Bash Programmierung

USEFUL THINGS:

 - tab: auto completion
 - tab 2x: list with all possibilitys
 - piping: command | commannd2: | = output send to the next command
 - command > test.txt: overwrite the output of the command in the textfile
 - command >> test.txt: append the output of the command in the textfile
 - command 2> test.txt: indicates that you are interested inredirecting only error output
 - command 2> error.txt > output.txt: combination of both commands
 - /dev/zero > /dev/sda: will erase all data on your hard drive and put zeroes there instead

 - Dash = normal user
 - Bash = root user -> more functions
 - STDIN = 0 (input)
 - STDOUT = 1 (output)
 - STDERR = 2 (errors)

COMMANDS:
 - aptitude: graphical interfaces for installed packages
    search KEYWORD: search an package with the keyword
 - cdrecord -data etherboot-net.iso
     dev=1,1,0
     -v: Speed
     -audio /folder/*.wav
 - chkconfig: for set off/on services at startup
 - dd if=/dev/cdrom of=/mycd.iso: to make a iso of the cdrom
     if: input file
     of: output file
 - df: shoes usage of harddisk space
 - dpkg: package manger database for apt-get
     -l: list all installed packages
 - dmesg | grep eth0 -> Hardware testen
 - du FILE: estimate file space
     -s: silent
 - eject: open the CD or DVD drive and eject the optical media that is currently in the drive
     -t: close the tray
 - env: Variables of the environment -> use with $variable in the shell
 - find /home -name "hosts*": shows all files that starts with hosts
     find / -user "alex": shows all files created by alex
     find / -user "alex" -exec cp {} /groups/sales \; -> exec start with the outputfiles a 2. com.
 - free: shows information about memory usage on your system
     -m: Shows in Meabyte
     -t: Shows total
 - getent passwd: zeigt passwd inkl. ldap an
 - grep TEXT: search for TEXT inside a txt document
     grep TEXT /etc/*: search in the subfolders of /etc
     ^text: searches for text at the beginning of a line
     text$: searches for text at the end of a line
     \<text: searches for text at the beginning of a word.
     text\>: searches for text at the end of a word
     -i: case insensitive
     -r: rekursiv
 - history: Shows a list of commands of the history -> to use a command: !number of command
     -c clear the history
 - less: to read files
     ls -l | less -> piping
 - ln -s ORIGINALFILE LINK: create a symbolic link
 - ls: list directory
    -d *.a: show lists of files that ends with .a
    -d [abc]*: show lists of files thet start with a, b or c
- lsmod: shows the loaded modules
- lsusb: shows the usb-connections
 - passwd: change Password of user
     -l: locks the account of a user
     -u: unlocks a locked account
     -e: Forces the user to change his or her password upon next login
 - partprobe /dev/sdb: refresh the partition informations for ther kernel -> /proc/partitions
 - ps aux: produces a list of all processes active at your server
 - ps -A: list all process status
 - man passwd: show manual about passwd
     -k test: show all manuals that have they keyword inside the manual
 - mkdir: create directory
     -p: create also subdirectory same (mkdir /same/test)
 - mount -o loop /mycd.iso /mnt: to mount an iso file in /mnt
     mount //192.168.1.100/clonezilla /home/usb -o user=silvan
     mount -t cifs -o username="wydsi1,domain=brig" //172.17.0.10/wydsi1 /mnt
     -> zuerst smbmount installieren!!! (smbfs)
     -t cifs -o username=yourname //lor/myshare /mnt: so mount a windows share
     -o remount,rw /: when system starts with errors and only read
     -t vfat: for type fat
     -t iso9660 -o loop: mount an iso-file
     -t cifs: for network connections as windows or samba
 - netstat -tulpen: produces a list of all processes that are offering network connections on your server
 - rm: remove files
     -rf remove directory with all files inside
 - smbmount //192.168.1.80/Exchange /backup/temp -o username=silvan,password=,uid=silvan
 - split –b 1000m /path/to/large/file /path/to/output/file/prefix
     cat prefix* > NEWFILENAME: for unspliting
 - su: switch user -> ohne user wird root genommen
 - tar
     -c: create archive
     -C: change to directory DIR
     -f: .tar file
     -g: create snapshot file for incremental backups
     -j: bz2
     -t: list content of archive
     -x: extract archive
     -z .gz
    
     -xf blah.tar: extract blah.tar
     -jxf: for .bz2 files
     -zxf: for .gz files
     -cf somefile.tar /somedirectory: make
     tar -czvg /backup/snapshot-file -f /backup/full-backup.tar.gz /home -> for incrementel backup
     tar c . | tar xC /home/test : copy all files from DIR (.) to /home/test
 - trail FILE -> show last 10 lines (rows) of a file
 - useradd USER
     -m: create Home folder -> when forget this option -> /etc/skel
     -e YYYY-MM-DD: expiration date of the user
     -G: add additional groups to the default (/etc/default/useradd)
     -g: sets the primary group of a us
 - userdel: doesn't delete the home folder
     -r: deletes also the home folder!
     -rf: deletes also the files that aren't owned by the person to delete
 - usermod
 - vol_id: shows informations about volumes
 - w3m: to show html files in w3m browser
 - who: displays a list of users currently logged in
 - wodim: for burning cd's
     --scanbus: shows the devices
 - zcat changelog.gz | less: to read .gz files in /usr/share/doc