Search Results

Search found 15300 results on 612 pages for 'programming languages'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 71/612 | < Previous Page | 67 68 69 70 71 72 73 74 75 76 77 78  | Next Page >

  • Language choice

    - by kzh
    For a starter of programming, there are a lot of programming language available to start with. Which should be the best choice for a starter to learn programming language?

    Read the article

  • Role of Combinators in Concatenative/Tacit Programming Languages.

    - by Bubba88
    Hi! I have a question about what exact role do higher-order compinators (or function producers) hold in concatenative/tacit programming. Additionally I would like to ask if there is another way to implement concatenative programming language rather than directly manipulating the stack. This might look like a newbie question, so if you feel like it, you can freely direct me to external source.

    Read the article

  • Is there a language that encourages good coding practices?

    - by Darrell Brogdon
    While I love PHP I find its biggest weakness is that it allows and even almost encourages programmers to write bad code. Is there a language that encourages good programming practices? Or, more specifically, a web-related language that encourages good practices. I'm interested in languages who have either a stated goal of encouraging good programming or are designed in such a way as to encourage good programming.

    Read the article

  • How did you get your first programming job?

    - by Gaz
    Hi All, I have some commercial programming experience although it was not my primary role (C# and Java), SCJP 6 cert, some SQL experience and have been doing a lot of Android programming (I have one app with 36,000 downloads). I have a degree in Chemistry and a Diploma in Programming (half a degree made up of 2nd/3rd year uni courses). I'm trying to get my first entry level programmer job but am finding it tough out there.......How did other people get there first jobs in programming?

    Read the article

  • Why Aren't Programs Written In Assembly More Often?

    - by mudge
    It seems to be a mainstream opinion that assembly programming takes longer and is more difficult to program in than a higher level language such as C. Therefore it seems to be recommend or assumed that it is better to write in a higher level language for these reasons and for the reason of better portability. Recently I've been writing in x86 assembly and it has dawned on me that perhaps these reasons are not really true, except perhaps portability. Perhaps it is more of a matter of familiarity and knowing how to write assembly well. I also noticed that programming in assembly is quite different than programming in an HLL. Perhaps a good and experienced assembly programmer could write programs just as easily and as quickly as an experienced C programmer writing in C. Perhaps it is because assembly programming is quite different than HLLs, and so requires different thinking, methods and ways, which makes it seem very awkward to program in for the unfamiliar, and so gives it its bad name for writing programs in. If portability isn't an issue, then really, what would C have over a good assembler such as NASM?

    Read the article

  • Alternative languages for embedded programming

    - by RHaguiuda
    I`m looking for alternatives programming languages (from assembly, C, C++ and basic) to embedded (microcontroller) programming. Is it possible for example, to programm microcontrollers in C# or Java? Maybe Ruby or Phyton? If possible, please post development tools and hardware used. Thanks

    Read the article

  • An Alphabet of Eponymous Aphorisms, Programming Paradigms, Software Sayings, Annoying Alliteration

    - by Brian Schroer
    Malcolm Anderson blogged about “Einstein’s Razor” yesterday, which reminded me of my favorite software development “law”, the name of which I can never remember. It took much Wikipedia-ing to find it (Hofstadter’s Law – see below), but along the way I compiled the following list: Amara’s Law: We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run. Brook’s Law: Adding manpower to a late software project makes it later. Clarke’s Third Law: Any sufficiently advanced technology is indistinguishable from magic. Law of Demeter: Each unit should only talk to its friends; don't talk to strangers. Einstein’s Razor: “Make things as simple as possible, but not simpler” is the popular paraphrase, but what he actually said was “It can scarcely be denied that the supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible without having to surrender the adequate representation of a single datum of experience”, an overly complicated quote which is an obvious violation of Einstein’s Razor. (You can tell by looking at a picture of Einstein that the dude was hardly an expert on razors or other grooming apparati.) Finagle's Law of Dynamic Negatives: Anything that can go wrong, will—at the worst possible moment. - O'Toole's Corollary: The perversity of the Universe tends towards a maximum. Greenspun's Tenth Rule: Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp. (Morris’s Corollary: “…including Common Lisp”) Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law. Issawi’s Omelet Analogy: One cannot make an omelet without breaking eggs - but it is amazing how many eggs one can break without making a decent omelet. Jackson’s Rules of Optimization: Rule 1: Don't do it. Rule 2 (for experts only): Don't do it yet. Kaner’s Caveat: A program which perfectly meets a lousy specification is a lousy program. Liskov Substitution Principle (paraphrased): Functions that use pointers or references to base classes must be able to use objects of derived classes without knowing it Mason’s Maxim: Since human beings themselves are not fully debugged yet, there will be bugs in your code no matter what you do. Nils-Peter Nelson’s Nil I/O Rule: The fastest I/O is no I/O.    Occam's Razor: The simplest explanation is usually the correct one. Parkinson’s Law: Work expands so as to fill the time available for its completion. Quentin Tarantino’s Pie Principle: “…you want to go home have a drink and go and eat pie and talk about it.” (OK, he was talking about movies, not software, but I couldn’t find a “Q” quote about software. And wouldn’t it be cool to write a program so great that the users want to eat pie and talk about it?) Raymond’s Rule: Computer science education cannot make anybody an expert programmer any more than studying brushes and pigment can make somebody an expert painter.  Sowa's Law of Standards: Whenever a major organization develops a new system as an official standard for X, the primary result is the widespread adoption of some simpler system as a de facto standard for X. Turing’s Tenet: We shall do a much better programming job, provided we approach the task with a full appreciation of its tremendous difficulty, provided that we respect the intrinsic limitations of the human mind and approach the task as very humble programmers.  Udi Dahan’s Race Condition Rule: If you think you have a race condition, you don’t understand the domain well enough. These rules didn’t exist in the age of paper, there is no reason for them to exist in the age of computers. When you have race conditions, go back to the business and find out actual rules. Van Vleck’s Kvetching: We know about as much about software quality problems as they knew about the Black Plague in the 1600s. We've seen the victims' agonies and helped burn the corpses. We don't know what causes it; we don't really know if there is only one disease. We just suffer -- and keep pouring our sewage into our water supply. Wheeler’s Law: All problems in computer science can be solved by another level of indirection... Except for the problem of too many layers of indirection. Wheeler also said “Compatibility means deliberately repeating other people's mistakes.”. The Wrong Road Rule of Mr. X (anonymous): No matter how far down the wrong road you've gone, turn back. Yourdon’s Rule of Two Feet: If you think your management doesn't know what it's doing or that your organisation turns out low-quality software crap that embarrasses you, then leave. Zawinski's Law of Software Envelopment: Every program attempts to expand until it can read mail. Zawinski is also responsible for “Some people, when confronted with a problem, think 'I know, I'll use regular expressions.' Now they have two problems.” He once commented about X Windows widget toolkits: “Using these toolkits is like trying to make a bookshelf out of mashed potatoes.”

    Read the article

  • Quadratic Programming with Oracle R Enterprise

    - by Jeff Taylor-Oracle
         I wanted to use quadprog with ORE on a server running Oracle Solaris 11.2 on a Oracle SPARC T-4 server For background, see: Oracle SPARC T4-2 http://docs.oracle.com/cd/E23075_01/ Oracle Solaris 11.2 http://www.oracle.com/technetwork/server-storage/solaris11/overview/index.html quadprog: Functions to solve Quadratic Programming Problems http://cran.r-project.org/web/packages/quadprog/index.html Oracle R Enterprise 1.4 ("ORE") 1.4 http://www.oracle.com/technetwork/database/options/advanced-analytics/r-enterprise/ore-downloads-1502823.html Problem: path to Solaris Studio doesn't match my installation: $ ORE CMD INSTALL quadprog_1.5-5.tar.gz * installing to library \u2018/u01/app/oracle/product/12.1.0/dbhome_1/R/library\u2019 * installing *source* package \u2018quadprog\u2019 ... ** package \u2018quadprog\u2019 successfully unpacked and MD5 sums checked ** libs /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95 -m64   -PIC  -g  -c aind.f -o aind.o bash: /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95: No such file or directory *** Error code 1 make: Fatal error: Command failed for target `aind.o' ERROR: compilation failed for package \u2018quadprog\u2019 * removing \u2018/u01/app/oracle/product/12.1.0/dbhome_1/R/library/quadprog\u2019 $ ls -l /opt/solarisstudio12.3/bin/f95 lrwxrwxrwx   1 root     root          15 Aug 19 17:36 /opt/solarisstudio12.3/bin/f95 -> ../prod/bin/f90 Solution: a symbolic link: $ sudo mkdir -p /opt/SunProd/studio12u3 $ sudo ln -s /opt/solarisstudio12.3 /opt/SunProd/studio12u3/ Now, it is all good: $ ORE CMD INSTALL quadprog_1.5-5.tar.gz * installing to library \u2018/u01/app/oracle/product/12.1.0/dbhome_1/R/library\u2019 * installing *source* package \u2018quadprog\u2019 ... ** package \u2018quadprog\u2019 successfully unpacked and MD5 sums checked ** libs /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95 -m64   -PIC  -g  -c aind.f -o aind.o /opt/SunProd/studio12u3/solarisstudio12.3/bin/ cc -xc99 -m64 -I/usr/lib/64/R/include -DNDEBUG -KPIC  -xlibmieee  -c init.c -o init.o /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95 -m64  -PIC -g  -c -o solve.QP.compact.o solve.QP.compact.f /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95 -m64  -PIC -g  -c -o solve.QP.o solve.QP.f /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95 -m64   -PIC  -g  -c util.f -o util.o /opt/SunProd/studio12u3/solarisstudio12.3/bin/ cc -xc99 -m64 -G -o quadprog.so aind.o init.o solve.QP.compact.o solve.QP.o util.o -xlic_lib=sunperf -lsunmath -lifai -lsunimath -lfai -lfai2 -lfsumai -lfprodai -lfminlai -lfmaxlai -lfminvai -lfmaxvai -lfui -lfsu -lsunmath -lmtsk -lm -lifai -lsunimath -lfai -lfai2 -lfsumai -lfprodai -lfminlai -lfmaxlai -lfminvai -lfmaxvai -lfui -lfsu -lsunmath -lmtsk -lm -L/usr/lib/64/R/lib -lR installing to /u01/app/oracle/product/12.1.0/dbhome_1/R/library/quadprog/libs ** R ** preparing package for lazy loading ** help *** installing help indices   converting help for package \u2018quadprog\u2019     finding HTML links ... done     solve.QP                                html      solve.QP.compact                        html  ** building package indices ** testing if installed package can be loaded * DONE (quadprog) ====== Here is an example from http://cran.r-project.org/web/packages/quadprog/quadprog.pdf > require(quadprog) > Dmat <- matrix(0,3,3) > diag(Dmat) <- 1 > dvec <- c(0,5,0) > Amat <- matrix(c(-4,-3,0,2,1,0,0,-2,1),3,3) > bvec <- c(-8,2,0) > solve.QP(Dmat,dvec,Amat,bvec=bvec) $solution [1] 0.4761905 1.0476190 2.0952381 $value [1] -2.380952 $unconstrained.solution [1] 0 5 0 $iterations [1] 3 0 $Lagrangian [1] 0.0000000 0.2380952 2.0952381 $iact [1] 3 2 Here, the standard example is modified to work with Oracle R Enterprise require(ORE) ore.connect("my-name", "my-sid", "my-host", "my-pass", 1521) ore.doEval(   function () {     require(quadprog)   } ) ore.doEval(   function () {     Dmat <- matrix(0,3,3)     diag(Dmat) <- 1     dvec <- c(0,5,0)     Amat <- matrix(c(-4,-3,0,2,1,0,0,-2,1),3,3)     bvec <- c(-8,2,0)    solve.QP(Dmat,dvec,Amat,bvec=bvec)   } ) $solution [1] 0.4761905 1.0476190 2.0952381 $value [1] -2.380952 $unconstrained.solution [1] 0 5 0 $iterations [1] 3 0 $Lagrangian [1] 0.0000000 0.2380952 2.0952381 $iact [1] 3 2 Now I can combine the quadprog compute algorithms with the Oracle R Enterprise Database engine functionality: Scale to large datasets Access to tables, views, and external tables in the database, as well as those accessible through database links Use SQL query parallel execution Use in-database statistical and data mining functionality

    Read the article

  • Parallel programming, are we not learning from history again?

    - by mezmo
    I started programming because I was a hardware guy that got bored, I thought the problems being solved in the software side of things were much more interesting than those in hardware. At that time, most of the electrical buses I dealt with were serial, some moving data as fast as 1.5 megabit!! ;) Over the years these evolved into parallel buses in order to speed communication up, after all, transferring 8/16/32/64, whatever bits at a time incredibly speeds up the transfer. Well, our ability to create and detect state changes got faster and faster, to the point where we could push data so fast that interference between parallel traces or cable wires made cleaning the signal too expensive to continue, and we still got reasonable performance from serial interfaces, heck some graphics interfaces are even happening over USB for a while now. I think I'm seeing a like trend in software now, our processors were getting faster and faster, so we got good at building "serial" software. Now we've hit a speed bump in raw processor speed, so we're adding cores, or "traces" to the mix, and spending a lot of time and effort on learning how to properly use those. But I'm also seeing what I feel are advances in things like optical switching and even quantum computing that could take us far more quickly that I was expecting back to the point where "serial programming" again makes the most sense. What are your thoughts?

    Read the article

  • How do I implement graphs and graph algorithms in a functional programming language?

    - by brad
    Basically, I know how to create graph data structures and use Dijkstra's algorithm in programming languages where side effects are allowed. Typically, graph algorithms use a structure to mark certain nodes as 'visited', but this has side effects, which I'm trying to avoid. I can think of one way to implement this in a functional language, but it basically requires passing around large amounts of state to different functions, and I'm wondering if there is a more space-efficient solution.

    Read the article

  • Complicated programming and math tasks online. Any?

    - by Tom
    Maybe it is not very thematic question in here, but I guess it will be interesting not only to me. I hope. So, I just want to get some cool tasks to do using programming languages or just pen and sheet of paper. I guess it can lead to improving my ability to do better code (more optimal I mean.) Do you know any websites where I can find it? Thanks.

    Read the article

  • Wildcard DNS entry to match lang subdomain

    - by Adam Benayoun
    Hey, We have a website www.example.com pointing to x.x.x.1 and a system with multiples minisites all having subdomains.examples.com pointing to x.x.x.2 Basically what we have in place is a wildcard DNS entry who could basically match any possible subdomain, once reaching x.x.x.2, the apache vhost would intercept and basically redirect it to a php script who in turn would know what minisites to serve. On www.example.com however, we server contents which are translates in several languages, until few weeks ago you could switch languages by clicking on a flag and you'd be served with the translated content. The only problem is that the URL wouldn't change and SEO wise this isn't the best solution. Now I cannot change the way subdomain are handled (being redirected to x.x.x.2) since we have hundreds, if not thousands of minisites live. I have to come up with a solution to have language.example.com redirecting to x.x.x.1 and then a rewrite rule who would basically rewrite the fake subdomain into a URL in order to pass the parameter of the language to example.com On solution is to list all possible language as DNS entries right before the wildcard DNS entry. The other solution which I am almost sure is not feasible is to have some kind of regex in a DNS entry matching all subdomain with 2 letters ( en|es|fr|cn|cl etc... ) Any ideas?

    Read the article

  • Solaris X86 64-bit Assembly Programming

    - by danx
    Solaris X86 64-bit Assembly Programming This is a simple example on writing, compiling, and debugging Solaris 64-bit x86 assembly language with a C program. This is also referred to as "AMD64" assembly. The term "AMD64" is used in an inclusive sense to refer to all X86 64-bit processors, whether AMD Opteron family or Intel 64 processor family. Both run Solaris x86. I'm keeping this example simple mainly to illustrate how everything comes together—compiler, assembler, linker, and debugger when using assembly language. The example I'm using here is a C program that calls an assembly language program passing a C string. The assembly language program takes the C string and calls printf() with it to print the string. AMD64 Register Usage But first let's review the use of AMD64 registers. AMD64 has several 64-bit registers, some special purpose (such as the stack pointer) and others general purpose. By convention, Solaris follows the AMD64 ABI in register usage, which is the same used by Linux, but different from Microsoft Windows in usage (such as which registers are used to pass parameters). This blog will only discuss conventions for Linux and Solaris. The following chart shows how AMD64 registers are used. The first six parameters to a function are passed through registers. If there's more than six parameters, parameter 7 and above are pushed on the stack before calling the function. The stack is also used to save temporary "stack" variables for use by a function. 64-bit Register Usage %rip Instruction Pointer points to the current instruction %rsp Stack Pointer %rbp Frame Pointer (saved stack pointer pointing to parameters on stack) %rdi Function Parameter 1 %rsi Function Parameter 2 %rdx Function Parameter 3 %rcx Function Parameter 4 %r8 Function Parameter 5 %r9 Function Parameter 6 %rax Function return value %r10, %r11 Temporary registers (need not be saved before used) %rbx, %r12, %r13, %r14, %r15 Temporary registers, but must be saved before use and restored before returning from the current function (usually with the push and pop instructions). 32-, 16-, and 8-bit registers To access the lower 32-, 16-, or 8-bits of a 64-bit register use the following: 64-bit register Least significant 32-bits Least significant 16-bits Least significant 8-bits %rax%eax%ax%al %rbx%ebx%bx%bl %rcx%ecx%cx%cl %rdx%edx%dx%dl %rsi%esi%si%sil %rdi%edi%di%axl %rbp%ebp%bp%bp %rsp%esp%sp%spl %r9%r9d%r9w%r9b %r10%r10d%r10w%r10b %r11%r11d%r11w%r11b %r12%r12d%r12w%r12b %r13%r13d%r13w%r13b %r14%r14d%r14w%r14b %r15%r15d%r15w%r15b %r16%r16d%r16w%r16b There's other registers present, such as the 64-bit %mm registers, 128-bit %xmm registers, 256-bit %ymm registers, and 512-bit %zmm registers. Except for %mm registers, these registers may not present on older AMD64 processors. Assembly Source The following is the source for a C program, helloas1.c, that calls an assembly function, hello_asm(). $ cat helloas1.c extern void hello_asm(char *s); int main(void) { hello_asm("Hello, World!"); } The assembly function called above, hello_asm(), is defined below. $ cat helloas2.s /* * helloas2.s * To build: * cc -m64 -o helloas2-cpp.s -D_ASM -E helloas2.s * cc -m64 -c -o helloas2.o helloas2-cpp.s */ #if defined(lint) || defined(__lint) /* ARGSUSED */ void hello_asm(char *s) { } #else /* lint */ #include <sys/asm_linkage.h> .extern printf ENTRY_NP(hello_asm) // Setup printf parameters on stack mov %rdi, %rsi // P2 (%rsi) is string variable lea .printf_string, %rdi // P1 (%rdi) is printf format string call printf ret SET_SIZE(hello_asm) // Read-only data .text .align 16 .type .printf_string, @object .printf_string: .ascii "The string is: %s.\n\0" #endif /* lint || __lint */ In the assembly source above, the C skeleton code under "#if defined(lint)" is optionally used for lint to check the interfaces with your C program--very useful to catch nasty interface bugs. The "asm_linkage.h" file includes some handy macros useful for assembly, such as ENTRY_NP(), used to define a program entry point, and SET_SIZE(), used to set the function size in the symbol table. The function hello_asm calls C function printf() by passing two parameters, Parameter 1 (P1) is a printf format string, and P2 is a string variable. The function begins by moving %rdi, which contains Parameter 1 (P1) passed hello_asm, to printf()'s P2, %rsi. Then it sets printf's P1, the format string, by loading the address the address of the format string in %rdi, P1. Finally it calls printf. After returning from printf, the hello_asm function returns itself. Larger, more complex assembly functions usually do more setup than the example above. If a function is returning a value, it would set %rax to the return value. Also, it's typical for a function to save the %rbp and %rsp registers of the calling function and to restore these registers before returning. %rsp contains the stack pointer and %rbp contains the frame pointer. Here is the typical function setup and return sequence for a function: ENTRY_NP(sample_assembly_function) push %rbp // save frame pointer on stack mov %rsp, %rbp // save stack pointer in frame pointer xor %rax, %r4ax // set function return value to 0. mov %rbp, %rsp // restore stack pointer pop %rbp // restore frame pointer ret // return to calling function SET_SIZE(sample_assembly_function) Compiling and Running Assembly Use the Solaris cc command to compile both C and assembly source, and to pre-process assembly source. You can also use GNU gcc instead of cc to compile, if you prefer. The "-m64" option tells the compiler to compile in 64-bit address mode (instead of 32-bit). $ cc -m64 -o helloas2-cpp.s -D_ASM -E helloas2.s $ cc -m64 -c -o helloas2.o helloas2-cpp.s $ cc -m64 -c helloas1.c $ cc -m64 -o hello-asm helloas1.o helloas2.o $ file hello-asm helloas1.o helloas2.o hello-asm: ELF 64-bit LSB executable AMD64 Version 1 [SSE FXSR FPU], dynamically linked, not stripped helloas1.o: ELF 64-bit LSB relocatable AMD64 Version 1 helloas2.o: ELF 64-bit LSB relocatable AMD64 Version 1 $ hello-asm The string is: Hello, World!. Debugging Assembly with MDB MDB is the Solaris system debugger. It can also be used to debug user programs, including assembly and C. The following example runs the above program, hello-asm, under control of the debugger. In the example below I load the program, set a breakpoint at the assembly function hello_asm, display the registers and the first parameter, step through the assembly function, and continue execution. $ mdb hello-asm # Start the debugger > hello_asm:b # Set a breakpoint > ::run # Run the program under the debugger mdb: stop at hello_asm mdb: target stopped at: hello_asm: movq %rdi,%rsi > $C # display function stack ffff80ffbffff6e0 hello_asm() ffff80ffbffff6f0 0x400adc() > $r # display registers %rax = 0x0000000000000000 %r8 = 0x0000000000000000 %rbx = 0xffff80ffbf7f8e70 %r9 = 0x0000000000000000 %rcx = 0x0000000000000000 %r10 = 0x0000000000000000 %rdx = 0xffff80ffbffff718 %r11 = 0xffff80ffbf537db8 %rsi = 0xffff80ffbffff708 %r12 = 0x0000000000000000 %rdi = 0x0000000000400cf8 %r13 = 0x0000000000000000 %r14 = 0x0000000000000000 %r15 = 0x0000000000000000 %cs = 0x0053 %fs = 0x0000 %gs = 0x0000 %ds = 0x0000 %es = 0x0000 %ss = 0x004b %rip = 0x0000000000400c70 hello_asm %rbp = 0xffff80ffbffff6e0 %rsp = 0xffff80ffbffff6c8 %rflags = 0x00000282 id=0 vip=0 vif=0 ac=0 vm=0 rf=0 nt=0 iopl=0x0 status=<of,df,IF,tf,SF,zf,af,pf,cf> %gsbase = 0x0000000000000000 %fsbase = 0xffff80ffbf782a40 %trapno = 0x3 %err = 0x0 > ::dis # disassemble the current instructions hello_asm: movq %rdi,%rsi hello_asm+3: leaq 0x400c90,%rdi hello_asm+0xb: call -0x220 <PLT:printf> hello_asm+0x10: ret 0x400c81: nop 0x400c85: nop 0x400c88: nop 0x400c8c: nop 0x400c90: pushq %rsp 0x400c91: pushq $0x74732065 0x400c96: jb +0x69 <0x400d01> > 0x0000000000400cf8/S # %rdi contains Parameter 1 0x400cf8: Hello, World! > [ # Step and execute 1 instruction mdb: target stopped at: hello_asm+3: leaq 0x400c90,%rdi > [ mdb: target stopped at: hello_asm+0xb: call -0x220 <PLT:printf> > [ The string is: Hello, World!. mdb: target stopped at: hello_asm+0x10: ret > [ mdb: target stopped at: main+0x19: movl $0x0,-0x4(%rbp) > :c # continue program execution mdb: target has terminated > $q # quit the MDB debugger $ In the example above, at the start of function hello_asm(), I display the stack contents with "$C", display the registers contents with "$r", then disassemble the current function with "::dis". The first function parameter, which is a C string, is passed by reference with the string address in %rdi (see the register usage chart above). The address is 0x400cf8, so I print the value of the string with the "/S" MDB command: "0x0000000000400cf8/S". I can also print the contents at an address in several other formats. Here's a few popular formats. For more, see the mdb(1) man page for details. address/S C string address/C ASCII character (1 byte) address/E unsigned decimal (8 bytes) address/U unsigned decimal (4 bytes) address/D signed decimal (4 bytes) address/J hexadecimal (8 bytes) address/X hexadecimal (4 bytes) address/B hexadecimal (1 bytes) address/K pointer in hexadecimal (4 or 8 bytes) address/I disassembled instruction Finally, I step through each machine instruction with the "[" command, which steps over functions. If I wanted to enter a function, I would use the "]" command. Then I continue program execution with ":c", which continues until the program terminates. MDB Basic Cheat Sheet Here's a brief cheat sheet of some of the more common MDB commands useful for assembly debugging. There's an entire set of macros and more powerful commands, especially some for debugging the Solaris kernel, but that's beyond the scope of this example. $C Display function stack with pointers $c Display function stack $e Display external function names $v Display non-zero variables and registers $r Display registers ::fpregs Display floating point (or "media" registers). Includes %st, %xmm, and %ymm registers. ::status Display program status ::run Run the program (followed by optional command line parameters) $q Quit the debugger address:b Set a breakpoint address:d Delete a breakpoint $b Display breakpoints :c Continue program execution after a breakpoint [ Step 1 instruction, but step over function calls ] Step 1 instruction address::dis Disassemble instructions at an address ::events Display events Further Information "Assembly Language Techniques for Oracle Solaris on x86 Platforms" by Paul Lowik (2004). Good tutorial on Solaris x86 optimization with assembly. The Solaris Operating System on x86 Platforms An excellent, detailed tutorial on X86 architecture, with Solaris specifics. By an ex-Sun employee, Frank Hofmann (2005). "AMD64 ABI Features", Solaris 64-bit Developer's Guide contains rules on data types and register usage for Intel 64/AMD64-class processors. (available at docs.oracle.com) Solaris X86 Assembly Language Reference Manual (available at docs.oracle.com) SPARC Assembly Language Reference Manual (available at docs.oracle.com) System V Application Binary Interface (2003) defines the AMD64 ABI for UNIX-class operating systems, including Solaris, Linux, and BSD. Google for it—the original website is gone. cc(1), gcc(1), and mdb(1) man pages.

    Read the article

  • What books should I read to be be able to communicate with programmers? [migrated]

    - by Zak833
    My experience is in online marketing, UI/UX and web design, but I know virtually no programming. I have recently been hired to build a new, fairly complex site from scratch, for which I will be working with an experienced programmer with whom I have worked extensively in the past. Although I have a decent understanding of certain technical concepts relating to web development, I would like to build a better appreciation of the programmer's craft, in order to improve communication with my programmer, as well as the client. I have heard Code Complete is quite a good book for this. Other than reading this and learning some basic programming, are there any other books or resources that could be recommended to the non-programmer who does not wish to become a programmer, yet wishes to understand the most common concepts involved in building software, web-based or otherwise?

    Read the article

  • How to be more logical? (less bugs/errors)

    - by SamB
    I have been programming for 6 years and I am in high school (I prefer not to disclose my age). I have dabbled in many different languages. Just to list a few: Java, PHP, C++, Python, Autohotkey, Mathematica and many more. I have a very good understanding of the basics of general programming. The only problem is I still create bugs all the time. I think too often. Do you have any hints besides continuing to program that will help me become a better programmer and make less errors?

    Read the article

  • Which paradigm to use for writing chess engine?

    - by poke
    If you were going to write a chess game engine, what programming paradigm would you use (OOP, procedural, etc) and why whould you choose it ? By chess engine, I mean the portion of a program that evaluates the current board and decides the computer's next move. I'm asking because I thought it might be fun to write a chess engine. Then it occured to me that I could use it as a project for learning functional programming. Then it occured to me that some problems aren't well suited to the functional paradigm. Then it occured to me that this might be good discussion fodder.

    Read the article

  • Future of Programmers [closed]

    - by Brian Paul
    Possible Duplicate: Will programmers be around in a few years? I have a passion of web development, but have been wondering of late, what is the future of web programming, and just programming in general. I will give an example to illustrate this, companies now most of them buy/ are willing to spend more money to implement enterprise level products, coming from big companies, than hiring a programmer, because when you look at the long term,instead of paying this programmer, and being tied to his ideas and skills, better buy a product, which you are guaranteed high level functions and support. Therefore what will be the future to programmers?

    Read the article

  • Does heavy library and snippet codes usage make you a bad programmer?

    - by Henrik P.
    Overall I'm in programming for about 8 years now and it seems to me that I'm relying more and more on open source libraries and snippets (damn you GitHub!) to "get the job done". I know that in time I could write me own implementation but I like to focus on the overall design. Is this normal (non cooperate environment)? Does it make you a bad programmer if "programming" is nothing more than cluing different libraries together. Feels like it. I know about "don't reinvent the wheel" but what happens when you don't invent a single wheel anymore. What's your take on this?

    Read the article

  • Return to the old C days.

    - by RPK
    Long back I used to program on C and than VB exploitation changed the career path. After VB came the .NET that proved to be a HoneyPot of Microsoft for old VB programmers and frustrated programmers of other hard to learn languages. The label on this HoneyPot was: "Getting things done." I now want to contribute to the Linux and other GNU projects. I feel whatever programming language you learn today, but if programming is your bread-and-butter, you must remain in touch with C. Many things have changed now. From the old Turbo-C for DOS to the present ...? Please advise me how to get back on the C track again. Reading again whole thing, chapter-by-chapter is not possible now, but I can learn by writing small utilities type of things, but sure GUI based. And yes, I hope, learning is going to be easy now with so many live forums and active community spots like StackOverflow etc.

    Read the article

  • Which paradigm to use for writing chess engine?

    - by poke
    If you were going to write a chess game engine, what programming paradigm would you use (OOP, procedural, etc) and why whould you choose it ? By chess engine, I mean the portion of a program that evaluates the current board and decides the computer's next move. I'm asking because I thought it might be fun to write a chess engine. Then it occured to me that I could use it as a project for learning functional programming. Then it occured to me that some problems aren't well suited to the functional paradigm. Then it occured to me that this might be good discussion fodder.

    Read the article

  • How can a solo programmer become a good team player?

    - by Nick
    I've been programming (obsessively) since I was 12. I am fairly knowledgeable across the spectrum of languages out there, from assembly, to C++, to Javascript, to Haskell, Lisp, and Qi. But all of my projects have been by myself. I got my degree in chemical engineering, not CS or computer engineering, but for the first time this fall I'll be working on a large programming project with other people, and I have no clue how to prepare. I've been using Windows all of my life, but this project is going to be very unix-y, so I purchased a Mac recently in the hopes of familiarizing myself with the environment. I was fortunate to participate in a hackathon with some friends this past year -- both CS majors -- and excitingly enough, we won. But I realized as I worked with them that their workflow was very different from mine. They used Git for version control. I had never used it at the time, but I've since learned all that I can about it. They also used a lot of frameworks and libraries. I had to learn what Rails was pretty much overnight for the hackathon (on the other hand, they didn't know what lexical scoping or closures were). All of our code worked well, but they didn't understand mine, and I didn't understand theirs. I hear references to things that real programmers do on a daily basis -- unit testing, code reviews, but I only have the vaguest sense of what these are. I normally don't have many bugs in my little projects, so I have never needed a bug tracking system or tests for them. And the last thing is that it takes me a long time to understand other people's code. Variable naming conventions (that vary with each new language) are difficult (__mzkwpSomRidicAbbrev), and I find the loose coupling difficult. That's not to say I don't loosely couple things -- I think I'm quite good at it for my own work, but when I download something like the Linux kernel or the Chromium source code to look at it, I spend hours trying to figure out how all of these oddly named directories and files connect. It's a programming sin to reinvent the wheel, but I often find it's just quicker to write up the functionality myself than to spend hours dissecting some library. Obviously, people who do this for a living don't have these problems, and I'll need to get to that point myself. Question: What are some steps that I can take to begin "integrating" with everyone else? Thanks!

    Read the article

  • How to become a good team player?

    - by Nick
    I've been programming (obsessively) since I was 12. I am fairly knowledgeable across the spectrum of languages out there, from assembly, to C++, to Javascript, to Haskell, Lisp, and Qi. But all of my projects have been by myself. I got my degree in chemical engineering, not CS or computer engineering, but for the first time this fall I'll be working on a large programming project with other people, and I have no clue how to prepare. I've been using Windows all of my life, but this project is going to be very unix-y, so I purchased a Mac recently in the hopes of familiarizing myself with the environment. I was fortunate to participate in a hackathon with some friends this past year -- both CS majors -- and excitingly enough, we won. But I realized as I worked with them that their workflow was very different from mine. They used Git for version control. I had never used it at the time, but I've since learned all that I can about it. They also used a lot of frameworks and libraries. I had to learn what Rails was pretty much overnight for the hackathon (on the other hand, they didn't know what lexical scoping or closures were). All of our code worked well, but they didn't understand mine, and I didn't understand theirs. I hear references to things that real programmers do on a daily basis -- unit testing, code reviews, but I only have the vaguest sense of what these are. I normally don't have many bugs in my little projects, so I have never needed a bug tracking system or tests for them. And the last thing is that it takes me a long time to understand other people's code. Variable naming conventions (that vary with each new language) are difficult (__mzkwpSomRidicAbbrev), and I find the loose coupling difficult. That's not to say I don't loosely couple things -- I think I'm quite good at it for my own work, but when I download something like the Linux kernel or the Chromium source code to look at it, I spend hours trying to figure out how all of these oddly named directories and files connect. It's a programming sin to reinvent the wheel, but I often find it's just quicker to write up the functionality myself than to spend hours dissecting some library. Obviously, people who do this for a living don't have these problems, and I'll need to get to that point myself. Question: What are some steps that I can take to begin "integrating" with everyone else? Thanks!

    Read the article

  • Why should a class be anything other than "abstract" or "final/sealed"

    - by Nicolas Repiquet
    After 10+ years of java/c# programming, I find myself creating either: abstract classes: contract not meant to be instantiated as-is. final/sealed classes: implementation not meant to serve as base class to something else. I can't think of any situation where a simple "class" (i.e. neither abstract nor final/sealed) would be "wise programming". Why should a class be anything other than "abstract" or "final/sealed" ? EDIT This great article explains my concerns far better than I can.

    Read the article

  • How do you accept arguments in the main.cpp file and reference another file?

    - by Jason H.
    I have a basic understanding of programming and I currently learning C++. I'm in the beginning phases of building my own CLI program for ubuntu. However, I have hit a few snags and I was wondering if I could get some clarification. The program I am working on is called "sat" and will be available via command line only. I have the main.cpp. However, my real question is more of a "best practices" for programming/organization. When my program "sat" is invoked I want it to take additional arguments. Here is an example: > sat task subtask I'm not sure if the task should be in its own task.cpp file for better organization or if it should be a function in the main.cpp? If the task should be in its own file how do you accept arguments in the main.cpp file and reference the other file? Any thoughts on which method is preferred and reference material to backup the reasoning?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 67 68 69 70 71 72 73 74 75 76 77 78  | Next Page >