added chmod util from NetBSD userland

Change-Id: Ice81a29becedcebfc1ff42ac9826c291b6451189
This commit is contained in:
Morgawr 2014-04-23 01:48:23 +02:00 committed by Lionel Sambuc
parent ec92655ec2
commit b6bd719869
10 changed files with 555 additions and 335 deletions

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@ -1,7 +1,7 @@
# $NetBSD: Makefile,v 1.22 2007/12/31 15:31:24 ad Exp $
# @(#)Makefile 8.1 (Berkeley) 5/31/93
SUBDIR= cat date df echo ed expr \
SUBDIR= cat chmod date df echo ed expr \
kill ksh ln ls mkdir pax pwd rm rmdir \
sleep stty sync test

6
bin/chmod/Makefile Normal file
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@ -0,0 +1,6 @@
# $NetBSD: Makefile,v 1.8 1997/07/20 22:36:34 christos Exp $
# @(#)Makefile 8.1 (Berkeley) 5/31/93
PROG= chmod
.include <bsd.prog.mk>

307
bin/chmod/chmod.1 Normal file
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@ -0,0 +1,307 @@
.\" $NetBSD: chmod.1,v 1.24 2012/10/22 17:47:06 christos Exp $
.\"
.\" Copyright (c) 1989, 1990, 1993, 1994
.\" The Regents of the University of California. All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" the Institute of Electrical and Electronics Engineers, Inc.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" @(#)chmod.1 8.4 (Berkeley) 3/31/94
.\"
.Dd October 22, 2012
.Dt CHMOD 1
.Os
.Sh NAME
.Nm chmod
.Nd change file modes
.Sh SYNOPSIS
.Nm
.Oo
.Fl R
.Op Fl H | Fl L | Fl P
.Oc
.Op Fl fh
.Ar mode
.Ar
.Nm
.Oo
.Fl R
.Op Fl H | Fl L | Fl P
.Oc
.Op Fl fh
.Fl Fl reference=rfile
.Ar
.Sh DESCRIPTION
The
.Nm
utility modifies the file mode bits of the listed files
as specified by the
.Ar mode
operand, or
copied from a reference
.Ar rfile ,
as specified with the
.Fl Fl reference
argument.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl H
If the
.Fl R
option is specified, symbolic links on the command line are followed.
(Symbolic links encountered in the tree traversal are not followed.)
.It Fl L
If the
.Fl R
option is specified, all symbolic links are followed.
.It Fl P
If the
.Fl R
option is specified, no symbolic links are followed.
.It Fl R
Change the modes of the file hierarchies rooted in the files
instead of just the files themselves.
.It Fl f
Do not display a diagnostic message or modify the exit status if
.Nm
fails to change the mode of a file.
.It Fl h
If
.Ar file
is symbolic link, the mode of the link is changed.
.El
.Pp
The
.Fl H ,
.Fl L
and
.Fl P
options are ignored unless the
.Fl R
option is specified.
In addition, these options override each other and the
command's actions are determined by the last one specified.
.Pp
Only the owner of a file or the super-user is permitted to change
the mode of a file.
.Sh EXIT STATUS
The
.Nm
utility exits 0 on success, and \*[Gt]0 if an error occurs.
.Sh MODES
Modes may be absolute or symbolic.
An absolute mode is an octal number constructed by
.Em or Ap ing
the following values:
.Pp
.Bl -tag -width 6n -compact -offset indent
.It Li 4000
set-user-ID-on-execution
.It Li 2000
set-group-ID-on-execution
.It Li 1000
sticky bit, see
.Xr chmod 2
.It Li 0400
read by owner
.It Li 0200
write by owner
.It Li 0100
execute (or search for directories) by owner
.It Li 0070
read, write, execute/search by group
.It Li 0007
read, write, execute/search by others
.El
.Pp
The read, write, and execute/search values for group and others
are encoded as described for owner.
.Pp
The symbolic mode is described by the following grammar:
.Bd -literal -offset indent
mode ::= clause [, clause ...]
clause ::= [who ...] [action ...] last_action
action ::= op [perm ...]
last_action ::= op [perm ...]
who ::= a | u | g | o
op ::= + | \- | =
perm ::= r | s | t | w | x | X | u | g | o
.Ed
.Pp
The
.Ar who
symbols ``u'', ``g'', and ``o'' specify the user, group, and other parts
of the mode bits, respectively.
The
.Ar who
symbol ``a'' is equivalent to ``ugo''.
.Pp
The
.Ar perm
symbols represent the portions of the mode bits as follows:
.Pp
.Bl -tag -width Ds -compact -offset indent
.It r
The read bits.
.It s
The set-user-ID-on-execution and set-group-ID-on-execution bits.
.It t
The sticky bit.
.It w
The write bits.
.It x
The execute/search bits.
.It X
The execute/search bits if the file is a directory or any of the
execute/search bits are set in the original (unmodified) mode.
Operations with the
.Ar perm
symbol ``X'' are only meaningful in conjunction with the
.Ar op
symbol ``+'', and are ignored in all other cases.
.It u
The user permission bits in the mode of the original file.
.It g
The group permission bits in the mode of the original file.
.It o
The other permission bits in the mode of the original file.
.El
.Pp
The
.Ar op
symbols represent the operation performed, as follows:
.Bl -tag -width 4n
.It +
If no value is supplied for
.Ar perm ,
the ``+'' operation has no effect.
If no value is supplied for
.Ar who ,
each permission bit specified in
.Ar perm ,
for which the corresponding bit in the file mode creation mask
is clear, is set.
Otherwise, the mode bits represented by the specified
.Ar who
and
.Ar perm
values are set.
.It \&\-
If no value is supplied for
.Ar perm ,
the ``\-'' operation has no effect.
If no value is supplied for
.Ar who ,
each permission bit specified in
.Ar perm ,
for which the corresponding bit in the file mode creation mask
is clear, is cleared.
Otherwise, the mode bits represented by the specified
.Ar who
and
.Ar perm
values are cleared.
.It =
The mode bits specified by the
.Ar who
value are cleared, or, if no who value is specified, the owner, group
and other mode bits are cleared.
Then, if no value is supplied for
.Ar who ,
each permission bit specified in
.Ar perm ,
for which the corresponding bit in the file mode creation mask
is clear, is set.
Otherwise, the mode bits represented by the specified
.Ar who
and
.Ar perm
values are set.
.El
.Pp
Each
.Ar clause
specifies one or more operations to be performed on the mode
bits, and each operation is applied to the mode bits in the
order specified.
.Pp
Operations upon the other permissions only (specified by the symbol
``o'' by itself), in combination with the
.Ar perm
symbols ``s'' or ``t'', are ignored.
.Sh EXAMPLES
.Bl -tag -width "u=rwx,go=u-w" -compact
.It Li 644
make a file readable by anyone and writable by the owner only.
.Pp
.It Li go-w
deny write permission to group and others.
.Pp
.It Li =rw,+X
set the read and write permissions to the usual defaults, but
retain any execute permissions that are currently set.
.Pp
.It Li +X
make a directory or file searchable/executable by everyone if it is
already searchable/executable by anyone.
.Pp
.It Li 755
.It Li u=rwx,go=rx
.It Li u=rwx,go=u-w
make a file readable/executable by everyone and writable by the owner only.
.Pp
.It Li go=
clear all mode bits for group and others.
.Pp
.It Li g=u-w
set the group bits equal to the user bits, but clear the group write bit.
.El
.Sh SEE ALSO
.Xr chflags 1 ,
.Xr install 1 ,
.Xr chmod 2 ,
.Xr stat 2 ,
.Xr umask 2 ,
.Xr fts 3 ,
.Xr setmode 3 ,
.Xr symlink 7 ,
.Xr chown 8
.Sh STANDARDS
The
.Nm
utility is expected to be
.St -p1003.2-92
compatible with the exception of the
.Ar perm
symbol
.Dq t
which is not included in that standard.
.Sh BUGS
There's no
.Ar perm
option for the naughty bits.

239
bin/chmod/chmod.c Normal file
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@ -0,0 +1,239 @@
/* $NetBSD: chmod.c,v 1.38 2012/10/22 18:00:46 christos Exp $ */
/*
* Copyright (c) 1989, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT(
"@(#) Copyright (c) 1989, 1993, 1994\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)chmod.c 8.8 (Berkeley) 4/1/94";
#else
__RCSID("$NetBSD: chmod.c,v 1.38 2012/10/22 18:00:46 christos Exp $");
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <err.h>
#include <errno.h>
#include <fts.h>
#include <limits.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>
__dead static void usage(void);
struct option chmod_longopts[] = {
{ "reference", required_argument, 0,
1 },
{ NULL, 0, 0,
0 },
};
int
main(int argc, char *argv[])
{
FTS *ftsp;
FTSENT *p;
void *set;
mode_t mval;
int Hflag, Lflag, Rflag, ch, fflag, fts_options, hflag, rval;
char *mode, *reference;
int (*change_mode)(const char *, mode_t);
setprogname(argv[0]);
(void)setlocale(LC_ALL, "");
Hflag = Lflag = Rflag = fflag = hflag = 0;
reference = NULL;
while ((ch = getopt_long(argc, argv, "HLPRXfghorstuwx",
chmod_longopts, NULL)) != -1)
switch (ch) {
case 1:
reference = optarg;
break;
case 'H':
Hflag = 1;
Lflag = 0;
break;
case 'L':
Lflag = 1;
Hflag = 0;
break;
case 'P':
Hflag = Lflag = 0;
break;
case 'R':
Rflag = 1;
break;
case 'f':
fflag = 1;
break;
case 'h':
/*
* In System V the -h option causes chmod to
* change the mode of the symbolic link.
* 4.4BSD's symbolic links didn't have modes,
* so it was an undocumented noop. In NetBSD
* 1.3, lchmod(2) is introduced and this
* option does real work.
*/
hflag = 1;
break;
/*
* XXX
* "-[rwx]" are valid mode commands. If they are the entire
* argument, getopt has moved past them, so decrement optind.
* Regardless, we're done argument processing.
*/
case 'g': case 'o': case 'r': case 's':
case 't': case 'u': case 'w': case 'X': case 'x':
if (argv[optind - 1][0] == '-' &&
argv[optind - 1][1] == ch &&
argv[optind - 1][2] == '\0')
--optind;
goto done;
case '?':
default:
usage();
}
done: argv += optind;
argc -= optind;
if (argc == 0 || (argc == 1 && reference == NULL))
usage();
fts_options = FTS_PHYSICAL;
if (Rflag) {
if (hflag) {
errx(EXIT_FAILURE,
"the -R and -h options may not be specified together.");
/* NOTREACHED */
}
if (Hflag)
fts_options |= FTS_COMFOLLOW;
if (Lflag) {
fts_options &= ~FTS_PHYSICAL;
fts_options |= FTS_LOGICAL;
}
} else if (!hflag)
fts_options |= FTS_COMFOLLOW;
if (hflag)
change_mode = lchmod;
else
change_mode = chmod;
if (reference == NULL) {
mode = *argv++;
if ((set = setmode(mode)) == NULL) {
err(EXIT_FAILURE, "Cannot set file mode `%s'", mode);
/* NOTREACHED */
}
mval = 0;
} else {
struct stat st;
if (stat(reference, &st) == -1)
err(EXIT_FAILURE, "Cannot stat `%s'", reference);
mval = st.st_mode;
set = NULL;
}
if ((ftsp = fts_open(argv, fts_options, 0)) == NULL) {
err(EXIT_FAILURE, "fts_open");
/* NOTREACHED */
}
for (rval = 0; (p = fts_read(ftsp)) != NULL;) {
switch (p->fts_info) {
case FTS_D:
if (!Rflag)
(void)fts_set(ftsp, p, FTS_SKIP);
break;
case FTS_DNR: /* Warn, chmod, continue. */
warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
rval = 1;
break;
case FTS_DP: /* Already changed at FTS_D. */
continue;
case FTS_ERR: /* Warn, continue. */
case FTS_NS:
warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
rval = 1;
continue;
case FTS_SL: /* Ignore. */
case FTS_SLNONE:
/*
* The only symlinks that end up here are ones that
* don't point to anything and ones that we found
* doing a physical walk.
*/
if (!hflag)
continue;
/* else */
/* FALLTHROUGH */
default:
break;
}
if ((*change_mode)(p->fts_accpath,
set ? getmode(set, p->fts_statp->st_mode) : mval)
&& !fflag) {
warn("%s", p->fts_path);
rval = 1;
}
}
if (errno) {
err(EXIT_FAILURE, "fts_read");
/* NOTREACHED */
}
exit(rval);
/* NOTREACHED */
}
static void
usage(void)
{
(void)fprintf(stderr,
"Usage: %s [-R [-H | -L | -P]] [-fh] mode file ...\n"
"\t%s [-R [-H | -L | -P]] [-fh] --reference=rfile file ...\n",
getprogname(), getprogname());
exit(1);
/* NOTREACHED */
}

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@ -4,7 +4,7 @@
SUBDIR= add_route arp ash at backup btrace \
cawf cd cdprobe cpp \
chmod ci cleantmp cmp co \
ci cleantmp cmp co \
compress cp crc cron crontab \
dd decomp16 DESCRIBE devmand devsize dhcpd \
dhrystone diff diskctl \

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@ -1,8 +0,0 @@
# LSC For now...
NOGCCERROR:= yes
PROG= chmod
MAN=
BINDIR=/bin
SYMLINKS+= $(BINDIR)/$(PROG) /usr/bin/chmod
.include <bsd.prog.mk>

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@ -1,249 +0,0 @@
/* chmod - Change file modes Author: V. Archer */
/* Copyright 1991 by Vincent Archer
* You may freely redistribute this software, in source or binary
* form, provided that you do not alter this copyright mention in any
* way.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <minix/minlib.h>
#include <stdio.h>
#ifndef S_ISLNK
#define S_ISLNK(mode) 0
#define lstat stat
#endif
#define USR_MODES (S_ISUID|S_IRWXU)
#define GRP_MODES (S_ISGID|S_IRWXG)
#define EXE_MODES (S_IXUSR|S_IXGRP|S_IXOTH)
#ifdef S_ISVTX
#define ALL_MODES (USR_MODES|GRP_MODES|S_IRWXO|S_ISVTX)
#else
#define ALL_MODES (USR_MODES|GRP_MODES|S_IRWXO)
#endif
/* Common variables */
char *symbolic;
mode_t new_mode, u_mask;
int rflag, errors;
struct stat st;
char path[PATH_MAX + 1];
int do_change(char *name);
void usage(void);
/* Parse a P1003.2 4.7.7-conformant symbolic mode. */
mode_t parsemode(const char *symbolic, mode_t oldmode)
{
mode_t who, mask, newmode, tmpmask;
char action;
newmode = oldmode & ALL_MODES;
while (*symbolic) {
who = 0;
for (; *symbolic; symbolic++) {
if (*symbolic == 'a') {
who |= ALL_MODES;
continue;
}
if (*symbolic == 'u') {
who |= USR_MODES;
continue;
}
if (*symbolic == 'g') {
who |= GRP_MODES;
continue;
}
if (*symbolic == 'o') {
who |= S_IRWXO;
continue;
}
break;
}
if (!*symbolic || *symbolic == ',') usage();
while (*symbolic) {
if (*symbolic == ',') break;
switch (*symbolic) {
default:
usage();
case '+':
case '-':
case '=': action = *symbolic++;
}
mask = 0;
for (; *symbolic; symbolic++) {
if (*symbolic == 'u') {
tmpmask = newmode & S_IRWXU;
mask |= tmpmask | (tmpmask << 3) | (tmpmask << 6);
symbolic++;
break;
}
if (*symbolic == 'g') {
tmpmask = newmode & S_IRWXG;
mask |= tmpmask | (tmpmask >> 3) | (tmpmask << 3);
symbolic++;
break;
}
if (*symbolic == 'o') {
tmpmask = newmode & S_IRWXO;
mask |= tmpmask | (tmpmask >> 3) | (tmpmask >> 6);
symbolic++;
break;
}
if (*symbolic == 'r') {
mask |= S_IRUSR | S_IRGRP | S_IROTH;
continue;
}
if (*symbolic == 'w') {
mask |= S_IWUSR | S_IWGRP | S_IWOTH;
continue;
}
if (*symbolic == 'x') {
mask |= EXE_MODES;
continue;
}
if (*symbolic == 's') {
mask |= S_ISUID | S_ISGID;
continue;
}
if (*symbolic == 'X') {
if (S_ISDIR(oldmode) || (oldmode & EXE_MODES))
mask |= EXE_MODES;
continue;
}
#ifdef S_ISVTX
if (*symbolic == 't') {
mask |= S_ISVTX;
who |= S_ISVTX;
continue;
}
#endif
break;
}
switch (action) {
case '=':
if (who)
newmode &= ~who;
else
newmode = 0;
case '+':
if (who)
newmode |= who & mask;
else
newmode |= mask & (~u_mask);
break;
case '-':
if (who)
newmode &= ~(who & mask);
else
newmode &= ~mask | u_mask;
}
}
if (*symbolic) symbolic++;
}
return(newmode);
}
/* Main module. The single option possible (-R) does not warrant a call to
* the getopt() stuff.
*/
int main(int argc, char *argv[])
{
int ex_code = 0;
argc--;
argv++;
if (argc && strcmp(*argv, "-R") == 0) {
argc--;
argv++;
rflag = 1;
} else
rflag = 0;
if (!argc--) usage();
if (!strcmp(argv[0], "--")) { /* Allow chmod -- -r, as in Draft11 example */
if (!argc--) usage();
argv++;
}
symbolic = *argv++;
if (!argc) usage();
if (*symbolic >= '0' && *symbolic <= '7') {
new_mode = 0;
while (*symbolic >= '0' && *symbolic <= '7')
new_mode = (new_mode << 3) | (*symbolic++ & 07);
if (*symbolic) usage();
new_mode &= ALL_MODES;
symbolic = (char *) 0;
} else
u_mask = umask(0);
while (argc--)
if (do_change(*argv++)) ex_code = 1;
return(ex_code);
}
/* Apply a mode change to a given file system element. */
int do_change(char *name)
{
mode_t m;
DIR *dirp;
struct dirent *entp;
char *namp;
if (lstat(name, &st)) {
perror(name);
return(1);
}
if (S_ISLNK(st.st_mode) && rflag) return(0); /* Note: violates POSIX. */
if (!symbolic)
m = new_mode;
else
m = parsemode(symbolic, st.st_mode);
if (chmod(name, m)) {
perror(name);
errors = 1;
} else
errors = 0;
if (S_ISDIR(st.st_mode) && rflag) {
if (!(dirp = opendir(name))) {
perror(name);
return(1);
}
if (name != path) strcpy(path, name);
namp = path + strlen(path);
*namp++ = '/';
while (entp = readdir(dirp))
if (entp->d_name[0] != '.' ||
(entp->d_name[1] &&
(entp->d_name[1] != '.' || entp->d_name[2]))) {
strcpy(namp, entp->d_name);
errors |= do_change(path);
}
closedir(dirp);
*--namp = '\0';
}
return(errors);
}
/* Display Posix prototype */
void usage()
{
std_err("Usage: chmod [-R] mode file...\n");
exit(1);
}

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@ -243,7 +243,6 @@
./usr/bin/checknr minix-sys
./usr/bin/chfn minix-sys
./usr/bin/chgrp minix-sys
./usr/bin/chmod minix-sys
./usr/bin/chpass minix-sys
./usr/bin/chsh minix-sys
./usr/bin/ci minix-sys

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@ -1,6 +1,6 @@
MAN= ash.1 at.1 \
bsfilt.1 cawf.1 chgrp.1 \
chmod.1 cmp.1 compress.1 \
cmp.1 compress.1 \
cp.1 crc.1 crontab.1 dd.1 \
dhrystone.1 dosdir.1 dosread.1 doswrite.1 \
eject.1 \

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@ -1,74 +0,0 @@
.TH CHMOD 1
.SH NAME
chmod \- change access mode for files
.SH SYNOPSIS
\fBchmod [\fB\-R\fR] \fImode \fIfile\fR ...\fR
.br
.de FL
.TP
\\fB\\$1\\fR
\\$2
..
.de EX
.TP 20
\\fB\\$1\\fR
# \\$2
..
.SH OPTIONS
.TP 5
.B \-R
# Change hierarchies recursively
.SH EXAMPLES
.TP 20
.B chmod 755 file
# Owner: rwx Group: r\-x Others: r\-x
.TP 20
.B chmod +x file1 file2
# Make \fIfile1\fR and \fIfile2\fR executable
.TP 20
.B chmod a\-w file
# Make \fIfile\fR read only
.TP 20
.B chmod u+s file
# Turn on SETUID for \fIfile\fR
.TP 20
.B chmod \-R o+w dir
# Allow writing for all files in dir
.SH DESCRIPTION
.PP
The given mode is applied to each file in the file list. If the \fB\-R\fR
flag is present, the files in a directory will be changed as well.
The mode can be either absolute or symbolic. Absolute modes are given as an
octal number that represents the new file mode. The mode bits are defined as
follows:
.ta 0.25i
.nf
.PP
4000 Set effective user id on execution to file's owner id
2000 Set effective group id on execution to file's group id
0400 file is readable by the owner of the file
0200 writeable by owner
0100 executable by owner
0070 same as above, for other users in the same group
0007 same as above, for all other users
.PP
.fi
Symbolic modes modify the current file mode in a specified way. The form is:
.PP
[who] op permissions { op permissions ...} {, [who] op ... }
.PP
The possibilities for \fIwho\fR are \fIu\fR, \fIg\fR, \fIo\fR, and \fIa\fR,
standing for user, group, other and all, respectively.
If \fIwho\fR is omitted, \fIa\fR is assumed, but the current umask is used.
The op can be \fI+\fR, \fI-\fR, or \fI=\fR; \fI+\fR turns on the
given permissions, \fI\- \fRturns them off; \fI=\fR sets the permissions
exclusively for the given \fIwho\fR.
For example \fIg=x\fR sets the group permissions to \fI--x\fR.
.PP
The possible permissions are \fIr\fR, \fIw\fR, \fIx\fR; which stand for read,
write, and execute; \fIs\fR turns on the set effective user/group id bits.
\fIs\fR only makes sense with \fIu\fR and \fIg\fR;\fR o+s\fR is
harmless.
.SH "SEE ALSO"
.BR ls (1),
.BR chmod (2).