CHMOD(1) >>>>> >>>>>>>> CHMOD(1)
>>>>>
chmod - >>>>>> >>>> >>> >>>>>
>>>>
chmod [OPTION]... MODE[,MODE]... FILE...
chmod [OPTION]... OCTAL-MODE FILE...
chmod [OPTION]... --reference=RFILE FILE...
>>>>>
>>>> >>>> >>>>>> >>>
>>>>>> GNU >> chmod. >>>> chmod >>>>
>>> >>>>> >>> >>> file >>>>
>>>> >>>>> mode> >>>>> >>>>
>> >>>> >>> >>>>>> >>>>> >>
>>>>>>>>> >>>>>>> >>>>>>
>> >>>> >>>>>> >>>> >>>
>>>>>> >>>>> >>>>>
>>>>>>>.
>>>>> >>>>> >>>>>> >>
[ugoa...][[-+=][perms...]...]> >>> perms >> >>>
>>> >> >>>> >> >>> >>
>>>>>>>> rwxXst> >> >>> >>>> >>
>>>>>>>> ugo. >>>> >>>>>
>>>>> >>>>> >>>>>>>
>>>>>> >>>>>>.
>>>>> >>>>>> >> >>>>>> ugoa
>> >>>> >>>>>>>>>> >>>>>
>>>> >>>>>>>: >>>>>>>>
>>>> >>>>> (u)> >>>>>>>>>>>
>>>>>>> >> >>>>>> >>>>> (g)>
>>>>>>>>>>> >>>>>>> >>>>
>>>>>> >>>>> (o)> >> >>
>>>>>>>>>> (a). >>> >> >>>>>
>> >> >>>> >>>> >>>>>>> >>>
>> >>>>> >>>>> (a)> >>>>
>>>>>> >>>>>>>> >> umask >>
>>>>>.
>>>> >>>>>> + >>> >>>>>
>>>> >>> >>>>> >>>>>>>>
>>> >>>> >>>>> >>>>>>>>
>>>>>> >>> >>>> >>>>>
>>>>>> - >>> >>>>>> >>>>>
>>>>>> = >>> >>>>>>> >>>>
>>>>>> >>> >>>>>>>>>
>>>>>>>> >>>> >>>>
>>>>>>>> >>>>>>>>> >>>>
>> >>>>> >>>>>> >>> >>>>>.
>>>>> >>>>>> rwxXst >>>> >>>
>>>>> >>>>>>>>>>
>>>>>>>>>: >>>>>>> (r)>
>>>>>>>> (w)> >>>>>>>> (>>
>>>>> >>>>>>> >>>>>>) (x)>
>>>>>>>>/>>>>> >>> >>> >>>
>>>>> >>>>> >> >>>> >>>>>>
>>>>>> >>>>>>> >>>>
>>>>>>>>>> (X)> >>>> >>>>
>>>>>>>> >> >>>>>>>> >>>
>>>>>>> (s)> >>>>>> >>>>>
>>>>>> >> >>>> >>>>>>> (t).
>>>> >> >>>> >> >>>> >> >>>
>>>>>>> >>>>> >>>>> >>>
>>>> >>>>>> >> >>>>>> ugo:
>>>>>>>>> >>>>>>>>
>>>>>>>> >>>> >>>> >>>>>
(u)> >> >>>>>>>>> >>>>>>>>
>>>>>>>>>> >>>>>>> >>
>>>>>> >>>>> (g)> >>
>>>>>>>>> >>>>>>>>
>>>>>>>>>> >>>>> >>>>> >>
>> >> >>>>>>> >>>>>>>>> (o).
>>>>> >>>>> >>>>>> >> >>>
>>>> >>> >>>>> >>>>>
>>>>>> (0-7)> >>>>> >>>>
>>>>>> >>> >>>>> 4 >2 >1.
>>>>>> >>>>>>> >>>>>>>>
>>>>>> >>>>>. >>>>> >>>>>
>>>>> >>>> >>> >>>>
>>>>>>>> (4) >>>> >>>>
>>>>>>>> (2) >>>>>> >>>>>>
>> >>>> >>>>>>> (1). >>>>>>
>>>>> >>>>>> >>>>>>>
>>>>>>>> >>>> >>>> >>>>>:
>>>>>>> (4)> >>>>>>>> (2)>
>>>>>>>> (1)> >>>>>> >>>>>>
>>>>>>> >>>>>>>>>>
>>>>>>> >> >>>>>> >>>>>>
>>>> >>>>>> >>>>>>>
>>>>>>>>>> >>>>>>> >>>>
>>>>>> >>>>>> >>>> >>>>>.
>> >>>> chmod >>>>>>> >>>>>>>
>>>>>>>> >>>> >>>>>> chmod >>
>>>>> >>>>> >>>>>>>>> >>
>>>> >>>>>>>> >>>>>
>>>>>>> >>>>>> >>>>>>>
>>>>>>> >>>>>>>. >>> >>>>
>>>> >>>> >>>> >>>>> >> >>>
>>>>>>>> >>>> chmod >>>>>>>
>>>>> >>>> >>>> >>>>. >>
>>>>>>>> >>>>>> chmod >>>>>>>
>>>>>>> >>>> >>>>>>>
>>>>> >>>>>> >>>>>>>> >>
>>>>>>. >>>>>>>> >>>> >>>>
>>> >>>>>> >>>>>> >> >>>
OPTIONS.
>>>> SETUID > SETGID
>>>> chmod >> >>> >>>>
>>>>>>>> >>>>>>> >>>>>>>
>>> >>> >>>> >>>>>> >>>>>
>> >>>>> >>>> >>>>>>>>
>>>>>> >>>>>>>> >> >>>
>>>>>> >>>>>>> >>>>>>>>
>>>>>>>>> >> >> >>>>>
>>>>>>>> >>>>>>>>>>
>>>>>>>>. >> >>>> >>>>
>>>>>> >>> >>>>> >>>> >>>
>>>> >>>>>>>> >>>> >>>>
>>>>>>>> >> MODE >> RFILE. >>>>>
>>> >>>>>> >>> >>>>>
>>>>>> >>>> >>>>>> chmod
>>>>>>>. >>> >>>>> >>>> >>
>>>> >>>>>> >>>>>>>.
>>>>>>> >>>>>>> >>>>> chmod
>>> >>>> >>> >>>> >>>>>>>>
>>>> >>>> >>>>>>>> >> >>
>>>> >>>> >>> >>>>>. >>>>>
>>> >> >>> >>>>>> >>>>>>>>
>>>>>>> >>>>>>> >>> u+s > g-s.
>>>> >>> >>>>>> >>>>>>
>>>>>>>> >>>>> >>>>>>>
>>>>> >>> >>>> >>>>>
>>>>>> >>> 00755> >> >>>>>
>>>> >>>>> >>> -6000> >> >>>>>
>>>>> >>>>> >>> =755.
>>>>> >>>>> >>>>>> >> >>>>
>>>>>>>
>>>>> >>>>> >>>>>> >> >>>>
>>>>>>> >> >> >>>>> >>>>>
>>>>>> >>> >>> >>>>>.
>>>>>>> >>>>>>> >>>>
>>>>>>>>>> >>> >>>>>>>>>
>> >>> >> >>>>> >>>>> >>>
>> >>>>>> >> >> >>>>>>
>>>>> >> >>>>>>> >>>> >>>
>>>>> >>>>> >>>>>>
>>>>>>> >>>>> >>>> >>
>>>>>> >>>>>>> >>>>>>> >>
>>>>>> >>> /tmp. >>>>>>>
>>>>>>> >>>>>>> >> >>>
>>>>>>> >>>>>>>> >>>>
>>>> >>>> >> >>>>>>>> >>>
>>>> >>>>>>> >>>> >>>>>>
>>>>> >>>> >>> >>>>>>>
>>>> >>> >>>> >>>>>>>.
>>>>>>>>
>>>> >>> >> FILE >>> MODE. >>
--reference> >>>> >>> >> FILE >>> >>>
RFILE.
-c, --changes
>>> >>>>>> >>>> >> >>>>
>>> >>> >>>>> >>>>>
-f, --silent, --quiet
>>>> >>>> >>>>> >>>>>
-v, --verbose
>>>> >>>>>>> >>> >>>
>>>>
--dereference
>>>> >>> >>>> >> >>>>
>>>>> >>>> >> >>>>>>
>>>>>> >>>>
-h, --no-dereference
>>>> >>> >> >>>> >>>>>
>>>> >> >>>>>>
--no-preserve-root
>> >>>>> '/' >>>>>> >>>>
(>>>>>>>)
--preserve-root
>>>> >> >>>>> >>>>>>>>
>>> '/'
--reference=RFILE
>>>>>> >>> RFILE >>>> >>
>>>>> >>> MODE. >>>>> >>>>
RFILE >>>>> >>> >>> >>>>>
>>>>>.
-R, --recursive
>>>> >>>>>>> >>>>>>>
>>>>>>>
>>>> >>>>>>>> >>>>>>>
>>>>> >>>>>> >> >>>>>>>
>>>>>> >>> >>>>> >>>>>> -R
>>>>. >>> >>>> >>>> >>
>>>>> >>>> >>>>>> >>>>>>
>>>. -H >> >>>>>>>.
-H >>> >>>> >>>>> >>>
>>>>>>> >>>> >>>>>
>>>>>> >>>>>>>
-L >>>> >> >>>> >>>>> >>>>>
>>>>>>
-P >> >>>> >> >>>>> >>>>>
--help >>>> >>> >>>>>>>> >>>>>
--version
>>>> >>>>>>> >>>>>>>
>>>>>
>> >>> MODE >>>> >>> >>>>>>
'[ugoa]*([-+=]([rwxXst]*|[ugo]))+|[-+=][0-7]+'.
>>>>>>
>>>> David MacKenzie > Jim Meyering.
>>>>>>> >> >>>>>>>
>>>> >> >>>>>> >>>: bug-coreutils@gnu.org
>>>> GNU coreutils >>>>>>>:
>>>>>> >>>> >>>>>>>>
>>>>>>> >>>:
>>>> >> >> >>>>> >>>>> >>>
>>>> >>>>>
>>>> >>>>> (C) 2026 >>>>>
>>>>>>>>> >>>>> (Free Software Foundation,
Inc.). >>>>> GPLv3+: GNU GPL >>>>>>> 3 >>
>>>>. .
>>> >>>>>> >>: >>> >> >>
>>>>>> >>>>>> >>>>>>. >>
>>>> >> >>>>> >>> >>>>>
>>>> >>>> >> >>>>>>>.
>>>> >>>>>
chmod(2)
>>>>>>> >>>>>>
>> >>>> >>>>> >>>: info '(coreutils) chmod
invocation'
>>>>>
>>>>>> >>> >>>>>> >>
>>>>>> >>>>>> >>>> >>>>
> >>>> >>>>>>>
>>> >>>>>>> >> >>>>>
>>>>>>> >>>> >>>> >>>
>>>>>> >>>>>>> 3
>> >> >>>>
>>>>>>> >>> >>>> >>>>
>>>>>. >> >>>> >> >>>>>>.
>>> >>>> >> >>>>> >> >>>>>
>>>> >>>>>> >>>> >>>>
>>>>> >>>> >>>>>>>> >>>
>>>>> >>>> >>>>>>>>>:
.
GNU coreutils 9.11 >>>>> 2026 CHMOD(1)