IT FAQ & How-to ...

... Of course, this page is still very small and there are much better at the web.
But, It is based on my own experience and I try to improve it step by step. ...

This little IT FAQ corner is (more or less) in frozen state currently as I found out that the utilized coding style is unusable for future extension and improvement. It's just one of my newcomer's sins. - However, there should be a re-implementation until June 2005! - In the meantime, you could use it "as it is" when you'd like. (All FrontPage issues are taken out as I stopped using this tool.) 


Main Issues

  • OS Issues for Unix (Linux, Solaris, etc.)
  • OS Issues for Windows 2000 & NT 4.0
  • Windows to Linux Migration
  • Programs for MS Windows
  • Programs for Unix
  • RDBMS Issues for Oracle
  • Internet FAQ
  •  
    Last Update: 15.03.2003


    Windows to Linux Migration


    Migration of Mozilla (1.0 or above) User Data from Windows to Linux

    Preparation at Windows & Linux

  • Backup at Windows: Before starting the migration itself, a backup of all Mozilla user data should be made. It might be needed in case of any problems or mistakes.
  • Linux: Download and install a recent Mozilla version on need. Initial set-up work: Internet access of the browser, configure and check the needed email accounts, other basic configuration and settings.
  • Navigator: Bookmarks

    Windows: The bookmarks are exported as following:

  • Choose the Bookmarks > Manage Bookmarks ... menu command. A window opens that has a title "Bookmarks for user". There, choose the Tools > Export... menu command.
  • Then, browse through the file system and save the bookmark file at a approprate directory, which should be accessable by the Linux system. After, the bookmark management window can be closed.
  • Linux: The bookmarks are imported as following:

  • Choose the Bookmarks > Manage Bookmarks ... menu command. A window opens that has a title "Bookmarks for user". There, choose the Tools > Import... menu command.
  • Then, browse through the file system and open the bookmark file, which was exported in Windows. After, the bookmark management window can be closed.
  • Navigator & Messenger: Helper Applications

    Both, at Linux as well as at Windows, it is easily feasible to open:

  • email file attachements and
  • HTML page links to none HTML files
  • automatically or by double click respectively.

    This might be typically done for:

  • text files, e.g., MS Words (*.doc)
  • presentations, e.g., MS Powerpoint (*.ppt)
  • tables, e.g., MS Excel (*.xls)
  • Adobe PDF files (*.pdf)
  • Zip archives (*.zip)
  • How could this be done:

  • Double click at the email attachement in order to open it. This causes the following window to appear:
    Mozilla window: downloading 1 / begin
  • Choose an appropriate application:
    Mozilla window: downloading 2 / choose application
  • The result is:
    Mozilla window: downloading 3
  • Open the advanced window and fill it:
    Mozilla window: downloading 4 / advanced
  • Deselect the "Always ask before opening this type of file" option when you like:
    Mozilla window: downloading 5 / deselect asking
  • Now, it should be feasible to open applications of this type directly.
    The Mozilla preferences window shows the already set MIME type mappings as following:
    Mozilla window: downloading 6 / current MIME types
    Needed corrections and additional settings can be made here.
  • Messenger: Existing Emails

    Mail folders / directories can be directly copied by operating system commands:

    Windows: Prepare the transfer

  • It might be recommended to excute all email transfer using the local email folder.
    Therefore, all account-specific folder entries should be moved to the local folder and it's sub folders via drag & drop.
  • Next, find out where the mail directory is on HD: Klick at the "Local Folders" main folder.
    Then, follow the link "View settings for this account". This opens the window Mail & Newsgroups Account Settings.
    Read the "Local Directory" field. - Example: "C:\... /Mail/Local Folders"
  • Linux: Copy the folders into the right destination directory

  • Klick at the "Local Folders" main folder. Then, follow the link "View settings for this account".
    This opens the window Mail & Newsgroups Account Settings.
  • Read the "Local Directory" field and choose anouther directory if needed.
    Example: "/home/petzi/.mozilla/petzi/z82nscaw.slt/Mail/Local Folders"
  • Copy yout existing Windows Emails directories to this directory. This could even be done simply by Konqueror using drag & drop.
  • Go to the "Local Folders" top directory and correct the file permissions: "chmod -R u+rw ." Done.
  • Address Book

    Export in Windows:

  • Klick at the "Tools > Export..." menu command.
  • Choose to export as ldif text file and browse for a propriate path.
    Do not forget to type the "ldif" file name extension in order to get no problems later.
  • Import in Linux:

  • Klick at the "Tools > Import..." menu command.
  • Select the "Address Book" radio button.
  • Choose to import an ldif text file, browse for the file and import it.

  • ...... to be continued ......


    OS Issues for Windows 2000 / NT 4.0


    Explorer: How to configure it in order to display hidden files, all sort of extensions and the full path?

    Select "Ansicht" (View) -> "Optionen" (Options) from the menu commands and make the following settings:

    Hidden files

    Ä   Alle Dateien anzeigen
    File extensions O   Keine Erweiterungen für registrierte Dateien
    Path Ä   Vollständiger Pfad in Titelleiste
    Title Bar Ä   Beschreibungsleiste für beide Fensterinhalte anzeigen

    How to get a screen shot in MS Windows? 
    from the active window:   press the ALT key together with the PRINT key
    from the full screen:  press the PRINT key only

    Then the result can be used in a lot of applications via the "Edit" => "Paste" ("Bearbeiten" => "Einfügen") command.


    Dynamic IP address: How to find out which is the active address and how to get a new one?

    Open the MS-DOS window a type the command "ipconfig" in order to display the existing address and type "ipconfig /renew" when there is the need to get a new one.


    OS Issues for Unix


    ASCII Code: Where can I find a list? Which code is BEL (the beep)?

    Execute "man ascii" for the full list. The beep is "\007".  In order to get a long beep, type the command:  echo "\007\007\007".


    Backspace: How to make the Backspace key working in the Unix command line?

    When you have bad luck with your Unix stty settings, your <Backspace> keystroke will not work in the Unix command line, i.e., you will get a "^H" string instead of the needed functionality.
    Temporarily, you can fix this by entering the following command: "stty erase <Backspace>". [Please, notice that "<Backspace>" is written for the backspace keystroke here!] But latest after your next login, the old problem will appear again.
    Hence, you should better put the command into one of your persistent settings. For instance, the ".kshrc" file is a appropriate location for the ksh. 
    Now, there is the next problem. When you try to edit the file via the good old "vi" command, the backspace will work. That means, that there is no direct chance to write the needed "stty erase <Backspace>" command successfully. Further, the attempt to use the backspace ASCII code "\008" instead of the backspace keystroke does not work as expected. - Finally, how to go around this additional problem?
    First, open a new shell and let your <Backspace> problem as it is for the moment. Instead, type the following command: 
          "echo 'stty erase <Backspace>'  >/tmp/myback". 
    Open your destination file via "vi" command. Go to the line where you want to put your stty command and import the temporary file via ":r /tmp/myback". This displays the needed command line "stty erase ^H" whereby the "^H" is actually the "<Backspace>" key.
    Now you can re-open the shell, for instance via "ksh". The problem should be fixed.


    How to find out IP addresses?

    One possibility is via nslookup command. For instance: "nslookup `hostname` " tells the IP address of the current host.


    How to access files that have special, difficult file names, the * character for instance?

    The file name is a string with only a very small number of restrictions in UNIX. Under certain circumstances there may exist very unusual files or paths, which are not easy to access. They may be created by a wrong input (* or a blank as file name are not too seldom) or may be wanted for certain purposes (packaging for instance). - The upcoming question is how to access them.
    In most of the cases, it is helpful to put them into apostrophes. For instance:

    rm *             # removes all files of the working directory rm '*'             # removes a single file which is named *
    vi                 # edits a nameless file vi ' '               # edits a file with a single blank as file name
    vi xx yy        # edits two files, xx and yy vi 'xx yy'        # edits only one file, whose name is xx blank yy
    cd $PATH   # resolve the PATH variable
                          and then go to the contained directory
    cd '$PATH'   # go the directory with $PATH as name, i.e., 
                            the $PATH will not be resolved by the shell 

    In the case that the file name itself contains apostrophes: Try double quotas or escape them via backslash.
    Take care that the ls command does not show any not printable characters. In such problem cases, it may help to combine sub strings with wildcards, for instance *sureString* or sure1*sure2.


    How to reboot a host immediately?

    Login as root and execute the command:   shutdown -i6 -g0 -y
    This is normally better than the reboot command as it takes care about the shutdown / startup sequences.


    How to mount a CD on Solaris?

    Example: 

    1st local mount -F hsfs -o ro /dev/dsk/c0t6d0s0 /cdrom
    share -F nfs -o ro -d "TEXT" /cdrom
    2nd remote mount -F nfs serverName:/cdrom /cdrom

    What are the most important share commands at Solaris?

    vi /etc/dfs/dfstab
    unshareall
    shareall
    showmount -e

    How to set the sticky bit?

    Example: 

    chmod 7655 filename result:  - rwS r-s r-x
    chmod 755 filename; chmod ug+s filename result:  - rws r-s r-x

    See "man chmod" in order to get more details!

     


    Programs for Microsoft Windows


    Where are my LRU (last recently used files) entries for Office?

    For instance in:  D::\WINNT\Profiles\Administrator\Anwendungsdaten\Microsoft\Office\Zuletzt verwendet


    Word: How can be avoided that MS Word changes such strings like "Oracle 8i" or "Oracle 9i" into "Oracle 8I" and "Oracle 9I"?

    The problem is a single setting within Word's Autocorrect feature, i.e., for the English word "I". The "9i" seams to be "9" times "I" for the MS people. Hence, this problem is related to the English language settings.
    How to go around? - Select "Autocorrect" from the "Tools" menu command. Then put "i" into the "Replace" text field. You should see that "i" is replaced be "I". Click the "Delete" button in order to remove this entry now. - This should have solved the problem.


    Word: How to use hyperlinks and bookmarks in word documents?

    From Word 97 on, hyperlinks are supported. 
    For internal links within a word document, first bookmarks need to be set before they can be used as link destinations.

    1st. To set a bookmark: First set the cursor to the text location where the bookmark should be set. After, choose Insert => Bookmark...  (german version: Einfügen => Textmarke) from the menu commands. An input window comes up where the name of a new bookmark must be typed in.

    2nd. Create a hyperlink, which may point to a bookmark: At first, don't forget to select the text where the hyperlink should be placed. Then, choose Insert => Hyperlink... (german version: Einfügen => Hyperlink) from the menu commands. An input window comes up whose appearance is Word version dependant. 
    Word 97: There should be an input field as "Named location in file (optional)". There, the bookmark name can be typed. Additionally, there is a "Browse" button.
    Word 2000: Click on the button for the current document. Then, select the needed bookmark and click the Okay button.


    Programs for Unix


    tr: How can a string be converted to upper case or lower case?

    Use the Unix "tr" command. - Examples: 
        cat yourFile | tr '[a-z]' '[A-Z]'    # converts to upper case
        cat yourFile | tr '[A-Z]' '[a-z]'    # converts to lower case
    It is strongly recommended to write the single quotation marks. Although, it may work without too. Without the apostrophes, you will get a bad surprise when you have a file named "t". This is no joke, but Unix.


    gtar: How to create and use compressed tar files?

    At first, the "gtar" command should be preferred instead of the "tar" command because it avoids tar limitations as the maximum path length for instance.
    Further, you should prefer relative paths because they are more flexible in use.
    The "z" flag is the option for the compression. Take care that the "f" option must be the last written option because it needs to be followed by the file name as parameter.
    Example:  Pack:       gtar -cvzf yourFileName.gtar.gz ./yourSourceDirectory
                   Contents:  gtar -tvzf yourFileName.gtar.gz
                   Unpack:   gtar -xvzf yourFileName.gtar.gz


    cvs: What are some of the most frequently needed options?

    Examples:

    cvs add fileName  adds a file to cvs
    cvs delete fileName  removes a file from cvs
    cvs status -v fileName  displays the the cvs file status including all valid tags
    cvs commit  makes all changes of the current directory and its subdirectories persistent 
    cvs rtag -RF newFlag moduleName  sets a new flag for a cvs module
    cvs export -f -r flagName moduleName  checks a cvs module out for reading only, whereby the given flag is taken
    cvs export -f -r HEAD moduleName  checks a cvs module out for reading only, whereby the newest flag is taken

     


    grep: How to search for lines that contain apostrophes?

    It is quite easy:   grep "'" fileName


    grep / find: How to search for a string in all or certain files of a directory tree?

    Examples:

    find startDirectory -type f | xargs grep 'searchString'
    grep 'searchString' `find startDirectory -name "fileName" `

    RDBMS Issues for Oracle


    What is the easiest way to clean-up Shared Memory and Semaphores?

        0) Shutdown all database instances when possible.
        1) The "ipcs -a" command displays the remaining shared memory and semaphore entries together with their key.
             Interesting are those only that belong to the Oracle user.
        2) The "ipcrm -m memKey" command allows to clean-up unwanted shared memory entries.
        3) The "ipcrm -s semKey" command allows to clean-up unwanted semaphores.


    What is the total Buffer Cache size and how to find out the single cache sizes?

    Total Buffer Cache size = DB_CACHE_SIZE + DB_KEEP_CACHE_SIZE + DB_RECYCLE_CACHE_SIZE + DB_2K_CACHE_SIZE + DB_4K_CACHE_SIZE + DB_8K_CACHE_SIZE + DB_16K_CACHE_SIZE + DB_32K_CACHE_SIZE

    They can be read from SQL Plus via the "show parameter cache_size" command.


    SQL*Plus: How can "vi" be defined as editor for SQL*Plus in UNIX?

    Enter the following commands before starting SQL*Plus:   VISUAL=vi; export VISUAL
     


    SQL*Plus: What is the glogin.sql default path?

    $ORACLE_HOME/sqlplus/admin.


    SQL: Which SQL query tells me the database SID?

    SELECT value FROM v$parameter where name = 'db_name';
     


    Internet FAQ


    Table frame colors, Internet Explorer versus Netscape: How to set table frame colors?

    Here is the problem that Netscape and Internet Explorer interpret the HTML in a different way:
    Internet Explorer: Uses the light / dark frame color and ignores the normal frame color.
    Netscape:            Uses the normal frame color and ignores the light / dark color. Derives this colors from normal frame.


    Netscape: Table background color: Why don't I get my cell background color within a table as expected although it looks fine in FrontPage and the saved HTML seams to be OK?

    It seams to be a Netscape bug, the problem is not with IE 4.5. Here, I suggest to avoid the following constellation for Netscape: 
    1st
    , a background image in the page properties (Of course, it's a must). 2nd, a further background image in the table properties (Although, it's very useful). 3rd, the attempt to overwrite single cell backgrounds by an own background color. 
    This might be the thing that fails in the browser. Additionally, everywhere a cell has such a problem, any included table at a lower hierarchy seams to have the same color problem.
    Workaround, for such kind of problems: The principle is to avoid the replacement of a table or cell background image by a background color, using the normal method. For instance:
    Method A (my favorite): 1st, once only, define a small image file (for instance a 1 * 1 pixel GIF file) which contains the needed color. 2nd, assign the needed background image in the table properties as wanted. 3rd, assign the extra-built color image file to the single cells instead of a background color.
    Method B (works, but not recommended): 1st, use the background image in the page properties as needed. 2nd, avoid the background image in the table properties. Workaround for 2nd: Apply the background image to all (single) cells of the table. 3rd, you can overwrite the single cell backgrounds by an own background color where you want. - Naturally, this solution is not actual elegant. The main problem with this solution are: Sad performance on enforced full page reload (because the bloody Netscape reads number of table cells times the background file!) and the HTML code is blown up by the single background references.


    Netscape: Table background image: How to apply a background image to a table with a fine performance?

    The problem is that is may take ages until Netscape has set the background image to a table. The reason is that Netscape reads the image file into each single table cell. Thereby, it does not matter if the background image is set via the table or the cell properties.
    Workaround: Put the original table into an additional single-cell wrapper table (border=0). Then, apply the background image to the the wrapper table instead of the original table. Then, Netscape reads the background image file once only in this case, which solves the problem!


    File Names: How to name files for uploads to the Web?

    In principle, feasible file names depend on the provider of the homepage space. However, there might be some general recommendations:

  • File names must follow the Windows file name restrictions and the Unix file name restrictions as well. This is needed as the provider very often uses Unix hosts in order to store the pages. But, most users access via a Windows (or Macintosh) system.
  • That means also, care must be taken about upper and lower case characters in the file names. With other words, "Index.htm" and "index.htm" are different files at a Unix host.
  • Another sort of problem is introduced by the browsers. I found out that "Netscape 6.2" does not support file names containing special characters like "ä", "ö", "ü", "ß". Of course, this should be a serious Netscape bug. However. Hence in order to be sure, it might be a good idea to avoid the usage of all characters, except "a" - "z", "A" - "Z", "0"-"9", "." and "_".