Copyright © Onno Zweers
Dit zijn aantekeningen bij mijn studie voor Linux Professional Institute certificaten. Normaal gebruik ik de uitstekende tutorials van IBM (van Ian Shields) maar voor enkele onderwerpen zijn de tutorials nog niet klaar.
Password veld:
This information supersedes any password present in /etc/group.
Password timeouts instellen.
gpasswd group gpasswd -a user group gpasswd -d user group gpasswd -R group gpasswd -r group gpasswd [-A user,...] [-M user,...] group
Group administrator can add and delete users using -a and -d options respectively. Administrators can use -r option to remove group password. When no password is set only group members can use newgrp to join the group. Option -R disables access via a password to the group through newgrp command (however members will still be able to switch to this group).
Maakt nieuwe groep aan.
groupadd [-g GID [-o]] [-f] [-K KEY=VALUE] group
-f = exit met status succes als de groep al bestaat. -g GID = group ID instellen. -K KEY=VALUE = Overrides /etc/login.defs defaults (GID_MIN, GID_MAX and others). Multiple -K options can be specified. Example: -K GID_MIN=100 -o = voeg groep toe met bestaand GID.
groupdel <group>
Je moet zelf controleren welke files er zijn met de groep.
-n name = nieuwe naam -g GID = nieuw group ID -o = override niet-uniek GID
-aS = status voor alle gebruikers. -d = password leegmaken. -e = expire: gebruiker moet zijn password wijzigen. -i days = account wordt inactief na zoveel dagen passwd niet gewijzigd. -l = lock account. -u = unlock account. -m days = minimum aantal dagen waarna gebruiker passwd mag veranderen. -x days = max dagen dat wachtwoord geldig is. -w days = aantal dagen waarschuwing voordat passwd gewijzigd moet worden.
Usage: useradd [options] LOGIN
Options:
-b, --base-dir BASE_DIR base directory for the new user account
home directory
-c, --comment COMMENT set the GECOS field for the new user account
-d, --home-dir HOME_DIR home directory for the new user account
-D, --defaults print or save modified default useradd
configuration
-e, --expiredate EXPIRE_DATE set account expiration date to EXPIRE_DATE
-f, --inactive INACTIVE set password inactive after expiration
to INACTIVE
-g, --gid GROUP force use GROUP for the new user account
-G, --groups GROUPS list of supplementary groups for the new
user account
-h, --help display this help message and exit
-k, --skel SKEL_DIR specify an alternative skel directory
-K, --key KEY=VALUE overrides /etc/login.defs defaults
-m, --create-home create home directory for the new user
account
-o, --non-unique allow create user with duplicate
(non-unique) UID
-p, --password PASSWORD use encrypted password for the new user
account
-r, --system create a system account
-s, --shell SHELL the login shell for the new user account
-u, --uid UID force use the UID for the new user account
-f = ook als gebruiker is ingelogd -r = verwijder home-dir van gebruiker
-aG groep1,groep2 = gebruiker toevoegen aan groepen. -e yyyy-mm-dd = vervaldatum. -dm dir = nieuwe home dir (oude wordt verplaatst). -l newlogin = inlognaam wordt gewijzigd.
# /etc/profile: system-wide .profile file for the Bourne shell (sh(1))
# and Bourne compatible shells (bash(1), ksh(1), ash(1), ...).
if [ "$PS1" ]; then
if [ "$BASH" ]; then
PS1='\u@\h:\w\$ '
if [ -f /etc/bash.bashrc ]; then
. /etc/bash.bashrc
fi
else
if [ "`id -u`" -eq 0 ]; then
PS1='# '
else
PS1='$ '
fi
fi
fi
umask 022
Commando’s uitvoeren in een gewijzigde environment.
env -i /bin/bash -c set
Maak variabelen beschikbaar aan volgende commando’s/programma’s.
-p = toon lijst gexporteerde variabelen.
set [--abefhkmnptuvxBCHP] [-o option] [arg ...]
Without options, the name and value of each shell variable are
displayed in a format that can be reused as input for setting or
resetting the currently-set variables. Read-only variables canâ
not be reset. In posix mode, only shell variables are listed.
The output is sorted according to the current locale. When
options are specified, they set or unset shell attributes. Any
arguments remaining after the options are processed are treated
as values for the positional parameters and are assigned, in
order, to $1, $2, ... $n. Options, if specified, have the folâ
lowing meanings:
-a Automatically mark variables and functions which are
modified or created for export to the environment of
subsequent commands.
-b Report the status of terminated background jobs immediâ
ately, rather than before the next primary prompt. This
is effective only when job control is enabled.
-e Exit immediately if a simple command (see SHELL GRAMMAR
above) exits with a non-zero status. The shell does not
exit if the command that fails is part of the command
list immediately following a while or until keyword,
part of the test in an if statement, part of a && or ââ
list, or if the commandâs return value is being inverted
via !. A trap on ERR, if set, is executed before the
shell exits.
-f Disable pathname expansion.
-h Remember the location of commands as they are looked up
for execution. This is enabled by default.
-k All arguments in the form of assignment statements are
placed in the environment for a command, not just those
that precede the command name.
-m Monitor mode. Job control is enabled. This option is
on by default for interactive shells on systems that
support it (see JOB CONTROL above). Background proâ
cesses run in a separate process group and a line conâ
taining their exit status is printed upon their compleâ
tion.
-n Read commands but do not execute them. This may be used
to check a shell script for syntax errors. This is
ignored by interactive shells.
-o option-name
The option-name can be one of the following:
allexport
Same as -a.
braceexpand
Same as -B.
emacs Use an emacs-style command line editing interâ
face. This is enabled by default when the shell
is interactive, unless the shell is started with
the --noediting option.
errtrace
Same as -E.
functrace
Same as -T.
errexit Same as -e.
hashall Same as -h.
histexpand
Same as -H.
history Enable command history, as described above under
HISTORY. This option is on by default in interâ
active shells.
ignoreeof
The effect is as if the shell command
ââIGNOREEOF=10ââ had been executed (see Shell
Variables above).
keyword Same as -k.
monitor Same as -m.
noclobber
Same as -C.
noexec Same as -n.
noglob Same as -f. nolog Currently ignored.
notify Same as -b.
nounset Same as -u.
onecmd Same as -t.
physical
Same as -P.
pipefail
If set, the return value of a pipeline is the
value of the last (rightmost) command to exit
with a non-zero status, or zero if all commands
in the pipeline exit successfully. This option
is disabled by default.
posix Change the behavior of bash where the default
operation differs from the POSIX 1003.2 standard
to match the standard (posix mode).
privileged
Same as -p.
verbose Same as -v.
vi Use a vi-style command line editing interface.
xtrace Same as -x.
If -o is supplied with no option-name, the values of the
current options are printed. If +o is supplied with no
option-name, a series of set commands to recreate the
current option settings is displayed on the standard
output.
-p Turn on privileged mode. In this mode, the $ENV and
$BASH_ENV files are not processed, shell functions are
not inherited from the environment, and the SHELLOPTS
variable, if it appears in the environment, is ignored.
If the shell is started with the effective user (group)
id not equal to the real user (group) id, and the -p
option is not supplied, these actions are taken and the
effective user id is set to the real user id. If the -p
option is supplied at startup, the effective user id is
not reset. Turning this option off causes the effective
user and group ids to be set to the real user and group
ids.
-t Exit after reading and executing one command.
-u Treat unset variables as an error when performing paramâ
eter expansion. If expansion is attempted on an unset
variable, the shell prints an error message, and, if not
interactive, exits with a non-zero status.
-v Print shell input lines as they are read.
-x After expanding each simple command, for command, case
command, select command, or arithmetic for command, disâ
play the expanded value of PS4, followed by the command
and its expanded arguments or associated word list.
-B The shell performs brace expansion (see Brace Expansion
above). This is on by default.
-C If set, bash does not overwrite an existing file with
the >, >&, and <> redirection operators. This may be
overridden when creating output files by using the rediâ
rection operator >| instead of >.
-E If set, any trap on ERR is inherited by shell functions,
command substitutions, and commands executed in a subâ
shell environment. The ERR trap is normally not inherâ
ited in such cases.
-H Enable ! style history substitution. This option is on
by default when the shell is interactive.
-P If set, the shell does not follow symbolic links when
executing commands such as cd that change the current
working directory. It uses the physical directory
structure instead. By default, bash follows the logical
chain of directories when performing commands which
change the current directory.
-T If set, any traps on DEBUG and RETURN are inherited by
shell functions, command substitutions, and commands
executed in a subshell environment. The DEBUG and
RETURN traps are normally not inherited in such cases.
-- If no arguments follow this option, then the positional
parameters are unset. Otherwise, the positional parameâ
ters are set to the args, even if some of them begin
with a -.
- Signal the end of options, cause all remaining args to
be assigned to the positional parameters. The -x and -v
options are turned off. If there are no args, the posiâ
tional parameters remain unchanged.
The options are off by default unless otherwise noted. Using +
rather than - causes these options to be turned off. The
options can also be specified as arguments to an invocation of
the shell. The current set of options may be found in $-. The
return status is always true unless an invalid option is encounâ
tered.