读到如下一段文字:
Writing multithreaded programs requires very careful design. The potential for introducing timing faults, or faults caused by the unintentional sharing of variables in a multithreaded program is considerable. Alan Cox (the Linux guru who wrote the forward to this book) has commented that threads are also known as “how to shoot yourself in both feet at once.”
“how to shoot yourself in both feet at once.”????
如下为解释:
与foot有关的用语实在多不胜数,除了前文所提及的外,还有to shoot oneself in the foot,例:
Our marketing strategy is a total disaster. Not only have our sales fallen, but because of our latest set of adverts, the competition have gone up! We have virtually shot ourselves in the foot.(我们的市场推广计划彻底失败。不但销路下降,由于我们近期的广告,竞争对手地位还上升了,我们这次真是自讨苦吃了。)
To shoot oneself in the foot这比喻源自弓箭手和枪手。为安全起见,他们往往把手上的武器指向地,可是假如武器走火,还是会射伤自己的脚。To shoot oneself in the foot这用语就指『因计划失误而害了自己』。
原来如此啊!
事物越搞越复杂,本来复杂性是用来解决问题的,结果反而自己迷失在复杂性里,自己搬石头砸了自己的脚。
技术是为了提高人们的生活水平的,结果偏偏有人在技术中迷失了方向,为了技术而技术。
另外找了一篇网上关于此的文章,顺便贴出。
感谢一位朋友帮助找的资料。
There are numerous variants of this on the Web. The original version was published in the December 1991 issue of Developer's Insight. I have been unable to track that down, but what follows is the closest approximation I can recover. If you know the actual languages included in the original article, please email me.
How to Shoot Yourself In the Foot
Developer's Insight, December 1991 (approx version)
The proliferation of modern programming languages (all of which seem to have stolen countless features from one another) sometimes makes it difficult to remember what language you're currently using. This guide is offered as a public service to help programmers who find themselves in such dilemmas.
-
C
-
You shoot yourself in the foot.
-
C++
-
You accidently create a dozen instances of yourself and shoot them all in the foot. Providing emergency medical assistance is impossible since you can't tell which are bitwise copies and which are just pointing at others and saying "That's me, over there."
-
FORTRAN
-
You shoot yourself in each toe, iteratively, until you run out of toes, then you read in the next foot and repeat. If you run out of bullets, you continue anyway because you have no exception-handling facility.
-
Modula-2
-
After realizing that you can't actually accomplish anything in this language, you shoot yourself in the head.
-
COBOL
-
USEing a COLT 45 HANDGUN, AIM gun at LEG.FOOT, THEN place ARM.HAND.FINGER on HANDGUN.TRIGGER and SQUEEZE. THEN return HANDGUN to HOLSTER. CHECK whether shoelace needs to be retied.
-
Lisp
-
You shoot yourself in the appendage which holds the gun with which you shoot yourself in the appendage which holds the gun with which you shoot yourself in the appendage which holds...
-
BASIC
-
Shoot yourself in the foot with a water pistol. On big systems, continue until entire lower body is waterlogged.
-
Forth
-
Foot yourself in the shoot.
-
APL
-
You shoot yourself in the foot; then spend all day figuring out how to do it in fewer characters.
-
Pascal
-
The compiler won't let you shoot yourself in the foot.
-
Snobol
-
If you succeed, shoot yourself in the left foot. If you fail, shoot yourself in the right foot.
-
HyperTalk
-
Put the first bullet of the gun into foot left of leg of you. Answer the result.
-
Prolog
-
You tell your program you want to be shot in the foot. The program figures out how to do it, but the syntax doesn't allow it to explain.
-
370 JCL
-
You send your foot down to MIS with a 4000-page document explaining how you want it to be shot. Three years later, your foot comes back deep-fried.
Of course, it didn't end there; there are many extensions to this idea (some included below). What many fail to recognise, however (especially those that add more complicated options for C, or reorder the list) is the meta-joke. Given the first line, the list starts off looking like yet another insult to C. But after reading the whole list, and coming back to the beginning, it becomes clear this is actually a compliment to C!
I have compiled the following lists from a variety of different sources on the Web, and from emailed suggestions; it includes contributions from Giles Constant, James Davis, Steve DiVerdi, Fritz Freiheit, Murray S. Kucherawy, Simon Mikkelsen, Doug Snell, Reynir Stefánsson, Wayne Throop, and Nick Wallis.
-
FORTRAN-77
-
You shoot yourself in each toe, iteratively, until you run out of toes, then you read in the next foot and repeat. If you run out of bullets, you continue anyway because you still can't do exception-processing.
-
Modula-2 (alternative)
-
You perform a shooting on what might be currently a foot with what might be currently a bullet shot by what might currently be a gun.
-
BASIC (compiled)
-
You shoot yourself in the foot with a BB using a SCUD missile launcher.
-
Visual Basic
-
You'll really only
appear to have shot yourself in the foot, but you'll have so much fun doing it that you won't care.
-
Forth (alternative)
-
BULLET DUP3 * GUN LOAD FOOT AIM TRIGGER PULL BANG! EMIT DEAD IF DROP ROT THEN (This takes about five bytes of memory, executes in two to ten clock cycles on any processor and can be used to replace any existing function of the language as well as in any future words). (Welcome to bottom up programming - where you, too, can perform compiler pre-processing instead of writing code)
-
APL (alternative)
-
You hear a gunshot and there's a hole in your foot, but you don't remember enough linear algebra to understand what happened.
or
@#&^$%&%^ foot
-
Pascal (alternative)
-
Same as Modula-2 except that the bullet is not the right type for the gun and your hand is blown off.
-
Snobol (alternative)
-
You grab your foot with your hand, then rewrite your hand to be a bullet. The act of shooting the original foot then changes your hand/bullet into yet another foot (a left foot).
-
Prolog (alternative)
-
You attempt to shoot yourself in the foot, but the bullet, failing to find its mark, backtracks to the gun, which then explodes in your face.
or
No.
-
COMAL
-
You attempt to shoot yourself in the foot with a water pistol, but the bore is clogged, and the pressure build-up blows apart both the pistol and your hand.
or
draw_pistol
aim_at_foot(left)
pull_trigger
hop(swearing)
-
Scheme
-
As Lisp, but none of the other appendages are aware of this happening.
-
Algol
-
You shoot yourself in the foot with a musket. The musket is aesthetically fascinating and the wound baffles the adolescent medic in the emergency room.
-
Ada
-
If you are dumb enough to actually use this language, the United States Department of Defense will kidnap you, stand you up in front of a firing squad and tell the soldiers, "Shoot at the feet."
or
The Department of Defense shoots you in the foot after offering you a blindfold and a last cigarette.
or
After correctly packaging your foot, you attempt to concurrently load the gun, pull the trigger, scream and shoot yourself in the foot. When you try, however, you discover that your foot is of the wrong type.
or
After correctly packing your foot, you attempt to concurrently load the gun, pull the trigger, scream, and confidently aim at your foot knowing it is safe. However the cordite in the round does an Unchecked Conversion, fires and shoots you in the foot anyway.
-
Eiffel
-
You create a GUN object, two FOOT objects and a BULLET object. The GUN passes both the FOOT objects a reference to the BULLET. The FOOT objects increment their hole counts and forget about the BULLET. A little demon then drives a garbage truck over your feet and grabs the bullet (both of it) on the way.
-
Smalltalk
-
You spend so much time playing with the graphics and windowing system that your boss shoots you in the foot, takes away your workstation and makes you develop in COBOL on a character terminal.
or
You send the message shoot to gun, with selectors bullet and myFoot. A window pops up saying Gunpowder doesNotUnderstand: spark. After several fruitless hours spent browsing the methods for Trigger, FiringPin and IdealGas, you take the easy way out and create ShotFoot, a subclass of Foot with an additional instance variable bulletHole.
-
Object Oriented Pascal
-
You perform a shooting on what might currently be a foot with what might currently be a bullet fired from what might currently be a gun.
-
PL/I
-
You consume all available system resources, including all the offline bullets. The Data Processing & Payroll Department doubles its size, triples its budget, acquires four new mainframes and drops the original one on your foot.
-
Postscript
-
foot bullets 6 locate loadgun aim gun shoot showpage
or
It takes the bullet ten minutes to travel from the gun to your foot, by which time you're long since gone out to lunch. The text comes out great, though.
-
PERL
-
You stab yourself in the foot repeatedly with an incredibly large and very heavy Swiss Army knife.
or
You pick up the gun and begin to load it. The gun and your foot begin to grow to huge proportions and the world around you slows down, until the gun fires. It makes a tiny hole, which you don't feel.
-
Assembly Language
-
You crash the OS and overwrite the root disk. The system administrator arrives and shoots you in the foot. After a moment of contemplation, the administrator shoots himself in the foot and then hops around the room rabidly shooting at everyone in sight.
or
You try to shoot yourself in the foot only to discover you must first reinvent the gun, the bullet, and your foot.
or
The bullet travels to your foot instantly, but it took you three weeks to load the round and aim the gun.
-
BCPL
-
You shoot yourself somewhere in the leg -- you can't get any finer resolution than that.
-
Concurrent Euclid
-
You shoot yourself in somebody else's foot.
-
Motif
-
You spend days writing a UIL description of your foot, the trajectory, the bullet and the intricate scrollwork on the ivory handles of the gun. When you finally get around to pulling the trigger, the gun jams.
-
Powerbuilder
-
While attempting to load the gun you discover that the LoadGun system function is buggy; as a work around you tape the bullet to the outside of the gun and unsuccessfully attempt to fire it with a nail. In frustration you club your foot with the butt of the gun and explain to your client that this approximates the functionality of shooting yourself in the foot and that the next version of Powerbuilder will fix it.
-
Standard ML
-
By the time you get your code to typecheck, you're using a shoot to foot yourself in the gun.
-
MUMPS
-
You shoot 583149 AK-47 teflon-tipped, hollow-point, armour-piercing bullets into even-numbered toes on odd-numbered feet of everyone in the building -- with one line of code. Three weeks later you shoot yourself in the head rather than try to modify that line.
-
Java
-
You locate the
Gun
class, but discover that the
Bullet
class is abstract, so you extend it and write the missing part of the implementation. Then you implement the
ShootAble
interface for your foot, and recompile the
Foot
class. The interface lets the bullet call the
doDamage
method on the
Foot
, so the
Foot
can damage itself in the most effective way. Now you run the program, and call the
doShoot
method on the instance of the
Gun
class. First the
Gun
creates an instance of
Bullet
, which calls the
doFire
method on the
Gun
. The
Gun
calls the
hit(Bullet)
method on the
Foot
, and the instance of
Bullet
is passed to the
Foot
. But this causes an
IllegalHitByBullet
exception to be thrown, and you die.
FOOTOS -- A Guide to Modern Operating Systems extended the joke to operating systems, with Unix playing the role of C, of course. And this too has grown...
-
Unix
-
You shoot yourself in the foot
or
% ls
foot.c foot.h foot.o toe.c toe.o
% rm * .o
rm: .o: No such file or directory
% ls
%
-
370 JCL (alternative)
-
You shoot yourself in the head just thinking about it.
-
DOS JCL
-
You first find the building you're in in the phone book, then find your office number in the corporate phone book. Then you have to write this down, then describe, in cubits, your
exact location, in relation to the door (right hand side thereof). Then you need to write down the location of the gun (loading it is a proprietary utility), then you load it, and the COBOL program, and run them, and, with luck, it may be run tonight.
-
VMS
-
$ MOUNT/DENSITY=.45/LABEL=BULLET/MESSAGE="BYE" BULLET::BULLET$GUN SYS$BULLET
$ SET GUN/LOAD/SAFETY=OFF/SIGHT=NONE/HAND=LEFT/CHAMBER=1/ACTION=AUTOMATIC/
LOG/ALL/FULL SYS$GUN_3$DUA3:[000000]GUN.GNU
$ SHOOT/LOG/AUTO SYS$GUN SYS$SYSTEM:[FOOT]FOOT.FOOT
%DCL-W-ACTIMAGE, error activating image GUN
-CLI-E-IMGNAME, image file $3$DUA240:[GUN]GUN.EXE;1
-IMGACT-F-NOTNATIVE, image is not an OpenVMS Alpha AXP image
or
%SYS-F-FTSHT, foot shot
(fifty lines of traceback omitted)
-
sh,
csh, etc
-
You can't remember the syntax for anything, so you spend five hours reading manual pages, then your foot falls asleep. You shoot the computer and switch to C.
-
Apple System 7
-
Double click the gun icon and a window giving a selection for guns, target areas, plus balloon help with medical remedies, and assorted sound effects. Click "shoot" button and a small bomb appears with note "Error of Type 1 has occurred."
-
Windows 3.1
-
Double click the gun icon and wait. Eventually a window opens giving a selection for guns, target areas, plus balloon help with medical remedies, and assorted sound effects. Click "shoot" button and a small box appears with note "Unable to open Shoot.dll, check that path is correct."
-
Windows 95
-
Your gun is not compatible with this OS and you must buy an upgrade and install it before you can continue. Then you will be informed that you don't have enough memory.
-
CP/M
-
I remember when shooting yourself in the foot with a BB gun was a big deal.
-
DOS
-
You finally found the gun, but can't locate the file with the foot for the life of you.
-
MSDOS
-
You shoot yourself in the foot, but can unshoot yourself with add-on software.
And it has extended even further, to databases, and other computer-related things...
-
Access
-
You try to point the gun at your foot, but it shoots holes in all your Borland distribution diskettes instead.
-
Paradox
-
Not only can you shoot yourself in the foot, your users can too.
-
dBase
-
You squeeze the trigger, but the bullet moves so slowly that by the time your foot feels the pain, you've forgotten why you shot yourself anyway.
or
You buy a gun. Bullets are only available from another company and are promised to work so you buy them. Then you find out that the next version of the gun is the one scheduled to actually shoot bullets.
-
DBase IV, V1.0
-
You pull the trigger, but it turns out that the gun was a poorly designed hand grenade and the whole building blows up.
-
SQL
-
You cut your foot off, send it out to a service bureau and when it returns, it has a hole in it but will no longer fit the attachment at the end of your leg.
or
Insert into Foot
Select Bullet
From Gun.Hand
Where Chamber = 'LOADED'
And Trigger = 'PULLED'
-
Clipper
-
You grab a bullet, get ready to insert it in the gun so that you can shoot yourself in the foot and discover that the gun that the bullets fits has not yet been built, but should be arriving in the mail _REAL_SOON_NOW_.
-
Oracle
-
The menus for coding foot_shooting have not been implemented yet and you can't do foot shooting in SQL.
-
English
-
You put your foot in your mouth, then bite it off. (For those who don't know, English is a McDonnell Douglas/PICK query language which allegedly requires 110% of system resources to run happily.)
-
Revelation [an implementation of the PICK Operating System]
-
You'll be able to shoot yourself in the foot just as soon as you figure out what all these bullets are for.
-
FlagShip
-
Starting at the top of your head, you aim the gun at yourself repeatedly until, half an hour later, the gun is finally pointing at your foot and you pull the trigger. A new foot with a hole in it appears but you can't work out how to get rid of the old one and your gun doesn't work anymore.
-
FidoNet
-
You put your foot in your mouth, then echo it internationally.
-
PicoSpan [a UNIX-based computer conferencing system]
-
You can't shoot yourself in the foot because you're not a host.
or (host variation)
Whenever you shoot yourself in the foot, someone opens a topic in policy about it.
-
Internet
-
You put your foot in your mouth, shoot it, then spam the bullet so that everybody gets shot in the foot.
-
troff
-
rmtroff -ms -Hdrwp | lpr -Pwp2 & .*place bullet in footer .B .NR FT +3i .in 4 .bu Shoot! .br .sp .in -4 .br .bp NR HD -2i .*
-
Genetic Algorithms
-
You create 10,000 strings describing the best way to shoot yourself in the foot. By the time the program produces the optimal solution, humans have evolved wings and the problem is moot.
-
CSP (Communicating Sequential Processes)
-
You only fail to shoot everything that isn't your foot.
In July 2002 Jim Nidositko emailed me the following story, with contributions to the list
Last summer, I found myself analyzing the plague of problems afflicting a sorely neglected MS-SQL Server implementation. This process was made more interesting by the fact that this analysis was being performed with an eye toward moving the database over to Sybase. My previous database experiences involved Oracle and Ingres, so I found myself learning about both platforms at the same time.
In short order I uncovered the fact of their shared heritage (early versions of MS-SQL Server were licensed from Sybase). This became a strong platform for understanding the differences between these two systems. I found it particularly fascinating that MS made it blindingly easy to get the system up and running, but in doing so it pretty much assured that you would shoot yourself in the foot by allowing the user to avoid performing basic tasks that are essential to good database design. Sybase, in contrast, makes it stupefyingly difficult to get a system up and running, thereby reducing your likelihood of foot shooting (by making it nearly impossible to shoot anything), but the Sybase documentation is so abysmal that you're also more or less assured of soundly shooting yourself for the difficulty of finding the information that will prevent this from among the confusing and circuitous cross references. This melange of similarities and contrasts inspired me to author the following vignettes. (Keep in mind, we were specifically trying to avoid any foot shooting, so these bits each end with advice toward that end.)
-
MS-SQL Server
-
MS-SQL Server’s gun comes pre-loaded with an unlimited supply of Teflon coated bullets, and it only has two discernible features: the muzzle and the trigger. If that wasn't enough, MS-SQL Server also puts the gun in your hand, applies local anesthetic to the skin of your forefinger and stitches it to the gun's trigger. Meanwhile, another process has set up a spinal block to numb your lower body. It will then proceeded to surgically remove your foot, cryogenically freeze it for preservation, and attach it to the muzzle of the gun so that no matter where you aim, you will shoot your foot. In order to avoid shooting yourself in the foot, you need to unstitch your trigger finger, remove your foot from the muzzle of the gun, and have it surgically reattached. Then you probably want to get some crutches and go out to buy a book on SQL Server Performance Tuning.
-
Sybase
-
Sybase's gun requires assembly, and you need to go out and purchase your own clip and bullets to load the gun. Assembly is complicated by the fact that Sybase has hidden the gun behind a big stack of reference manuals, but it hasn't told you where that stack is. While you were off finding the gun, assembling it, buying bullets, etc., Sybase was also busy surgically removing your foot and cryogenically freezing it for preservation. Instead of attaching it to the muzzle of the gun, though, it packed your foot on dry ice and sent it UPS-Ground to an unnamed hookah bar somewhere in the middle east. In order to shoot your foot, you must modify your gun with a GPS system for targeting and hire some guy named "Indy" to find the hookah bar and wire the coordinates back to you. By this time, you've probably become so daunted at the tasks stand between you and shooting your foot that you hire a guy who's read all the books on Sybase to help you shoot your foot. If you're lucky, he'll be smart enough both to find your foot and to stop you from shooting it.
In May 2003 Kristof Elst emailed me his contribution to the list
I'm a highly frustrated Magic Software developer who would rather be back to coding tsql. So I made my own version.
-
Magic software
-
You spend 1 week looking up the correct syntax for GUN. When you find it, you realise that GUN will not let you shoot in your own foot. It will allow you to shoot almost anything but your foot. You then decide to build your own gun. You can't use the standard barrel since this will only allow for standard bullets, which will not fire if the barrel is pointed at your foot. After four weeks, you have created your own custom gun. It blows up in your hand without warning, because you failed to initialise the safety catch and it doesn't know whether the initial state is "0", 0, NULL, "ZERO", 0.0, 0,0, "0.0", or "0,00". You fix the problem with your remaining hand by nesting 12 safety catches, and then decide to build the gun without safety catch. You then shoot the management and retire to a happy life where you code in languages that will allow you to shoot your foot in under 10 days.