311             union semun unsemds;
2312 
2313             if(cmd == SETVAL) {
2314                 unsemds.val = PTR2nat(a);
2315             }
2316             else {
2317 #ifdef EXTRA_F_IN_SEMUN_BUF
2318                 unsemds.buff = (struct semid_ds *)a;
2319 #else
2320                 unsemds.buf = (struct semid_ds *)a;
2321 #endif
2322             }
2323 	    ret = Semctl(id, n, cmd, unsemds);
2324 #else
2325 	    /* diag_listed_as: sem%s not implemented */
2326 	    Perl_croak(aTHX_ "%s not implemented", PL_op_desc[optype]);
2327 #endif
2328         }
2329 	break;
2330 #endif
2331 #ifdef HAS_SHM
2332     case OP_SHMCTL:
2333 	ret = shmctl(id, cmd, (struct shmid_ds *)a);
2334 	break;
2335 #endif
2336     }
2337     if (getinfo && ret >= 0) {
2338 	SvCUR_set(astr, infosize);
2339 	*SvEND(astr) = '\0';
2340 	SvSETMAGIC(astr);
2341     }
2342     return ret;
2343 }
2344 
2345 I32
2346 Perl_do_msgsnd(pTHX_ SV **mark, SV **sp)
2347 {
2348 #ifdef HAS_MSG
2349     STRLEN len;
2350     const I32 id = SvIVx(*++mark);
2351     SV * const mstr = *++mark;
2352     const I32 flags = SvIVx(*++mark);
2353     const char * const mbuf = SvPV_const(mstr, len);
2354     const I32 msize = len - sizeof(long);
2355 
2356     PERL_ARGS_ASSERT_DO_MSGSND;
2357     PERL_UNUSED_ARG(sp);
2358 
2359     if (msize < 0)
2360 	Perl_croak(aTHX_ "Arg too short for msgsnd");
2361     SETERRNO(0,0);
2362     if (id >= 0 && flags >= 0) {
2363       return msgsnd(id, (struct msgbuf *)mbuf, msize, flags);
2364     } else {
2365       SETERRNO(EINVAL,LIB_INVARG);
2366       return -1;
2367     }
2368 #else
2369     PERL_UNUSED_ARG(sp);
2370     PERL_UNUSED_ARG(mark);
2371     /* diag_listed_as: msg%s not implemented */
2372     Perl_croak(aTHX_ "msgsnd not implemented");
2373     return -1;
2374 #endif
2375 }
2376 
2377 I32
2378 Perl_do_msgrcv(pTHX_ SV **mark, SV **sp)
2379 {
2380 #ifdef HAS_MSG
2381     char *mbuf;
2382     long mtype;
2383     I32 msize, flags, ret;
2384     const I32 id = SvIVx(*++mark);
2385     SV * const mstr = *++mark;
2386 
2387     PERL_ARGS_ASSERT_DO_MSGRCV;
2388     PERL_UNUSED_ARG(sp);
2389 
2390     /* suppress warning when reading into undef var --jhi */
2391     if (! SvOK(mstr))
2392 	sv_setpvs(mstr, "");
2393     msize = SvIVx(*++mark);
2394     mtype = (long)SvIVx(*++mark);
2395     flags = SvIVx(*++mark);
2396     SvPV_force_nolen(mstr);
2397     mbuf = SvGROW(mstr, sizeof(long)+msize+1);
2398 
2399     SETERRNO(0,0);
2400     if (id >= 0 && msize >= 0 && flags >= 0) {
2401         ret = msgrcv(id, (struct msgbuf *)mbuf, msize, mtype, flags);
2402     } else {
2403         SETERRNO(EINVAL,LIB_INVARG);
2404         ret = -1;
2405     }
2406     if (ret >= 0) {
2407 	SvCUR_set(mstr, sizeof(long)+ret);
2408 	*SvEND(mstr) = '\0';
2409 	/* who knows who has been playing with this message? */
2410 	SvTAINTED_on(mstr);
2411     }
2412     return ret;
2413 #else
2414     PERL_UNUSED_ARG(sp);
2415     PERL_UNUSED_ARG(mark);
2416     /* diag_listed_as: msg%s not implemented */
2417     Perl_croak(aTHX_ "msgrcv not implemented");
2418     return -1;
2419 #endif
2420 }
2421 
2422 I32
2423 Perl_do_semop(pTHX_ SV **mark, SV **sp)
2424 {
2425 #ifdef HAS_SEM
2426     STRLEN opsize;
2427     const I32 id = SvIVx(*++mark);
2428     SV * const opstr = *++mark;
2429     const char * const opbuf = SvPV_const(opstr, opsize);
2430 
2431     PERL_ARGS_ASSERT_DO_SEMOP;
2432     PERL_UNUSED_ARG(sp);
2433 
2434     if (opsize < 3 * SHORTSIZE
2435 	|| (opsize % (3 * SHORTSIZE))) {
2436 	SETERRNO(EINVAL,LIB_INVARG);
2437 	return -1;
2438     }
2439     SETERRNO(0,0);
2440     /* We can't assume that sizeof(struct sembuf) == 3 * sizeof(short). */
2441     {
2442         const int nsops  = opsize / (3 * sizeof (short));
2443         int i      = nsops;
2444         short * const ops = (short *) opbuf;
2445         short *o   = ops;
2446         struct sembuf *temps, *t;
2447         I32 result;
2448 
2449         Newx (temps, nsops, struct sembuf);
2450         t = temps;
2451         while (i--) {
2452             t->sem_num = *o++;
2453             t->sem_op  = *o++;
2454             t->sem_flg = *o++;
2455             t++;
2456         }
2457         result = semop(id, temps, nsops);
2458         Safefree(temps);
2459         return result;
2460     }
2461 #else
2462     /* diag_listed_as: sem%s not implemented */
2463     Perl_croak(aTHX_ "semop not implemented");
2464 #endif
2465 }
2466 
2467 I32
2468 Perl_do_shmio(pTHX_ I32 optype, SV **mark, SV **sp)
2469 {
2470 #ifdef HAS_SHM
2471     char *shm;
2472     struct shmid_ds shmds;
2473     const I32 id = SvIVx(*++mark);
2474     SV * const mstr = *++mark;
2475     const I32 mpos = SvIVx(*++mark);
2476     const I32 msize = SvIVx(*++mark);
2477 
2478     PERL_ARGS_ASSERT_DO_SHMIO;
2479     PERL_UNUSED_ARG(sp);
2480 
2481     SETERRNO(0,0);
2482     if (shmctl(id, IPC_STAT, &shmds) == -1)
2483 	return -1;
2484     if (mpos < 0 || msize < 0
2485 	|| (size_t)mpos + msize > (size_t)shmds.shm_segsz) {
2486 	SETERRNO(EFAULT,SS_ACCVIO);		/* can't do as caller requested */
2487 	return -1;
2488     }
2489     if (id >= 0) {
2490         shm = (char *)shmat(id, NULL, (optype == OP_SHMREAD) ? SHM_RDONLY : 0);
2491     } else {
2492         SETERRNO(EINVAL,LIB_INVARG);
2493         return -1;
2494     }
2495     if (shm == (char *)-1)	/* I hate System V IPC, I really do */
2496 	return -1;
2497     if (optype == OP_SHMREAD) {
2498 	char *mbuf;
2499 	/* suppress warning when reading into undef var (tchrist 3/Mar/00) */
2500 	SvGETMAGIC(mstr);
2501 	SvUPGRADE(mstr, SVt_PV);
2502 	if (! SvOK(mstr))
2503 	    sv_setpvs(mstr, "");
2504 	SvPOK_only(mstr);
2505 	mbuf = SvGROW(mstr, (STRLEN)msize+1);
2506 
2507 	Copy(shm + mpos, mbuf, msize, char);
2508 	SvCUR_set(mstr, msize);
2509 	*SvEND(mstr) = '\0';
2510 	SvSETMAGIC(mstr);
2511 	/* who knows who has been playing with this shared memory? */
2512 	SvTAINTED_on(mstr);
2513     }
2514     else {
2515 	STRLEN len;
2516 
2517 	const char *mbuf = SvPV_const(mstr, len);
2518 	const I32 n = ((I32)len > msize) ? msize : (I32)len;
2519 	Copy(mbuf, shm + mpos, n, char);
2520 	if (n < msize)
2521 	    memzero(shm + mpos + n, msize - n);
2522     }
2523     return shmdt(shm);
2524 #else
2525     /* diag_listed_as: shm%s not implemented */
2526     Perl_croak(aTHX_ "shm I/O not implemented");
2527     return -1;
2528 #endif
2529 }
2530 
2531 #endif /* SYSV IPC */
2532 
2533 /*
2534 =head1 IO Functions
2535 
2536 =for apidoc start_glob
2537 
2538 Function called by C<do_readline> to spawn a glob (or do the glob inside
2539 perl on VMS).  This code used to be inline, but now perl uses C<File::Glob>
2540 this glob starter is only used by miniperl during the build process,
2541 or when PERL_EXTERNAL_GLOB is defined.
2542 Moving it away shrinks F<pp_hot.c>; shrinking F<pp_hot.c> helps speed perl up.
2543 
2544 =cut
2545 */
2546 
2547 PerlIO *
2548 Perl_start_glob (pTHX_ SV *tmpglob, IO *io)
2549 {
2550     SV * const tmpcmd = newSV(0);
2551     PerlIO *fp;
2552     STRLEN len;
2553     const char *s = SvPV(tmpglob, len);
2554 
2555     PERL_ARGS_ASSERT_START_GLOB;
2556 
2557     if (!IS_SAFE_SYSCALL(s, len, "pattern", "glob"))
2558         return NULL;
2559 
2560     ENTER;
2561     SAVEFREESV(tmpcmd);
2562 #ifdef VMS /* expand the wildcards right here, rather than opening a pipe, */
2563            /* since spawning off a process is a real performance hit */
2564 
2565 PerlIO *
2566 Perl_vms_start_glob
2567    (pTHX_ SV *tmpglob,
2568     IO *io);
2569 
2570     fp = Perl_vms_start_glob(aTHX_ tmpglob, io);
2571 
2572 #else /* !VMS */
2573 #ifdef DOSISH
2574 #ifdef OS2
2575     sv_setpv(tmpcmd, "for a in ");
2576     sv_catsv(tmpcmd, tmpglob);
2577     sv_catpv(tmpcmd, "; do echo \"$a\\0\\c\"; done |");
2578 #else
2579 #ifdef DJGPP
2580     sv_setpv(tmpcmd, "/dev/dosglob/"); /* File System Extension */
2581     sv_catsv(tmpcmd, tmpglob);
2582 #else
2583     sv_setpv(tmpcmd, "perlglob ");
2584     sv_catsv(tmpcmd, tmpglob);
2585     sv_catpv(tmpcmd, " |");
2586 #endif /* !DJGPP */
2587 #endif /* !OS2 */
2588 #else /* !DOSISH */
2589 #if defined(CSH)
2590     sv_setpvn(tmpcmd, PL_cshname, PL_cshlen);
2591     sv_catpv(tmpcmd, " -cf 'set nonomatch; glob ");
2592     sv_catsv(tmpcmd, tmpglob);
2593     sv_catpv(tmpcmd, "' 2>/dev/null |");
2594 #else
2595     sv_setpv(tmpcmd, "echo ");
2596     sv_catsv(tmpcmd, tmpglob);
2597     sv_catpv(tmpcmd, "|tr -s ' \t\f\r' '\\n\\n\\n\\n'|");
2598 #endif /* !CSH */
2599 #endif /* !DOSISH */
2600     {
2601 	GV * const envgv = gv_fetchpvs("ENV", 0, SVt_PVHV);
2602 	SV ** const home = hv_fetchs(GvHV(envgv), "HOME", 0);
2603 	SV ** const path = hv_fetchs(GvHV(envgv), "PATH", 0);
2604 	if (home && *home) SvGETMAGIC(*home);
2605 	if (path && *path) SvGETMAGIC(*path);
2606 	save_hash(gv_fetchpvs("ENV", 0, SVt_PVHV));
2607 	if (home && *home) SvSETMAGIC(*home);
2608 	if (path && *path) SvSETMAGIC(*path);
2609     }
2610     (void)do_open6(PL_last_in_gv, SvPVX_const(tmpcmd), SvCUR(tmpcmd),
2611                    NULL, NULL, 0);
2612     fp = IoIFP(io);
2613 #endif /* !VMS */
2614     LEAVE;
2615 
2616     if (!fp && ckWARN(WARN_GLOB)) {
2617         Perl_warner(aTHX_ packWARN(WARN_GLOB), "glob failed (can't start child: %s)",
2618                     Strerror(errno));
2619     }
2620 
2621     return fp;
2622 }
2623 
2624 /*
2625  * ex: set ts=8 sts=4 sw=4 et:
2626  */
2627