Unix Toolbox
Hardware | Statistics | Users | Limits | Runlevels | root password | Compile kernel
Running kernel and system information# uname -a # Get the kernel version (and BSD version) # cat /etc/SuSE-release # Get SuSE version # cat /etc/debian_version # Get Debian versionUse /etc/
DISTR-release with DISTR= lsb (Ubuntu), redhat, gentoo, mandrake, sun (Solaris), and so on.
# uptime # Show how long the system has been running + load # hostname # system's host name # hostname -i # Display the IP address of the host. # man hier # Description of the file system hierarchy # last reboot # Show system reboot history
# dmesg # Detected hardware and boot messages # lsdev # information about installed hardware # dd if=/dev/mem bs=1k skip=768 count=256 2>/dev/null | strings -n 8 # Read BIOS
# cat /proc/cpuinfo # CPU model # cat /proc/meminfo # Hardware memory # grep MemTotal /proc/meminfo # Display the physical memory # watch -n1 'cat /proc/interrupts' # Watch changeable interrupts continuously # free -m # Used and free memory (-m for MB) # cat /proc/devices # Configured devices # lspci -tv # Show PCI devices # lsusb -tv # Show USB devices # lshal # Show a list of all devices with their properties # dmidecode # Show DMI/SMBIOS: hw info from the BIOS
# sysctl hw.model # CPU model # sysctl hw # Gives a lot of hardware information # sysctl vm # Memory usage # dmesg | grep "real mem" # Hardware memory # sysctl -a | grep mem # Kernel memory settings and info # sysctl dev # Configured devices # pciconf -l -cv # Show PCI devices # usbdevs -v # Show USB devices # atacontrol list # Show ATA devices
# top # display and update the top cpu processes # mpstat 1 # display processors related statistics # vmstat 2 # display virtual memory statistics # iostat 2 # display I/O statistics (2 s intervals) # systat -vmstat 1 # BSD summary of system statistics (1 s intervals) # systat -tcp 1 # BSD tcp connections (try also -ip) # systat -netstat 1 # BSD active network connections # systat -ifstat 1 # BSD network traffic through active interfaces # systat -iostat 1 # BSD CPU and and disk throughput # tail -n 500 /var/log/messages # Last 500 kernel/syslog messages # tail /var/log/warn # System warnings messages see syslog.conf
# id # Show the active user id with login and group # last # Show last logins on the system # who # Show who is logged on the system # groupadd admin # Add group "admin" and user colin (Linux/Solaris) # useradd -c "Colin Barschel" -g admin -m colin # userdel colin # Delete user colin (Linux/Solaris) # adduser joe # FreeBSD add user joe (interactive) # rmuser joe # FreeBSD delete user joe (interactive) # pw groupadd admin # Use pw on FreeBSD # pw groupmod admin -m newmember # Add a new member to a group # pw useradd colin -c "Colin Barschel" -g admin -m -s /bin/tcsh # pw userdel colin; pw groupdel adminEncrypted passwords are stored in /etc/shadow for Linux and Solaris and /etc/master.passwd on FreeBSD. If the master.passwd is modified manually (say to delete a password), run
# pwd_mkdb -p master.passwd to rebuild the database.# echo "Sorry no login now" > /etc/nologin # (Linux) # echo "Sorry no login now" > /var/run/nologin # (FreeBSD)
ulimit. The status is checked
with ulimit -a. For example to change the open files limit from
1024 to 10240 do:
# ulimit -n 10240 # This is only valid within the shell
The ulimit command can be used in a script to change the limits for the script only.
/etc/security/limits.conf. For example:
# cat /etc/security/limits.conf
* hard nproc 250 # Limit user processes asterisk hard nofile 409600 # Limit application open files
/etc/sysctl.conf.
# sysctl -a # View all system limits # sysctl fs.file-max # View max open files limit # sysctl fs.file-max=102400 # Change max open files limit # cat /etc/sysctl.conf fs.file-max=102400 # Permanent entry in sysctl.conf # cat /proc/sys/fs/file-nr # How many file descriptors are in use
limits in csh or tcsh or as in Linux, use ulimit in an sh or bash shell.
/etc/login.conf. An unlimited value is still limited by the system maximal value.
/etc/sysctl.conf or /boot/loader.conf. The syntax is the same as Linux but the keys are different.
# sysctl -a # View all system limits # sysctl kern.maxfiles=XXXX # maximum number of file descriptors kern.ipc.nmbclusters=32768 # Permanent entry in /etc/sysctl.conf kern.maxfiles=65536 # Typical values for Squid kern.maxfilesperproc=32768 kern.ipc.somaxconn=8192 # TCP queue. Better for apache/sendmail # sysctl kern.openfiles # How many file descriptors are in use # sysctl kern.ipc.numopensockets # How many open sockets are in useSee The FreeBSD handbook Chapter 11http://www.freebsd.org/handbook/configtuning-kernel-limits.html for details.
/etc/system will increase the maximum file descriptors per proc:
set rlim_fd_max = 4096 # Hard limit on file descriptors for a single proc set rlim_fd_cur = 1024 # Soft limit on file descriptors for a single proc
init which then starts rc
which starts all scripts belonging to a runlevel. The scripts are
stored in /etc/init.d and are linked into /etc/rc.d/rcN.d with N the
runlevel number.# grep default: /etc/inittabThe actual runlevel (the list is shown below) can be changed with
id:3:initdefault:
init. For example to go from 3 to 5:
# init 5 # Enters runlevel 5
chkconfig to configure the programs that will be started at boot in a runlevel.
# chkconfig --list # List all init scripts # chkconfig --list sshd # Report the status of sshd # chkconfig sshd --level 35 on # Configure sshd for levels 3 and 5 # chkconfig sshd off # Disable sshd for all runlevelsDebian and Debian based distributions like Ubuntu or Knoppix use the command
update-rc.d to manage the runlevels scripts. Default is to start in 2,3,4 and 5 and shutdown in 0,1 and 6.
# update-rc.d sshd defaults # Activate sshd with the default runlevels # update-rc.d sshd start 20 2 3 4 5 . stop 20 0 1 6 . # With explicit arguments # update-rc.d -f sshd remove # Disable sshd for all runlevels # shutdown -h now (or # poweroff) # Shutdown and halt the system
/etc/ttys. All OS scripts are located in /etc/rc.d/ and in /usr/local/etc/rc.d/ for third-party applications. The activation of the service is configured in /etc/rc.conf and /etc/rc.conf.local. The default behavior is configured in /etc/defaults/rc.conf. The scripts responds at least to start|stop|status.
# /etc/rc.d/sshd statusThe process
sshd is running as pid 552.
# shutdown now # Go into single-user mode # exit # Go back to multi-user mode # shutdown -p now # Shutdown and halt the system # shutdown -r now # Reboot
init can also be used to reach one of the following states level. For example # init 6 for reboot.
USR2)TERM)INT)TSTP)HUP)init=/bin/shThe kernel will mount the root partition and
init will start the bourne shell
instead of rc and then a runlevel. Use the command passwd at the prompt to change the password and then reboot. Forget the single user mode as you need the password for that.# mount -o remount,rw /
# passwd # or delete the root password (/etc/shadow) # sync; mount -o remount,ro / # sync before to remount read only # reboot
# mount -o rw /dev/ad4s3a /mntAlternatively on FreeBSD, boot in single user mode, remount / rw and use passwd.
# chroot /mnt # chroot into /mnt # passwd # reboot
# mount -u /; mount -a # will mount / rw
# passwd
# reboot
# lsmod # List all modules loaded in the kernel # modprobe isdn # To load a module (here isdn)
# kldstat # List all modules loaded in the kernel # kldload crypto # To load a module (here crypto)
# cd /usr/src/linux
# make mrproper # Clean everything, including config files # make oldconfig # Create a new config file from the current kernel # make menuconfig # or xconfig (Qt) or gconfig (GTK) # make # Create a compressed kernel image # make modules # Compile the modules # make modules_install # Install the modules # make install # Install the kernel # reboot
GENERIC directly.
# cd /usr/src/sys/i386/conf/To rebuild the full OS:
# cp GENERIC MYKERNEL
# cd /usr/src
# make buildkernel KERNCONF=MYKERNEL
# make installkernel KERNCONF=MYKERNEL
# make buildworld # Build the full OS but not the kernel # make buildkernel # Use KERNCONF as above if appropriate # make installkernel # reboot # mergemaster -p # Compares only files known to be essential # make installworld # mergemaster # Update all configuration and other files # rebootFor small changes in the source, sometimes the short version is enough:
# make kernel world # Compile and install both kernel and OS
# mergemaster
# reboot
Listing | Priority | Background/Foreground | Top | Kill
ps.
# ps -auxefw # Extensive list of all running process
However more typical usage is with a pipe or with pgrep:
# ps axww | grep cron
586 ?? Is 0:01.48 /usr/sbin/cron -s
# pgrep -l sshd # Find the PIDs of processes by (part of) name # fuser -va 22/tcp # List processes using port 22 # fuser -va /home # List processes accessing the /home partiton # strace df # Trace system calls and signals # truss df # same as above on FreeBSD/Solaris/Unixware # history | tail -50 # Display the last 50 used commands
renice. Negative numbers have a higher priority, the lowest is -20 and "nice" have a positive value.
# renice -5 586 # Stronger priority
586: old priority 0, new priority -5
Start the process with a defined priority with nice. Positive is "nice" or weak, negative is strong scheduling priority. Make sure you know if /usr/bin/nice or the shell built-in is used (check with # which nice).
# nice -n -5 top # Stronger priority (/usr/bin/nice) # nice -n 5 top # Weaker priority (/usr/bin/nice) # nice +5 top # tcsh builtin nice (same as above!)
bg and fg. For example start two processes, bring them in the background, list the processes with jobs and bring one in the foreground.
# ping cb.vu > ping.logUse
^Z # ping is suspended (stopped) with [Ctrl]-[Z]
# bg # put in background and continues running # jobs -l # List processes in background [1] - 36232 Running ping cb.vu > ping.log [2] + 36233 Suspended (tty output) top # fg %2 # Bring process 2 back in foreground
nohup to start a process which has to keep running when the shell is closed (immune to hangups).
# nohup ping -i 60 > ping.log &
top displays running information of processes.
# topWhile top is running press the key h for a help overview. Useful keys are:
kill or killall.
# ping -i 60 cb.vu > ping.log &Important signals are:
[1] 4712
# kill -s TERM 4712 # same as kill -15 4712 # killall -1 httpd # Kill HUP processes by exact name # pkill -9 http # Kill TERM processes by (part of) name # pkill -TERM -u www # Kill TERM processes owned by www # fuser -k -TERM -m /home # Kill every process accessing /home (to umount)
HUP (hang up)INT (interrupt)QUIT (quit)KILL (non-catchable, non-ignorable kill)TERM (software termination signal)Disk info | Boot | Disk usage | Opened files | Mount/remount | Mount SMB | Mount image | Burn ISO | Create image | Memory disk | Disk performance
chmod and chown.
The default umask can be changed for all users in /etc/profile for
Linux or /etc/login.conf for FreeBSD. The default umask is usually 022.
The umsak is subtracted from 777, thus umask 022 results in a
permission 0f 755.
1 --x execute # Mode 764 = exec/read/write | read/write | read 2 -w- write # For: |-- Owner --| |- Group-| |Oth| 4 r-- read ugo=a u=user, g=group, o=others, a=everyone
# chmod [OPTION] MODE[,MODE] FILE # MODE is of the form [ugoa]*([-+=]([rwxXst])) # chmod 640 /var/log/maillog # Restrict the log -rw-r----- # chmod u=rw,g=r,o= /var/log/maillog # Same as above # chmod -R o-r /home/* # Recursive remove other readable for all users # chmod u+s /path/to/prog # Set SUID bit on executable (know what you do!) # find / -perm -u+s -print # Find all programs with the SUID bit # chown user:group /path/to/file # Change the user and group ownership of a file # chgrp group /path/to/file # Change the group ownership of a file
# diskinfo -v /dev/ad2 # information about disk (sector/size) FreeBSD # hdparm -I /dev/sda # information about the IDE/ATA disk (Linux) # fdisk /dev/ad2 # Display and manipulate the partition table # smartctl -a /dev/ad2 # Display the disk SMART info
# unload
# load kernel.old
# boot
# mount | column -t # Show mounted file-systems on the system # df # display free disk space and mounted devices # cat /proc/partitions # Show all registered partitions (Linux)
# du -sh * # Directory sizes as listing # du -csh # Total directory size of the current directory # du -ks * | sort -n -r # Sort everything by size in kilobytes # ls -lSr # Show files, biggest last
# umount /home/
umount: unmount of /home # umount impossible because a file is locking home failed: Device busy
# fstat -f /home # for a mount point # fstat -p PID # for an application with PID # fstat -u user # for a user nameFind opened log file (or other opened files), say for Xorg:
# ps ax | grep Xorg | awk '{print $1}'
1252
# fstat -p 1252
USER CMD PID FD MOUNT INUM MODE SZ|DV R/W
root Xorg 1252 root / 2 drwxr-xr-x 512 r
root Xorg 1252 text /usr 216016 -rws--x--x 1679848 r
root Xorg 1252 0 /var 212042 -rw-r--r-- 56987 w
The file with inum 212042 is the only file in /var:
# find -x /var -inum 212042
/var/log/Xorg.0.log
fuser or lsof:
# fuser -m /home # List processes accessing /home
# lsof /home
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
tcsh 29029 eedcoba cwd DIR 0,18 12288 1048587 /home/eedcoba (guam:/home)
lsof 29140 eedcoba cwd DIR 0,18 12288 1048587 /home/eedcoba (guam:/home)
About an application:
ps ax | grep Xorg | awk '{print $1}'
3324
# lsof -p 3324
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
Xorg 3324 root 0w REG 8,6 56296 12492 /var/log/Xorg.0.log
About a single file:
# lsof /var/log/Xorg.0.log
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
Xorg 3324 root 0w REG 8,6 56296 12492 /var/log/Xorg.0.log
# mount /cdromOr find the device in /dev/ or with dmesg
# mount -v -t cd9660 /dev/cd0c /mnt # cdrom # mount_cd9660 /dev/wcd0c /cdrom # other method # mount -v -t msdos /dev/fd0c /mnt # floppyEntry in /etc/fstab:
# Device Mountpoint FStype Options Dump Pass#To let users do it:
/dev/acd0 /cdrom cd9660 ro,noauto 0 0
# sysctl vfs.usermount=1 # Or insert the line "vfs.usermount=1" in /etc/sysctl.conf
# mount -t auto /dev/cdrom /mnt/cdrom # typical cdrom mount command # mount /dev/hdc -t iso9660 -r /cdrom # typical IDE # mount /dev/sdc0 -t iso9660 -r /cdrom # typical SCSIEntry in /etc/fstab:
/dev/cdrom /media/cdrom subfs noauto,fs=cdfss,ro,procuid,nosuid,nodev,exec 0 0
# fdisk /dev/sda # Find the FreeBSD partition /dev/sda3 * 5357 7905 20474842+ a5 FreeBSD # mount -t ufs -o ufstype=ufs2,ro /dev/sda3 /mnt /dev/sda10 = /tmp; /dev/sda11 /usr # The other slices
# mount -o remount,ro / # Linux # mount -o ro / # FreeBSDCopy the raw data from a cdrom into an iso image:
# dd if=/dev/cd0c of=file.iso
# smbclient -U user -I 192.168.16.229 -L //smbshare/ # List the shares
# mount -t smbfs -o username=winuser //smbserver/myshare /mnt/smbshare
# mount -t cifs -o username=winuser,password=winpwd //192.168.16.229/myshare /mnt/share
Additionally with the package mount.cifs it is possible to store the credentials in a file, for example /home/user/.smb:
username=winuserAnd mount as follow:
password=winpwd
# mount -t cifs -o credentials=/home/user/.smb //192.168.16.229/myshare /mnt/smbshare
# smbutil view -I 192.168.16.229 //winuser@smbserver # List the shares
# mount_smbfs -I 192.168.16.229 //winuser@smbserver/myshare /mnt/smbshare
# mount -t iso9660 -o loop file.iso /mnt # Mount a CD image # mount -t ext3 -o loop file.img /mnt # Mount an image with ext3 fs
# mdconfig -a -t vnode -f file.iso -u 0Or with virtual node:
# mount -t cd9660 /dev/md0 /mnt
# umount /mnt; mdconfig -d -u 0 # Cleanup the md device
# vnconfig /dev/vn0c file.iso; mount -t cd9660 /dev/vn0c /mnt
# umount /mnt; vnconfig -u /dev/vn0c # Cleanup the vn device
# lofiadm -a file.iso
# mount -F hsfs -o ro /dev/lofi/1 /mnt
# umount /mnt; lofiadm -d /dev/lofi/1 # Cleanup the lofi device
conv=notrunc, the image will be smaller if there is less content on the cd. See below and the dd examples.
# dd if=/dev/hdc of=/tmp/mycd.iso bs=2048 conv=notruncUse mkisofs to create a CD/DVD image from files in a directory. To overcome the file names restrictions: -r enables the Rock Ridge extensions common to UNIX systems, -J enables Joliet extensions used by Microsoft systems. -L allows ISO9660 filenames to begin with a period.
# mkisofs -J -L -r -V TITLE -o imagefile.iso /path/to/dirOn FreeBSD, mkisofs is found in the ports in sysutils/cdrtools.
hw.ata.ata_dma="1"Use
hw.ata.atapi_dma="1"
burncd with an ATAPI device (burncd is part of the base system) and cdrecord (in sysutils/cdrtools) with a SCSI drive.
# burncd -f /dev/acd0 data imagefile.iso fixate # For ATAPI drive # cdrecord -scanbus # To find the burner device (like 1,0,0) # cdrecord dev=1,0,0 imagefile.iso
cdrecord with Linux as described above. Additionally it is possible to use the native ATAPI interface which is found with:
# cdrecord dev=ATAPI -scanbusAnd burn the CD/DVD as above.
# dd bs=1k if=imagefile.nrg of=imagefile.iso skip=300
bchunk programhttp://freshmeat.net/projects/bchunk/ can do this. It is in the FreeBSD ports in sysutils/bchunk.
# bchunk imagefile.bin imagefile.cue imagefile.iso
# dd if=/dev/random of=/usr/vdisk.img bs=1K count=1M
# mdconfig -a -t vnode -f /usr/vdisk.img -u 1 # Creates device /dev/md1 # bsdlabel -w /dev/md1 # newfs /dev/md1c # mount /dev/md1c /mnt # umount /mnt; mdconfig -d -u 1; rm /usr/vdisk.img # Cleanup the md device
# dd if=/dev/zero of=/usr/vdisk.img bs=1024k count=1024
# mkfs.ext3 /usr/vdisk.img
# mount -o loop /usr/vdisk.img /mnt
# umount /mnt; rm /usr/vdisk.img # Cleanup
/dev/zero is much faster than urandom, but less secure for encryption.
# dd if=/dev/urandom of=/usr/vdisk.img bs=1024k count=1024
# losetup /dev/loop0 /usr/vdisk.img # Creates and associates /dev/loop0 # mkfs.ext3 /dev/loop0 # mount /dev/loop0 /mnt # losetup -a # Check used loops # umount /mnt # losetup -d /dev/loop0 # Detach # rm /usr/vdisk.img
# mount_mfs -o rw -s 64M md /memdisk
# umount /memdisk; mdconfig -d -u 0 # Cleanup the md device md /memdisk mfs rw,-s64M 0 0 # /etc/fstab entry
# mount -t tmpfs -osize=64m tmpfs /memdisk
# time dd if=/dev/ad4s3c of=/dev/null bs=1024k count=1000
# time dd if=/dev/zero bs=1024k count=1000 of=/home/1Gb.file
# hdparm -tT /dev/hda # Linux only
Routing | Additional IP | Change MAC | Ports | Firewall | IP Forward | NAT | DNS | DHCP | Traffic | QoS | NIS
# mii-diag eth0 # Show the link status (Linux) # ifconfig fxp0 # Check the "media" field on FreeBSD # arp -a # Check the router (or host) ARP entry (all OS) # ping cb.vu # The first thing to try... # traceroute cb.vu # Print the route path to destination # mii-diag -F 100baseTx-FD eth0 # Force 100Mbit Full duplex (Linux) # ifconfig fxp0 media 100baseTX mediaopt full-duplex # Same for FreeBSD # netstat -s # System-wide statistics for each network protocol
# route -n # Linux # netstat -rn # Linux, BSD and UNIX # route print # Windows
# route add 212.117.0.0/16 192.168.1.1Add the route permanently in /etc/rc.conf
# route delete 212.117.0.0/16
# route add default 192.168.1.1
static_routes="myroute"
route_myroute="-net 212.117.0.0/16 192.168.1.1"
# route add -net 192.168.20.0 netmask 255.255.255.0 gw 192.168.16.254
# ip route add 192.168.20.0/24 via 192.168.16.254 # same as above with ip route # route add -net 192.168.20.0 netmask 255.255.255.0 dev eth0 # route add default gw 192.168.51.254 # ip route add default via 192.168.51.254 # same as above with ip route # route delete -net 192.168.20.0 netmask 255.255.255.0
# Route add 192.168.50.0 mask 255.255.255.0 192.168.51.253Use add -p to make the route persistent.
# Route add 0.0.0.0 mask 0.0.0.0 192.168.51.254
# ifconfig eth0 192.168.50.254 netmask 255.255.255.0 # First IP # ifconfig eth0:0 192.168.51.254 netmask 255.255.255.0 # Second IP
# ifconfig fxp0 inet 192.168.50.254/24 # First IP # ifconfig fxp0 alias 192.168.51.254 netmask 255.255.255.0 # Second IPPermanent entries in /etc/rc.conf
ifconfig_fxp0="inet 192.168.50.254 netmask 255.255.255.0"
ifconfig_fxp0_alias0="192.168.51.254 netmask 255.255.255.0"
# ifconfig eth0 hw ether 00:01:02:03:04:05 # Linux # ifconfig fxp0 link 00:01:02:03:04:05 # FreeBSD
# netstat -an | grep LISTEN
# lsof -i # Linux list all Internet connections # socklist # Linux display list of open sockets # sockstat -4 # FreeBSD application listing # netstat -anp --udp --tcp | grep LISTEN # Linux # netstat -tup # List active connections to/from system (Linux) # netstat -tupl # List listening ports from system (Linux) # netstat -ano # Windows
# iptables -L -n -v # For status Open the iptables firewall # iptables -Z # Zero the packet and byte counters in all chains # iptables -F # Flush all chains # iptables -X # Delete all chains # iptables -P INPUT ACCEPT # Open everything # iptables -P FORWARD ACCEPT # iptables -P OUTPUT ACCEPT
# ipfw show # For status # ipfw list 65535 # if answer is "65535 deny ip from any to any" the fw is disabled # sysctl net.inet.ip.fw.enable=0 # Disable # sysctl net.inet.ip.fw.enable=1 # Enable
# cat /proc/sys/net/ipv4/ip_forward # Check IP forward 0=off, 1=on
# echo 1 > /proc/sys/net/ipv4/ip_forward
or edit /etc/sysctl.conf with:
net.ipv4.ip_forward = 1
# sysctl net.inet.ip.forwarding # Check IP forward 0=off, 1=on # sysctl net.inet.ip.forwarding=1 # sysctl net.inet.ip.fastforwarding=1 # For dedicated router or firewall Permanent with entry in /etc/rc.conf: gateway_enable="YES" # Set to YES if this host will be a gateway.
# iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE # to activate NAT # iptables -t nat -A PREROUTING -p tcp -d 78.31.70.238 --dport 20022 -j DNAT \ --to 192.168.16.44:22 # Port forward 20022 to internal IP port ssh # iptables -t nat -A PREROUTING -p tcp -d 78.31.70.238 --dport 993:995 -j DNAT \ --to 192.168.16.254:993:995 # Port forward of range 993-995 # ip route flush cache # iptables -L -t nat # Check NAT statusDelete the port forward with -D instead of -A.
# natd -s -m -u -dynamic -f /etc/natd.conf -n fxp0Port forward with:
Or edit /etc/rc.conf with:
firewall_enable="YES" # Set to YES to enable firewall functionality firewall_type="open" # Firewall type (see /etc/rc.firewall) natd_enable="YES" # Enable natd (if firewall_enable == YES). natd_interface="tun0" # Public interface or IP address to use. natd_flags="-s -m -u -dynamic -f /etc/natd.conf"
# cat /etc/natd.conf
same_ports yes
use_sockets yes
unregistered_only
# redirect_port tcp insideIP:2300-2399 3300-3399 # port range redirect_port udp 192.168.51.103:7777 7777
nameserver 78.31.70.238Check the system domain name with:
search sleepyowl.net intern.lab
domain sleepyowl.net
# hostname -d # Same as dnsdomainname
# ipconfig /? # Display help # ipconfig /all # See all information including DNS # ipconfig /flushdns # Flush the DNS cache
213.133.105.2 ns.second-ns.de can be used for testing. See from which server the client receives the answer (simplified answer).
# dig sleepyowl.netThe router 192.168.51.254 answered and the response is the A entry. Any entry can be queried and the DNS server can be selected with @:
sleepyowl.net. 600 IN A 78.31.70.238
;; SERVER: 192.168.51.254#53(192.168.51.254)
# dig MX google.comThe program host is also powerful.
# dig @127.0.0.1 NS sun.com # To test the local server # dig @204.97.212.10 NS MX heise.de # Query an external server # dig AXFR @ns1.xname.org cb.vu # Get the full zone (zone transfer)
# host -t MX cb.vu # Get the mail MX entry # host -t NS -T sun.com # Get the NS record over a TCP connection # host -a sleepyowl.net # Get everything
dig, host and nslookup:
# dig -x 78.31.70.238
# host 78.31.70.238
# nslookup 78.31.70.238
named locally to resolve the hostname queries. The format is simple, for example:
78.31.70.238 sleepyowl.net sleepyowlThe priority between hosts and a dns query, that is the name resolution order, can be configured in
/etc/nsswitch.conf AND /etc/host.conf. The file also exists on Windows, it is usually in:
C:\WINDOWS\SYSTEM32\DRIVERS\ETC
# dhcpcd -n eth0 # Trigger a renew # dhcpcd -k eth0 # release and shutdownThe lease with the full information is stored in:
/var/lib/dhcpcd/dhcpcd-eth0.info
# dhclient bge0The lease with the full information is stored in:
/var/db/dhclient.leases.bge0Use
/etc/dhclient.confto prepend options or force different options:
# cat /etc/dhclient.conf
interface "rl0" {
prepend domain-name-servers 127.0.0.1;
default domain-name "sleepyowl.net";
supersede domain-name "sleepyowl.net";
}
ipconfig:
# ipconfig /renew # renew all adapters # ipconfig /renew LAN # renew the adapter named "LAN" # ipconfig /release WLAN # release the adapter named "WLAN"Yes it is a good idea to rename you adapter with simple names!
# tcpdump -nl -i bge0 not port ssh and src \(192.168.16.121 or 192.168.16.54\)Additional important options:
# tcpdump -l > dump && tail -f dump # Buffered output # tcpdump -i rl0 -w traffic.rl0 # Write traffic in binary file # tcpdump -r traffic.rl0 # Read from file (also for ethereal # tcpdump port 80 # The two classic commands # tcpdump host google.com # tcpdump -i eth0 -X port \(110 or 143\) # Check if pop or imap is secure # tcpdump -n -i eth0 icmp # Only catch pings # tcpdump -i eth0 -s 0 -A port 80 | grep GET # -s 0 for full packet -A for ASCII
-A Print each packets in clear text (without header)-X Print packets in hex and ASCII-l Make stdout line buffered-D Print all interfaces available# nmap cb.vu # scans all reserved TCP ports on the host # nmap -sP 192.168.16.0/24 # Find out which IP are used and by which host on 0/24 # nmap -sS -sV -O cb.vu # Do a stealth SYN scan with version and OS detection PORT STATE SERVICE VERSION 22/tcp open ssh OpenSSH 3.8.1p1 FreeBSD-20060930 (protocol 2.0) 25/tcp open smtp Sendmail smtpd 8.13.6/8.13.6 80/tcp open http Apache httpd 2.0.59 ((FreeBSD) DAV/2 PHP/4. [...] Running: FreeBSD 5.X Uptime 33.120 days (since Fri Aug 31 11:41:04 2007)
# tc qdisc add dev eth0 root tbf rate 480kbit latency 50ms burst 1540
# tc -s qdisc ls dev eth0 # Status # tc qdisc del dev eth0 root # Delete the queue # tc qdisc change dev eth0 root tbf rate 220kbit latency 50ms burst 1540
dummynet traffic shaper
which is configured with ipfw. Pipes are used to set limits the
bandwidth in units of [K|M]{bit/s|Byte/s}, 0 means unlimited bandwidth.
Using the same pipe number will reconfigure it. For example limit the
upload bandwidth to 500 Kbit.
# kldload dummynet # load the module if necessary # ipfw pipe 1 config bw 500Kbit/s # create a pipe with limited bandwidth # ipfw add pipe 1 ip from me to any # divert the full upload into the pipe
tc to optimize VoIP. See the full example on voip-info.org or www.howtoforge.com.
Suppose VoIP uses udp on ports 10000:11024 and device eth0 (could also
be ppp0 or so). The following commands define the QoS to three queues
and force the VoIP traffic to queue 1 with QoS 0x1e (all bits set). The default traffic flows into queue 3 and QoS Minimize-Delay flows into queue 2.
# tc qdisc add dev eth0 root handle 1: prio priomap 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 0Status and remove with
# tc qdisc add dev eth0 parent 1:1 handle 10: sfq
# tc qdisc add dev eth0 parent 1:2 handle 20: sfq
# tc qdisc add dev eth0 parent 1:3 handle 30: sfq
# tc filter add dev eth0 protocol ip parent 1: prio 1 u32 \
match ip dport 10000 0x3C00 flowid 1:1 # use server port range match ip dst 123.23.0.1 flowid 1:1 # or/and use server IP
# tc -s qdisc ls dev eth0 # queue status # tc qdisc del dev eth0 root # delete all QoS
# 2^13 (8192) < 10000 < 2^14 (16384) # ending is 2^14 = 16384 # echo "obase=16;(2^14)-1024" | bc # mask is 0x3C00
# ipfw pipe 1 config bw 500Kbit/sStatus and remove with
# ipfw queue 1 config pipe 1 weight 100
# ipfw queue 2 config pipe 1 weight 10
# ipfw queue 3 config pipe 1 weight 1
# ipfw add 10 queue 1 proto udp dst-port 10000-11024
# ipfw add 11 queue 1 proto udp dst-ip 123.23.0.1 # or/and use server IP # ipfw add 20 queue 2 dsp-port ssh # ipfw add 30 queue 3 from me to any # all the rest
# ipfw list # rules status # ipfw pipe list # pipe status # ipfw flush # deletes all rules but default
# ypwhich # get the connected NIS server name # domainname # The NIS domain name as configured # ypcat group # should display the group from the NIS server # cd /var/yp && make # Rebuild the yp databaseIs ypbind running?
# ps auxww | grep ypbind
/usr/sbin/ypbind -s -m -S servername1,servername2 # FreeBSD /usr/sbin/ypbind # Linux # yppoll passwd.byname Map passwd.byname has order number 1190635041. Mon Sep 24 13:57:21 2007 The master server is servername.domain.net.
# cat /etc/yp.conf
ypserver servername
domain domain.net broadcast
Public key | Fingerprint | SCP | Tunneling
~/.ssh/id_dsa is the private key, ~/.ssh/id_dsa.pub is the public key.~/.ssh/authorized_keys2 on your home on the server.# ssh-keygen -t dsa -N ''
# cat ~/.ssh/id_dsa.pub | ssh you@host-server "cat - >> ~/.ssh/authorized_keys2"
# cd ~/.ssh
# ssh-keygen -i -f keyfilename.pub >> authorized_keys2
# scp .ssh/puttykey.pub root@192.168.51.254:.ssh/
# cd ~/.ssh
# ssh-keygen -i -f puttykey.pub >> authorized_keys2
ssh-keygen -l to get the fingerprint (on the server):
# ssh-keygen -l -f /etc/ssh/ssh_host_rsa_key.pub # For RSA key 2048 61:33:be:9b:ae:6c:36:31:fd:83:98:b7:99:2d:9f:cd /etc/ssh/ssh_host_rsa_key.pub # ssh-keygen -l -f /etc/ssh/ssh_host_dsa_key.pub # For DSA key (default) 2048 14:4a:aa:d9:73:25:46:6d:0a:48:35:c7:f4:16:d4:ee /etc/ssh/ssh_host_dsa_key.pubNow the client connecting to this server can verify that he is connecting to the right server:
# ssh linda
The authenticity of host 'linda (192.168.16.54)' can't be established.
DSA key fingerprint is 14:4a:aa:d9:73:25:46:6d:0a:48:35:c7:f4:16:d4:ee.
Are you sure you want to continue connecting (yes/no)? yes
# scp file.txt host-two:/tmpIn Konqueror or Midnight Commander it is possible to access a remote file system with the address fish://user@gate. However the implementation is very slow.
# scp joe@host-two:/www/*.html /www/tmp
# scp -r joe@host-two:/www /www/tmp
# ssh -L localport:desthost:destport user@gate # desthost as seen from the gate # ssh -R destport:desthost:localport user@gate # forwards your localport to destination # ssh -X user@gate # To force X forwardingThis will connect to gate and forward the local port to the host desthost:destport. Note desthost is the destination host as seen by the gate, so if the connection is to the gate, then desthost is localhost. More than one port forward is possible.
# ssh -L 2401:localhost:2401 -L 8080:localhost:80 user@gate
# ssh -L 139:smbserver:139 -L 3388:smbserver:3389 user@gateThe smb share can now be accessed with \\127.0.0.1\, but only if the local share is disabled, because the local share is listening on port 139.
# ssh -R 2022:localhost:22 user@gate # forwards client 22 to gate:2022
On client cliadmin (from host to gate):
# ssh -L 3022:localhost:2022 admin@gate # forwards client 3022 to gate:2022
Now the admin can connect directly to the client cliuser with:
# ssh -p 3022 admin@localhost # local:3022 -> gate:2022 -> client:22
# ssh -R 15900:localhost:5900 user@gateOn client cliadmin (from host to gate):
# ssh -L 5900:localhost:15900 admin@gateNow the admin can connect directly to the client VNC with:
# vncconnect -display :0 localhost
PermitRootLogin yes
PermitTunnel yes
cli># ssh -w5:5 root@hserver
srv># ifconfig tun5 10.0.1.1 netmask 255.255.255.252 # Executed on the server shell
cli># ssh -w5:5 root@hserver
srv># ifconfig tun5 10.0.1.1 10.0.1.2 # Executed on the server shell
cli># ifconfig tun5 10.0.1.2 netmask 255.255.255.252 # Client is on Linux cli># ifconfig tun5 10.0.1.2 10.0.1.1 # Client is on FreeBSDThe two hosts are now connected and can transparently communicate with any layer 3/4 protocol using the tunnel IP addresses.
gateA># ssh -w5:5 root@gateB
gateB># ifconfig tun5 10.0.1.1 netmask 255.255.255.252 # Executed on the gateB shell gateB># route add -net 192.168.51.0 netmask 255.255.255.0 dev tun5
gateB># echo 1 > /proc/sys/net/ipv4/ip_forward # Only needed if not default gw gateB># iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
gateA># ssh -w5:5 root@gateB # Creates the tun5 devices gateB># ifconfig tun5 10.0.1.1 10.0.1.2 # Executed on the gateB shell gateB># route add 192.168.51.0/24 10.0.1.2
gateB># sysctl net.inet.ip.forwarding=1 # Only needed if not default gw gateB># natd -s -m -u -dynamic -n fxp0 # see NAT gateA># sysctl net.inet.ip.fw.enable=1
gateA># ifconfig tun5 10.0.1.2 netmask 255.255.255.252
gateA># route add -net 192.168.16.0 netmask 255.255.255.0 dev tun5
gateA># echo 1 > /proc/sys/net/ipv4/ip_forward
gateA># iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
gateA># ifconfig tun5 10.0.1.2 10.0.1.1The two private networks are now transparently connected via the SSH VPN. The IP forward and NAT settings are only necessary if the gates are not the default gateways. In this case the clients would not know where to forward the response, and nat must be activated.
gateA># route add 192.168.16.0/24 10.0.1.2
gateA># sysctl net.inet.ip.forwarding=1
gateA># natd -s -m -u -dynamic -n fxp0 # see NAT gateA># sysctl net.inet.ip.fw.enable=1
# rsync -a /home/colin/ /backup/colin/Same as before but over the network and with compression. Rsync uses SSH for the transport per default and will use the ssh key if they are set. Use ":" as with SCP. A typical remote copy:
# rsync -a /var/ /var_bak/
# rsync -aR --delete-during /home/user/ /backup/ # use relative (see below)
# rsync -axSRzv /home/user/ user@server:/backup/user/Exclude any directory tmp within /home/user/ and keep the relative folders hierarchy, that is the remote directory will have the structure /backup/home/user/. This is typically used for backups.
# rsync -azR --exclude /tmp/ /home/user/ user@server:/backup/Use port 20022 for the ssh connection:
# rsync -az -e 'ssh -p 20022' /home/colin/ user@server:/backup/colin/Using the rsync daemon (used with "::") is much faster, but not encrypted over ssh. The location of /backup is defined by the configuration in /etc/rsyncd.conf. The variable RSYNC_PASSWORD can be set to avoid the need to enter the password manually.
# rsync -axSRz /home/ ruser@hostname::rmodule/backup/Some important options:
# rsync -axSRz ruser@hostname::rmodule/backup/ /home/ # To copy back
-a, --archive archive mode; same as -rlptgoD (no -H)-r, --recursive recurse into directories-R, --relative use relative path names-H, --hard-links preserve hard links-S, --sparse handle sparse files efficiently-x, --one-file-system don't cross file system boundaries --exclude=PATTERN exclude files matching PATTERN --delete-during receiver deletes during xfer, not before --delete-after receiver deletes after transfer, not beforersync and ssh are available in a Windows command shell.
# ssh-keygen -t dsa -N '' # Creates a public and a private key # rsync user@server:.ssh/authorized_keys2 . # Copy the file locally from the server # cat id_dsa.pub >> authorized_keys2 # Or use an editor to add the key # rsync authorized_keys2 user@server:.ssh/ # Copy the file back to the server # del authorized_keys2 # Remove the local copyNow test it with (in one line):
rsync -rv "/cygdrive/c/Documents and Settings/%USERNAME%/My Documents/" \
'user@server:My\ Documents/'
@ECHO OFF
REM rsync the directory My Documents
SETLOCAL
SET CWRSYNCHOME=C:\PROGRAM FILES\CWRSYNC
SET CYGWIN=nontsec
SET CWOLDPATH=%PATH%
REM uncomment the next line when using cygwin
SET PATH=%CWRSYNCHOME%\BIN;%PATH%
echo Press Control-C to abort
rsync -av "/cygdrive/c/Documents and Settings/%USERNAME%/My Documents/" \
'user@server:My\ Documents/'
pause
# sudo /etc/init.d/dhcpd restart # Run the rc script as root # sudo -u sysadmin whoami # Run cmd as an other user
/etc/sudoers and must only be edited with visudo. The basic syntax is (the lists are comma separated):
user hosts = (runas) commands # In /etc/sudoers
users one or more users or %group (like %wheel) to gain the rightshosts list of hosts (or ALL)runas list of users (or ALL) that the command rule can be run as. It is enclosed in ( )!commands list of commands (or ALL) that will be run as root or as (runas)# cat /etc/sudoers
# Host aliases are subnets or hostnames. Host_Alias DMZ = 212.118.81.40/28 Host_Alias DESKTOP = work1, work2 # User aliases are a list of users which can have the same rights User_Alias ADMINS = colin, luca, admin User_Alias DEVEL = joe, jack, julia Runas_Alias DBA = oracle,pgsql # Command aliases define the full path of a list of commands Cmnd_Alias SYSTEM = /sbin/reboot,/usr/bin/kill,/sbin/halt,/sbin/shutdown,/etc/init.d/ Cmnd_Alias PW = /usr/bin/passwd [A-z]*, !/usr/bin/passwd root # Not root pwd! Cmnd_Alias DEBUG = /usr/sbin/tcpdump,/usr/bin/wireshark,/usr/bin/nmap
# The actual rules root,ADMINS ALL = (ALL) NOPASSWD: ALL # ADMINS can do anything w/o a password. DEVEL DESKTOP = (ALL) NOPASSWD: ALL # Developers have full right on desktops DEVEL DMZ = (ALL) NOPASSWD: DEBUG # Developers can debug the DMZ servers. # User sysadmin can mess around in the DMZ servers with some commands. sysadmin DMZ = (ALL) NOPASSWD: SYSTEM,PW,DEBUG sysadmin ALL,!DMZ = (ALL) NOPASSWD: ALL # Can do anything outside the DMZ. %dba ALL = (DBA) ALL # Group dba can run as database user. # anyone can mount/unmount a cd-rom on the desktop machines ALL DESKTOP = NOPASSWD: /sbin/mount /cdrom,/sbin/umount /cdrom
# openssl des -salt -in file -out file.desNote that the file can of course be a tar archive.
# openssl des -d -salt -in file.des -out file
# tar -cf - directory | openssl des -salt -out directory.tar.des # Encrypt # openssl des -d -salt -in directory.tar.des | tar -x # Decrypt
# tar -zcf - directory | openssl des -salt -out directory.tar.gz.des # Encrypt # openssl des -d -salt -in directory.tar.gz.des | tar -xz # Decrypt
Linux with LUKS | Linux dm-crypt only | FreeBSD GELI | FBSD pwd only
There are (many) other alternative methods to encrypt disks, I only show here the methods I know and use. Keep in mind that the security is only good as long the OS has not been tempered with. An intruder could easily record the password from the keyboard events. Furthermore the data is freely accessible when the partition is attached and will not prevent an intruder to have access to it in this state.dm-crypt (device-mapper) facility available on the 2.6 kernel. In this example, lets encrypt the partition /dev/sdc1, it could be however any other partition or disk, or USB or a file based partition created with losetup. In this case we would use /dev/loop0. See file image partition. The device mapper uses labels to identify a partition. We use sdc1 in this example, but it could be any string.
# cryptsetup --help, if nothing about LUKS shows up, use the instructions below Without LUKS. First create a partition if necessary: fdisk /dev/sdc.
# dd if=/dev/urandom of=/dev/sdc1 # Optional. For paranoids only (takes days) # cryptsetup -y luksFormat /dev/sdc1 # This destroys any data on sdc1 # cryptsetup luksOpen /dev/sdc1 sdc1 # mkfs.ext3 /dev/mapper/sdc1 # create ext3 file system # mount -t ext3 /dev/mapper/sdc1 /mnt # umount /mnt # cryptsetup luksClose sdc1 # Detach the encrypted partition
# cryptsetup luksOpen /dev/sdc1 sdc1
# mount -t ext3 /dev/mapper/sdc1 /mnt
# umount /mnt
# cryptsetup luksClose sdc1
# cryptsetup -y create sdc1 /dev/sdc1 # or any other partition like /dev/loop0 # dmsetup ls # check it, will display: sdc1 (254, 0) # mkfs.ext3 /dev/mapper/sdc1 # This is done only the first time! # mount -t ext3 /dev/mapper/sdc1 /mnt # umount /mnt/ # cryptsetup remove sdc1 # Detach the encrypted partitionDo exactly the same (without the mkfs part!) to re-attach the partition. If the password is not correct, the mount command will fail. In this case simply remove the map sdc1 (
cryptsetup remove sdc1) and create it again.
gbde and geli. I now use geli because it is faster and also uses the crypto device for hardware acceleration. See The FreeBSD handbook Chapter 18.6http://www.freebsd.org/handbook/disks-encrypting.html for all the details. The geli module must be loaded or compiled into the kernel:
options GEOM_ELI
device crypto # or as module: # echo 'geom_eli_load="YES"' >> /boot/loader.conf # or do: kldload geom_eli
/root/ad1.key
to attach the partition. The master key is stored inside the partition
and is not visible. See below for typical USB or file based image.
# dd if=/dev/random of=/root/ad1.key bs=64 count=1 # this key encrypts the mater key # geli init -s 4096 -K /root/ad1.key /dev/ad1 # -s 8192 is also OK for disks # geli attach -k /root/ad1.key /dev/ad1 # DO make a backup of /root/ad1.key # dd if=/dev/random of=/dev/ad1.eli bs=1m # Optional and takes a long time # newfs /dev/ad1.eli # Create file system # mount /dev/ad1.eli /mnt
# geli attach -k /root/ad1.key /dev/ad1
# fsck -ny -t ffs /dev/ad1.eli # In doubt check the file system # mount /dev/ad1.eli /mnt
# umount /mnt
# geli detach /dev/ad1.eli
# grep geli /etc/rc.conf
geli_devices="ad1"
geli_ad1_flags="-k /root/ad1.key"
# grep geli /etc/fstab
/dev/ad1.eli /home/private ufs rw 0 0
/cryptedfile of 1 GB.
# dd if=/dev/zero of=/cryptedfile bs=1M count=1000 # 1 GB file # mdconfig -at vnode -f /cryptedfile # geli init /dev/md0 # encrypts with password only # geli attach /dev/md0 # newfs -U -m 0 /dev/md0.eli # mount /dev/md0.eli /mnt # umount /dev/md0.eli # geli detach md0.eliIt is now possible to mount this image on an other system with the password only.
# mdconfig -at vnode -f /cryptedfile
# geli attach /dev/md0
# mount /dev/md0.eli /mnt
[ CA_default ]Make sure the directories exist or create them
dir = /usr/local/certs/CA # Where everything is kept certs = $dir/certs # Where the issued certs are kept crl_dir = $dir/crl # Where the issued crl are kept database = $dir/index.txt # database index file.
# mkdir -p /usr/local/certs/CA
# cd /usr/local/certs/CA
# mkdir certs crl newcerts private
# echo "01" > serial # Only if serial does not exist # touch index.txt
# openssl req -new -x509 -days 730 -config /etc/ssl/openssl.cnf \
-keyout CA/private/cakey.pem -out CA/cacert.pem
-nodes.
# openssl req -new -keyout newkey.pem -out newreq.pem \
-config /etc/ssl/openssl.cnf
# openssl req -nodes -new -keyout newkey.pem -out newreq.pem \
-config /etc/ssl/openssl.cnf # No encryption for the key
# cat newreq.pem newkey.pem > new.pemNow servernamekey.pem is the private key and servernamecert.pem is the server certificate.
# openssl ca -policy policy_anything -out servernamecert.pem \
-config /etc/ssl/openssl.cnf -infiles new.pem
# mv newkey.pem servernamekey.pem
-----BEGIN RSA PRIVATE KEY-----What we have now in the directory /usr/local/certs/:
MIICXQIBAAKBgQDutWy+o/XZ/[...]qK5LqQgT3c9dU6fcR+WuSs6aejdEDDqBRQ
-----END RSA PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
MIIERzCCA7CgAwIBAgIBBDANB[...]iG9w0BAQQFADCBxTELMAkGA1UEBhMCREUx
-----END CERTIFICATE-----
# openssl x509 -text -in servernamecert.pem # View the certificate info # openssl req -noout -text -in server.csr # View the request info
Server setup | CVS test | SSH tunneling | CVS usage
# mkdir -p /usr/local/cvsAdd a readers file if you want to differentiate read and write permissions Note: Do not (ever) edit files directly into the main cvs, but rather checkout the file, modify it and check it in. We did this with the file writers to define the write access.
# setenv CVSROOT /usr/local/cvs # Set CVSROOT to the new location (local) # cvs init # Creates all internal CVS config files # cd /root # cvs checkout CVSROOT # Checkout the config files to modify them # cd CVSROOT edit config ( fine as it is) # cvs commit config cat >> writers # Create a writers file (optionally also readers) colin ^D # Use [Control][D] to quit the edit # cvs add writers # Add the file writers into the repository # cvs edit checkoutlist # cat >> checkoutlist writers ^D # Use [Control][D] to quit the edit # cvs commit # Commit all the configuration changes
cvspserver stream tcp nowait cvs /usr/bin/cvs cvs \It is a good idea to block the cvs port from the Internet with the firewall and use an ssh tunnel to access the repository remotely.
--allow-root=/usr/local/cvs pserver
# htpasswd -cb passwd user1 password1 # -c creates the file
# htpasswd -b passwd user2 password2
Now add :cvs at the end of each line to tell the
cvs server to change the user to cvs (or whatever your cvs server is
running under). It looks like this:
# cat passwd
user1:xsFjhU22u8Fuo:cvs
user2:vnefJOsnnvToM:cvs
# cvs -d :pserver:colin@192.168.50.254:/usr/local/cvs login
Logging in to :pserver:colin@192.168.50.254:2401/usr/local/cvs
CVS password:
setenv CVSROOT string on a csh, tcsh shell, or with export CVSROOT=string on a sh, bash shell.
# setenv CVSROOT :pserver:<username>@<host>:/cvsdirectoryWhen the login succeeded one can import a new project into the repository: cd into your project root directory
For example: # setenv CVSROOT /usr/local/cvs # Used locally only # setenv CVSROOT :local:/usr/local/cvs # Same as above # setenv CVSROOT :ext:user@cvsserver:/usr/local/cvs # Direct access with SSH # setenv CVS_RSH ssh # for the ext access # setenv CVSROOT :pserver:user@cvsserver.254:/usr/local/cvs # network with pserver
cvs import <module name> <vendor tag> <initial tag>Where MyProject is the name of the new project in the repository (used later to checkout). Cvs will import the current directory content into the new project.
cvs -d :pserver:colin@192.168.50.254:/usr/local/cvs import MyProject MyCompany START
# cvs -d :pserver:colin@192.168.50.254:/usr/local/cvs checkout MyProject
or # setenv CVSROOT :pserver:colin@192.168.50.254:/usr/local/cvs # cvs checkout MyProject
# ssh -L2401:localhost:2401 colin@cvs_server # Connect directly to the CVS server. Or: # ssh -L2401:cvs_server:2401 colin@gateway # Use a gateway to reach the CVSon shell 2:
# setenv CVSROOT :pserver:colin@localhost:/usr/local/cvs
# cvs login
Logging in to :pserver:colin@localhost:2401/usr/local/cvs
CVS password:
# cvs checkout MyProject/src
# cvs import [options] directory-name vendor-tag release-tagAfter a while a new directory "/devel/tools/" was added and it has to be imported too.
# cd /devel # Must be inside the project to import it # cvs import myapp Company R1_0 # Release tag can be anything in one word
# cd /devel/tools
# cvs import myapp/tools Company R1_0
# cvs co myapp/tools # Will only checkout the directory tools # cvs co -r R1_1 myapp # Checkout myapp at release R1_1 (is sticky) # cvs -q -d update -P # A typical CVS update # cvs update -A # Reset any sticky tag (or date, option) # cvs add newfile # Add a new file # cvs add -kb newfile # Add a new binary file # cvs commit file1 file2 # Commit the two files only # cvs commit -m "message" # Commit all changes done with a message
# cd /devel/project
# diff -Naur olddir newdir > patchfile # Create a patch from a directory or a file # diff -Naur oldfile newfile > patchfile
# cd /devel/project
# patch --dry-run -p0 < patchfile # Test the path without applying it # patch -p0 < patchfile # patch -p1 < patchfile # strip off the 1st level from the path
Server setup | SVN+SSH | SVN over http | SVN usage
Subversion (SVN)http://subversion.tigris.org/ is a version control system designed to be the successor of CVS (Concurrent Versions System). The concept is similar to CVS, but many shortcomings where improved. See also the SVN bookhttp://svnbook.red-bean.com/en/1.4/./home/svn/ must exist):
# svnadmin create --fs-type fsfs /home/svn/project1Now the access to the repository is made possible with:
file:// Direct file system access with the svn client with. This requires local permissions on the file system.svn:// or svn+ssh:// Remote access with the svnserve server (also over SSH). This requires local permissions on the file system.http:// Remote access with webdav using apache. No local users are necessary for this method.# svn import /project1/ file:///home/svn/project1/trunk -m 'Initial import'The new directory "trunk" is only a convention, this is not required.
# svn checkout file:///home/svn/project1
file:// with svn+ssh/hostname. For example:
# svn checkout svn+ssh://hostname/home/svn/project1As with the local file access, every user needs an ssh access to the server (with a local account) and also read/write access. This method might be suitable for a small group. All users could belong to a subversion group which owns the repository, for example:
# groupadd subversion
# groupmod -A user1 subversion
# chown -R root:subversion /home/svn
# chmod -R 770 /home/svn
LoadModule dav_module modules/mod_dav.so
LoadModule dav_svn_module modules/mod_dav_svn.so
LoadModule authz_svn_module modules/mod_authz_svn.so # Only for access control
<Location /svn>The apache server needs full access to the repository:
DAV svn
# any "/svn/foo" URL will map to a repository /home/svn/foo SVNParentPath /home/svn AuthType Basic AuthName "Subversion repository" AuthzSVNAccessFile /etc/apache2/svn.acl AuthUserFile /etc/apache2/svn-passwd Require valid-user </Location>
# chown -R www:www /home/svnCreate a user with htpasswd2:
# htpasswd -c /etc/svn-passwd user1 # -c creates the file
# Default it read access. "* =" would be default no access [/] * = r [groups] project1-developers = joe, jack, jane # Give write access to the developers [project1:] @project1-developers = rw
import command. Import is also used to add a directory with its content to an existing project.
# svn help import # Get help for any command # Add a new directory (with content) into the src dir on project1 # svn import /project1/newdir http://host.url/svn/project1/trunk/src -m 'add newdir'
# svn co http://host.url/svn/project1/trunk # Checkout the most recent version # Tags and branches are created by copying # svn mkdir http://host.url/svn/project1/tags/ # Create the tags directory # svn copy -m "Tag rc1 rel." http://host.url/svn/project1/trunk \ http://host.url/svn/project1/tags/1.0rc1 # svn status [--verbose] # Check files status into working dir # svn add src/file.h src/file.cpp # Add two files # svn commit -m 'Added new class file' # Commit the changes with a message # svn ls http://host.url/svn/project1/tags/ # List all tags # svn move foo.c bar.c # Move (rename) files # svn delete some_old_file # Delete files
less | vi | mail | tar | dd | screen | find | Miscellaneous
less command displays a text document on the console. It is present on most installation.
# less unixtoolbox.xhtmlSome important commands are (^N stands for [control]-[N]):
mail command is a basic
application to read and send email, it is usually installed. To send an
email simply type "mail user@domain". The first line is the subject,
then the mail content. Terminate and send the email with a single dot
(.) in a new line. Example:
# mail c@cb.vuThis is also working with a pipe:
Subject: Your text is full of typos
"For a moment, nothing happened. Then, after a second or so,
nothing continued to happen."
.
EOT
#
# echo "This is the mail body" | mail c@cb.vuThis is also a simple way to test the mail server.
tar (tape archive)
creates and extracts archives of file and directories. The archive .tar
is uncompressed, a compressed archive has the extension .tgz or .tar.gz
(zip) or .tbz (bzip2). Do not use absolute path when creating an
archive, you probably want to unpack it somewhere else. Some typical
commands are:
# cd /Only include one (or two) directories from a tree, but keep the relative structure. For example archive /usr/local/etc and /usr/local/www and the first directory in the archive should be local/.
# tar -cf home.tar home/ # archive the whole /home directory (c for create) # tar -czf home.tgz home/ # same with zip compression # tar -cjf home.tbz home/ # same with bzip2 compression
# tar -C /usr -czf local.tgz local/etc local/www
# tar -C /usr -xzf local.tgz # To untar the local dir into /usr # cd /usr; tar -xzf local.tgz # Is the same as above
# tar -tzf home.tgz # look inside the archive without extracting (list) # tar -xf home.tar # extract the archive here (x for extract) # tar -xzf home.tgz # same with zip compression # tar -xjf home.tgz # same with bzip2 compression # tar -xjf home.tgz home/colin/file.txt # Restore a single file
# tar c dir/ | gzip | ssh user@remote 'dd of=dir.tgz' # arch dir/ and store remotely. # tar cvf - `find . -print` > backup.tar # arch the current directory. # tar -cf - -C /etc . | tar xpf - -C /backup/etc # Copy directories # tar -cf - -C /etc . | ssh user@remote tar xpf - -C /backup/etc # Remote copy. # tar -czf home.tgz --exclude '*.o' --exclude 'tmp/' home/
dd (disk dump) is used to copy partitions and disks and for other copy tricks. Typical usage:
# dd if=<source> of=<target> bs=<byte size> conv=<conversion>Important conv options:
notrunc do not truncate the output file, all zeros will be written as zeros.noerror continue after read errors (e.g. bad blocks)sync pad every input block with Nulls to ibs-size# dd if=/dev/hda of=/dev/hdc bs=16065b # Copy disk to disk (same size) # dd if=/dev/sda7 of /home/root.img bs=4096 conv=notrunc,noerror # Backup / # dd if /home/root.img of=/dev/sda7 bs=4096 conv=notrunc,noerror # Restore / # dd bs=1M if=/dev/ad4s3e | gzip -c > ad4s3e.gz # Zip the backup # gunzip -dc ad4s3e.gz | dd of=/dev/ad0s3e bs=1M # Restore the zip # dd bs=1M if=/dev/ad4s3e | gzip | ssh eedcoba@fry 'dd of=ad4s3e.gz' # also remote # gunzip -dc ad4s3e.gz | ssh eedcoba@host 'dd of=/dev/ad0s3e bs=1M' # dd if=/dev/ad0 of=/dev/ad2 skip=1 seek=1 bs=4k conv=noerror # Skip MBR # This is necessary if the destination (ad2) is smaller.
dd will read every single block of the partiton, even the blocks. In case of problems it is better to use the option conv=sync,noerror
so dd will skip the bad block and write zeros at the destination.
Accordingly it is important to set the block size equal or smaller than
the disk block size. A 1k size seems safe, set it with bs=1k.
If a disk has bad sectors and the data should be recovered from a
partiton, create an image file with dd, mount the image and copy the
content to a new disk. With the option noerror, dd will skip the bad sectors and write zeros instead, thus only the data contained in the bad sectors will be lost.
# dd if=/dev/hda of=/dev/null bs=1m # Check for bad blocks # dd bs=1k if=/dev/hda1 conv=sync,noerror,notrunc | gzip | ssh \ # Send to remote root@fry 'dd of=hda1.gz bs=1k' # dd bs=1k if=/dev/hda1 conv=sync,noerror,notrunc of=hda1.img # Store into an image # mount -o loop /hda1.img /mnt # Mount the image # rsync -ax /mnt/ /newdisk/ # Copy on a new disk # dd if=/dev/hda of=/dev/hda # Refresh the magnetic state # The above is useful to refresh a disk. It is perfectly safe, but must be unmounted.
# dd if=/dev/zero of=/dev/hdc count=1 # Delete MBR and partiton table # dd if=/dev/zero of=/dev/hdc # Delete full disk # dd if=/dev/urandom of=/dev/hdc # Delete full disk better # kill -USR1 PID # View dd progress (Linux only!)
# screenWithin the screen session we can start a long lasting program (like top). Detach the terminal and reattach the same terminal from an other machine (over ssh for example).
# topNow detach with Ctrl-a Ctrl-d. Reattach the terminal with
# screen -ror better:
# screen -R -DAttach here and now. In detail this means: If a session is running, then reattach. If necessary detach and logout remotely first. If it was not running create it and notify the user.
-x (on BSD) -xdev (on Linux) Stay on the same file system (dev in fstab).-exec cmd {} \; Execute the command and replace {} with the full path-iname Like -name but is case insensitive-ls Display information about the file (like ls -la)-size n n is +-n (k M G T P)-cmin n File's status was last changed n minutes ago.# find . -type f ! -perm -444 # Find files not readable by all # find . -type d ! -perm -111 # Find dirs not accessible by all # find /home/user/ -cmin 10 -print # Files created or modified in the last 10 min. # find . -name '*.[ch]' | xargs grep -E 'expr' # Search 'expr' in this dir and below. # find / -name "*.core" | xargs rm # Find core dumps and delete them # find / -name "*.core" -print -exec rm {} \; # Other syntax # find . \( -name "*.png" -o -name "*.jpg" \) -print # iname is not case sensitive # find . \( -iname "*.png" -o -iname "*.jpg" \) -print -exec tar -rf images.tar {} \; # find . -type f -name "*.txt" ! -name README.txt -print # Exclude README.txt files # find /var/ -size +1M -exec ls -lh {} \; # find /var/ -size +1M -ls # This is simpler # find . -size +10M -size -50M -print # find /usr/ports/ -name work -type d -print -exec rm -rf {} \; # Clean the ports Find files with SUID; those file have to be kept secure # find / -type f -user root -perm -4000 -exec ls -l {} \;
# which command # Show full path name of command # time command # See how long a command takes to execute # time cat # Use time as stopwatch. Ctrl-c to stop # set | grep $USER # List the current environment # cal -3 # Display a three month calendar # date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]] # date 10022155 # Set date and time # whatis grep # Display a short info on the command or word # whereis java # Search path and standard directories for word # setenv varname value # Set env. variable varname to value (csh/tcsh) # export varname="value" # set env. variable varname to value (sh/ksh/bash) # pwd # Print working directory # mkdir -p /path/to/dir # no error if existing, make parent dirs as needed # rmdir /path/to/dir # Remove directory # rm -rf /path/to/dir # Remove directory and its content (force) # cp -la /dir1 /dir2 # Archive and hard link files instead of copy # cp -lpR /dir1 /dir2 # Same for FreeBSD # mv /dir1 /dir2 # Rename a directory
# rpm -qa # List installed packages (RH, SuSE, RPM based) # dpkg -l # Debian, Ubuntu # pkg_info # FreeBSD list all installed packages # pkg_info -W smbd # FreeBSD show which package smbd belongs to # pkginfo # Solaris
# rpm -i pkgname.rpm # install the package (RH, SuSE, RPM based) # rpm -e pkgname # Remove package
# apt-get update # First update the package lists # apt-get install emacs # Install the package emacs # dpkg --remove emacs # Remove the package emacs
# pkg_add -r rsync # Fetch and install rsync. # pkg_delete /var/db/pkg/rsync-xx # Delete the rsync packageSet where the packages are fetched from with the
PACKAGESITE variable. For example:
# export PACKAGESITE=ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/packages/Latest/
# or ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/packages-6-stable/Latest/
/usr/ports/ is a collection of software ready to compile and install. The ports are updated with the program portsnap.
# portsnap fetch extract # Create the tree when running the first time # portsnap fetch update # Update the port tree # cd /usr/ports/net/rsync/ # Select the package to install # make install distclean # Install and cleanup (also see man ports) # make package # Make a binary package for the port
ldd and managed with ldconfig.
# ldd /usr/bin/rsync # List all needed runtime libraries # ldconfig -n /path/to/libs/ # Add a path to the shared libraries directories # ldconfig -m /path/to/libs/ # FreeBSD # LD_LIBRARY_PATH # The variable set the link library path
iconv can convert from
one encoding to an other.
# iconv -f <from_encoding> -t <to_encoding> <input_file>Without the -f option, iconv will use the local char-set, which is usually fine if the document displays well.
# iconv -f ISO8859-1 -t UTF-8 -o file.input > file_utf8
# iconv -l # List known coded character sets
dos2unix and unix2dos if you have them.
# sed 's/.$//' dosfile.txt > unixfile.txtConvert Unix to DOS newlines within a Windows environment. Use sed from mingw or cygwin.
# sed -n p unixfile.txt > dosfile.txt
gs (GhostScript) to jpeg (or png) images for each page. Also much shorter with convert (from ImageMagick or GraphicsMagick).
# gs -dBATCH -dNOPAUSE -sDEVICE=jpeg -r150 -dTextAlphaBits=4 -dGraphicsAlphaBits=4 \Ghostscript can also concatenate multiple pdf files into a single one.
-dMaxStripSize=8192 -sOutputFile=unixtoolbox_%d.jpg unixtoolbox.pdf
# convert unixtoolbox.pdf unixtoolbox-%03d.png
# convert *.jpeg images.pdf # Create a simple PDF with all pictures
# gs -q -sPAPERSIZE=a4 -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=all.pdf \
file1.pdf file2.pdf ... # On Windows use '#' instead of '='
# mencoder -o videoout.avi -oac mp3lame -ovc lavc -srate 11025 \
-channels 1 -af-adv force=1 -lameopts preset=medium -lavcopts \
vcodec=msmpeg4v2:vbitrate=600 -mc 0 vidoein.AVI
cdparanoiahttp://xiph.org/paranoia/ can save the audio tracks (FreeBSD port in audio/cdparanoia/), oggenc can encode in Ogg Vorbis format, lame converts to mp3.
# cdparanoia -B # Copy the tracks to wav files in current dir # lame -b 256 in.wav out.mp3 # Encode in mp3 256 kb/s # for i in *.wav; do lame -b 256 $i `basename $i .wav`.mp3; done # oggenc in.wav -b 256 out.ogg # Encode in Ogg Vorbis 256 kb/s
# lpr unixtoolbox.ps # Print on default printer # export PRINTER=hp4600 # Change the default printer # lpr -Php4500 #2 unixtoolbox.ps # Use printer hp4500 and print 2 copies # lpr -o Duplex=DuplexNoTumble ... # Print duplex along the long side # lpr -o PageSize=A4,Duplex=DuplexNoTumble ... # lpq # Check the queue on default printer # lpq -l -Php4500 # Queue on printer hp4500 with verbose # lprm - # Remove all users jobs on default printer # lprm -Php4500 3186 # Remove job 3186. Find job nbr with lpq # lpc status # List all available printers # lpc status hp4500 # Check if printer is online and queue length
# psql -d template1 -U pgsql
> alter user pgsql with password 'pgsql_password'; # Use username instead of "pgsql"
createuser, dropuser, createdb and dropdb
are convenient shortcuts equivalent to the SQL commands. The new user
is bob with database bobdb ; use as root with pgsql the database super
user:
# createuser -U pgsql -P bob # -P will ask for password # createdb -U pgsql -O bob bobdb # new bobdb is owned by bob # dropdb bobdb # Delete database bobdb # dropuser bob # Delete user bobThe general database authentication mechanism is configured in pg_hba.conf
$PGSQL_DATA_D/postgresql.conf specifies the address to bind to. Typically listen_addresses = '*' for Postgres 8.x.$PGSQL_DATA_D/pg_hba.conf defines the access control. Examples:
# TYPE DATABASE USER IP-ADDRESS IP-MASK METHOD
host bobdb bob 212.117.81.42 255.255.255.255 password
host all all 0.0.0.0/0 password
# pg_dump --clean dbname > dbname_sql.dumpBackup and restore all databases (including users):
# psql dbname < dbname_sql.dump
# pg_dumpall --clean > full.dumpIn this case the restore is started with the database postgres which is better when reloading an empty cluster.
# psql -f full.dump postgres
# /etc/init.d/mysql stop
or # killall mysqld # mysqld --skip-grant-tables # mysqladmin -u root password 'newpasswd' # /etc/init.d/mysql start
# mysql -u root mysql
mysql> UPDATE USER SET PASSWORD=PASSWORD("newpassword") where user='root';
mysql> FLUSH PRIVILEGES; # Use username instead of "root" mysql> quit
# mysql -u root mysql
mysql> CREATE DATABASE bobdb;
mysql> GRANT ALL ON *.* TO 'bob'@'%' IDENTIFIED BY 'pwd'; # Use localhost instead of % # to restrict the network access mysql> DROP DATABASE bobdb; # Delete database mysql> DROP USER bob; # Delete user mysql> DELETE FROM mysql.user WHERE user='bob and host='hostname'; # Alt. command mysql> FLUSH PRIVILEGES;
/etc/my.cnf contains the IP address to bind to. Typically comment the line bind-address = out.
# mysql -u root mysql
mysql> GRANT ALL ON bobdb.* TO bob@'xxx.xxx.xxx.xxx' IDENTIFIED BY 'PASSWORD';
mysql> REVOKE GRANT OPTION ON foo.* FROM bar@'xxx.xxx.xxx.xxx';
mysql> FLUSH PRIVILEGES; # Use 'hostname' or also '%' for full access
# mysqldump -u root -psecret --add-drop-database dbname > dbname_sql.dumpBackup and restore all databases:
# mysql -u root -psecret -D dbname < dbname_sql.dump
# mysqldump -u root -psecret --add-drop-database --all-databases > full.dumpHere is "secret" the mysql root password, there is no space after -p. When the -p option is used alone (w/o password), the password is asked at the command prompt.
# mysql -u root -psecret < full.dump
sqlite3 for a 3.x database.
# sqlite database.db .dump > dump.sql # dump # sqlite database.db < dump.sql # restore
sqlite database_v2.db .dump | sqlite3 database_v3.db
usrquota to the fstab mount options, for example:
/dev/sda2 /home reiserfs rw,acl,user_xattr,usrquota 1 1Initialize the quota.user file with
# mount -o remount /home
# mount # Check if usrquota is active, otherwise reboot
quotacheck.
# quotacheck -vum /homeActivate the quota either with the provided script (e.g. /etc/init.d/quotad on SuSE) or with
# chmod 644 /home/aquota.user # To let the users check their own quota
quotaon:
quotaon -vu /homeCheck that the quota is active with:
quota -v
options QUOTAAs with Linux, add the quota to the fstab options (userquota, not usrquota):
/dev/ad0s1d /home ufs rw,noatime,userquota 2 2Enable disk quotas in /etc/rc.conf and start the quota.
# mount /home # To remount the partition
# grep quotas /etc/rc.conf
enable_quotas="YES" # turn on quotas on startup (or NO). check_quotas="YES" # Check quotas on startup (or NO). # /etc/rc.d/quota start
edquota
for single users. A quota can be also duplicated to many users. The
file structure is different between the quota implementations, but the
principle is the same: the values of blocks and inodes can be limited. Only change the values of soft and hard. If not specified, the blocks are 1k. The grace period is set with edquota -t. For example:
# edquota -u colin
Disk quotas for user colin (uid 1007):
Filesystem blocks soft hard inodes soft hard
/dev/sda8 108 1000 2000 1 0 0
Quotas for user colin:
/home: kbytes in use: 504184, limits (soft = 700000, hard = 800000)
inodes in use: 1792, limits (soft = 0, hard = 0)
edquota -p is used to duplicate a quota to other users. For example to duplicate a reference quota to all users:
# edquota -p refuser `awk -F: '$3 > 499 {print $1}' /etc/passwd`
# edquota -p refuser user1 user2 # Duplicate to 2 users
quota (the file quota.user must be readable). Root can check all quotas.
# quota -u colin # Check quota for a user # repquota /home # Full report for the partition for all users
grep Pattern matchingsed Search and Replace strings or characterscut Print specific columns from a markersort Sort alphabetically or numericallyuniq Remove duplicate lines from a file# ifconfig | sed 's/ / /g' | cut -d" " -f1 | uniq | grep -E "[a-z0-9]+" | sort -rThe first character in the sed pattern is a tab. To write a tab on the console, use ctrl-v ctrl-tab.
# ifconfig | sed '/.*inet addr:/!d;s///;s/ .*//'|sort -t. -k1,1n -k2,2n -k3,3n -k4,4n
# cmd 1> file # Redirect stdout to file. # cmd 2> file # Redirect stderr to file. # cmd 1>> file # Redirect and append stdout to file. # cmd &> file # Redirect both stdout and stderr to file. # cmd >file 2>&1 # Redirects stderr to stdout and then to file. # cmd1 | cmd2 # pipe stdout to cmd2 # cmd1 2>&1 | cmd2 # pipe stdout and stderr to cmd2Modify your configuration in ~/.bashrc (it can also be ~/.bash_profile). The following entries are useful, reload with ". .bashrc".
# in .bashrc
bind '"\e[A"':history-search-backward # Use up and down arrow to search bind '"\e[B"':history-search-forward # the history. Invaluable! set -o emacs # Set emacs mode in bash (see below) set bell-style visible # Do not beep, inverse colors # Set a nice prompt like [user@host]/path/todir> PS1="\[\033[1;30m\][\[\033[1;34m\]\u\[\033[1;30m\]" PS1="$PS1@\[\033[0;33m\]\h\[\033[1;30m\]]\[\033[0;37m\]" PS1="$PS1\w\[\033[1;30m\]>\[\033[0m\]"
# To check the currently active aliases, simply type alias alias ls='ls -aF' # Append indicator (one of */=>@|) alias ll='ls -aFls' # Listing alias la='ls -all' alias ..='cd ..' alias ...='cd ../..' export HISTFILESIZE=5000 # Larger history export CLICOLOR=1 # Use colors (if possible) export LSCOLORS=ExGxFxdxCxDxDxBxBxExEx
# cmd >& file # Redirect both stdout and stderr to file. # cmd >>& file # Append both stdout and stderr to file. # cmd1 | cmd2 # pipe stdout to cmd2 # cmd1 |& cmd2 # pipe stdout and stderr to cmd2The settings for csh/tcsh are set in
~/.cshrc, reload with "source .cshrc". Examples:
# in .cshrc
alias ls 'ls -aF'
alias ll 'ls -aFls'
alias la 'ls -all'
alias .. 'cd ..'
alias ... 'cd ../..'
set prompt = "%B%n%b@%B%m%b%/> " # like user@host/path/todir> set history = 5000 set savehist = ( 6000 merge ) set autolist # Report possible completions with tab set visiblebell # Do not beep, inverse colors
# Bindkey and colors bindkey -e Select Emacs bindings # Use emacs keys to edit the command prompt bindkey -k up history-search-backward # Use up and down arrow to search bindkey -k down history-search-forward setenv CLICOLOR 1 # Use colors (if possible) setenv LSCOLORS ExGxFxdxCxDxDxBxBxExExThe emacs mode enables to use the emacs keys shortcuts to modify the command prompt line. This is extremely useful (not only for emacs users). The most used commands are:
Basics | Script example | sed/useful commands
The Bourne shell (/bin/sh) is present on all Unix installations and scripts written in this language are (quite) portable;man 1 sh is a good reference.
MESSAGE="Hello World" # Assign a string PI=3.1415 # Assign a decimal number N=8 TWON=`expr $N * 2` # Arithmetic expression (only integers) TWON=$(($N * 2)) # Other syntax TWOPI=`echo "$PI * 2" | bc -l` # Use bc for floating point operations ZERO=`echo "c($PI/4)-sqrt(2)/2" | bc -l`The command line arguments are
$0, $1, $2, ... # $0 is the command itself
$# # The number of arguments $* # All arguments (also $@)
$$ # The current process ID $? # exit status of last command command if [ $? != 0 ]; then echo "command failed" fi mypath=`pwd`
mypath=${mypath}/file.txt
echo ${mypath##*/} # Display the filename only echo ${mypath%%.*} # Full path without extention var2=${var:=string} # Use var if set, otherwise use string
# assign string to var and then to var2.
for file in `ls`
do echo $file done count=0
while [ $count -lt 5 ]; do echo $count sleep 1 count=$(($count + 1))
done myfunction() { find . -type f -name "*.$1" -print # $1 is first argument of the function } myfunction "txt"
MYHOME=/home/colin
cat > testhome.sh << _EOF
# All of this goes into the file testhome.sh if [ -d "$MYHOME" ] ; then echo $MYHOME exists
else echo $MYHOME does not exist
fi _EOF sh testhome.sh
#!/bin/sh # This script creates a book in pdf format ready to print on a duplex printer if [ $# -ne 1 ]; then # Check the argument echo 1>&2 "Usage: $0 HtmlFile" exit 1 # non zero exit if error fi file=$1 # Assign the filename fname=${file%.*} # Get the name of the file only fext=${file#*.} # Get the extension of the file prince $file -o $fname.pdf # from www.princexml.com pdftops -paper A4 -noshrink $fname.pdf $fname.ps # create postscript booklet cat $fname.ps |psbook|psnup -Pa4 -2 |pstops -b "2:0,1U(21cm,29.7cm)" > $fname.book.ps
ps2pdf13 -sPAPERSIZE=a4 -sAutoRotatePages=None $fname.book.ps $fname.book.pdf
# use #a4 and #None on Windows! exit 0 # exit 0 means successful
sed 's/string1/string2/g' # Replace string1 with string2 sed -i 's/wroong/wrong/g' *.txt # Replace a recurring word with g sed 's/\(.*\)1/\12/g' # Modify anystring1 to anystring2 sed '/<p>/,/<\/p>/d' t.xhtml # Delete lines that start with <p> # and end with </p> sed '/ *#/d; /^ *$/d' # Remove comments and blank lines sed 's/[ \t]*$//' # Remove trailing spaces (use tab as \t) sed 's/^[ \t]*//;s/[ \t]*$//' # Remove leading and trailing spaces sed 's/[^*]/[&]/' # Enclose first char with [] top->[t]op
sort -t. -k1,1n -k2,2n -k3,3n -k4,4n # Sort IPv4 ip addresses echo 'Test' | tr '[:lower:]' '[:upper:]' # Case conversion echo foo.bar | cut -d . -f 1 # Returns foo PID=$(ps | grep script.sh | grep bin | awk '{print $1}') # PID of a running script PID=$(ps axww | grep [p]ing | awk '{print $1}') # PID of ping (w/o grep pid) IP=$(ifconfig $INTERFACE | sed '/.*inet addr:/!d;s///;s/ .*//') # Linux IP=$(ifconfig $INTERFACE | sed '/.*inet /!d;s///;s/ .*//') # FreeBSD if [ `diff file1 file2 | wc -l` != 0 ]; then [...] fi # File changed? cat /etc/master.passwd | grep -v root | grep -v \*: | awk -F":" \ # Create http passwd '{ printf("%s:%s\n", $1, $2) }' > /usr/local/etc/apache2/passwd testuser=$(cat /usr/local/etc/apache2/passwd | grep -v \ # Check user in passwd root | grep -v \*: | awk -F":" '{ printf("%s\n", $1) }' | grep ^user$)
strcpy(newstr,str) /* copy str to newstr */ expr1 ? expr2 : expr3 /* if (expr1) expr2 else expr3 */ x = (y > z) ? y : z; /* if (y > z) x = y; else x = z; */ int a[]={0,1,2}; /* Initialized array (or a[3]={0,1,2}; */ int a[2][3]={{1,2,3},{4,5,6}}; /* Array of array of ints */ int i = 12345; /* Convert in i to char str */ char str[10]; sprintf(str, "%d", i);
#include <stdio.h>Compile with:
main() {
int number=42;
printf("The answer is %i\n", number);
}
# gcc simple.c -o simple
# ./simple
The answer is 42
*pointer // Object pointed to by pointer &obj // Address of object obj obj.x // Member x of class obj (object obj) pobj->x // Member x of class pointed to by pobj // (*pobj).x and pobj->x are the same
#ifndef IPV4_H
#define IPV4_H
#include <string>
namespace GenericUtils { // create a namespace
class IPv4 { // class definition
public:
IPv4();
~IPv4();
std::string IPint_to_IPquad(unsigned long ip);// member interface
};
} //namespace GenericUtils #endif // IPV4_H
#include "IPv4.h"
#include <string>
#include <sstream>
using namespace std; // use the namespaces
using namespace GenericUtils;
IPv4::IPv4() {} // default constructor/destructor
IPv4::~IPv4() {}
string IPv4::IPint_to_IPquad(unsigned long ip) { // member implementation
ostringstream ipstr; // use a stringstream
ipstr << ((ip &0xff000000) >> 24) // Bitwise right shift
<< "." << ((ip &0x00ff0000) >> 16)
<< "." << ((ip &0x0000ff00) >> 8)
<< "." << ((ip &0x000000ff));
return ipstr.str();
}
#include "IPv4.h"Compile and execute with:
#include <iostream>
#include <string>
using namespace std;
int main (int argc, char* argv[]) {
string ipstr; // define variables
unsigned long ipint = 1347861486; // The IP in integer form GenericUtils::IPv4 iputils; // create an object of the class
ipstr = iputils.IPint_to_IPquad(ipint); // call the class member
cout << ipint << " = " << ipstr << endl; // print the result return 0;
}
# g++ -c IPv4.cpp simplecpp.cpp # Compile in objects # g++ IPv4.o simplecpp.o -o simplecpp.exe # Link the objects to final executable # ./simplecpp.exe 1347861486 = 80.86.187.238Use
ldd to check which libraries are used by the
executable and where they are located. This command is also used to
check if a shared library is missing or if the executable is static.
# ldd /sbin/ifconfig
CC = g++
CFLAGS = -O
OBJS = IPv4.o simplecpp.o
simplecpp: ${OBJS}
${CC} -o simplecpp ${CFLAGS} ${OBJS}
clean:
rm -f ${TARGET} ${OBJS}
| Linux Documentation | en.tldp.org |
| Linux Man Pages | www.linuxmanpages.com |
| Linux commands directory | www.oreillynet.com/linux/cmd |
| Linux doc man howtos | linux.die.net |
| FreeBSD Handbook | www.freebsd.org/handbook |
| FreeBSD Man Pages | www.freebsd.org/cgi/man.cgi |
| FreeBSD user wiki | www.freebsdwiki.net |
| Solaris Man Pages | docs.sun.com/app/docs/coll/40.10 |
| Rosetta Stone for Unix | bhami.com/rosetta.html (a Unix command translator) |
| Unix guide cross reference | unixguide.net/unixguide.shtml |
| Linux commands line list | www.linuxguide.it/commands_list.php |
| Short Linux reference | www.pixelbeat.org/cmdline.html |
That's all folks!