Focus-follows-mouse coupled with the disabled Raise-on-focus window property is a mode of operation for a window manager, highly targeted at the professional use, unheard of in the Microsoft Windows world. Yet, it takes some fine configuration tweaks to get it to the prime-time. Read More
Every time I need to mention some automation development work while talking to a client, I find myself overly watchful not to say the words “scripting” or “script” excessively. That’s how much of “sloppiness” is felt to be connotative to those terms in the public opinion.
Ergo, you can see how glad I was to find in the Chapter 7 of the “UNIX and Linux System Administration Handbook” this understanding that
There’s no real distinction between “scripting” and “programming.” Language developers sometimes take offense when their babies are lumped into the “scripting” category, not just because the label suggests a certain lack of completeness, but also because some scripting languages of the past have earned reputations for poor design.
Of course, the importance of scripting cannot be overestimated as it is the main mediator in performing administrative changes reliably, in a consistent and repeatable manner, which are so important in the system administrator’s job as in no other “soft” profession.
Speaking of the subtle differences between “scripting” and “programming”, one could point out the issue of computing system efficiency. Indeed, “scripted” procedures are often several times “slower” than “programmed” counterparts. Administrative work, however, is more about the effectiveness of the administrator, which is the efficiency of the binding administrator+computing_system. As the book authors put it,
Optimization can have an amazingly low return on investment, even for scripts that run regularly out of cron.
Which is more significant out of the two Linus Torvalds’ biggest invetions: Linux kernel of Git? – another great question from the book. On one hand, Linux (albeit not the kernel alone) in this very 5th edition of the book has ousted all the other Unix systems of other editions, including commercial ones – so, perhaps it is quite important. On the other hand,
Mistakes are a fact of life.
That’s another great sysadmin’s dilemma: do you do updates often, trying to keep your systems at the “cutting edge” and have all the security patches upplied immediately upon official release, or do you roll the updates out as discretely as possible, not trying to fix something that’s not [still] broken? That, and the fine topic of PXE, is discussed in the Chapter 6 of the “UNIX and Linux System Administration Handbook”.
On one hand,
gratuitously upgrading systems costs time and money
Those who put these principles into practice must be willing to collect an extensive catalog of active releases.
On the other,
Patching outdated versions of the operating system is often infeasible, so administrators are faced
with the choice of skipping updates on some computers or crash-upgrading these machines to a newer internal release.
So what do you do? That’s your artful choice of balance between the two extremes.
Another controversial point of the chapter, about the notable superiority of APT over YUM – they go as far as talking of APT as a superset of YUM, – makes me once again question, why would someone willfully choose Red Had or CentOS over Debian or even Ubuntu, barring the corporate pressure?
Life Balance is a really neat dynamic ToDo list manager. Ideally, if used appropriately it can almost exactly suggest you what you need (and would enjoy) to do at any given moment in your life.
Like all near-perfect things it has a number of drawbacks though:
The tar’s “–exclude=PATTERN” option has always had me perplexed. As this is mostly intended for automation scenarios, I have never paid much attention to this option resorting to its more “pro-batch” variant “–exclude-from FILE”.
But today, as I went about making some backups I thought it’s enough, I need to learn how to use this option effectively. Having realized that the documentation on the matter is quite lacking, I decided to make a simple experiment.
Here are the commands I typed (in a bash terminal) to learn more about the “–exclude=PATTERN” option:
Use the following one-line script to control witch EXIF data to leave in the photos published online:
exiftool -P -overwrite_original -all= -tagsFromFile @ -ExposureTime -MeteringMode -Flash -FocalLength -FocalLengthIn35mmFormat -FocusDistance -VibrationReduction -FocusMode -CreateDate -DateTimeOriginal -ISO -FNumber -UserComment -copyright='(c)2011, Alexander Shcheblikin' -artist='Alexander Shcheblikin' -model="Sasha's DX dSLR" _DSC*jpg
This should all be entered on one line (note: the dashes which hang over the ends of the lines must actually be adjacent to the command line switches following them).
This is a power tool affecting multiple files at once and it will process all the files matching _DSC*jpg pattern in the current directory.
To retain original files remove the
exiftool is available natively in Linux/UNIX as a Perl library and a front-end script and as a standalone executable for Windows and a package for Mac OS X.