Wicked Cool Shell Scripts 569
| Wicked Cool Shell Scripts - 101 Scripts for Linux, Mac OS X, and UNIX Systems | |
| author | Dave Taylor |
| pages | 368 |
| publisher | No Starch Press |
| rating | 10 |
| reviewer | Mary Norbury-Glaser |
| ISBN | 1593270127 |
| summary | 101 Scripts for Linux, Mac OS X, and UNIX Systems |
Chapters are divided into an array of topics sure to catch the attention of any UNIX based system user: The Missing Code Library, Improving on User Commands, Creating Utilities, Tweaking Unix, System Administration: Managing Users, System Administration: System Maintenance, Web and Internet Users, Webmaster Hacks, Web and Internet Administration, Internet Server Administration, Mac OS X Scripts, and Shell Script Fun and Games.
In true "cookbook" fashion, each hack is numbered and divided into The Code, How It Works, Running the Script, The Results and Hacking the Script. Throughout, the author clearly describes the syntax and functionality of each script, often with additional notes in How It Works detailing the syntax process and interesting asides. But Hacking the Script is what gives Wicked Cool Shell Scripts true value; where applicable, the author uses this section to describe script modifications to achieve a variety of alternative real world, practical results. This additional section alone easily triples the total number of scripts the reader is exposed to.
This book enables the reader to get "up close and personal" with their UNIX based system and explore the possibilities afforded by becoming intimate with the command line interface. The reader will find themselves easily propelled into the world of scripting, thanks entirely to Dave Taylor's ability to take what some might describe as a fairly dry topic and translate it into a logical and user friendly construct. Just reading through the table of contents is inspiring and intriguing; did you know you could write a script to retrieve movie info from IMDb? or track the value of your stock portfolio? or that you can use a very simple script to check spelling on your web pages?
Sysadmins and webmasters will find this book fundamentally critical to day-to-day operations; there are dozens of invaluable, customizable scripts highlighted in this book to enable professionals to save time and add simple, elegant solutions to annoying issues in their work environment. User account management, rotating log files, cron scripts, web page tweaks, apache passwords, synchronizing via ftp, etc. are all eminently useful and tweakable.
Geeky home users will discover they can use these scripts to work with files and directories, create spell-checking utilities, calculate loan payments, create summary listings of their iTunes libraries, and of course, play games. Many of the sysadmin scripts would also be of interest to the power user: analyzing disk usage, killing processes by name and backing up directories, to name a few. Both types of users will find this book inspiring and truly fun!
One of the secret pleasures of a technical book reviewer is finding those wonky bits of code that suffer from misplaced or missing punctuation, misspelled words and other basic typographic errors inherent in the book publishing process. I randomly selected many of these scripts to try out in the process of doing this review and...dang, haven't found any errata yet. But be sure to check out the errata page on Dave Taylor's web site for any that more astute readers may find (there were none, as of this writing).
Also be sure to take a closer look at Dave's shell script library, which lists additional scripts that didn't make the cut for the book. As convenient as it is to download the entire script library, I would like to stress the value of buying the book, which will provide you with invaluable instruction and guidance in understanding the syntax of the scripts and it also illustrates how making small but significant tweaks can modify the output to match your specific needs.
(A special nod of appreciation to Dave Taylor's Tintin references!)
You can purchase Wicked Cool Shell Scripts - 101 Scripts for Linux, Mac OS X, and UNIX Systems from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
What about us Windows users?! (Score:4, Funny)
Re:What about us Windows users?! (Score:5, Informative)
Re:What about us Windows users?! (Score:3, Funny)
deltree
OR if ur NT based
deltree
Everyone try it! Enjoy!
Re:What about us Windows users?! (Score:5, Funny)
Re:What about us Windows users?! (Score:3, Interesting)
Re:What about us Windows users?! (Score:5, Funny)
Re:What about us Windows users?! (Score:4, Interesting)
C:\> sh.exe myscript.sh
MinGW (Score:4, Informative)
The latest version of sh.exe is 465k bytes, it sounds like you have an old version. You should upgrade it. :)
Re:What about us Windows users?! (Score:5, Informative)
Cygwin [cygwin.com] is your friend. For just one example, you can write a script that uses sed to extract information from the filenames of your mp3z and feed the results into id3ed to tack on an ID3 tag. Try doing that with a batch file.
Re:What about us Windows users?! (Score:3, Interesting)
Take the DELETE command. It has trouble deleting multiple files at a time. It can't delete directories. Then look at Unix rm. It's easy to see why batch files are a joke.
The shell itself is definitely more flexible overall, though. Definitely more scriptable. The Bourne way of doing conditions, loops, pipes and whatnot are definitely more intuitive, more flexib
Re:What about us Windows users?! (Score:5, Informative)
That's true, but the fallacy is that you're assuming Windows should be scripted in the same fashion as *nix. That's simply not the case. Batch/Command scripting is nice for small bits, and can actually be fairly powerful in an obtuse sort of way, but the real power in automating Windows comes by using the Windows Scripting Host, JScript or VBScript, and all of the ActiveX/COM interfaces into the functionality of the OS and other applications. A classic example is iterating through users. In *nix, you write a shell script to parse through /etc/passwd. In Windows, you write a jscript to instantiate the objects that deal with Active Directory, and iterate through user objects (each of which you can perform actions upon, wherein *nix you'd have to invoke other applications). One approach is not necessarily "better" than the other, but you can't assume that your *nix administration experience will directly translate into Windows administration. You'd laugh if a Windows admin felt the reverse was true. What really gets me is when people complain about Windows not being automation-friendly because they're used to *nix scripting. Yes, you cannot pipe notepad.exe into winword.exe, for example, but Word has a very rich automation interface that you can hook into and use from a simple JScript.
What? Try running "help del" from a cmd.exe window some time. Also, look at "help rd". If you want to remove a directory tree, you use the "remove directory" command. "del" deletes files. "rd" deletes directories (and can delete files within directories if you tell it to).
Consider cmd.exe to be the functional equivalent of csh. It's a decent interactive shell, and has some good functionality (especially later versions of cmd.exe in win2k and xp), but you'd have to be nuts to do any extensive scripting with it. Just as you'd pull out bash or perl to do more complex tasks in *nix rather than using csh, you should use WSH in Windows for more complicated tasks.
Re:Is that a recipe for bloat? (Score:5, Informative)
The trick with Windows is that you can do many of these same things, but this power comes from doing it in WSH or VB (or C/C++ or an ASP or whatever language you're comfortable with. I've even done it in Perl.) You use the COM interfaces of the shell object to enumerate through directory trees and files. You can stream each of those files into the COM interface of another program that accepts streams. You can search, you can pipe stuff all over, and you're not limited to a single instance of stdin, stdout and/or stderr.
It's not unlike shell scripting, it's just a different language. Each application is able to expose whatever it feels is most important in whatever fashion it thinks is best. DevStudio, for example, lets the scripting host user get to the workspace, the project, and any of the tools.
The biggest problem I have with it is that stdio is not "guaranteed" to be supported by every application under Windows. stdio is the glue that binds all the UNIX utilities together. That's the beauty of stdio -- as the sole mechanism for I/O for most tools, it became the defacto application interaction interface. Windows doesn't have that: most Windows apps don't offer any automated IO at all. And some of the ones that do seem to have interfaces pasted on after the fact. But the ones that do expose properties and methods via COM are easy to access, and easy to control from anywhere. And using the interfaces tends to remove the ambiguities: in UNIX if you're using 'cut' to parse a phone list but the name field sometimes contains commas, you end up hacking around solutions to make them work. A COM-based solution would provide an interface containing a Name field.
Windows is not alone in this limiation, either. UNIX suffers from a similar problem: how do you meaningfully pipe data to and from an X window, or even to a curses app? Is it consistent between apps? Most apps I am familiar with that offer such features in their applications had to have code added to actively support a meaningful commandline interface to their programs through the use of dozens of command line switches. Without this sort of code, using stdio to parse the output of a curses-based application becomes a tedium of screen scraping.
Don't get me wrong: I have a bevy of UNIX-like command line utilities for Windows, I use Cygwin and bash when I need to (although the file system mapping is worse than I could have imagined), and I will fire up a CMD script long before I think to write it as a VB or C++ program. I'm far more comfortable with the sh-style tools -- I grew up with them.
I'm not saying stdio is better or worse than using the COM interfaces of Windows; I'm just saying it's "different." And you certainly shouldn't be reinventing the wheel to script up utilities in Windows.
Re:What about us Windows users?! (Score:5, Funny)
Re:What about us Windows users?! (Score:4, Funny)
grep "+-"|\
sed 's/\\//g;s/\//
awk '{print $2,$3,$4,$5}'|\
sed 's/
I HAVE NO IDEA WHAT THIS REGEX BULLSHIT MEANS (Score:3, Interesting)
But then I discovered The Regex Coach [weitz.de].
Woo (Score:4, Funny)
*Bookmarks this page for when I get money*
the best shell script (Score:3, Funny)
rm -rf *
Re:the best shell script (Score:5, Funny)
A better idea is to write "rm -rf ~/*", name the script "ls" and put it in your home directory to punish people with "." in $PATH . Now _that's_ teh funnay.
Re:the best shell script (Score:3, Interesting)
Re:the best shell script (Score:4, Funny)
One of the reasons I love unix, is that it will let you shoot yourself in the foot, and it will steady the gun while you take aim at your toe.
sounds cool (Score:5, Interesting)
Re:sounds cool (Score:4, Insightful)
Re:sounds cool (Score:3, Funny)
No one expects you to comment your shell scripts. No one expects you to account for corner cases. If they don't work you can blame bash and insist they install ksh instead. And people won't think you're a real programmer, so they won't assign that nasty driver bug to you. And you can obfuscate them almost as much as Perl!
Usage guide found on page one. (Score:5, Funny)
Step 2. Type 'chmod a+x
Hmm. (Score:5, Funny)
Please please tell me it's not
#!/bin/sh
wget 'http://imdb.com/title/tt0151804/'
http://imdb.com/robots.txt (Score:5, Informative)
Re:Hmm. (Score:5, Funny)
Re:Hmm. (Score:3, Interesting)
#!/bin/sh
lynx -dump 'http://imdb.com/title/tt0151804/'
Re:Hmm. (Score:3, Informative)
Easier for people to read, but if you were dumping the results into another program/script, the raw HTML might be easier to parse. (Then again, you can just change -dump to -source to have Lynx dump raw HTML instead of formatted text, in case you don't have wget.)
Re:Hmm. (Score:3, Informative)
wget -c http://www.intuitive.com/wicked/scripts/AllFiles.
Very cool.
Why shell? (Score:3, Flamebait)
Re:Why shell? (Score:5, Funny)
Re:Why shell? (Score:3, Funny)
Re:Why shell? (Score:3, Informative)
Re:Why shell? (Score:3, Funny)
Why settle for less, if you can settle on most [jedsoft.org]?
Yeah, most's feature list [jedsoft.org] is pretty impressive. And just look at the screenshots!!! [jedsoft.org]
Re:Why shell? (Score:5, Informative)
(i) Many people, like myself, don't know perl, and don't see the point in learning when shell scripts are perfectly adequate for their purposes.
(ii) Sometimes it's just easier. viz. this quote [bash.org] from bash.org:
Re:Why shell? (Score:4, Interesting)
Recently I had a 4 line script that helped me reconfigure a bunch of workstations. He wanted in redone in perl, so a 4 line hack became a 50 line perl script.
Re:Why shell? (Score:3, Insightful)
The real question is, was your 4 line shell script only 4 lines long because it really was that simple, or was it because, as you say, it was a "hack?"
I'll take 10 lines of code I can understand over 1 line I can't, any day of the week.
Re:Why shell? (Score:4, Interesting)
Show me a shell script that takes more lines of code to do the same job in Perl. Perl has many more features like grep, map, hashes, , symbolic references, etc. that make short work of simple tasks that do not exist in shell.
More likely the reduction of lines of code would be converting from shell to perl.
I bet your boss know shell and Perl and has (in my humble opinion) make the right choice in standardization.
I would recommend that you spend a little time with Perl (or python or ruby) and bet you would change your mind in short time.
Re:Why shell? (Score:3, Informative)
#!/usr/bin/perl
system("command 1");
system("command 2");
$some_returned_value = `command 3`;
system("command 4");
Course, you still have to bother with Perl variables. But it should still be possible to do it in 4 lines.
And if he thinks that's a hack, well, Perl is one huge freaking hack. To quote Larry Wall:
"The Amulet isn't exactly beautiful though--in fact, up close it still looks like a bunch of beads melted together. Well, all right, I admit it. It's downright ugly. But never mi
Because Perl's on NFS and not mounted yet? (Score:3, Insightful)
Try getting to anything in NFS when running in single-user mode.
Re:Why shell? (Score:3, Insightful)
Because Perl exists in random locations.
Because a particular Perl installation will have random modules installed.
Because Perl is not on *everything*.
Because writing a shell script take a fraction of the time a Perl script takes.
Because Perl encourages monolithic scripting.
Perl has tried so very hard (and suceeded) to become a fully featured programming language, it hasn't been suited to small scripting tasks sin
Re:Why shell? (Score:5, Insightful)
During boot up scripts, until you get past the point that /usr is mounted (you do put /usr on a different partition right?), you can't use anything. That's how you determine what goes on /bin and what goes in /usr/bin (well mostly). When things go wrong, and you need to recover, trying to fix things on a busted machine, is much more reliable if you are using shell then perl (it's got a smaller foot print, and it's not an intertangled mess of libraries).
Intertangled messes of libraries are a great thing when you are developing. They are a beast, if things are broken. What if you fsck can't finish because part of the library is dorked. Thus you can't mount the filesystems you need to use to fix the problem.
During boot up, you want to use the easiest, and most reliable method of booting. Shell scripts are probably better off then perl scripts. It's easy to have readable, reliable shell scripts with scoping, it's just not something you are used to doing apparently.
Besides all that, you'd spend all your time in perl doing exec/fork/system. The /bin/sh is more efficient at doing that then perl is (in terms of code, if not runtime).
Kirby
/usr and / (Score:3, Informative)
Actually, we decided here ( a fairly large installation) long ago to merge / and /usr.
Our main reason was simplification and this allows us the benefit of not worrying what is in /usr/bin and what is in /bin. (Actually, on Solaris, /bin is just a link to /usr/bin ). Everything in /usr and
/ should not be touched anyhow except through the
normal pkg management tools. We do of course maintain a separate /usr/local.
The main disadvantage is that a fsck would take longer because / is now a large filesystems.
Re:Why shell? (Score:5, Interesting)
Libraries other than the standard set of libraries are not be required for doing the simple tasks that shell scripts often do. I am sure the entire functionality of bash is well within the core of Perl.
It's easy to have readable, reliable shell scripts with scoping, it's just not something you are used to doing apparently.
No I admit I do very little in shell scripting mainly because I do not see the need. Perl supports many many features that ease program and script development.
Also perl has builtins like open, readdir, socket, etc. In shell programming would you not have to do things like `cat file` to read file? Does this not increase the overhead of shell scripts by forking another shell?
Eventhough my original post was mod'd flamebait it is not just a curious enquiry.
Re:Why shell? (Score:5, Informative)
why not dynamically compiled? Well if your glibc barfs all dynamically compiled binaries barf with it - including perl, and including any shells that you use to start up your system. With a statically compiled shell to handle all of those startup scripts you can boot linux without glibc working, and you probably have enough of a system still running to get things fixed. with a dynamically linked startup file interpreter, when glibc or something glibc depends on goes, your whole system goes, single-user mode and all.
Besides, while perl can execute system commands and make decisions based on input, i think the shell is a better tool for things like this. sh and bash were designed to do startup scripts (among other things) and they do them well. why fix what isn't broken? shell scripts work, and they can do anything you'd need them to do during startup.
Re:because perl is a pig that runs out of memory (Score:3, Informative)
No, your pathetically puny little machine thrashes and crashes trying to crunch seriously large amounts of data with that script you threw together in 15 minutes while ignoring all the comments in the Camel Book about performance implications of things like "@array = <FILE>". Perl is written in C, and runs just fine when used appropriately.
When the only tool you have is a hammer... (Score:5, Insightful)
Actually, I agree that shell scripting is a powerful tool and well worth understanding. But 'a loan calculator' script? Gee, once you know the formula, a coupla minutes in a spreadsheet will do the trick.
I guess all people, myself included, fall into the hammer/nail trap. I know C very well, so I use it for just about every little app. Hmm... maybe I oughta buy this book.
-RatOmeter
Re:When the only tool you have is a hammer... (Score:4, Insightful)
Hmm... (Score:5, Funny)
Hopefully it also features a grammar checking script to ensure that you don't start using phrases like 'Wicked Cool'.
Re:Hmm... (Score:5, Funny)
Re:Hmm... (Score:5, Funny)
#/bin/shizle -yo
#declare a gangsta (variable) called slim
I'm a big ass gangsta and my name is slim
#link in the math pimp (library)
math pimp is in tow and don't you fsck with him
#initialize slim to the hos (linked list) 4,3,2,1
# this causes an error because there is no rhyme
4 and 3 and 2 and 1 now slim and his hos be comming for you
#open a shoutout (file)
Yo, here's a shoutout to the users out there
hey Andy (CR LF)
hey Amy (CR LF)
hey Ben (CR LF)
hey Zack (CR LF)
#exit with no error code
peace out
%
errah
Re:Hmm... (Score:4, Funny)
Wore that shirt to my parents one time and my mom didn't exactly get it. Unix does not equal Eunuchs. Try explaining that to your mom.
101 Prompts? (Score:5, Interesting)
Re:101 Prompts? (Score:3, Interesting)
It would save the current cursor position, write the date and time on the top line of the screen, jump back to where it had been, write the current directory, and do it all in nice colors!
I do like Gentoo Linux's default prompt, which I've now copied to all my linux machines. Now if they'd just alias ls='ls --color' by default, I'd be real happy!
Re:101 Prompts? (Score:5, Informative)
I don't know if such a book (or chapter in a book) exists, but here are some links:
Have fun...
Re:101 Prompts? (Score:3, Informative)
Amazing how much free information you can get when you look for it.
Webmasters?? (Score:3, Insightful)
What webmaster uses SHELL scripts?!
I understand, PHP, Perl, some other CGI. Marginal use for scripts for log analysis, maybe some file management, making their own work a bit easier.
But shells were never meant to do any web work. They are too slow, too heavyweight, too vulnerable to abuse by malicious users to be used as server side extensions!
Re:Webmasters?? (Score:3, Insightful)
I don't believe that the reviewer ment that the scripts were being used for a web site, but as a tool for automating web site administration.
Re:Webmasters?? (Score:5, Interesting)
Um, me.
My web server has 6 megs of RAM. (it's an embedded device). That gives me two choices: C or sh. Obviously sh doesn't work for everything, but it's sure a heck of a lot nicer than using C for the non-critical stuff.
Ironically, I usually use Python for administration type tasks during development on real computers, and sh for the web sites themselves on the embedded servers.
Bryan
Re:Webmasters?? (Score:3, Funny)
Mordac: I am Mordac, the Preventor of Information Services. You have exceeded your storage space on the server.
Alice: Here's 25 cents so you can double my storage space.
Mordac: I think my mystique just took a hit.
Quick Hacks (Score:5, Informative)
If the script is not working as you want, put a
on the fist line and on the last line.You will see the exact execution path and variable expansion, very neat for debugging
Re:Quick Hacks (Score:5, Informative)
sh -x scriptname
set -eu (Score:3, Informative)
-e: bomb out immediately when a command exits w/nonzero status
-u: bomb out when de-referencing uninitialized variables ("var=" counts as initialization).
John.
shell scripts vs. programming languages... (Score:5, Interesting)
Why would you use awk and sed along with a really ugly shell script to get something done when you could have just as easily used perl to acheive the same effect?
Sometimes you should just use what is best for the job. I really don't think that using shell scripts to pull IMDB movie info is the best way to go.
YMMV,
Don't start this argument!@ (Score:3, Insightful)
Why? If I know awk better than PERL, its a much better idea to use AWK.
Vice versa.
P.S.- At two different points in my life I did serious perl scripting. Now, I can't remember a darn thing. Awk looks like C. So these days, I use awk. Different strokes for people with different amounts of brain power/memory.
And some scripters tend to be just as zealous about the power of scripting as perl mongers are about perl!
Re:Don't start this argument!@ (Score:3, Interesting)
just to give you an example. I like that both Perl and awk give you associative arrays for free.
The last time I needed to analyze network usage per processor per second I wrote an awk script.
I find it hard to believe that someone who actually knew perl would go back to using awk.
Believe it. Its just what I do now.
Re:shell scripts vs. programming languages... (Score:3, Funny)
You speak of the ugliness of shell scripting and then mention Perl as the solution?
Que?
Re:shell scripts vs. programming languages... (Score:3, Insightful)
'cause every executable becomes a function which you pass params and get return values, if you want to.
Re:shell scripts vs. programming languages... (Score:3, Insightful)
quick-n-dirty hack and/or small script that will grow ==> shell. Yes, I know perl can be quick-n-dirty, too, but then what's the point? I'd rather read shell q-n-d than perl q-n-d line noise.
complex stuff (like parsing html/xml), and/or something that might get complex in future ==> perl
John.
Re:shell scripts vs. programming languages... (Score:5, Informative)
Well, I think Silent Bob (garcia) is directly attacking me as the author of these fine tools: Linux tools for geocaching [rkkda.com]
I do know Perl as well as all of the original Unix tools: awk, sed, and of course my favorite: shell.
The short and main explanation is that shell/awk/sed lend themselves very well to what is known as the "Unix tools" approach. Its a way of thinking using a small set of core tools that pays big rewards in productivity.
In the case of my geocaching tools, two things were plainly obvious to me at the start. 1) I would be scraping the pages with curl, because there is no better and easier tool for that job, and 2) gpsbabel would be a main part of almost every tool because it knows how to work with a bajillion waypoint formats. So the onl;y question after that is which language to use to glue those commands together. Shell, awk, and perl can all do that. I used shell to tie it all together because that is what shell is best at.
In a few of the tools, geo-map in particular, I did make a mistake in the glue choice. My excuse there is that it evolved far beyond its original design goals. So it ended up requiring a lot of floating point calculations and therefore I had to run several mini-awk scripts within it. If I were to rewrite it today, I would make it a pure AWK script. Why not perl? Because, IMHO, awk has the cleanest syntax of any of the scripting languages.
So, then, when *would* I use perl? In general, I select perl when 1) there is a pre-written module that does a job that would be hard to do with shell/awk/sed, and 2) the use of that module is truly necessary. That second point is very important to me. The mere existance of a Perl module does not necessarily mean its the best or fastest way to solve the problem.
Perl was the language of choice for "Belle", which is a 4000 line IRC robot I coauthored for use in my daytrading activities. The IRC module was what tipped the scale for Perl in that case.
Another problem with perl modules is that using them guarantees that you will lose some percentage of potential users of your program. Having to find and install additional packages puts many people off. I try to make my scripts completely self-contained (including usage doco) so that people don't have to go thru these hassles.
Anyway, you can argue with any of my points, but what you can't argue with is that I have the largest set of command line tools for geocaching that work, regardless what my language choice was.
-Rick
A very cool shell script (Score:5, Funny)
Tintin and Asterix! (Score:4, Interesting)
And a special nod of appreciation to norburym for mentioning the Tintin references in the review!
It was cool to see a reference to one of my favorite fiction/comic books on Slashdot. I hate to call Tintin and Asterix comic books because they're so much more than mere comics. I've noticed though, that not many people are as hooked to the Tintin and Asterix series in the US as in Europe/Asia. They're great for kids and much *much* better than the shitload of comics that they read nowadays.
I've had trouble finding them in the public libraries (in 3 states) and even the big book stores. So people who haven't heard/read these books, are definetly missing out on some cool reading. Check them out at your local library or atleast their websites: Tintin [tintin.be] and Asterix [asterix.tm.fr].
Note: I am in no way affiliated to these books/publishers/websites. I'm just an avid fan :)
But Asterix is evil (Score:3, Informative)
Ummm... (Score:4, Funny)
Cliff-Hanger spoiler... :D (Score:3, Funny)
But does it have... (Score:3, Funny)
Is there a shell script to... (Score:5, Funny)
Is there a shell script included that makes it look like you are working? Isn't that the purpose of all good shell scripts?
Freedom is trouble :)
dated title (Score:3, Interesting)
pushd and popd (and other tricks) (Score:5, Informative)
Here's other stuff I have grouped by sections in my .cshrc
First, I have my shell variables. The comments say what they do. The most important one is autolist.
Second, bindkeys are pretty neat. I rebind the up and down arrow keys. By default they scroll up and down one at a time through the history. You can bind them to search the history based on what you've typed so far.
Third, completes allow for customizing tab completion. When I change directories, tab only completes directory names. This also works for aliases, sets, setenvs, etc.
Fourth, I have all my aliases. I had to cut a bunch because of the lameness filter.
Re:pushd and popd (and other tricks) (Score:3, Informative)
One of the things that a lot of people don't realize is that you can still set the colors and such in tcsh just like in bash - only the syntax is different. Here's how I have mine set on one of the machines I log into:
set prompt = "%{^[[032;1m%}`whoami`%{^[[0m%} %c3 %B%#%b "
Good stuff.
Tab completion (Score:3, Informative)
Really??? (Score:5, Funny)
Quick! Somebody pick this up for Taco!
Hmmm (Score:3, Funny)
This might be because it's
Book Recommendation (Score:5, Informative)
Cool scripts (Score:4, Informative)
My favourite shell script... (Score:3, Informative)
My personal favorite; (Score:5, Interesting)
Do *not* run this on your production servers.
Re:My personal favorite; (Score:3, Informative)
But yes, it is a shell fork bomb.
Re:My personal favorite; (Score:4, Informative)
It reads... define function ':' as follows: pipe the output from function ':' into function ':' -- do that in the background (ie fork). Call the function ':'.
I had no idea how it worked, either, but I looked it up
cd with history (Score:5, Informative)
The shell helper that I am totally lost without is one that adds directory history to bash and ksh. You can find it here: _cd [rr.com]
I guess I never really got the idea of a stack of dirs being useful, since I seem to bounce around more at random than anything else. I prefer to have a cache of places I've recently been.
Bonus puzzle for slashdot readers: using the cd with history function, what directory is this command likely to take me to?
shell scripts still useful. (Score:3, Interesting)
I work for a large company (50,000 employees), and the directory lookup site of choice is driven behind-the-scenes by about 6,000 lines of shell script (bourne). Having written this application, one of the most common back-handed compliments I get is when users ask what I did to optimize this application to make it SO FAST! I just smile.
(btw, this lookup tool does more than simple fill-in-the-blank lookups -- it has a first-name-alias lookaside table (so I can find "Sue", even though she's in the database as "Susan", it is case insensitive (yawn), order insenstive, field insensitive (there's only ONE input box), and more than returning just the phone number of the employee, it draws the entire hierarchy around the employee (direct reports, peers, management chain). And, there are buttons for each person on the page to: send page; send e-mail; generate and org chart..., and much much more)
Don't mean to make it sound like an ad for the application -- just thought it might be reassuring to other shell programmers that a shell script can be a major corporation's tool.
The *free* guide to Bash shell scripting (Score:5, Informative)
From the site:
This tutorial assumes no previous knowledge of scripting or programming, but progresses rapidly toward an intermediate/advanced level of instruction (...all the while sneaking in little snippets of UNIX wisdom and lore). It serves as a textbook, a manual for self-study, and a reference and source of knowledge on shell scripting techniques. The exercises and heavily-commented examples invite active reader participation, under the premise that the only way to really learn scripting is to write scripts.
Laid off haiku (Score:3, Funny)
Re:RTFT (Score:3, Informative)
I RTFT. Shell scripts can be BASH, CSH, TSH, SH, KSH, the list goes on. That's if you're assuming by "shell" they don't mean all interpreted languages -- I've seen a number of Perl / Python / Whatever scripts put in the general category of shell scripts before.
I am also curious what tools are assumed to be available to the user. There are a lot of programs available that are standard (i.e. wget), but is the author assuming a standard unix distribution, or does he say "if you have ___"?
Re:Sounds useful, but what languages are used? (Score:4, Insightful)
The programming languages like C, C++, Java etc, are strongly typed languages and the compiler will give you sufficient information to correct your incorrect syntax problems.
So even when you switch from say C++ and Java, with a little common sense and reading the compiler errors and warnings you can easily pick up java syntax, keywords etc.
But with scripting languages it is not so, as they are not compiled. This is especially a headache when you are dealing with multiple unix machines having differnet shells.
I once worked at a job where I had to use , csh (c-shell) , sh (original bourn shell) , ksh ( korn shell ) and bash (bourn shell ) on different linux, solaris and HP-UX boxes. It was a real headache maintaining the scripts.
All these scripts differ quite a lot in syntax , especially for arethmatic, redirects , invoking sub shells , comparision operators etc.
What is needed is a good shell cross referencing manaul which will provide comparative features of at least the major shells like , bash , sh, ksh, csh, tcsh , zsh.
Re:Doing things yourself (Score:5, Insightful)
So what? I just bought a cookbook on sauces. What's different? Maybe I like a little more garlic in most my sauces so I'll throw some in here and there. Most of the sauce recipes, i would have never have thought to go with something I usually eat. Why does there need to be a "challenge"? It simply makes my meal more enjoyable.
Having 101 shell scripts that I can tinker with and add things that I like, or use them in a way that makes using my computer more enjoyable is great!
Re:Doing things yourself (Score:3, Insightful)
Yeah, and she only knew how to make a couple of kinds of sauce. Even a master chef needs a cookbook. Or a hundred.
The whole "real hackers do it themselves" argument is crap. No man is an island, and we all learn something from others. If someone wants to be an elite h4x0r d00d, does he have to be raised like a veal in front of a computer with nobody to tell him how to turn the fucking thing on?
The whole point of networks is to sha
Solaris has killall (Score:4, Insightful)
Yes (Score:3, Informative)
Kjella