LINUX FOR u !

LINUX FOR YOU MY FRIENDS : THESE ARE VERY HANDY N GOOD TO HANDLE :

Linux Commands Line list v1.2 :


COMMAND DESCRIPTION


System information
arch show architecture of machine(1)
uname -m show architecture of machine(2)
uname -r show used kernel version
dmidecode -q show hardware system components - (SMBIOS / DMI)
hdparm -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(1)
init 0 shutdown system(2)
telinit 0 shutdown system(3)
shutdown -h hours:minutes & planned shutdown of the system
shutdown -c cancel a planned shutdown of the system
shutdown -r now reboot(1)
reboot reboot(2)
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 ~user1 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
tree show files and directories in a tree starting from root(1)
lstree show files and directories in a tree starting from root(2)
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 file1 modify timestamp of a file or directory - (YYMMDDhhmm)
file file1 outputs the mime type of the file as text
iconv -l lists known encodings
iconv -f fromEncoding -t toEncoding inputFile > outputFile creates a new from the given input file by assuming it is encoded in fromEncoding and converting it to toEncoding.
find . -maxdepth 1 -name *.jpg -print -exec convert "{}" -resize 80x60 "thumbs/{}" \; batch resize files in the current directory and send them to a thumbnails directory (requires convert from Imagemagick)


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 -sk * | 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 "Name Surname " -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 Files (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 -R user1 directory1 change user owner of a directory and all the files and directories contained inside
chgrp group1 file1 change group of files
chown user1:group1 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/file1 set SUID bit on a binary file - the user that running that file gets same privileges as owner
chmod u-s /bin/file1 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/public set STIKY bit on a directory - allows files deletion only to legitimate owners
chmod o-t /home/public disable STIKY bit on a directory


Special Attributes on files (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 localinstall package_name.rpm That will install an RPM, and try to resolve all the dependencies for you using your repositories.
yum update package_name.rpm 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 deb 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 the package list
apt-get upgrade upgrade all of the installed packages
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
apt-cache search searched-package returns list of packages which corresponds string "searched-packages"


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 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 of a file, and write result to a new file
cat file1 | command( sed, grep, awk, grep, etc...) >> result.txt general syntax to manipulate a 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


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
dd if=/dev/sda of=/tmp/file1 backup content of the harddrive to a file
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
dd if=/dev/hdc | md5sum perform an md5sum on a device, like a CD


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 of system
host www.example.com lookup hostname to resolve name to ip address and viceversa(1)
nslookup www.example.com lookup hostname to resolve name to ip address and viceversa(2)
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
hostname show hostname
host www.example.com lookup hostname to resolve name to ip address and viceversa
nslookup www.example.com lookup hostname to resolve name to ip address and viceversa
whois www.example.com lookup on Whois database


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


Others 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 - use '-k' option to find any related commands
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 /usr/bin/ssh show shared libraries required by ssh program
alias hh='history' set an alias for a command - hh = history
chsh change shell command
chsh --list-shells nice command to know if you have to remote into another box
who -a show who is logged on, and print: time of last system boot, dead processes, system login processes, active processes spawned by init, current runlevel, last system clock change





www.linuxguide.it

LINUX FOR U !

TO MY FRIENDS N ALL WHO LOVE UNIX-LINUX-MAC :

LINUX BASIC COMMANDS
alias: Allows you to set aliases and view the current aliases.
awk: Search for a pattern within a file.
alien: Converts .tgz and rpm's to .deb format.
banner: Prints characters as a poster.
badblocks: Searches a device for bad blocks.
biff: Turns mail notification on and off.
bg: move a job running in the foreground to the background.
bzip2: Used to compress and decompress files. Similar to gzip.
cardctl: Used to control PCMCIA cards.
cfdisk: Used to partition a hard disk.
cp: Copy
chattr: Changes the attributes of a file or folder.
chroot: Change the root directory for a command.
chmod: Used to change permissions on a directory or file.
chown: Used to change the owner of a file or directory.
chgrp: Used to change the group a file belongs to.
clear: Clears the screen
cpio: Copies file.
cat: Displays the content of a file
chpasswd: Used to change a large number of passwords at once.
cd: Changes directories.
chage: Sets password aging parameters.
cal: Displays a calendar.
cron: Used to execute commands at a certain time.
crontab: Allows you to view or edit the current cron jobs.
dselect: A graphical front end for dpkg.
dpkg: Installs packages on debain distro's.
date: Prints current date to the screen
du: Lists disk usage in a directory.
df: Reports disk usage information. df -h
dmesg: Used to view the kernel boot file.
dump: Used for backing up.
edquota: Sets quotas for specific users.
env: Lists current environment variables.
fdisk: Used to create/edit/delete partitions.
fsck: Checks a file system for consistency.
fg: Used to send jobs to the background.
fuser: Checks to see what processes and users have open files.
find: Searches for a file.
free: Will show total memory, used memory, and free memory.
gcc: Used to compile C, Assembler, and Preprocessed C source.
gpasswd: Used to set a password for a group.
grep: Used to search through a file for a specified pattern.
getty: Set terminal type, modes, speed, and line discipline
groupadd: Create new group account.
groupdel: Deletes a group.
groupmod: Used to modify a group.
groups: Shows what groups a user is part of.
gunzip: Uncompress files compressed by gzip.
head: Displays the first 10 lines of a file to the screen.
hdparm: Gets disk information.
history: Lists recently executed commands.
host: Used to get DNS info.
htpasswd: Allows you to set usernames and passwords for your
websever.
id: Display information about yourself or another user.
insmod: Installs modules.
init: Used to change run levels.
isapnp: Sets up ISA cards.
icmpinfo: Intercept and interpret ICMP packets
jobs: Used to show jobs running in the background.
join: Join lines of two sorted.
kill: Used to kill a process.
killall: Kill processes by command name.
kernelcfg: A graphical application configures Linux.
klogd: Control which kernel messages.
linuxconf: A command line GUI which lets you configure your linux
lpc: Used to control a line printer.
lpq: View the print spool queue.
lpr: Send files to the printer spool queue.
ls: Displays a directories contents.
ln: Used to create hard and symbolic links.
less: Display the contents of a file
locate: Search for a file or directory.
ldd: Shows what shared libraries a program is dependent on.
ldconfig: Used to configure/view shared libraries.
last: Lists logins and reboots.
lastlog: Print the last login times for system accounts.
lsmod: Lists loaded modules.
lsattr: Lists the attributes for a file or folder.
logrotate: Used to manipulate log files.
mount: Used by itself, reports the currently mounted files.
modinfo: Give info about the module.
modprobe: Queries modules.
man: Displays the Man page for a given command.
mesg: Used to allow/not allow 'write'.
manpath: Attempts to determine the path to a man page.
mail: Used to send and receive mail.
mkdir: Make directory
mke2fs: Used to format a partition with the Ext2 file system.
mv: Move/Rename
merge: Merge multiple files together.
more: Lets you page through text one screen full at a time.
minicom: Great utility for troublshooting a modem.
mkbootdisk: Used to make a boot disk.
ntsysv: Used to select what services should automatically start.
nice: Used to set process priorities.
nslookup: Used to get DNS info from name servers.
netstat: Shows active sockets.
ps: Displays current processes
ping: Used to test connectivity between two hosts.
pwd: Present Working Directory
pwconv: Used to set up the /etc/shadow file.
pnpdump: Determines settings for existing ISA cards.
quota: Allows users to view their own disk quotas.
quotaon: Turns on disk quotas for the system.
quotaoff: Turns off disk quotas for the system.
repquota: Provides reports of disk usage for various users.
rmmod: Removes modules.
rm: Remove
rmdir: Remove directory
rpm: (RedHat flavors only)Used to install RPM's
rpcinfo: Used to see what rpc services are available.
route: Used to view/change routes between you and other hosts.
smbclient: Used to connect to Windows shares or Samba.
smbadduser: Maps linux user names to Windows NT user names.
smbpasswd: Used to update the smbpasswd file with new accounts.
set: Used to read and write variables.
setquota: Used to set disk quotas.
sort: Sorts lines in a file by alphabetical order.
sndconfig: Used to probe and configure a sound card.
su: Change to Super User (root).
spell: Checks for spelling errors in a file.
startx: Start the X Server (GUI)
shutdown: Shutdown machine
suspend: Places a shell in the background.
showmount: Shows mount information for an NFS server.
swapon: Turns on the swapfile.
swapoff: Turns off the swapfile.
testparm: Used to troubleshoot Samba.
tar: Used to compress multiple files.
timeconfig: Used to set the timezone on your machine.
tac: View a file from the last line up.
touch: Creates an empty file.
tail: Displays the last 10 lines of a file to the screen.
talk: Used to chat with another user on the same machine.
tr: Converts one set of characters to another.
traceroute: Used to track the path a packet takes to a host.
top: Shows information about the most CPU-intensive Apps.
useradd: Add a user.
usermod: Modify a user.
userdel: Delete a user.
umount: Removes a device from the filesystem.
updatedb: Updates the locate database.
uname: Determines OS name, version and machine name.
vmstat: Lists information on memory usage.
vi: A text editor
whereis: Finds documentation files.
who: Tells you who is logged into your server.
whoami: Tells you your user information.
wc: Print the number of bytes, words, and lines in files
which: Finds the full path for a command.
write: Used to send a message to another user.
whois: Used to query servers for info on.
wall: Writes a message to all logged in users.
xman: Graphical interface for man pages.
xf86config: Used to configure X.
zcat: Read files that have been compressed with gzip.

An A-Z Index of the Linux BASH command line
alias Create an alias
apropos Search Help manual pages (man -k)
awk Find and Replace text, database sort/validate/index

break Exit from a loop
builtin Run a shell builtin
bzip2 Compress or decompress named file(s)

cal Display a calendar
case Conditionally perform a command
cat Display the contents of a file
cd Change Directory
cfdisk Partition table manipulator for Linux
chgrp Change group ownership
chmod Change access permissions
chown Change file owner and group
chroot Run a command with a different root directory
cksum Print CRC checksum and byte counts
clear Clear terminal screen
cmp Compare two files
comm Compare two sorted files line by line
command Run a command - ignoring shell functions
continue Resume the next iteration of a loop
cp Copy one or more files to another location
cron Daemon to execute scheduled commands
crontab Schedule a command to run at a later time
csplit Split a file into context-determined pieces
cut Divide a file into several parts

date Display or change the date & time
dc Desk Calculator
dd Data Dump - Convert and copy a file
declare Declare variables and give them attributes
df Display free disk space
diff Display the differences between two files
diff3 Show differences among three files
dig DNS lookup
dir Briefly list directory contents
dircolors Colour setup for `ls'
dirname Convert a full pathname to just a path
dirs Display list of remembered directories
du Estimate file space usage



echo Display message on screen
egrep Search file(s) for lines that match an extended expression
eject Eject removable media
enable Enable and disable builtin shell commands
env Environment variables
ethtool Ethernet card settings
eval Evaluate several commands/arguments
exec Execute a command
exit Exit the shell
expand Convert tabs to spaces
export Set an environment variable
expr Evaluate expressions

false Do nothing, unsuccessfully
fdformat Low-level format a floppy disk
fdisk Partition table manipulator for Linux
fgrep Search file(s) for lines that match a fixed string
file Determine file type
find Search for files that meet a desired criteria
fmt Reformat paragraph text
fold Wrap text to fit a specified width.
for Expand words, and execute commands
format Format disks or tapes
free Display memory usage
fsck File system consistency check and repair
ftp File Transfer Protocol
function Define Function Macros

gawk Find and Replace text within file(s)
getopts Parse positional parameters
grep Search file(s) for lines that match a given pattern
groups Print group names a user is in
gzip Compress or decompress named file(s)

hash Remember the full pathname of a name argument
head Output the first part of file(s)
history Command History
hostname Print or set system name

id Print user and group id's
if Conditionally perform a command
ifconfig Configure a network interface
import Capture an X server screen and save the image to file
install Copy files and set attributes

join Join lines on a common field

kill Stop a process from running

less Display output one screen at a time
let Perform arithmetic on shell variables
ln Make links between files
local Create variables
locate Find files
logname Print current login name
logout Exit a login shell
look Display lines beginning with a given string
lpc Line printer control program
lpr Off line print
lprint Print a file
lprintd Abort a print job
lprintq List the print queue
lprm Remove jobs from the print queue
ls List information about file(s)
lsof List open files

make Recompile a group of programs
man Help manual
mkdir Create new folder(s)
mkfifo Make FIFOs (named pipes)
mkisofs Create an hybrid ISO9660/JOLIET/HFS filesystem
mknod Make block or character special files
more Display output one screen at a time
mount Mount a file system
mtools Manipulate MS-DOS files
mv Move or rename files or directories

netstat Networking information
nice Set the priority of a command or job
nl Number lines and write files
nohup Run a command immune to hangups
nslookup Query Internet name servers interactively

passwd Modify a user password
paste Merge lines of files
pathchk Check file name portability
ping Test a network connection
popd Restore the previous value of the current directory
pr Prepare files for printing
printcap Printer capability database
printenv Print environment variables
printf Format and print data
ps Process status
pushd Save and then change the current directory
pwd Print Working Directory

quota Display disk usage and limits
quotacheck Scan a file system for disk usage
quotactl Set disk quotas

ram ram disk device
rcp Copy files between two machines.
read read a line from standard input
readonly Mark variables/functions as readonly
remsync Synchronize remote files via email
return Exit a shell function
rm Remove files
rmdir Remove folder(s)
rsync Remote file copy (Synchronize file trees)

screen Terminal window manager
scp Secure copy (remote file copy)
sdiff Merge two files interactively
sed Stream Editor
select Accept keyboard input
seq Print numeric sequences
set Manipulate shell variables and functions
sftp Secure File Transfer Program
shift Shift positional parameters
shopt Shell Options
shutdown Shutdown or restart linux
sleep Delay for a specified time
sort Sort text files
source Run commands from a file `.'
split Split a file into fixed-size pieces
ssh Secure Shell client (remote login program)
strace Trace system calls and signals
su Substitute user identity
sum Print a checksum for a file
symlink Make a new name for a file
sync Synchronize data on disk with memory

tail Output the last part of files
tar Tape ARchiver
tee Redirect output to multiple files
test Evaluate a conditional expression
time Measure Program running time
times User and system times
touch Change file timestamps
top List processes running on the system
traceroute Trace Route to Host
trap Run a command when a signal is set(bourne)
tr Translate, squeeze, and/or delete characters
true Do nothing, successfully
tsort Topological sort
tty Print filename of terminal on stdin
type Describe a command

ulimit Limit user resources
umask Users file creation mask
umount Unmount a device
unalias Remove an alias
uname Print system information
unexpand Convert spaces to tabs
uniq Uniquify files
units Convert units from one scale to another
unset Remove variable or function names
unshar Unpack shell archive scripts
until Execute commands (until error)
useradd Create new user account
usermod Modify user account
users List users currently logged in
uuencode Encode a binary file
uudecode Decode a file created by uuencode

v Verbosely list directory contents (`ls -l -b')
vdir Verbosely list directory contents (`ls -l -b')
vi Text Editor

watch Execute/display a program periodically
wc Print byte, word, and line counts
whereis Report all known instances of a command
which Locate a program file in the user's path.
while Execute commands
who Print all usernames currently logged in
whoami Print the current user id and name (`id -un')
Wget Retrieve web pages or files via HTTP, HTTPS or FTP

xargs Execute utility, passing constructed argument list(s)
yes Print a string until interrupted

An A-Z Index of the Apple OS X command line
The tcsh command shell of Darwin (the open source core of OSX)
alias Create an alias
alloc List used and free memory
awk Find and Replace text within file(s)

basename Convert a full pathname to just a folder path
bash Bourne-Again SHell (Linux)
bless Set volume bootability and startup disk options.
break Exit from a loop

cal Display a calendar
case Conditionally perform a command
cat Display the contents of a file
cd Change Directory
chflags Change a file or folder's flags.
chgrp Change group ownership
chmod Change access permissions
chown Change file owner and group
chroot Run a command with a different root directory
cksum Print CRC checksum and byte counts
clear Clear terminal screen
cmp Compare two files
comm Compare two sorted files line by line
complete Edit a command completion [word/pattern/list]
continue Resume the next iteration of a loop
cp Copy one or more files to another location
cron Daemon to execute scheduled commands
crontab Schedule a command to run at a later date/time
cut Divide a file into several parts

date Display or change the date & time
dc Desk Calculator
dd Data Dump - Convert and copy a file
df Display free disk space
diff Display the differences between two files
diff3 Show differences among three files
dig DNS lookup
dirname Convert a full pathname to just a path
dirs Display list of remembered directories
diskutil Disk utilities - Format, Verify, Repair
ditto Copy files and folders
dscl Directory Service command line utility
du Estimate file space usage

echo Display message on screen
ed A line-oriented text editor (edlin)
enable Stop or start printers and classes.
env Set environment and run a utility
eval Evaluate several commands/arguments
exec Execute a command
exit Exit the shell
expect Programmed dialogue with interactive programs
Also see AppleScript
expand Convert tabs to spaces
expr Evaluate expressions

false Do nothing, unsuccessfully
fdisk Partition table manipulator for Darwin UFS/HFS/DOS
find Search for files that meet a desired criteria
fmt Reformat paragraph text
fold Wrap text to fit a specified width
for Expand words, and execute commands
foreach Loop, expand words, and execute commands
fsck Filesystem consistency check and repair
fs_usage Filesystem usage (process/pathname)
ftp Internet file transfer program

GetFileInfo Get attributes of HFS+ files
getopt Parse positional parameters
goto Jump to label and continue execution
grep Search file(s) for lines that match a given pattern
groups Print group names a user is in
gzip Compress or decompress files

head Display the first lines of a file
hdiutil Manipulate iso disk images
history Command History
hostname Print or set system name

id Print user and group names/id's
if Conditionally perform a command
info Help info
install Copy files and set attributes

jobs List active jobs
join Join lines on a common field

kill Stop a process from running

l List files in long format (ls -l)
ll List files in long format, showing invisible files (ls -la)
less Display output one screen at a time
ln Make links between files (hard links, symbolic links)
locate Find files
logname Print current login name
login log into the computer
logout Exit a login shell (bye)
lpr Print files
lprm Remove jobs from the print queue
lpstat Printer status information
ls List information about file(s)
lsbom List a bill of materials file
lsof List open files

man Help manual
mkdir Create new folder(s)
mkfifo Make FIFOs (named pipes)
more Display output one screen at a time
mount Mount a file system
mv Move or rename files or directories

net Manage network resources
nice Set the priority of a command
nohup Run a command immune to hangups

onintr Control the action of a shell interrupt
open Open a file/folder/URL/Application
osascript Execute AppleScript

passwd Modify a user password
paste Merge lines of files
pbcopy Copy data to the clipboard
pbpaste Paste data from the Clipboard
pico Simple text editor
ping Test a network connection
pmset Power Management settings
popd Restore the previous value of the current directory
pr Convert text files for printing
printenv Print environment variables
printf Format and print data
ps Process status
pushd Save and then change the current directory
pwd Print Working Directory

quota Display disk usage and limits

rcp Copy files between machines.
repeat Execute a command multiple times
rm Remove files
rmdir Remove folder(s)
rpm Remote Package Manager
rsync Remote file copy - Sync file tree (also RsyncX)

say Convert text to audible speech
sched Schedule a command to run at a later time.
screencapture Capture screen image to file or disk
sdiff Merge two files interactively
security Administer Keychains, keys, certificates and the Security framework
sed Stream Editor
set Set a shell variable = value
setenv Set an environment variable = value
setfile Set attributes of HFS+ files
shift Shift positional parameters
shutdown Shutdown or restart OS X
sleep Delay for a specified time
softwareupdate System software update tool
sort Sort text files
split Split a file into fixed-size pieces
stop Stop a job or process
su Substitute user identity
sudo Execute a command as another user
sum Print a checksum for a file
switch Conditionally perform a command

tail Output the last part of files
tar Tape ARchiver
tee Redirect output to multiple files
test Condition evaluation
time Measure Program Resource Use
touch Change file timestamps
traceroute Trace Route to Host
tr Translate, squeeze, and/or delete characters
true Do nothing, successfully
tty Print filename of terminal on stdin
type Describe a command

umask Users file creation mask
umount a device
unalias Remove an alias
uname Print system information
unexpand Convert spaces to tabs
uniq Uniquify files
units Convert units from one scale to another
unset Remove variable or function names
unsetenv Remove environment variable
users Print login names of users currently logged in
uuencode Encode a binary file
uudecode Decode a file created by uuencode

vi Text Editor

wc Print byte, word, and line counts
where Report all known instances of a command
which Locate a program file in the user's path
while Execute commands
who Print all usernames currently logged on
whoami Print the current user id and name (`id -un')

xargs Execute utility - passing arguments
yes Print a string until interrupted