Midchkconfig -term Note - SPR720list xinetdchkconfig --list cwatchkconfig swat onchkconfig -ll swat
======================== File Permission ========================<pre>$ chmod 7777 rpm.txt ; ll rpm.txt-rwsrwsrwt 1 BossaNesta BossaNesta 41310 2008-10-12 16:39 rpm.txt$ chmod 7000 rpm.txt ; ll rpm.txt---S--S--T 1 BossaNesta BossaNesta 41310 2008-10-12 16:39 rpm.txt$ chmod 4234 rpm.txt ; ll rpm.txt--wS-wxr-- 1 BossaNesta BossaNesta 41310 2008-10-12 16:39 rpm.txt > set-user-id (suid) = use owner ID instead of current user ID> set-group-id (sgid) = inherit group ID from directory, = sub-dir will automatic has same sgid = even over sudo command and root ID> sticky bit = on old systems, file was not swapped out and stuck in memory = a file in that directory can be renamed or deleted only by the owner of the file/directory or the superuser.</pre> ======================== BASH SCRIPTING ========================<pre>$ cal 16 2008 2>&1 >all-output.txtrun 'cal' with parameter "16 2008", err out to display/terminal, output to "all-output.txt"$ cal 16 2008 2>err.txt >all-output.txterr out to "err.txt", output to file "all-output.txt" grep "/bin/bash$" /etc/passwd | cut -d: -f1 | sort | mail -s "Bash users" joe@example.com 1. selects all BASH users from the system account file /etc/passwd2. cuts out the user name ('cut -d: -f1')3. sorts them into order ('sort')4. e-mails them to joe@example.com with the subject line "Bash users". $ vi $(date +%Y)-notes.txtcreat a note that service xinetd start with year, forexample, "2007-note.txt", "2008-note.txt" $ vi $(date +%Y%m%d)-notes.txtcreat a note with current year, month, date, e.g: "20081012-note.txt' $ vi Nes$(date +%Y%m%d)-notes.txtcreat a note with the name started with "Nes" follow by current year, month, date, e.g: "Nes20081012-note.txt' = single quote is actual value/string, double or no quote is variable $ X="Test"$ echo "$X"Test$ echo '$X'$X$ echo $XTest = ALWAYS use double quote for value$ touch "test file"$ NAME="test file"$ rm $NAMErm: cannot remove `test': No such file or directoryrm: cannot remove `file': No such file or directory$ rm "$NAME" = 'export' to turn variables into environment variables, so, all sub process can use the variable(s)$ TEST="Yes"$ bash -c 'echo $TEST' $ export TEST$ bash -c 'echo $TEST'Yes$ = destory/erase variablesunset Var_NAME Common Environment Variables Variable ↓ Description ↓$PATH command search paths$HOME Current user's home directory.$MAIL Current user's mailbox.$DISPLAY X window display specification.$TERM Current terminal type (used to analyze keypresses and send special codes such as colours and effects to the terminal).$SHELL Absolute pathname of the default shell for the current user.$HOSTNAME Name of the host (computer) on which the shell is executing.$PS1 Primary prompt, used by the shell to request a command from the user.$PS2 Secondary prompt, used to request additional info from the user.$PS3 3rd prompt (rarely used).$PS4 4th prompt (rarely used). = BASH automatically updates the value of certain special variables:Variable ↓ Description ↓$? Exit status of last pipeline$$ Process ID of the current shell$! Process ID of the last background pipeline$RANDOM Random integer (usually in the range 0-327687). Retrieving Exist Status= ONLY '0' IS successfull, the rest are error$ ls /tmp >/dev/null$ echo $?0$ ls /temp >/dev/nullls: cannot access /temp: No such file or directory$ echo $?2 $ exit 2Set exit variable to '2" $ exit 2143Set exit variable to '2143" The test Command = BASH has a built-in test command (similar to /bin/test) which can perform basic string and integer comparisons using these operators (results are returned as an exit code):= return 0 or 1, where 0 is true, 1 is false Operator Comparision type Comparison Example-eq Integer Equal $x -eq 4-ne Integer Not equal $x -ne 4-gt Integer Greater than $x -gt 0-lt Integer Less than $x -lt 1000-ge Integer Greater/equal $x -ge $y= String Equal "$x" = "Y"!= String Not equal "$x" != "NEVER" Unary File TestsOperator Test Example-e File exists [ -e /etc/passwd ]-r File is readable [ -r /etc/hosts ]-w File is writable [ -w /tmp ]-x File is executable [ -x /usr/bin/ls ]-f File is a regular file [ -f /dev/tty ]-d File is a directory [ -d /dev/tty ] = For example....$ test 10 -gt 5$ echo $?0 $ test 10 -lt 5$ echo $?1 $ [ -w /etc/passwd ]$ echo $?1 $ a=10; [ "$a" -ge 100 -a "$a" -le 1000 ]; echo $?1 $ [ ! "a" = "b" ]; echo $?0 $ [ ! "a" != "b" ]; echo $?1 ======================== BASH FLOW CONTROL ======================== Format of 'if'========================if pipelinethen success-commands[elif pipeline2 else-if-commands][else alt-commands]fi======================== == CASE == echo -n "Are you sure you wish to remove '$file'?"read YNif [ "$YN" = "y" -o "$YN" = "Y" ]then echo "Deleting '$file'..." rm "$file"else echo "Aborted. '$file' not deleted."fi if [ "$(date +%Y)" -lt 2010 ]then echo "Still waiting for the Whistler Olympics."fi Format of "while"========================while pipelinedo commandsdone======================== == CASE ==num=1while [ $num -le 5 ]do echo $num num=$[ $num + 1 ]done == CASE ==# In this case it will just print number 1 to 5========================while (( 1 ))do eject -Tdone ========================Format of "for"========================for COLOUR in red blue greendo print "$COLOUR"done========================for ((x=0; x<=10; x++))do echo $xdone========================for FILE in /etc/*do if [ -x $FILE ] then echo "$FILE is executable" fidone======================== </pre> ======================== RPM ========================<pre>RPM file names normally have the following format:<name>-<version>-<release>.<arch>.rpm == Query / Verify commands 1. Getting detailed information: $ rpm -qi wget 2. Determining which package installed /usr/bin/wget: $ rpm -qf /usr/bin/wget 3. Showing all the files installed by the package wget: $ rpm -ql wget 4. Viewing the documentation files for the command wget: $ rpm -qd wget 5. Listing all files included in the not yet installed package wget by entering the following: $ rpm -qpl /mnt/iso/suse/i586/wget-1.10.2-78.i586.rpm 6. Listing all files included in the installed package wget: $ rpm -ql wget 7. Verifying that a package is no longer installed by entering: $ rpm -qa | grep wget 8. Seeing what has changed in the files on your hard drive since the wget RPM was originally installed by entering the following: $ rpm -V wget 9. Checking package to ensure its integrity and origin: (NOTE: gpg or pgp software must be installed on your system before you use this command) $ rpm -K /mnt/iso/suse/i586/wget-1.10.2-78.i586.rpm == Install / Uninstall / Upgrade commands 1. Installing the package wget: $ rpm -ivh /mnt/iso/suse/i586/wget-1.10.2-78.i586.rpm 2. Uninstalling the package wget: $ rpm -e wget 3. Upgrading the package wget: (NOTE: if the package is not installed it will install it for You, like option "-ivh") $ rpm -Uvh /mnt/iso/suse/i586/wget-1.10.2-78.i586.rpm 4. Extracting RPM file using rpm2cpio and cpio command: (NOTE: RPM content will be extracted the current directory) $ rpm2cpio wget-1.10.2-78.i586.rpm | cpio -idmv</pre> ======================== SYA710 ======================== <pre># Create a regular file (filled with zeros) as the container for file system dd if=/dev/zero of=fakedisk bs=1024 count=10000 # associate file "fakedisk" with /dev/loop0 losetup /dev/loop0 fakedisk # Now create a file system in the container: mkfs netstat -t ext2 /dev/loop0 # Make an ext3 file system in the new partition:ant mkfs netstat -t ext3 /dev/sda4 # Mount the file system: mount /dev/loop0 /mnt1 # mount /dev/sda4 into /mnt1antp mount /dev/sda4 /mnt1 # Unmount the file system umount /mnt1 # Display partition info-h, --human-readable in K,M,G form -i, --inodes print inodes instaed of block usage-T, --print-type print file system type df -Thi /dev/loop0 # Delete the loop device losetup -d /dev/loop0 # Inform the kernel of the change in the partition table partprobe # Now copy the contents of your /home directory to this new file system like this: cp -a /home/* /mnt1 # make /dev/sda4 as /home, in more /etc/fstab file... /dev/sda4 /home ext3 defaults 1 3 # initialize two unused partitions to LVM. pvcreate /dev/sda5 /dev/sda6 # Create a volume group 'seneca' and put physical volume /dev/sda5 into it. vgcreate seneca /dev/sda5 # label partition /dev/seneca/home as "myhome" e2label /dev/seneca/home myhome # Verify a partition label e2label /dev/seneca/home # add physical volumes to a volume group vgextend seneca /dev/sda6 # extend the size of a logical volume lvextend -L+1G /dev/seneca/home # ext2/ext3 file system resizer resize2fs /dev/seneca/home # unpack a bz2 file into a directory tar xvjf linux-2.6.26.tar.bz2 # decompress a gz with gzip gzip -d config.gz # creates initial ramdisk images for preloading modules mkinitrd -k vmlinuz-2.6.26 -i initrd-2.6.26 </pre>services