ToDo List
- Environment Variables
- C++ Compile Test
alternatives --help
alternatives version 1.7.4 - Copyright (C) 2001 Red Hat, Inc.
This may be freely redistributed under the terms of the GNU Public License.
usage: alternatives --install <link> <name> <path> <priority>
[--initscript <service>]
[--family <family>]
[--slave <link> <name> <path>]*
alternatives --remove <name> <path>
alternatives --auto <name>
alternatives --config <name>
alternatives --display <name>
alternatives --set <name> <path>
alternatives --list
common options: --verbose --test --help --usage --version --keep-missing
--altdir <directory> --admindir <directory>
tar --help
Usage: tar [OPTION...] [FILE]...
GNU `tar' saves many files together into a single tape or disk archive, and can
restore individual files from the archive.
Examples:
tar -cf archive.tar foo bar # Create archive.tar from files foo and bar.
tar -tvf archive.tar # List all files in archive.tar verbosely.
tar -xf archive.tar # Extract all files from archive.tar.
Main operation mode:
-A, --catenate, --concatenate append tar files to an archive
-c, --create create a new archive
-d, --diff, --compare find differences between archive and file system
--delete delete from the archive (not on mag tapes!)
-r, --append append files to the end of an archive
-t, --list list the contents of an archive
--test-label test the archive volume label and exit
-u, --update only append files newer than copy in archive
-x, --extract, --get extract files from an archive
Operation modifiers:
--check-device check device numbers when creating incremental
archives (default)
-g, --listed-incremental=FILE handle new GNU-format incremental backup
-G, --incremental handle old GNU-format incremental backup
--ignore-failed-read do not exit with nonzero on unreadable files
--level=NUMBER dump level for created listed-incremental archive
-n, --seek archive is seekable
--no-check-device do not check device numbers when creating
incremental archives
--no-seek archive is not seekable
--occurrence[=NUMBER] process only the NUMBERth occurrence of each file
in the archive; this option is valid only in
conjunction with one of the subcommands --delete,
--diff, --extract or --list and when a list of
files is given either on the command line or via
the -T option; NUMBER defaults to 1
--sparse-version=MAJOR[.MINOR]
set version of the sparse format to use (implies
--sparse)
-S, --sparse handle sparse files efficiently
Overwrite control:
-k, --keep-old-files don't replace existing files when extracting,
treat them as errors
--keep-directory-symlink preserve existing symlinks to directories when
extracting
--keep-newer-files don't replace existing files that are newer than
their archive copies
--no-overwrite-dir preserve metadata of existing directories
--overwrite overwrite existing files when extracting
--overwrite-dir overwrite metadata of existing directories when
extracting (default)
--recursive-unlink empty hierarchies prior to extracting directory
--remove-files remove files after adding them to the archive
--skip-old-files don't replace existing files when extracting,
silently skip over them
-U, --unlink-first remove each file prior to extracting over it
-W, --verify attempt to verify the archive after writing it
Select output stream:
--ignore-command-error ignore exit codes of children
--no-ignore-command-error treat non-zero exit codes of children as
error
-O, --to-stdout extract files to standard output
--to-command=COMMAND pipe extracted files to another program
Handling of file attributes:
--atime-preserve[=METHOD] preserve access times on dumped files, either
by restoring the times after reading
(METHOD='replace'; default) or by not setting the
times in the first place (METHOD='system')
--delay-directory-restore delay setting modification times and
permissions of extracted directories until the end
of extraction
--group=NAME force NAME as group for added files
--mode=CHANGES force (symbolic) mode CHANGES for added files
--mtime=DATE-OR-FILE set mtime for added files from DATE-OR-FILE
-m, --touch don't extract file modified time
--no-delay-directory-restore
cancel the effect of --delay-directory-restore
option
--no-same-owner extract files as yourself (default for ordinary
users)
--no-same-permissions apply the user's umask when extracting permissions
from the archive (default for ordinary users)
--numeric-owner always use numbers for user/group names
--owner=NAME force NAME as owner for added files
-p, --preserve-permissions, --same-permissions
extract information about file permissions
(default for superuser)
--preserve same as both -p and -s
--same-owner try extracting files with the same ownership as
exists in the archive (default for superuser)
-s, --preserve-order, --same-order
member arguments are listed in the same order as
the files in the archive
Handling of extended file attributes:
--acls Enable the POSIX ACLs support
--no-acls Disable the POSIX ACLs support
--no-selinux Disable the SELinux context support
--no-xattrs Disable extended attributes support
--selinux Enable the SELinux context support
--xattrs Enable extended attributes support
--xattrs-exclude=MASK specify the exclude pattern for xattr keys
--xattrs-include=MASK specify the include pattern for xattr keys
Device selection and switching:
-f, --file=ARCHIVE use archive file or device ARCHIVE
--force-local archive file is local even if it has a colon
-F, --info-script=NAME, --new-volume-script=NAME
run script at end of each tape (implies -M)
-L, --tape-length=NUMBER change tape after writing NUMBER x 1024 bytes
-M, --multi-volume create/list/extract multi-volume archive
--rmt-command=COMMAND use given rmt COMMAND instead of rmt
--rsh-command=COMMAND use remote COMMAND instead of rsh
--volno-file=FILE use/update the volume number in FILE
Device blocking:
-b, --blocking-factor=BLOCKS BLOCKS x 512 bytes per record
-B, --read-full-records reblock as we read (for 4.2BSD pipes)
-i, --ignore-zeros ignore zeroed blocks in archive (means EOF)
--record-size=NUMBER NUMBER of bytes per record, multiple of 512
Archive format selection:
-H, --format=FORMAT create archive of the given format
FORMAT is one of the following:
gnu GNU tar 1.13.x format
oldgnu GNU format as per tar <= 1.12
pax POSIX 1003.1-2001 (pax) format
posix same as pax
ustar POSIX 1003.1-1988 (ustar) format
v7 old V7 tar format
--old-archive, --portability
same as --format=v7
--pax-option=keyword[[:]=value][,keyword[[:]=value]]...
control pax keywords
--posix same as --format=posix
-V, --label=TEXT create archive with volume name TEXT; at
list/extract time, use TEXT as a globbing pattern
for volume name
Compression options:
-a, --auto-compress use archive suffix to determine the compression
program
-I, --use-compress-program=PROG
filter through PROG (must accept -d)
-j, --bzip2 filter the archive through bzip2
-J, --xz filter the archive through xz
--lzip filter the archive through lzip
--lzma filter the archive through lzma
--lzop
--no-auto-compress do not use archive suffix to determine the
compression program
-z, --gzip, --gunzip, --ungzip filter the archive through gzip
-Z, --compress, --uncompress filter the archive through compress
Local file selection:
--add-file=FILE add given FILE to the archive (useful if its name
starts with a dash)
--backup[=CONTROL] backup before removal, choose version CONTROL
-C, --directory=DIR change to directory DIR
--exclude=PATTERN exclude files, given as a PATTERN
--exclude-backups exclude backup and lock files
--exclude-caches exclude contents of directories containing
CACHEDIR.TAG, except for the tag file itself
--exclude-caches-all exclude directories containing CACHEDIR.TAG
--exclude-caches-under exclude everything under directories containing
CACHEDIR.TAG
--exclude-tag=FILE exclude contents of directories containing FILE,
except for FILE itself
--exclude-tag-all=FILE exclude directories containing FILE
--exclude-tag-under=FILE exclude everything under directories
containing FILE
--exclude-vcs exclude version control system directories
-h, --dereference follow symlinks; archive and dump the files they
point to
--hard-dereference follow hard links; archive and dump the files they
refer to
-K, --starting-file=MEMBER-NAME
begin at member MEMBER-NAME when reading the
archive
--newer-mtime=DATE compare date and time when data changed only
--no-null disable the effect of the previous --null option
--no-recursion avoid descending automatically in directories
--no-unquote do not unquote filenames read with -T
--null -T reads null-terminated names, disable -C
-N, --newer=DATE-OR-FILE, --after-date=DATE-OR-FILE
only store files newer than DATE-OR-FILE
--one-file-system stay in local file system when creating archive
-P, --absolute-names don't strip leading `/'s from file names
--recursion recurse into directories (default)
--suffix=STRING backup before removal, override usual suffix ('~'
unless overridden by environment variable
SIMPLE_BACKUP_SUFFIX)
-T, --files-from=FILE get names to extract or create from FILE
--unquote unquote filenames read with -T (default)
-X, --exclude-from=FILE exclude patterns listed in FILE
File name transformations:
--strip-components=NUMBER strip NUMBER leading components from file
names on extraction
--transform=EXPRESSION, --xform=EXPRESSION
use sed replace EXPRESSION to transform file
names
File name matching options (affect both exclude and include patterns):
--anchored patterns match file name start
--ignore-case ignore case
--no-anchored patterns match after any `/' (default for
exclusion)
--no-ignore-case case sensitive matching (default)
--no-wildcards verbatim string matching
--no-wildcards-match-slash wildcards do not match `/'
--wildcards use wildcards (default)
--wildcards-match-slash wildcards match `/' (default for exclusion)
Informative output:
--checkpoint[=NUMBER] display progress messages every NUMBERth record
(default 10)
--checkpoint-action=ACTION execute ACTION on each checkpoint
--full-time print file time to its full resolution
--index-file=FILE send verbose output to FILE
-l, --check-links print a message if not all links are dumped
--no-quote-chars=STRING disable quoting for characters from STRING
--quote-chars=STRING additionally quote characters from STRING
--quoting-style=STYLE set name quoting style; see below for valid STYLE
values
-R, --block-number show block number within archive with each message
--show-defaults show tar defaults
--show-omitted-dirs when listing or extracting, list each directory
that does not match search criteria
--show-transformed-names, --show-stored-names
show file or archive names after transformation
--totals[=SIGNAL] print total bytes after processing the archive;
with an argument - print total bytes when this
SIGNAL is delivered; Allowed signals are: SIGHUP,
SIGQUIT, SIGINT, SIGUSR1 and SIGUSR2; the names
without SIG prefix are also accepted
--utc print file modification times in UTC
-v, --verbose verbosely list files processed
--warning=KEYWORD warning control
-w, --interactive, --confirmation
ask for confirmation for every action
Compatibility options:
-o when creating, same as --old-archive; when
extracting, same as --no-same-owner
Other options:
-?, --help give this help list
--restrict disable use of some potentially harmful options
--usage give a short usage message
--version print program version
Mandatory or optional arguments to long options are also mandatory or optional
for any corresponding short options.
The backup suffix is `~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.
The version control may be set with --backup or VERSION_CONTROL, values are:
none, off never make backups
t, numbered make numbered backups
nil, existing numbered if numbered backups exist, simple otherwise
never, simple always make simple backups
Valid arguments for the --quoting-style option are:
literal
shell
shell-always
c
c-maybe
escape
locale
clocale
*This* tar defaults to:
--format=gnu -f- -b20 --quoting-style=escape --rmt-command=/etc/rmt
--rsh-command=/usr/bin/ssh
Report bugs to <bug-tar@gnu.org>.
chown
chown Command
Purpose
Changes the owner or group associated with a file.
Syntax
chown [ -f ] [ -h ] [ -R ] Owner [ :Group ] { File ... | Directory
... }
Description
The chown command changes the owner of the file specified by the File
parameter to the user specified by the Owner parameter. The value
of the Owner parameter can be a user ID or a login name found in the
/etc/passwd file. Optionally, a group can also be specified. The value
of the Group parameter can be a group ID or a group name found in
the /etc/group file.
Only the root user can change the owner of a file. You can change
the group of a file only if you are a root user or if you own the
file. If you own the file but are not a root user, you can change
the group only to a group of which you are a member.
When a symbolic link is encountered and you have not specified the
-h flag, the chown command changes the ownership of the file or directory
pointed to by the link and not the ownership of the link itself.
If you specify the -h flag, the chown command has the opposite effect
and changes the ownership of the link itself and not that of the file
or directory pointed to by the link.
If you specify the -R flag, the chown command recursively descends
the specified directories.
If you specify both the -h flag and the -R flag, the chown command
descends the specified directories recursively, and when a symbolic
link is encountered, the ownership of the link itself is changed and
not that of the file or directory pointed to by the link.
Flags
-f Suppresses all error messages except usage messages.
-h Changes the ownership of an encountered symbolic link and not that
of the file or directory pointed to by the symbolic link.
-R Descends directories recursively, changing the ownership for each
file. When a symbolic link is encountered and the link points to a
directory, the ownership of that directory is changed but the directory
is not further transversed.
Security
Access Control: This program should be installed as a normal user
program in the Trusted Computing Base.
Exit Status
This command returns the following exit values:
0 The command executed successfully and all requested changes were
made.
>0 An error occurred.
Examples
1. To change the owner of the file program.c:
chown jim program.c
The user access permissions for program.c now apply to jim. As the
owner, jim can use the chmod command to permit or deny other users
access to program.c.
2. To change the owner and group of all files in the directory /tmp/src
to owner john and group build:
chown -R john:build /tmp/src
Implementation Specifics
Software Product/Option: Base Operating System/ AIX 3.2 to 4.1 Compatibility
Links
Standards Compliance: OSF/1, OSF Level 3, BSD 4.3, SVID 3, SVID 2,
XPG4, XPG3, POSIX
Files
/usr/bin/chown The chown command
/etc/group File that contains group IDs
/etc/passwd File that contains user IDs
Related Information
The chgrp command, chmod command.
The chown subroutine, fchown subroutine.
The File Ownership and User Groups in AIX Version 4.1 System User's
Guide: Operating System and Devices introduces file ownership and
permissions to access files and directories.
The Security Administration in AIX Version 4.1 System Management Guide:
Operating System and Devices describes system security.
=================================================================
=================================================================
chown, fchown, lchown, chownx, or fchownx Subroutine
Purpose
Changes file ownership.
Library
Standard C Library (libc.a)
Syntax
Syntax for the chown, fchown, and lchown Subroutines:
#include
int chown (Path, Owner, Group)
const char *Path;
uid_t Owner;
gid_t Group;
int fchown (FileDescriptor, Owner, Group)
int FileDescriptor;
uid_t Owner;
gid_t Group;
int lchown (Path, Owner, Group)
const char *fname
uid_t uid
gid_t gid
Syntax for the chownx and fchownx Subroutines:
#include
#include
int chownx (Path, Owner, Group, Flags)
char *Path;
uid_t Owner;
gid_t Group;
int Flags;
int fchownx (FileDescriptor, Owner, Group, Flags)
int FileDescriptor;
uid_t Owner;
gid_t Group;
int Flags;
Description
The chown, chownx, fchown, fchownx, and lchown subroutines set the
file owner and group IDs of the specified file system object. Root
user authority is required to change the owner of a file.
A function lchown function sets the owner ID and group ID of the named
file similarity to chown function except in the case where the named
file is a symbolic link. In this case lchown function changes the
ownership of the symbolic link file itself, while chown function changes
the ownership of the file or directory to which the symbolic link
refers.
Parameters
FileDescriptor Specifies the file descriptor of an open file.
Flags Specifies whether the file owner ID or group ID should be changed.
This parameter is constructed by logically ORing the following values:
T_OWNER_AS_IS Ignores the value specified by the Owner parameter and
leaves the owner ID of the file unaltered.
T_GROUP_AS_IS Ignores the value specified by the Group parameter and
leaves the group ID of the file unaltered.
Group Specifies the new group of the file. If this value is -1, the
group is not changed. (A value of -1 indicates only that the group
is not changed; it does not indicate a group that is not valid. An
owner or group ID cannot be invalid.)
Owner Specifies the new owner of the file. If this value is -1, the
owner is not changed. (A value of -1 indicates only that the group
is not changed; it does not indicate a group that is not valid. An
owner or group ID cannot be invalid.)
Path Specifies the full path name of the file. If Path resolves to
a symbolic link, the ownership of the file or directory pointed to
by the symbolic link is changed.
Return Values
Upon successful completion, the chown, chownx, fchown, fchownx, and
lchown subroutines return a value of 0. If the chown, chownx, fchown,
fchownx, or lchown subroutine is unsuccessful, a value of -1 is returned
and the errno global variable is set to indicate the error.
Error Codes
The chown, chownx, or lchown subroutine is unsuccessful and the owner
and group of a file remain unchanged if one of the following is true:
EACCESS Search permission is denied on a component of the Path parameter.
EDQUOT The new group for the file system object cannot be set because
the group's quota of disk blocks or i-nodes has been exhausted on
the file system.
EFAULT The Path parameter points to a location outside of the allocated
address space of the process.
EINVAL The owner or group ID supplied is not valid.
ELOOP Too many symbolic links were encountered in translating the
Path parameter.
ENAMETOOLONG A component of the Path parameter exceeded 255 characters,
or the entire Path parameter exceeded 1023 characters.
ENOENT A symbolic link was named, but the file to which it refers
does not exist; or a component of the Path parameter does not exist;
or the process has the disallow truncation attribute set; or the Path
parameter is null.
ENOTDIR A component of the path prefix is not a directory.
EPERM The effective user ID does not match the owner of the file,
and the calling process does not have the appropriate privileges.
EROFS The named file resides on a read-only file system.
ESTALE The root or current directory of the process is located in
a virtual file system that has been unmounted.
The fchown or fchownx subroutine is unsuccessful and the file owner
and group remain unchanged if one of the following is true:
EBADF The named file resides on a read-only file system.
EDQUOT The new group for the file system object cannot be set because
the group's quota of disk blocks or i-nodes has been exhausted on
the file system.
EIO An I/O error occurred during the operation.
Security
Access Control: The invoker must have search permission for all components
of the Path parameter.
=================================================================
=================================================================
chown, fchown, lchown, chownx, or fchownx Subroutine
Purpose
Changes file ownership.
Library
Standard C Library (libc.a)
Syntax
Syntax for the chown, fchown, and lchown Subroutines:
#include
int chown (Path, Owner, Group)
const char *Path;
uid_t Owner;
gid_t Group;
int fchown (FileDescriptor, Owner, Group)
int FileDescriptor;
uid_t Owner;
gid_t Group;
int lchown (Path, Owner, Group)
const char *fname
uid_t uid
gid_t gid
Syntax for the chownx and fchownx Subroutines:
#include
#include
int chownx (Path, Owner, Group, Flags)
char *Path;
uid_t Owner;
gid_t Group;
int Flags;
int fchownx (FileDescriptor, Owner, Group, Flags)
int FileDescriptor;
uid_t Owner;
gid_t Group;
int Flags;
Description
The chown, chownx, fchown, fchownx, and lchown subroutines set the
file owner and group IDs of the specified file system object. Root
user authority is required to change the owner of a file.
A function lchown function sets the owner ID and group ID of the named
file similarity to chown function except in the case where the named
file is a symbolic link. In this case lchown function changes the
ownership of the symbolic link file itself, while chown function changes
the ownership of the file or directory to which the symbolic link
refers.
Parameters
FileDescriptor Specifies the file descriptor of an open file.
Flags Specifies whether the file owner ID or group ID should be changed.
This parameter is constructed by logically ORing the following values:
T_OWNER_AS_IS Ignores the value specified by the Owner parameter and
leaves the owner ID of the file unaltered.
T_GROUP_AS_IS Ignores the value specified by the Group parameter and
leaves the group ID of the file unaltered.
Group Specifies the new group of the file. If this value is -1, the
group is not changed. (A value of -1 indicates only that the group
is not changed; it does not indicate a group that is not valid. An
owner or group ID cannot be invalid.)
Owner Specifies the new owner of the file. If this value is -1, the
owner is not changed. (A value of -1 indicates only that the group
is not changed; it does not indicate a group that is not valid. An
owner or group ID cannot be invalid.)
Path Specifies the full path name of the file. If Path resolves to
a symbolic link, the ownership of the file or directory pointed to
by the symbolic link is changed.
Return Values
Upon successful completion, the chown, chownx, fchown, fchownx, and
lchown subroutines return a value of 0. If the chown, chownx, fchown,
fchownx, or lchown subroutine is unsuccessful, a value of -1 is returned
and the errno global variable is set to indicate the error.
Error Codes
The chown, chownx, or lchown subroutine is unsuccessful and the owner
and group of a file remain unchanged if one of the following is true:
EACCESS Search permission is denied on a component of the Path parameter.
EDQUOT The new group for the file system object cannot be set because
the group's quota of disk blocks or i-nodes has been exhausted on
the file system.
EFAULT The Path parameter points to a location outside of the allocated
address space of the process.
EINVAL The owner or group ID supplied is not valid.
ELOOP Too many symbolic links were encountered in translating the
Path parameter.
ENAMETOOLONG A component of the Path parameter exceeded 255 characters,
or the entire Path parameter exceeded 1023 characters.
ENOENT A symbolic link was named, but the file to which it refers
does not exist; or a component of the Path parameter does not exist;
or the process has the disallow truncation attribute set; or the Path
parameter is null.
ENOTDIR A component of the path prefix is not a directory.
EPERM The effective user ID does not match the owner of the file,
and the calling process does not have the appropriate privileges.
EROFS The named file resides on a read-only file system.
ESTALE The root or current directory of the process is located in
a virtual file system that has been unmounted.
The fchown or fchownx subroutine is unsuccessful and the file owner
and group remain unchanged if one of the following is true:
EBADF The named file resides on a read-only file system.
EDQUOT The new group for the file system object cannot be set because
the group's quota of disk blocks or i-nodes has been exhausted on
the file system.
EIO An I/O error occurred during the operation.
Security
Access Control: The invoker must have search permission for all components
of the Path parameter.
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