How To Adopt 10 'Good' Unix Habits

An anonymous reader writes to mention an article at the IBM site from earlier this week, which purports to offer good Unix 'habits' to learn. The ten simple suggestions may be common sense to the seasoned admin, but users with less experience may find some helpful hints here. From the article: "Quote variables with caution - Always be careful with shell expansion and variable names. It is generally a good idea to enclose variable calls in double quotation marks, unless you have a good reason not to. Similarly, if you are directly following a variable name with alphanumeric text, be sure also to enclose the variable name in square brackets ([]) to distinguish it from the surrounding text. Otherwise, the shell interprets the trailing text as part of your variable name -- and most likely returns a null value."

Comments

FP?

[Shadow-isoHunt]

export POST="first"

Re:FP?

[Anonymous Coward]

Imbecile! POST wasn't defined yet! This won't work on /bin/sh, only with the proprietary bash shell.

welll..

[macadamia_harold]

An anonymous reader writes to mention an article at the IBM site from earlier this week, which purports to offer good Unix 'habits' to learn.

I seriously doubt reading this article is going to get anyone to start showering on a regular basis.

Re:welll..

[SharpFang]

Ie there is NOTHING bad about piping cats

PETA would disagree.

Re:welll..

[jc42]

Ie there is NOTHING bad about piping cats

PETA would disagree.

Oh? Just imagine the cacophony of a bunch of cats playing bagpipes while "singing" along.

Re:welll..

[db32]

I frequently cat bleh | grep whatever just because it was the first way I learned and reflexively do it that way. grep whatever * actually tells me what file it found the match in, rather than just showing me the line. So while piping cats isn't inherently bad, there is frequently better ways to do it that also give more correct output, but it depends on what the desired output is. However "I grepped all the files for 'bleh'" sounds infinitely less disturbing than "I grepped what came out of the cat I piped"

Very helpful

[EvanED]

I really like this example:

~ $ time grep and tmp/a/longfile.txt | wc -l
2811

real 0m0.097s
user 0m0.006s
sys 0m0.032s
~ $ time grep -c and tmp/a/longfile.txt
2811

real 0m0.013s
user 0m0.006s
sys 0m0.005s

I am so glad that he showed what a difference can make, because I was *really* getting annoyed at having to wait that extra .084 seconds.

Re:Very helpful

[trip11]

There is no such thing as .084 seconds. Surely you mean .084 hours.

Re:Don't use shell

[Bazman]

If I've got a simple task to do (eg the text-file-of-URLS example) then I knock it up in shell script. By the time that simple task has feature-creeped up to more than 20 lines I start to wish I'd written it in Perl. So I rewrite. By the time that Perl script has crept up to more than 200 lines I start to wish it was written in Python. So I rewrite. By the time that Python script has crept up to 2000 lines I start to wish I'd farmed the job out to a team of programmers, and I give up caring what language its written in and make them do it as a web service. Then I write a small shell script to call their web service. When that shell script has feature-creeped up to more than 20 lines...

Re:cat file | grep something

[AndroidCat]

Articles on terminating zombie children are always a treat too.

Re:Don't use shell

[Fred_A]

Um, whats wrong with

wget -i filename

It's not a shellscript, that's what wrong with it. Please pay attention next time.