400 commands for GNU / Linux you should know

System Information

arch : show the architecture of the machine (1).
uname-m : show the architecture of the machine (2).
uname-r : show the kernel version used.
dmidecode-q : display the components (hardware) system.
hdparm-i / dev / hda : show the characteristics of a hard disk.
hdparm-tT / dev / sda : make reading test on a hard disk.
cat / proc / cpuinfo : CPU information show.
cat / proc / interrupts : interrupts show.
cat / proc / meminfo : verify memory usage.
cat / proc / swaps : swap files show.
cat / proc / version : display the version of the kernel.
cat / proc / net / dev : network adapters and display statistics.
cat / proc / mounts : display the mounted file system.
lspci-tv : show PCI devices.
lsusb-tv -Display USB devices.
date : display the system date.
cal 2011 : show calendar 2011.
Lime July 2011 : show the calendar for the month July 2011.
041217002011.00 date : place (declare, set) date and time.
clock-w : save changes to the BIOS date.

Turn off (Reset System or Log out)

shutdown-h now : Shut down system (1).
init 0 : Shut down system (2).
telinit 0 : Shut down system (3).
halt : shutdown the system (4).
shutdown-h hours: minutes & : planned shutdown of the system.
shutdown-c : cancel a planned shutdown of the system.
shutdown-r now : Restart (1).
reboot : Reboot (2).
logout : Logout.

Files and Directories

cd / home : enter the "home" directory.
cd .. : go back one level.
cd .. / .. : back 2 levels.
cd: go to the root directory.
cd ~ user1 : user1 directory go.
cd - : go (back) to the previous directory.
pwd : show the path of the working directory.
ls : see the files in a directory.
ls-F : see the files in a directory.
ls-l : show details of files and folders in a directory.
ls-a : show hidden files.
ls * [0-9] *: show the files and folders that contain numbers.
tree : display files and folders in a tree starting from the root. (1)
lstree : display files and folders in a tree starting from the root. (2)
mkdir dir1 : create a folder or directory called 'dir1?.
mkdir dir1 dir2 : create two folders or directories simultaneously (Create two directories at once).
mkdir-p / tmp/dir1/dir2 : create a directory tree.
rm-f file1 : delete the file called 'file1?.
rmdir dir1 : delete the folder called 'dir1?.
rm-rf dir1 : delete a folder called 'dir1? with its contents recursively. (If I delete recursive'm saying it with contents).
rm-rf dir1 dir2 : delete two folders (directories) with its contents recursively.
new_dir dir1 mv : rename or move a file or folder (directory).
file1 cp : copy a file.
cp file1 file2 : copy two files together.
cp dir / *. : copy all the files in a directory within the current working directory.
cp-a / tmp/dir1. : copy a directory within the current working directory.
cp-a dir1 : copy a directory.
cp-a dir1 dir2 : copy two unison directory.
ln-s file1 lnk1 : create a symbolic link to the file or directory.
lnk1 file1 ln : creating a physical link to the file or directory.
touch-t 0712250000 file1 : modify the real time (time of creation) of a file or directory.
file1 file : output (screen dump) the mime type of a text file.
iconv-l : lists of known ciphers.
iconv-f-t toEncoding fromEncoding inputFile> outputFile : creates a new form of the input file is encoded in assuming and making a ToEncoding fromEncoding.
find. -Maxdepth 1-name *. Jpg-print-exec convert "{}"-resize 80 × 60 "thumbs / {}" \; : grouping resized files in the current directory and send them to directories in thumbnail view (requires converting from ImageMagick).

Find files

find /-name file1 : file and directory search from the root of the system.
find /-user user1 : find files and directories belonging to user 'user1?.
find / home/user1-name \ *. bin : search files with '. bin 'in the directory' / home/user1?.
find / usr / bin-type f-atime +100 : search binary files not used in the last 100 days.
find / usr / bin-type f-mtime -10 : search files created or changed within the last 10 days.
find /-name \ *. rpm-exec chmod 755 '{}' \; : search files with '. rpm' and modify permissions.
find /-xdev-name \ *. rpm : Search files with '. rpm' extension ignoring removable devices such as cdrom, pen-drive, etc. ....
locate \ *. ps : find files with '. ps' executed first with the command 'updatedb'.
whereis halt : show location of a binary file, help, or source. In this case asks where the command 'halt'.
Which halt : to show the full path (full path) to a binary / executable.

Mounting a file system

mount / dev/hda2 / mnt/hda2 : mount a disk called hda2. Check first the existence of the directory '/ mnt/hda2?, If not, create it.
umount / dev/hda2 : removing a disk called hda2. Out first from point '/ mnt/hda2.
fuser-km / mnt/hda2 : force umount when the device is busy.
umount-n / mnt/hda2 : running disassembly without reading the file / etc / mtab. Useful when the file is read-only or the hard drive is full.
mount / dev/fd0 / mnt / floppy : mount a floppy disk (floppy).
mount / dev / cdrom / mnt / cdrom : mount a cdrom / dvdrom.
mount / dev / hdc / mnt / cdrecorder : mount a rewritable cd or dvdrom.
mount / dev / hdb / mnt / cdrecorder : mount a rewritable cd / dvdrom (a dvd).
file.iso mount-o loop / mnt / cdrom : mount a file or iso image.
mount-t vfat / dev/hda5 / mnt/hda5 : mount a FAT32 file system.
mount / dev/sda1 / mnt / usbdisk : mount a usb thumb drive or a memory (without specifying the filesystem type).

Disk Space

df-h : display a list of mounted partitions.
ls-LSR | more : show the size of the files and directories sorted by size.
du-sh dir1 : Estimate the space used by the directory 'dir1?.
du-sk * | sort-rn : show the size of the files and directories sorted by size.
rpm-q-a-qf '% 10 {SIZE} t% {NAME} n' | sort-k1, 1n : show space used by the installed rpm packages organized by size (Fedora, Redhat and others).
dpkg-query-W-f = '$ {Installed-Size; 10} t $ {Package} n' | sort-k1, 1n : show space used by the packages installed, organized by size (Ubuntu, Debian and others) .

Users and Groups

groupadd nombre_del_grupo : create a new group.
groupdel nombre_del_grupo : delete a group.
groupmod-n nuevo_nombre_del_grupo viejo_nombre_del_grupo : rename a group.
useradd-c "Name Surname"-g admin-d / home/user1-s / bin / bash user1 : Create a new user belonging to the "admin".
useradd user1 : create a new user.
userdel-r user1 : delete a user ('-r' eliminates home directory).
usermod-c "User FTP "-g system-d / ftp/user1-s / bin / nologin user1 : change user attributes.
passwd : Changing password.
user1 passwd : change the password of a user (only root).
chage-E 2011-12-31 user1 : place a time limit for the user's password. In this case says that the key expires on December 31, 2011.
pwck : correct syntax check the file format of '/ etc / passwd' and the existence of users.
grpck : check correct syntax and format of the file '/ etc / group' and the existence of groups.
newgrp group_name : Registers a new group to change the default group of newly created files.

File Permissions (Use "+" to place permissions and "-" to remove)

ls-lh : Show permissions.
ls / tmp | pr-T5-W $ COLUMNS : terminal split into 5 columns.
chmod ugo + rwx directory1 : ® readable place, write (w) and execute (x) to the owner (u) group (g) and others (o) on the directory 'directory1?.
chmod go-rwx directory1 : ® remove read permission, write (w) and (x) running the group (g) and others (o) on the directory 'directory1?.
user1 file1 chown : change owner of a file.
chown-R user1 directory1 : change the owner of a directory and all files and directories contained within.
file1 group1 chgrp : changing group of files.
chown user1: group1 file1 : change user and group ownership of a file.
find /-perm-u + s : display all system files with SUID configured.
chmod u + s / bin/file1 : set the SUID bit on a binary file. The user that running that file takes the same privileges as the owner.
chmod us / bin/file1 : disable SUID bit on a binary file.
chmod g+ s / home / public : place a SGID bit on a directory-similar to SUID but for directory.
chmod gs / home / public : disable SGID bit on a directory.
chmod o + t / home / public : place a bit STIKY in a directory. Allows deletion of files only rightful owners.
ot chmod / home / public : STIKY disable bit in a directory.

Special Attributes on files (Use "+" to place permissions and "-" to remove)

chattr + a file1 : enter by opening a file only append mode.
chattr + c file1 : allows a file to be compressed / decompressed automatically.
chattr + d file1 : ensures that the program ignore delete files during backup.
chattr + i file1 : convert the file unchanged, so it can not be removed, altered, renamed, or bound.
chattr + s file1 : allows a file to be deleted safely.
chattr + S file1 : ensures that a file is modified, the changes are written in synchronous mode as with sync.
chattr + u file1 : allows you to retrieve the contents of a file even if it is canceled.
lsattr : show special attributes.

Archives and compressed files

bunzip2 file1.bz2 : decompress in file called 'file1.bz2?.
bzip2 file1 : compress a file called 'file1?.
gunzip file1.gz : decompress a file called 'file1.gz'.
gzip file1 : compress a file called 'file1?.
gzip -9 file1 : compress with maximum compression.
rar to file1.rar TEST_FILE : create a zip file called 'file1.rar'.
rar to file1.rar file1 file2 dir1 : compress 'file1?,' file2? and 'dir1? simultaneously.
rar x file1.rar : unpack rar file.
unrar x file1.rar : unpack rar file.
tar-cvf archive.tar file1 : create an uncompressed tarball.
tar-cvf archive.tar file1 file2 dir1 : create an archive containing 'file1?,' file2? y'dir1?.
tar-tf archive.tar : display the contents of a file.
tar-xvf archive.tar : extract a tarball.
archive.tar tar-xvf-C / tmp : extract a tarball in / tmp.
archive.tar.bz2 dir1 tar-cvfj : create a tarball compressed into bzip2.
tar-xvfj archive.tar.bz2 : decompress a bzip2 compressed tar file
archive.tar.gz dir1 tar-cvfz : create a gzipped tarball.
tar-xvfz archive.tar.gz : decompress a gzip compressed tar archive.
file1.zip zip file1 : create a zipped file.
zip-r dir1 file1 file2 file1.zip : compress in zip several files and directories simultaneously.
file1.zip unzip : unzip a zip file.

Packages RPM (Red Hat, Fedora and the like)

rpm-ivh package.rpm : installing an rpm package.
rpm-ivh-nodeeps package.rpm : installing an rpm package ignoring dependencies requests.
rpm-U package.rpm : upgrade a rpm package without changing configuration files.
rpm-F package.rpm : upgrade a rpm package only if it is installed.
rpm-e package_name.rpm : remove a rpm package.
rpm-qa : show all rpm packages installed on the system.
rpm-qa | grep httpd : show all rpm packages with the name "httpd".
rpm-qi package_name : get information on a specific package installed.
rpm-qg "System Environment / Daemons" : mostar rpm packages of a software group.
rpm-ql package_name : show list of files given by a rpm package installed.
rpm-qc package_name : show configuration files list given by a rpm package installed.
rpm-q package_name-whatrequires : show list of dependencies required for a rpm package.
rpm-q package_name-whatprovides : mostar the ability given by a rpm package.
rpm-q package_name-scripts : scripts show started during installation / removal.
rpm-q package_name-changelog : mostar history revisions of a rpm package.
rpm-qf / etc / httpd / conf / httpd.conf : check which rpm package belongs to a given file.
rpm-qp package.rpm-l : show list of files given by a rpm package not yet been installed.
rpm-import / media / cdrom / RPM-GPG-KEY : Import digital signature public key.
rpm-checksig package.rpm : verify rpm package integrity.
rpm-qa gpg-pubkey : verify the integrity of all rpm packages installed.
rpm-V package_name : check the file size, licenses, rates, owner, group, check MD5 digest and last modified.
rpm-Va : check all rpm packages installed on the system. Use with caution.
rpm-Vp package.rpm : verify a rpm package not yet installed.
rpm2cpio package.rpm | cpio-extract-make-directories * bin *: extracting executable file from a rpm package.
rpm-ivh / usr / src / redhat / RPMS / `arch` / package.rpm : install a package built from a source rpm.
rpmbuild-rebuild package_name.src.rpm : build a rpm package from a source rpm.

YUM packages updater (Red Hat, Fedora and the like)

yum install package_name : download and install a rpm package.
package_name.rpm localinstall yum : This will install an RPM and attempt to resolve all dependencies for you, using your repositories.
package_name.rpm yum update : update all rpm packages installed on the system.
yum update package_name : modernize / upgrade a rpm package.
yum remove package_name : remove a rpm package.
yum list : list all packages installed on the system.
yum search package_name : Find a package repository rpm.
yum clean packages : rpm clean a cache erasing downloaded packages.
yum clean headers : remove all header files that the system uses to resolve the dependency.
yum clean all : delete from the cache packages and header files.

Deb packages (Debian, Ubuntu and derivatives)

dpkg-i package.deb : install / upgrade a deb package.
dpkg-r package_name : remove a deb package system.
dpkg-l : show all deb packages installed on the system.
dpkg-l | grep httpd : show all deb packages with the name "httpd"
package_name dpkg-s : to obtain information on a specific package installed on the system.
dpkg-L package_name : mostar list of files given by a package installed on the system.
dpkg-contents package.deb : show list of files given by a package not yet installed.
dpkg-S / bin / ping : check which package owns a given file.

APT packages updater (Debian, Ubuntu and derivatives)

apt-get install package_name : install / upgrade a deb package.
apt-cdrom install package_name : install / upgrade a deb package from cdrom.
apt-get update : update the package list.
apt-get upgrade : update all installed packages.
apt-get remove package_name : remove a deb package system.
apt-get check : check the correct resolution of dependencies.
apt-get clean : clean up cache from packages downloaded.
apt-cache search searched-package : returns list of packages that corresponds to the series' wanted packages. "

View the contents of a file

cat file1 : view the contents of a file starting from the first row.
tac file1 : view the contents of a file starting from the last line.
more file1 : view the contents along a.
less file1 : commando-like 'more' but can save the file movement and backward movement.
-2 file1 head : see the first two lines of a file.
tail -2 file1 : see the last two lines of a file.
tail-f / var / log / messages : see in real time what has been added to the file.

Manipulating text

cat file1 file2 .. | Command <> file1_in.txt_or_file1_out.txt : general syntax for text manipulation using PIPE, STDIN and STDOUT.
cat file1 | command (sed, grep, awk, grep, etc ...)> result.txt : general syntax to manipulate a text from a file and write the output to a new file.
cat file1 | command (sed, grep, awk, grep, etc ...) »result.txt : general syntax to manipulate a text from a file and add result in an existing file.
Aug grep / var / log / messages : search words "Aug" on file '/ var / log / messages'.
grep ^ Aug / var / log / messages : look for words that begin with "Aug" on file '/ var / log / messages'
grep [0-9] / var / log / messages : select all lines in the file '/ var / log / messages' that contain numbers.
Aug grep-R / var / log / *: search for the string "Aug" in directory '/ var / log' and below.
sed 's/stringa1/stringa2/g' example.txt : relocate "string1" with "string2" in sample.txt
sed '/ ^ $ / d' example.txt : delete all blank lines from the sample.txt
sed '/ * # / d, / ^ $ / d' example.txt : Remove comments and blank lines sample.txt
echo 'esempio' | tr '[: lower:]' '[: upper:]' : convert lowercase to uppercase.
sed-e '1 d 'result.txt : deletes the first line of the file sample.txt
sed-n '/ stringa1 / p' : display only lines that contain the word "string1".

Character set and file conversion

fileunix.txt filedos.txt dos2unix : converting a text file format from MSDOS to UNIX.
fileunix.txt unix2dos filedos.txt : convert a text file format from UNIX to MSDOS.
recode .. HTML <page.txt> page.html : convert a text file to html.
recode-l | more : show all available format conversions.

Analysis of the file system

badblocks-v / dev/hda1 : Check for bad blocks on disk hda1.
fsck / dev/hda1 : repair / check integrity Linux system file on disk hda1.
fsck.ext2 / dev/hda1 : repair / check integrity ext 2 file system on disk hda1.
e2fsck / dev/hda1 : repair / check integrity ext 2 file system on disk hda1.
e2fsck-j / dev/hda1 : repair / check integrity ext 3 file system on disk hda1.
fsck.ext3 / dev/hda1 : repair / check integrity ext 3 file system on disk hda1.
fsck.vfat / dev/hda1 : repair / check integrity of the file system on disk hda1 fat.
fsck.msdos / dev/hda1 : repair / check integrity of a file system on disk hda1 two.
dosfsck / dev/hda1 : repair / check integrity of a file system on disk hda1 two.

Format a filesystem

mkfs / dev/hda1 : create a Linux file system on the partition type hda1.
mke2fs / dev/hda1 : create a system file type hda1 Linux ext 2.
mke2fs-j / dev/hda1 : create a Linux file system type ext3 (journal) on hda1 partition.
mkfs-t vfat 32-F / dev/hda1 : create a FAT32 file system on hda1.
fdformat-n / dev/fd0 : flooply format a disk.
mkswap / dev/hda3 : create a swap file system.

Working with SWAP

mkswap / dev/hda3 : create file system swap.
swapon / dev/hda3 : activating a new swap partition.
swapon / dev/hda2 / dev/hdb3 : activate two swap partitions.

You save (Backup)

dump-0AJ-f / tmp/home0.bak / home : make a complete saves directory '/ home'.
dump-1aj-f / tmp/home0.bak / home : make incremental saves directory '/ home'.
restore-if / tmp/home0.bak : restoring a saved interactively.
rsync-rogpav-delete / home / tmp : synchronization between directories.
-rogpav rsync-e ssh-delete / home ip_address :/ tmp : tunnel rsync through SSH .
rsync-az-e ssh-delete ip_addr :/ home / public / home / local : synchronize a local directory with a remote directory via ssh and compression.
rsync-az-e ssh-delete / home / local ip_addr :/ home / public : Synchronize a remote directory with a local directory via ssh and compression.
dd bs = 1M if = / dev / hda | gzip | ssh user @ ip_addr 'dd of = hda.gz' : make a save on a hard disk on a remote host via ssh.
dd if = / dev / sda of = / tmp/file1 : save the contents of a hard drive to a file. (In this case the hard drive is "sda" and the file "file1").
tar-Puf backup.tar / home / user : make incremental saves directory '/ home / user'.
(Cd / tmp / local / && tar c.) | Ssh-C user @ ip_addr 'cd / home / share / && tar x-p' : copy the contents of a directory on a remote directory via ssh.
(Tar c / home) | ssh-C user @ ip_addr 'cd / home / backup-home && tar x-p' : copy a local directory on a remote directory via ssh.
tar cf -. | (Cd / tmp / backup, tar xf -) : local copy preserving permits and links from one directory to another.
find / home/user1-name '*. txt' | xargs cp-av-target-directory = / home / backup /-parents : find and copy all files with '. txt' from one directory to another.
find / var / log-name '*. log' | tar cv-files-from = - | bzip2> log.tar.bz2 : find all files with '. log' and make a bzip file.
dd if = / dev / hda of = / dev/fd0 bs = 512 count = 1 : make a copy of MRB (Master Boot Record) to floppy.
dd if = / dev/fd0 of = / dev / hda bs = 512 count = 1 : restore the backup of the MBR (Master Boot Record) saved on a floppy.

CD-ROM

gracetime cdrecord-v = 2 dev = / dev / cdrom-eject blank = fast-force : clean or erase a rewritable cd.
mkisofs / dev / cdrom> cd.iso : create an iso image of cdrom on disk.
mkisofs / dev / cdrom | gzip> cd_iso.gz : create a compressed iso image of cdrom on disk.
mkisofs-J-allow-leading-dots-R-V "CD Label"-iso-level 4-o. / cd.iso data_cd : create an iso image from a directory.
cdrecord-v dev = / dev / cdrom cd.iso : burn an iso image.
gzip-dc cd_iso.gz | cdrecord dev = / dev / cdrom - : burn an iso image compression.
cd.iso mount-o loop / mnt / iso : mount an iso image.
cd-paranoia-B : take songs from a cd to wav files.
cd-paranoia - "-3" : take the first 3 songs from a CD to wav files.
cdrecord-scanbus : scan bus to identify the channel scsi.
dd if = / dev / hdc | md5sum : md5sum operating a device such as a CD.

Working with the Network ( LAN and Wi-Fi)

ifconfig eth0 : show the configuration of an Ethernet network card.
ifup eth0 : activate an interface 'eth0?.
ifdown eth0 : disable an interface 'eth0?.
ifconfig eth0 192.168.1.1 netmask 255.255.255.0 : set an IP address.
ifconfig eth0 promisc : configure 'eth0? common mode for packets (sniffing).
dhclient eth0 : active interface 'eth0? dhcp mode.
route-n : show route table.
route add-net 0/0 gw ip_gateway : default input configuration.
route add-net 255.255.0.0 netmask 192.168.0.0 gw 192.168.1.1 : Configure static route for network search '192 .168.0.0/16?.
route of 0/0 gw ip_gateway : remove the static route.
echo "1"> / proc/sys/net/ipv4/ip_forward : enable ip route.
hostname : display the system hostname.
host www.example.com : find the host name to resolve the name to an IP address (1).
nslookup www.example.com : find the host name to resolve the name to an IP direccióm and vice versa (2).
ip link show : mostar the link status of all interfaces.
mii-tool eth0 : mostar the link status of 'eth0?.
ethtool eth0 : card display statistics for 'eth0?.
netstat-tup : show all active network connections and their PID.
netstat-tupl : show all network services listening on the system and its PID.
tcp port 80 tcpdump : show all traffic HTTP .
iwlist scan : show wireless networks.
iwconfig eth1 : show the configuration of a wireless network card.
whois www.example.com : search Whois database.

Microsoft Windows Networking (SAMBA)

nbtscan ip_addr : network name resolution changes.
nmblookup-A ip_addr : network name resolution changes.
smbclient-L ip_addr / hostname : remote actions show a windows host.

IP Tables (FIRE)

iptables-t filter-L : show all chains of the filter table.
iptables-t nat-L : show all chains of the nat table.
iptables-t filter-F : clear all rules from the filter table.
iptables-t nat-F : clean all nat table rules.
iptables-t filter-X : delete any user-created chain.
iptables-t filter-A INPUT-p tcp-dport telnet-j ACCEPT : allow telnet connections to ent.
iptables-t filter-A OUTPUT-p tcp-dport http-j DROP : block connections HTTP to exit.
iptables-t filter-A FORWARD-p tcp-dport pop3-j ACCEPT : connections allow POP to a front chain.
iptables-t filter-A INPUT-j LOG-log-prefix "DROP INPUT" : recording an input string.
iptables-t nat-A POSTROUTING-o eth0-j MASQUERADE : configure a PAT (Port Address Translation) on eth0, hiding the forced departure packages.
iptables-t nat-A PREROUTING-d 192.168.0.1-p tcp-m tcp-dport 22-j DNAT-to-destination 10.0.0.2:22 : diriguidos redirect packets from one host to another.

Monitoring and debugging

top : show tasks using most cpu linux.
ps-eafw : Linux displays tasks.
ps-e-o pid, args-forest : shows Linux tasks in a hierarchical fashion.
pstree : show system processes tree.
kill -9 ID_Processo : force close and finish process.
kill -1 ID_Processo : force a process to reload the configuration.
lsof-p $ $ : display a list of files opened by processes.
lsof / home/user1 : lists open files on a given road system.
strace-c ls> / dev / null : show system calls made and received by a process.
strace-f-e open ls> / dev / null : display library calls.
watch-n1 'cat / proc / interrupts' : show interruptions in real time.
last reboot : reboot show history.
lsmod : display the loaded kernel.
free-m : Displays the status of RAM in megabytes.
smartctl-A / dev / hda : monitor the reliability of a hard drive via SMART.
smartctl-i / dev / hda : check if SMART is enabled on a hard disk.
tail / var / log / dmesg : show events inherent in the charging process of the kernel.
tail / var / log / messages : show system events.

Other useful commands

apropos ... keyword : display a list of commands that belong to the keywords of a program, are useful when you know what makes your program, but sconoces the command name.
man ping : display manual pages on-line, for example, in a ping command, use the '-k' to find any related command.
whatis ... keyword : Displays the description of what the program does.
mkbootdisk-device / dev/fd0 `uname-r` : create a floppy boteable.
gpg-c file1 : encrypt a file with GNU security guard.
file1.gpg gpg : decode a file with GNU Security Guard.
wget-r www.example.com : download an entire website.
wget-c www.example.com / file.iso : download a file with the possibility to stop the download and resume later.
echo 'wget-c www.example.com / files.iso '| at 9:00 : Start a download at any time. In this case begin at 9 am.
ldd / usr / bin / ssh : display the shared libraries required by ssh.
hh alias = 'history' : place an alias for a commando-hh = history.
chsh : change the command Shell.
chsh-list-shells : it is an appropriate command to find out if you have to remote into another terminal.
who-to : show who is registered, and print time of last import system, dead processes, system logging processes, active processes produced by init, current and past performance of the system clock changes