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This sucks, Open office 2.3 spreadsheet cannot open or import text files that are larger than 65,536 rows. Basically, I need 100k rows. However, it is possible to recompile OO to extend rows limitation. From the OO wiki hack page:

Well, it depends on what your goal is. For personal use you may set MAXROWCOUNT_DEFINE in sc/inc/address.hxx to a different value, multiple of 128, and recompile the application respectively the libsc680*.so and shove it under your existing installation. However, doing so implies that you don't save to any binary file format like Excel or whatsoever, otherwise you risk loss of data. You'll also encounter drawing layer misfits in higher row numbers, may experience performance problems, and there may be other quirks lurking. Note that it generally works for data and formulas, but otherwise is completely untested.

For the number of columns the same applies to the MAXCOLCOUNT_DEFINE in sc/inc/address.hxx, just that the value must be a multiple of 16 instead.

My text file is truncated at 65,536 and I was dumped with the following error message:
Text files that are larger than 65,536 rows cannot be imported

I'm going to recompile my OO. Another good option is using MySQL. However, I'm not in mood to write a php / python scripts to just create graphs and other stuff.

Reboot Linux box after a kernel panic

If you want the server to get rebooted automatically after kernel hit by a pain error message, try adding panic=N to /etc/sysctl.conf file.

It specify kernel behavior on panic. By default, the kernel will not reboot after a panic, but this option will cause a kernel reboot after N seconds. For example following boot parameter will force to reboot Linux after 10 seconds.
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Restrict the use of su command

su is used to become another user during a login session. Invoked without a username, su defaults to becoming the super user. The user will be prompted for a password, if appropriate. Invalid passwords will produce an error message. All attempts, both valid and invalid, are logged to detect abuses of the system.

By default almost all distro allows to use su command. However you can restrict the use of su command for security reasons.

Both UNIX and Linux have a group called wheel. If user is member of this group she can use su command. We can add user to this group.

For example add existing user rocky to wheel group
# usermod -G wheel rocky

Now open /etc/pam.d/su PAM config file:
# vi /etc/pam.d/su
Append line as follows:
auth required /lib/security/pam_wheel.so use_uid
auth required pam_wheel.so use_uid

Save and close the file.

Because of above setting only members of the administrative group wheel can use the su command. However I still recommend sudo over su for better control, security and ease of use. This is also default behavior on FreeBSD.