Linux Command

转自 from http://www.linuxguide.it/linux_commands_line_en.htm

System information
arch show architecture of machine
uname -r show used kernel version
dmidecode -q show hardware system components - (SMBIOS / DMI)
hdaparm -i /dev/hda displays the characteristics of a hard-disk
hdparm -tT /dev/sda perform test reading on a hard-disk
cat /proc/cpuinfo show information CPU info
cat /proc/interrupts show interrupts
cat /proc/meminfo verify memory use
cat /proc/swaps show file(s) swap
cat /proc/version show version of the kernel
cat /proc/net/dev show network adpters and statistics
cat /proc/mounts show mounted file system(s)
lspci -tv display PCI devices
lsusb -tv show USB devices
date show system date
cal 2007 show the timetable of 2007
date 041217002007.00 set date and time - MonthDayhoursMinutesYear.Seconds
clock -w
save date changes on BIOS

Shutdown, Restart of a system and Logout
shutdown -h now shutdown system
init 0
telinit 0
shutdown -r hours:minutes & planned shutdown of the system
shutdown -c cancel a planned shutdown of the system
shutdown -r now reboot
reboot
logout leaving session

Files and Directory
cd /home enter to directory '/ home'
cd .. go back one level
cd ../.. go back two levels
cd go to home directory
cd ~utente go to home directory
cd - go to previous directory
pwd show the path of work directory
ls view files of directory
ls -F view files of directory
ls -l show details of files and directory
ls -a show hidden files
ls *[0-9]* show files and directory containing numbers
lstree show files and directories in a tree starting from root
mkdir dir1 create a directory called 'dir1'
mkdir dir1 dir2 create two directories simultaneously
mkdir -p /tmp/dir1/dir2 create a directory tree
rm -f file1 delete file called 'file1'
rmdir dir1 delete directory called 'dir1'
rm -rf dir1 remove a directory called 'dir1' and contents recursively
rm -rf dir1 dir2 remove two directories and their contents recursively
mv dir1 new_dir rename / move a file or directory
cp file1 file2 copying a file
cp dir/* . copy all files of a directory within the current work directory
cp -a /tmp/dir1 . copy a directory within the current work directory
cp -a dir1 dir2 copy a directory
ln -s file1 lnk1 create a symbolic link to file or directory
ln file1 lnk1 create a physical link to file or directory
touch -t 0712250000 fileditest modify timestamp of a file or directory - (YYMMDDhhmm)

File search
find / -name file1 search file and directory into root filesystem from '/'
find / -user user1 search files and directories belonging to 'user1'
find /home/user1 -name *.bin search files with '. bin' extension within directory '/ home/user1'
find /usr/bin -type f -atime +100 search binary files are not used in the last 100 days
find /usr/bin -type f -mtime -10 search files created or changed within 10 days
find / -name *.rpm -exec chmod 755 {} ; search files with '.rpm' extension and modify permits
find / -xdev -name *.rpm search files with '.rpm' extension ignoring removable partitions as cdrom, pen-drive, etc.¡­
locate *.ps find files with the '.ps' extension - first run 'updatedb' command
whereis halt show location of a binary file, source or man
which halt show full path to a binary / executable

Mounting a Filesystem
mount /dev/hda2 /mnt/hda2 mount disk called hda2 - verify existence of the directory '/ mnt/hda2'
umount /dev/hda2 unmount disk called hda2 - exit from mount point '/ mnt/hda2' first
fuser -km /mnt/hda2 force umount when the device is busy
umount -n /mnt/hda2 run umount without writing the file /etc/mtab - useful when the file is read-only or the hard disk is full
mount /dev/fd0 /mnt/floppy mount a floppy disk
mount /dev/cdrom /mnt/cdrom mount a cdrom / dvdrom
mount /dev/hdc /mnt/cdrecorder mount a cdrw / dvdrom
mount /dev/hdb /mnt/cdrecorder mount a cdrw / dvdrom
mount -o loop file.iso /mnt/cdrom mount a file or iso image
mount -t vfat /dev/hda5 /mnt/hda5 mount a Windows FAT32 file system
mount /dev/sda1 /mnt/usbdisk mount a usb pen-drive or flash-drive
mount -t smbfs -o username=user,password=pass //winclient/share /mnt/share
mount a windows network share

Disk Space
df -h show list of partitions mounted
ls -lSr |more show size of the files and directories ordered by size
du -sh dir1 estimate space used by directory 'dir1'
du -sh * | sort -rn show 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 rpm packages installed sorted by size (fedora, redhat and like)
dpkg-query -W -f='${Installed-Size;10}t${Package}n' | sort -k1,1n show space used by deb packages installed sorted by size (ubuntu, debian and like)

Users and Groups
groupadd group_name create a new group
groupdel group_name delete a group
groupmod -n new_group_name old_group_name rename a group
useradd -c "Nome Cognome" -g admin -d /home/user1 -s /bin/bash user1 create a new user belongs "admin" group
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 change password
passwd user1 change a user password (only by root)
chage -E 2005-12-31 user1 set deadline for user password
pwck check correct syntax and file format of '/etc/passwd' and users existence
grpck check correct syntax and file format of '/etc/group' and groups existence
newgrp group_name log in to a new group to change default group of newly created files

Permits on File - use "+" to set permissions and "-" to remove
ls -lh show permits
ls /tmp | pr -T5 -W$COLUMNS divide terminal into 5 columns
chmod ugo+rwx directory1 set permissions reading (r), write (w) and (x) access to users owner (u) group (g) and others (o)
chmod go-rwx directory1 remove permits reading (r), write (w) and (x) access to users group (g) and others (or
chown user1 file1 change owner of a file
chown user1 -R directory1 change user owner of a directory and all the files and directories contained inside
chgrp gruppo1 file1 change group of files
chown user1:gruppo1 file1 change user and group ownership of a file
find / -perm -u+s view all files on the system with SUID configured
chmod u+s /bin/file_eseguibile set SUID bit on a binary file - the user that running that file gets same privileges as owner
chmod u-s /bin/file_binario disable SUID bit on a binary file
chmod g+s /home/public set SGID bit on a directory - similar to SUID but for directory
chmod g-s /home/public disable SGID bit on a directory
chmod o+t /home/comune set STIKY bit on a directory - allows files deletion only to legitimate owners
chmod o-t /home/comune disable STIKY bit on a directory

Special Attributes on file - use "+" to set permissions and "-" to remove
chattr +a file1 allows write opening of a file only append mode
chattr +c file1 allows that a file is compressed / decompressed automatically by the kernel
chattr +d file1 makes sure that the program ignores Dump the files during backup
chattr +i file1 makes it an immutable file, which can not be removed, altered, renamed or linked
chattr +s file1 allows a file to be deleted safely
chattr +S file1 makes sure that if a file is modified changes are written in synchronous mode as with sync
chattr +u file1 allows you to recover the contents of a file even if it is canceled
lsattr show specials attributes

Archives and compressed files
bunzip2 file1.bz2 decompress a 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 a file1.rar test_file create an archive rar called 'file1.rar'
rar a file1.rar file1 file2 dir1 compress 'file1', 'file2' and 'dir1' simultaneously
rar x file1.rar decompress rar archive
unrar x file1.rar decompress rar archive
tar -cvf archive.tar file1 create a uncompressed tarball
tar -cvf archive.tar file1 file2 dir1 create an archive containing 'file1', '
file2' and 'dir1'
tar -tf archive.tar show contents of an archive
tar -xvf archive.tar extract a tarball
tar -xvf archive.tar -C /tmp extract a tarball into / tmp
tar -cvfj archive.tar.bz2 dir1 create a tarball compressed into bzip2
tar -xvfj archive.tar.bz2 decompress a compressed tar archive in bzip2
tar -cvfz archive.tar.gz dir1 create a tarball compressed into gzip
tar -xvfz archive.tar.gz decompress a compressed tar archive in gzip
zip file1.zip file1 create an archive compressed in zip
zip -r file1.zip file1 file2 dir1 compress in zip several files and directories simultaneously
unzip file1.zip decompress a zip archive

RPM Packages - Fedora, Red Hat and like
rpm -ivh package.rpm install a rpm package
rpm -ivh --nodeeps package.rpm install a 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 already 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 obtain information on a specific package installed
rpm -qg "System Environment/Daemons" show rpm packages of a group software
rpm -ql package_name show list of files provided by a rpm package installed
rpm -qc package_name show list of configuration files provided by a rpm package installed
rpm -q package_name --whatrequires show list of dependencies required for a rpm packet
rpm -q package_name --whatprovides show capability provided by a rpm package
rpm -q package_name --scripts show scripts started during installation / removal
rpm -q package_name --changelog show history of revisions of a rpm package
rpm -qf /etc/httpd/conf/httpd.conf verify which rpm package belongs to a given file
rpm -qp package.rpm -l show list of files provided by a rpm package not yet
installed
rpm --import /media/cdrom/RPM-GPG-KEY import public-key digital signature
rpm --checksig package.rpm verify the integrity of a rpm package
rpm -qa gpg-pubkey verify integrity of all rpm packages installed
rpm -V package_name check file size, permissions, type, owner, group, MD5 checksum and last modification
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* extract executable file from a rpm package
rpm -ivh /usr/src/redhat/RPMS/`arch`/package.rpm install a package built from a rpm source
rpmbuild --rebuild package_name.src.rpm build a rpm package from a rpm source

YUM packages updater - Fedora, RedHat and like
yum install package_name download and install a rpm package
yum update update all rpm packages installed on the system
yum update package_name 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 on rpm repository
yum clean packages clean up rpm cache erasing downloaded packages
yum clean headers remove all files headers that the system uses to resolve dependency
yum clean all remove from the cache packages and headers files

DEB packages - Debian, Ubuntu and like
dpkg -i package.deb install / upgrade a deb package
dpkg -r package_name remove a deb package from the system
dpkg -l show all deb packages installed on the system
dpkg -l | grep httpd show all rpm packages with the name "httpd"
dpkg -s package_name obtain information on a specific package installed on system
dpkg -L package_name show list of files provided by a package installed on system
dpkg --contents package.deb show list of files provided by a package not yet installed
dpkg -S /bin/ping verify which package belongs to a given file

APT packages updater - Debian, Ubuntu e like
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 all deb packages installed on system
apt-get remove package_name remove a deb package from system
apt-get check verify correct resolution of dependencies
apt-get clean clean up cache from packages downloaded

View file content
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 content of a file along
less file1 similar to 'more' command but which allows backward movement in the file as well as forward movement
head -2 file1 view first two lines of a file
tail -2 file1 view last two lines of a file
tail -f /var/log/messages view in real time what is added to a file

Text Manipulation
cat file_test | [operation: sed, grep, awk, grep, etc] > result.txt syntax to elaborate the text of a file, and write result to a new file
cat file_originale | [operazione: sed, grep, awk, grep, etc] >> result.txt syntax to elaborate the text of a file and append result in existing file
grep Aug /var/log/messages look up words "Aug" on file '/var/log/messages'
grep ^Aug /var/log/messages look up words that begin with "Aug" on file '/var
/log/messages'
grep [0-9] /var/log/messages select from file '/var/log/messages' all lines that contain numbers
grep Aug -R /var/log/* search string "Aug" at directory '/var/log' and below
sed 's/stringa1/stringa2/g' example.txt replace "string1" with "string2" in example.txt
sed '/^$/d' example.txt remove all blank lines from example.txt
sed '/ *#/d; /^$/d' example.txt remove comments and blank lines from example.txt
echo 'esempio' | tr '[:lower:]' '[:upper:]' convert from lower case in upper case
sed -e '1d' result.txt eliminates the first line from file example.txt
sed -n '/stringa1/p' view only lines that contain the word "string1"
sed -e 's/ *$//' example.txt remove empty characters at the end of each row
sed -e 's/stringa1//g' example.txt remove only the word "string1" from text and leave intact all
sed -n '1,5p;5q' example.txt view from 1th to 5th row
sed -n '5p;5q' example.txt view row number 5
sed -e 's/00*/0/g' example.txt replace more zeros with a single zero
cat -n file1 number row of a file
cat example.txt | awk 'NR%2==1' remove all even lines from example.txt
echo a b c | awk '{print $1}' view the first column of a line
echo a b c | awk '{print $1,$3}' view the first and third column of a line
paste file1 file2 merging contents of two files for columns
paste -d '+' file1 file2 merging contents of two files for columns with '+' delimiter on the center
sort file1 file2 sort contents of two files
sort file1 file2 | uniq sort contents of two files omitting lines repeated
sort file1 file2 | uniq -u sort contents of two files by viewing only unique line
sort file1 file2 | uniq -d sort contents of two files by viewing only duplicate line
comm -1 file1 file2 compare contents of two files by deleting only unique lines from 'file1'
comm -2 file1 file2 compare contents of two files by deleting only unique lines from 'file2'
comm -3 file1 file2 compare contents of two files by deleting only the lines that appear on both files

Character set and Format file conversion
dos2unix filedos.txt fileunix.txt convert a text file format from MSDOS to UNIX
unix2dos fileunix.txt 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 formats conversion
linux commands line v1.1 - LinuxGuide.it
Filesystem Analysis
badblocks -v /dev/hda1 check bad blocks in disk hda1
fsck /dev/hda1 repair / check integrity of linux filesystem on disk hda1
fsck.ext2 /dev/hda1 repair / check integrity of ext2 filesystem on disk hda1
e2fsck /dev/hda1 repair / check integrity of ext2 filesystem on disk hda1
e2fsck -j /dev/hda1 repair / check integrity of ext3 filesystem on disk hda1
fsck.ext3 /dev/hda1 repair / check integrity of ext3 filesystem on disk hda1
fsck.vfat /dev/hda1 repair / check integrity of fat filesystem on disk hda1
fsck.msdos /dev/hda1 repair / check integrity of dos filesystem on disk hda1
dosfsck /dev/hda1 repair / check integrity of dos filesystems on disk hda1

Format a Filesystem
mkfs /dev/hda1 create a filesystem type linux on hda1 partition
mke2fs /dev/hda1 create a filesystem type linux ext2 on hda1 partition
mke2fs -j /dev/hda1 create a filesystem type linux ext3 (journal) on hda1 partition
mkfs -t vfat 32 -F /dev/hda1 create a FAT32 filesystem
fdformat -n /dev/fd0 format a floppy disk
mkswap /dev/hda3 create a swap filesystem

SWAP filesystem
mkswap /dev/hda3 create a swap filesystem
swapon /dev/hda3 activating a new swap partition
swapon /dev/hda2 /dev/hdb3 activate two swap partitions

Backup
dump -0aj -f /tmp/home0.bak /home make a full backup of directory '/home'
dump -1aj -f /tmp/home0.bak /home make a incremental backup of directory '/home'
restore -if /tmp/home0.bak restoring a backup interactively
rsync -rogpav --delete /home /tmp synchronization between directories
rsync -rogpav -e ssh --delete /home ip_address:/tmp rsync via SSH tunnel
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 backup of a local hard disk on remote host via ssh
tar -Puf backup.tar /home/user make a incremental backup of directory '/home/user'
( cd /tmp/local/ && tar c . ) | ssh -C user@ip_addr 'cd /home/share/ && tar x
-p' copy content of a directory on remote directory via ssh
( tar c /home ) | ssh -C user@ip_addr 'cd /home/backup-home && tar x -p' copy a local directory on remote directory via ssh
tar cf - . | (cd /tmp/backup ; tar xf - ) local copy preserving permits and links from a directory to another
find /home/user1 -name '*.txt' | xargs cp -av --target-directory=/home/backup/ --parents find and copy all files with '.txt' extention from a directory to another
find /var/log -name '*.log' | tar cv --files-from=- | bzip2 > log.tar.bz2 find all files with '.log' extention and make an bzip archive
dd if=/dev/hda of=/dev/fd0 bs=512 count=1 make a copy of MBR (Master Boot Record) to floppy
dd if=/dev/fd0 of=/dev/hda bs=512 count=1 restore MBR from backup copy saved to floppy

CDROM
cdrecord -v gracetime=2 dev=/dev/cdrom -eject blank=fast -force clean a rewritable cdrom
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 "Label CD" -iso-level 4 -o ./cd.iso data_cd create an iso image of a directory
cdrecord -v dev=/dev/cdrom cd.iso burn an ISO image
gzip -dc cd_iso.gz | cdrecord dev=/dev/cdrom - burn a compressed ISO image
mount -o loop cd.iso /mnt/iso mount an ISO image
cd-paranoia -B rip audio tracks from a CD to wav files
cd-paranoia -- "-3" rip first three audio tracks from a CD to wav files
cdrecord --scanbus scan bus to identify the channel scsi

Networking - LAN and WiFi
ifconfig eth0 show 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 configure IP Address
ifconfig eth0 promisc configure 'eth0' in promiscuous mode to gather packets (sniffing)
dhclient eth0 active interface 'eth0' in dhcp mode
route -n show routing table
route add -net 0/0 gw IP_Gateway configura default gateway
route add -net 192.168.0.0 netmask 255.255.0.0 gw 192.168.1.1 configure static route to reach network '192.168.0.0/16'
route del 0/0 gw IP_gateway remove static route
echo "1" > /proc/sys/net/ipv4/ip_forward activate ip routing
hostname show hostname
host www.linuxguide.it lookup hostname to resolve name to ip address and viceversa
ip link show show link status of all interfaces
mii-tool eth0 show link status of 'eth0'
ethtool eth0 show statistics of network card 'eth0'
netstat -tup show all active network connections and their PID
netstat -tupl show all network services listening on the system and their PID
tcpdump tcp port 80 show all HTTP traffic
iwlist scan show wireless networks
iwconfig eth1 show configuration of a wireless network card
linux commands line v1.1 - LinuxGuide.it
Microsoft Windows networks - SAMBA
nbtscan ip_addr netbios name resolution
nmblookup -A ip_addr netbios name resolution
smbclient -L ip_addr/hostname show remote shares of a windows host
smbget -Rr smb://ip_addr/share like wget can download files from a host windows via smb
mount -t smbfs -o username=user,password=pass //winclient/share /mnt/share mount a windows network share

IPTABLES - firewall
iptables -t filter -L show all chains of filtering table
iptables -t nat -L show all chains of nat table
iptables -t filter -F clear all rules from filtering table
iptables -t nat -F clear all rules from table nat
iptables -t filter -X delete any chains created by user
iptables -t filter -A INPUT -p tcp --dport telnet -j ACCEPT allow telnet connections to input
iptables -t filter -A OUTPUT -p tcp --dport http -j DROP block HTTP connections to output
iptables -t filter -A FORWARD -p tcp --dport pop3 -j ACCEPT allow POP3 connections to forward chain
iptables -t filter -A INPUT -j LOG --log-prefix "DROP INPUT" logging sulla chain di input Logging on chain input
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE configure a PAT (Port Address Traslation) on eth0 masking outbound packets
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 redirect packets addressed to a host to another host

Monitoring and debugging
top display linux tasks using most cpu
ps -eafw displays linux tasks
ps -e -o pid,args --forest displays linux tasks in a hierarchical mode
pstree mostra un albero dei processi sistema Shows a tree system processes
kill -9 ID_Processo force closure of the process and finish it
kill -1 ID_Processo force a process to reload configuration
lsof -p $$ display a list of files opened by processes
lsof /home/user1 displays a list of open files in a given path system
strace -c ls >/dev/null display system calls made and received by a process
strace -f -e open ls >/dev/null display library calls
watch -n1 'cat /proc/interrupts' display interrupts in real-time
last reboot show history reboot
lsmod display kernel loaded
free -m displays status of RAM in megabytes
smartctl -A /dev/hda monitoring reliability of a hard-disk through SMART
smartctl -i /dev/hda check if SMART is active on a hard-disk
tail /var/log/dmesg show events inherent to the process of booting kernel
tail /var/log/messages show system events

Other useful commands
apropos ...keyword display a list of commands that pertain to keywords of a program , useful when you know what your program does, but you don't know the name of the command
man ping display the on-line manual pages for example on ping command
whatis ...keyword displays description of what a program does
mkbootdisk --device /dev/fd0 `uname -r` create a boot floppy
gpg -c file1 encrypt a file with GNU Privacy Guard
gpg file1.gpg decrypt a file with GNU Privacy Guard
wget -r www.example.com download an entire web site
wget -c www.example.com/file.iso download a file with the ability to stop the download and resume later
echo 'wget -c www.example.com/files.iso' | at 09:00 start a download at any given time
ldd ssh show shared libraries required by ssh program
alias hh='history' set an alias for a command - hh = history