1 '\" te
2 .\" Copyright (c) 2008, Sun Microsystems, Inc. All Rights Reserved.
3 .\" Copyright 1989 AT&T.
4 .\" Portions Copyright (c) 1992, X/Open Company Limited. All Rights Reserved.
5 .\" Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at
6 .\" http://www.opengroup.org/bookstore/.
7 .\" The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.
8 .\" This notice shall appear on any product containing this material.
9 .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
10 .\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
11 .\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
12 .TH EXEC 2 "Jun 16, 2008"
13 .SH NAME
14 exec, execl, execle, execlp, execv, execve, execvp \- execute a file
15 .SH SYNOPSIS
16 .LP
17 .nf
18 #include <unistd.h>
19
20 \fBint\fR \fBexecl\fR(\fBconst char *\fR\fIpath\fR, \fBconst char *\fR\fIarg0\fR, \fB\&...
21 /* const char *\fR\fIargn\fR, \fB(char *)0 */);\fR
22 .fi
23
24 .LP
25 .nf
26 \fBint\fR \fBexecv\fR(\fBconst char *\fR\fIpath\fR, \fBchar *const\fR \fIargv[]\fR);
27 .fi
28
29 .LP
30 .nf
31 \fBint\fR \fBexecle\fR(\fBconst char *\fR\fIpath\fR, \fBconst char *\fR\fIarg0\fR, \fB\&...
32 /* const char *\fR\fIargn\fR, \fB(char *)0\fR,\fBchar *const\fR \fIenvp\fR[]*/);
33 .fi
34
35 .LP
36 .nf
37 \fBint\fR \fBexecve\fR(\fBconst char *\fR\fIpath\fR, \fBchar *const\fR \fIargv[]\fR,
38 \fBchar *const\fR \fIenvp[]\fR);
39 .fi
40
41 .LP
42 .nf
43 \fBint\fR \fBexeclp\fR(\fBconst char *\fR\fIfile\fR, \fBconst char *\fR\fIarg0\fR, \fB\&...
44 /* const char *\fR\fIargn\fR, \fB(char *)0 */);\fR
45 .fi
46
47 .LP
48 .nf
49 \fBint\fR \fBexecvp\fR(\fBconst char *\fR\fIfile\fR, \fBchar *const\fR \fIargv[]\fR);
50 .fi
51
52 .SH DESCRIPTION
53 .sp
54 .LP
55 Each of the functions in the \fBexec\fR family replaces the current process
56 image with a new process image. The new image is constructed from a regular,
57 executable file called the \fBnew process image file\fR. This file is either an
58 executable object file or a file of data for an interpreter. There is no return
59 from a successful call to one of these functions because the calling process
60 image is overlaid by the new process image.
61 .sp
62 .LP
63 An interpreter file begins with a line of the form
64 .sp
65 .in +2
66 .nf
67 #! pathname [\fIarg\fR]
68 .fi
69 .in -2
70
71 .sp
72 .LP
73 where \fIpathname\fR is the path of the interpreter, and \fIarg\fR is an
74 optional argument. When an interpreter file is executed, the system invokes the
75 specified interpreter. The pathname specified in the interpreter file is passed
76 as \fIarg0\fR to the interpreter. If \fIarg\fR was specified in the interpreter
77 file, it is passed as \fIarg1\fR to the interpreter. The remaining arguments to
78 the interpreter are \fIarg0\fR through \fIargn\fR of the originally exec'd
79 file. The interpreter named by \fIpathname\fR must not be an interpreter file.
80 .sp
81 .LP
82 When a C-language program is executed as a result of this call, it is entered
83 as a C-language function call as follows:
84 .sp
85 .in +2
86 .nf
87 int main (int argc, char *argv[]);
88 .fi
89 .in -2
90
91 .sp
92 .LP
93 where \fIargc\fR is the argument count and \fIargv\fR is an array of character
94 pointers to the arguments themselves. In addition, the following variable:
95 .sp
96 .in +2
97 .nf
98 extern char **environ;
99 .fi
100 .in -2
101
102 .sp
103 .LP
104 is initialized as a pointer to an array of character pointers to the
105 environment strings. The \fIargv\fR and \fIenviron\fR arrays are each
106 terminated by a null pointer. The null pointer terminating the \fIargv\fR array
107 is not counted in \fIargc\fR.
108 .sp
109 .LP
110 The value of \fIargc\fR is non-negative, and if greater than 0, \fIargv\fR[0]
111 points to a string containing the name of the file. If \fIargc\fR is 0,
112 \fIargv\fR[0] is a null pointer, in which case there are no arguments.
113 Applications should verify that \fIargc\fR is greater than 0 or that
114 \fIargv\fR[0] is not a null pointer before dereferencing \fIargv\fR[0].
115 .sp
116 .LP
117 The arguments specified by a program with one of the \fBexec\fR functions are
118 passed on to the new process image in the \fBmain()\fR arguments.
119 .sp
120 .LP
121 The \fIpath\fR argument points to a path name that identifies the new process
122 image file.
123 .sp
124 .LP
125 The \fIfile\fR argument is used to construct a pathname that identifies the new
126 process image file. If the \fIfile\fR argument contains a slash character, it
127 is used as the pathname for this file. Otherwise, the path prefix for this file
128 is obtained by a search of the directories passed in the \fBPATH\fR environment
129 variable (see \fBenviron\fR(5)). The environment is supplied typically by the
130 shell. If the process image file is not a valid executable object file,
131 \fBexeclp()\fR and \fBexecvp()\fR use the contents of that file as standard
132 input to the shell. In this case, the shell becomes the new process image. The
133 standard to which the caller conforms determines which shell is used. See
134 \fBstandards\fR(5).
135 .sp
136 .LP
137 The arguments represented by \fIarg0\fR\&.\|.\|. are pointers to
138 null-terminated character strings. These strings constitute the argument list
139 available to the new process image. The list is terminated by a null pointer.
140 The \fIarg0\fR argument should point to a filename that is associated with the
141 process being started by one of the \fBexec\fR functions.
142 .sp
143 .LP
144 The \fIargv\fR argument is an array of character pointers to null-terminated
145 strings. The last member of this array must be a null pointer. These strings
146 constitute the argument list available to the new process image. The value in
147 \fIargv\fR[0] should point to a filename that is associated with the process
148 being started by one of the \fBexec\fR functions.
149 .sp
150 .LP
151 The \fIenvp\fR argument is an array of character pointers to null-terminated
152 strings. These strings constitute the environment for the new process image.
153 The \fIenvp\fR array is terminated by a null pointer. For \fBexecl()\fR,
154 \fBexecv()\fR, \fBexecvp()\fR, and \fBexeclp()\fR, the C-language run-time
155 start-off routine places a pointer to the environment of the calling process in
156 the global object \fBextern char **environ\fR, and it is used to pass the
157 environment of the calling process to the new process image.
158 .sp
159 .LP
160 The number of bytes available for the new process's combined argument and
161 environment lists is \fBARG_MAX\fR. It is implementation-dependent whether null
162 terminators, pointers, and/or any alignment bytes are included in this total.
163 .sp
164 .LP
165 File descriptors open in the calling process image remain open in the new
166 process image, except for those whose close-on-exec flag \fBFD_CLOEXEC\fR is
167 set; see \fBfcntl\fR(2). For those file descriptors that remain open, all
168 attributes of the open file description, including file locks, remain
169 unchanged.
170 .sp
171 .LP
172 The preferred hardware address translation size (see \fBmemcntl\fR(2)) for the
173 stack and heap of the new process image are set to the default system page
174 size.
175 .sp
176 .LP
177 Directory streams open in the calling process image are closed in the new
178 process image.
179 .sp
180 .LP
181 The state of conversion descriptors and message catalogue descriptors in the
182 new process image is undefined. For the new process, the equivalent of:
183 .sp
184 .in +2
185 .nf
186 setlocale(LC_ALL, "C")
187 .fi
188 .in -2
189
190 .sp
191 .LP
192 is executed at startup.
193 .sp
194 .LP
195 Signals set to the default action (\fBSIG_DFL\fR) in the calling process image
196 are set to the default action in the new process image (see \fBsignal\fR(3C)).
197 Signals set to be ignored (\fBSIG_IGN\fR) by the calling process image are set
198 to be ignored by the new process image. Signals set to be caught by the calling
199 process image are set to the default action in the new process image (see
200 \fBsignal.h\fR(3HEAD)). After a successful call to any of the \fBexec\fR
201 functions, alternate signal stacks are not preserved and the \fBSA_ONSTACK\fR
202 flag is cleared for all signals.
203 .sp
204 .LP
205 After a successful call to any of the \fBexec\fR functions, any functions
206 previously registered by \fBatexit\fR(3C) are no longer registered.
207 .sp
208 .LP
209 The saved resource limits in the new process image are set to be a copy of the
210 process's corresponding hard and soft resource limits.
211 .sp
212 .LP
213 If the \fBST_NOSUID\fR bit is set for the file system containing the new
214 process image file, then the effective user \fBID\fR and effective group
215 \fBID\fR are unchanged in the new process image. If the set-user-\fBID\fR mode
216 bit of the new process image file is set (see \fBchmod\fR(2)), the effective
217 user \fBID\fR of the new process image is set to the owner \fBID\fR of the new
218 process image file. Similarly, if the set-group-\fBID\fR mode bit of the new
219 process image file is set, the effective group \fBID\fR of the new process
220 image is set to the group \fBID\fR of the new process image file. The real user
221 \fBID\fR and real group \fBID\fR of the new process image remain the same as
222 those of the calling process image. The effective user ID and effective group
223 ID of the new process image are saved (as the saved set-user-ID and the saved
224 set-group-ID for use by \fBsetuid\fR(2).
225 .sp
226 .LP
227 The privilege sets are changed according to the following rules:
228 .RS +4
229 .TP
230 1.
231 The inheritable set, I, is intersected with the limit set, L. This
232 mechanism enforces the limit set for processes.
233 .RE
234 .RS +4
235 .TP
236 2.
237 The effective set, E, and the permitted set, P, are made equal to the new
238 inheritable set.
239 .RE
240 .sp
241 .LP
242 The system attempts to set the privilege-aware state to non-PA both before
243 performing any modifications to the process IDs and privilege sets as well as
244 after completing the transition to new UIDs and privilege sets, following the
245 rules outlined in \fBprivileges\fR(5).
246 .sp
247 .LP
248 If the {\fBPRIV_PROC_OWNER\fR} privilege is asserted in the effective set, the
249 set-user-ID and set-group-ID bits will be honored when the process is being
250 controlled by \fBptrace\fR(3C). Additional restriction can apply when the
251 traced process has an effective UID of 0. See \fBprivileges\fR(5).
252 .sp
253 .LP
254 Any shared memory segments attached to the calling process image will not be
255 attached to the new process image (see \fBshmop\fR(2)). Any mappings
256 established through \fBmmap()\fR are not preserved across an \fBexec\fR. Memory
257 mappings created in the process are unmapped before the address space is
258 rebuilt for the new process image. See \fBmmap\fR(2).
259 .sp
260 .LP
261 Memory locks established by the calling process via calls to \fBmlockall\fR(3C)
262 or \fBmlock\fR(3C) are removed. If locked pages in the address space of the
263 calling process are also mapped into the address spaces the locks established
264 by the other processes will be unaffected by the call by this process to the
265 \fBexec\fR function. If the \fBexec\fR function fails, the effect on memory
266 locks is unspecified.
267 .sp
268 .LP
269 If \fB_XOPEN_REALTIME\fR is defined and has a value other than \(mi1, any named
270 semaphores open in the calling process are closed as if by appropriate calls to
271 \fBsem_close\fR(3C)
272 .sp
273 .LP
274 Profiling is disabled for the new process; see \fBprofil\fR(2).
275 .sp
276 .LP
277 Timers created by the calling process with \fBtimer_create\fR(3C) are deleted
278 before replacing the current process image with the new process image.
279 .sp
280 .LP
281 For the \fBSCHED_FIFO\fR and \fBSCHED_RR\fR scheduling policies, the policy and
282 priority settings are not changed by a call to an \fBexec\fR function.
283 .sp
284 .LP
285 All open message queue descriptors in the calling process are closed, as
286 described in \fBmq_close\fR(3C).
287 .sp
288 .LP
289 Any outstanding asynchronous I/O operations may be cancelled. Those
290 asynchronous I/O operations that are not canceled will complete as if the
291 \fBexec\fR function had not yet occurred, but any associated signal
292 notifications are suppressed. It is unspecified whether the \fBexec\fR function
293 itself blocks awaiting such I/O completion. In no event, however, will the new
294 process image created by the \fBexec\fR function be affected by the presence of
295 outstanding asynchronous I/O operations at the time the \fBexec\fR function is
296 called.
297 .sp
298 .LP
299 All active contract templates are cleared (see \fBcontract\fR(4)).
300 .sp
301 .LP
302 The new process also inherits the following attributes from the calling
303 process:
304 .RS +4
305 .TP
306 .ie t \(bu
307 .el o
308 controlling terminal
309 .RE
310 .RS +4
311 .TP
312 .ie t \(bu
313 .el o
314 current working directory
315 .RE
316 .RS +4
317 .TP
318 .ie t \(bu
319 .el o
320 file-locks (see \fBfcntl\fR(2) and \fBlockf\fR(3C))
321 .RE
322 .RS +4
323 .TP
324 .ie t \(bu
325 .el o
326 file mode creation mask (see \fBumask\fR(2))
327 .RE
328 .RS +4
329 .TP
330 .ie t \(bu
331 .el o
332 file size limit (see \fBulimit\fR(2))
333 .RE
334 .RS +4
335 .TP
336 .ie t \(bu
337 .el o
338 limit privilege set
339 .RE
340 .RS +4
341 .TP
342 .ie t \(bu
343 .el o
344 nice value (see \fBnice\fR(2))
345 .RE
346 .RS +4
347 .TP
348 .ie t \(bu
349 .el o
350 parent process \fBID\fR
351 .RE
352 .RS +4
353 .TP
354 .ie t \(bu
355 .el o
356 pending signals (see \fBsigpending\fR(2))
357 .RE
358 .RS +4
359 .TP
360 .ie t \(bu
361 .el o
362 privilege debugging flag (see \fBprivileges\fR(5) and \fBgetpflags\fR(2))
363 .RE
364 .RS +4
365 .TP
366 .ie t \(bu
367 .el o
368 process \fBID\fR
369 .RE
370 .RS +4
371 .TP
372 .ie t \(bu
373 .el o
374 process contract (see \fBcontract\fR(4) and \fBprocess\fR(4))
375 .RE
376 .RS +4
377 .TP
378 .ie t \(bu
379 .el o
380 process group \fBID\fR
381 .RE
382 .RS +4
383 .TP
384 .ie t \(bu
385 .el o
386 process signal mask (see \fBsigprocmask\fR(2))
387 .RE
388 .RS +4
389 .TP
390 .ie t \(bu
391 .el o
392 processor bindings (see \fBprocessor_bind\fR(2))
393 .RE
394 .RS +4
395 .TP
396 .ie t \(bu
397 .el o
398 processor set bindings (see \fBpset_bind\fR(2))
399 .RE
400 .RS +4
401 .TP
402 .ie t \(bu
403 .el o
404 project \fBID\fR
405 .RE
406 .RS +4
407 .TP
408 .ie t \(bu
409 .el o
410 real group \fBID\fR
411 .RE
412 .RS +4
413 .TP
414 .ie t \(bu
415 .el o
416 real user \fBID\fR
417 .RE
418 .RS +4
419 .TP
420 .ie t \(bu
421 .el o
422 resource limits (see \fBgetrlimit\fR(2))
423 .RE
424 .RS +4
425 .TP
426 .ie t \(bu
427 .el o
428 root directory
429 .RE
430 .RS +4
431 .TP
432 .ie t \(bu
433 .el o
434 scheduler class and priority (see \fBpriocntl\fR(2))
435 .RE
436 .RS +4
437 .TP
438 .ie t \(bu
439 .el o
440 \fBsemadj\fR values (see \fBsemop\fR(2))
441 .RE
442 .RS +4
443 .TP
444 .ie t \(bu
445 .el o
446 session membership (see \fBexit\fR(2) and \fBsignal\fR(3C))
447 .RE
448 .RS +4
449 .TP
450 .ie t \(bu
451 .el o
452 supplementary group \fBIDs\fR
453 .RE
454 .RS +4
455 .TP
456 .ie t \(bu
457 .el o
458 task \fBID\fR
459 .RE
460 .RS +4
461 .TP
462 .ie t \(bu
463 .el o
464 time left until an alarm clock signal (see \fBalarm\fR(2))
465 .RE
466 .RS +4
467 .TP
468 .ie t \(bu
469 .el o
470 \fBtms_utime\fR, \fBtms_stime\fR, \fBtms_cutime\fR, and \fBtms_cstime\fR (see
471 \fBtimes\fR(2))
472 .RE
473 .RS +4
474 .TP
475 .ie t \(bu
476 .el o
477 trace flag (see \fBptrace\fR(3C) request 0)
478 .RE
479 .sp
480 .LP
481 A call to any \fBexec\fR function from a process with more than one thread
482 results in all threads being terminated and the new executable image being
483 loaded and executed. No destructor functions will be called.
484 .sp
485 .LP
486 Upon successful completion, each of the functions in the \fBexec\fR family
487 marks for update the \fBst_atime\fR field of the file. If an \fBexec\fR
488 function failed but was able to locate the \fBprocess image file\fR, whether
489 the \fBst_atime\fR field is marked for update is unspecified. Should the
490 function succeed, the process image file is considered to have been opened with
491 \fBopen\fR(2). The corresponding \fBclose\fR(2) is considered to occur at a
492 time after this open, but before process termination or successful completion
493 of a subsequent call to one of the \fBexec\fR functions. The \fIargv\fR[\|] and
494 \fIenvp\fR[\|] arrays of pointers and the strings to which those arrays point
495 will not be modified by a call to one of the \fBexec\fR functions, except as a
496 consequence of replacing the process image.
497 .sp
498 .LP
499 The saved resource limits in the new process image are set to be a copy of the
500 process's corresponding hard and soft limits.
501 .SH RETURN VALUES
502 .sp
503 .LP
504 If a function in the \fBexec\fR family returns to the calling process image, an
505 error has occurred; the return value is \fB\(mi1\fR and \fBerrno\fR is set to
506 indicate the error.
507 .SH ERRORS
508 .sp
509 .LP
510 The \fBexec\fR functions will fail if:
511 .sp
512 .ne 2
513 .na
514 \fB\fBE2BIG\fR\fR
515 .ad
516 .RS 16n
517 The number of bytes in the new process's argument list is greater than the
518 system-imposed limit of {\fBARG_MAX\fR} bytes. The argument list limit is sum
519 of the size of the argument list plus the size of the environment's exported
520 shell variables.
521 .RE
522
523 .sp
524 .ne 2
525 .na
526 \fB\fBEACCES\fR\fR
527 .ad
528 .RS 16n
529 Search permission is denied for a directory listed in the new process file's
530 path prefix.
531 .sp
532 The new process file is not an ordinary file.
533 .sp
534 The new process file mode denies execute permission.
535 .sp
536 The {\fBFILE_DAC_SEARCH\fR} privilege overrides the restriction on directory
537 searches.
538 .sp
539 The {\fBFILE_DAC_EXECUTE\fR} privilege overrides the lack of execute
540 permission.
541 .RE
542
543 .sp
544 .ne 2
545 .na
546 \fB\fBEAGAIN\fR\fR
547 .ad
548 .RS 16n
549 Total amount of system memory available when reading using raw I/O is
550 temporarily insufficient.
551 .RE
552
553 .sp
554 .ne 2
555 .na
556 \fB\fBEFAULT\fR\fR
557 .ad
558 .RS 16n
559 An argument points to an illegal address.
560 .RE
561
562 .sp
563 .ne 2
564 .na
565 \fB\fBEINVAL\fR\fR
566 .ad
567 .RS 16n
568 The new process image file has the appropriate permission and has a recognized
569 executable binary format, but the system does not support execution of a file
570 with this format.
571 .RE
572
573 .sp
574 .ne 2
575 .na
576 \fB\fBEINTR\fR\fR
577 .ad
578 .RS 16n
579 A signal was caught during the execution of one of the functions in the
580 \fIexec\fR family.
581 .RE
582
583 .sp
584 .ne 2
585 .na
586 \fB\fBELOOP\fR\fR
587 .ad
588 .RS 16n
589 Too many symbolic links were encountered in translating \fIpath\fR or
590 \fIfile\fR.
591 .RE
592
593 .sp
594 .ne 2
595 .na
596 \fB\fBENAMETOOLONG\fR\fR
597 .ad
598 .RS 16n
599 The length of the \fIfile\fR or \fIpath\fR argument exceeds {\fBPATH_MAX\fR},
600 or the length of a \fIfile\fR or \fIpath\fR component exceeds {\fBNAME_MAX\fR}
601 while {\fB_POSIX_NO_TRUNC\fR} is in effect.
602 .RE
603
604 .sp
605 .ne 2
606 .na
607 \fB\fBENOENT\fR\fR
608 .ad
609 .RS 16n
610 One or more components of the new process path name of the file do not exist or
611 is a null pathname.
612 .RE
613
614 .sp
615 .ne 2
616 .na
617 \fB\fBENOLINK\fR\fR
618 .ad
619 .RS 16n
620 The \fIpath\fR argument points to a remote machine and the link to that machine
621 is no longer active.
622 .RE
623
624 .sp
625 .ne 2
626 .na
627 \fB\fBENOTDIR\fR\fR
628 .ad
629 .RS 16n
630 A component of the new process path of the file prefix is not a directory.
631 .RE
632
633 .sp
634 .LP
635 The \fBexec\fR functions, except for \fBexeclp()\fR and \fBexecvp()\fR, will
636 fail if:
637 .sp
638 .ne 2
639 .na
640 \fB\fBENOEXEC\fR\fR
641 .ad
642 .RS 11n
643 The new process image file has the appropriate access permission but is not in
644 the proper format.
645 .RE
646
647 .sp
648 .LP
649 The \fBexec\fR functions may fail if:
650 .sp
651 .ne 2
652 .na
653 \fB\fBENAMETOOLONG\fR\fR
654 .ad
655 .RS 16n
656 Pathname resolution of a symbolic link produced an intermediate result whose
657 length exceeds {\fBPATH_MAX\fR}.
658 .RE
659
660 .sp
661 .ne 2
662 .na
663 \fB\fBENOMEM\fR\fR
664 .ad
665 .RS 16n
666 The new process image requires more memory than is allowed by the hardware or
667 system-imposed by memory management constraints. See \fBbrk\fR(2).
668 .RE
669
670 .sp
671 .ne 2
672 .na
673 \fB\fBETXTBSY\fR\fR
674 .ad
675 .RS 16n
676 The new process image file is a pure procedure (shared text) file that is
677 currently open for writing by some process.
678 .RE
679
680 .SH USAGE
681 .sp
682 .LP
683 As the state of conversion descriptors and message catalogue descriptors in the
684 new process image is undefined, portable applications should not rely on their
685 use and should close them prior to calling one of the \fBexec\fR functions.
686 .sp
687 .LP
688 Applications that require other than the default POSIX locale should call
689 \fBsetlocale\fR(3C) with the appropriate parameters to establish the locale of
690 thenew process.
691 .sp
692 .LP
693 The \fIenviron\fR array should not be accessed directly by the application.
694 .SH ATTRIBUTES
695 .sp
696 .LP
697 See \fBattributes\fR(5) for descriptions of the following attributes:
698 .sp
699
700 .sp
701 .TS
702 box;
703 c | c
704 l | l .
705 ATTRIBUTE TYPE ATTRIBUTE VALUE
706 _
707 Interface Stability Committed
708 _
709 MT-Level See below.
710 _
711 Standard See \fBstandards\fR(5).
712 .TE
713
714 .sp
715 .LP
716 The \fBexecle()\fR and \fBexecve()\fR fucntions are Async-Signal-Safe.
717 .SH SEE ALSO
718 .sp
719 .LP
720 \fBksh\fR(1), \fBps\fR(1), \fBsh\fR(1), \fBalarm\fR(2), \fBbrk\fR(2),
721 \fBchmod\fR(2), \fBexit\fR(2), \fBfcntl\fR(2), \fBfork\fR(2),
722 \fBgetpflags\fR(2), \fBgetrlimit\fR(2), \fBmemcntl\fR(2), \fBmmap\fR(2),
723 \fBnice\fR(2), \fBpriocntl\fR(2), \fBprofil\fR(2), \fBsemop\fR(2),
724 \fBshmop\fR(2), \fBsigpending\fR(2), \fBsigprocmask\fR(2), \fBtimes\fR(2),
725 \fBumask\fR(2), \fBlockf\fR(3C), \fBptrace\fR(3C), \fBsetlocale\fR(3C),
726 \fBsignal\fR(3C), \fBsystem\fR(3C), \fBtimer_create\fR(3C), \fBa.out\fR(4),
727 \fBcontract\fR(4), \fBprocess\fR(4), \fBattributes\fR(5), \fBenviron\fR(5),
728 \fBprivileges\fR(5), \fBstandards\fR(5)
729 .SH WARNINGS
730 .sp
731 .LP
732 If a program is \fBsetuid\fR to a user \fBID\fR other than the superuser, and
733 the program is executed when the real user \fBID\fR is super-user, then the
734 program has some of the powers of a super-user as well.