from binutils/readelf.c:

     /* The difference between readelf and objdump:
      
       Both programs are capabale of displaying the contents of ELF format files,
       so why does the binutils project have two file dumpers ?
       
       The reason is that objdump sees an ELF file through a BFD filter of the
       world; if BFD has a bug where, say, it disagrees about a machine constant
       in e_flags, then the odds are good that it will remain internally
       consistent.  The linker sees it the BFD way, objdump sees it the BFD way,
       GAS sees it the BFD way.  There was need for a tool to go find out what
       the file actually says.
     
       This is why the readelf program does not link against the BFD library - it
       exists as an independent program to help verify the correct working of BFD.
     
       There is also the case that readelf can provide more information about an
       ELF file than is provided by objdump.  In particular it can display DWARF
       debugging information which (at the moment) objdump cannot.  */
     

what is the different between timestamp data type without parameter and with parameter 0:

`timestamp` VS `timestamp(0)`




Oracle timestamp data type

I&#39;ve been receiving an error on one of my pages that the linq query has timed out as it is taking too long.  It makes the page unusable.

It&#39;s a reports page which is only accessed by administrators around once a day.  It&#39;s unavoidable to trim this query down at all, it just has to sort through a lot of data.

Solutions to fix this I&#39;ve read are by increasing the timeout property in the data context, but I&#39;d like to avoid doing that as it would change it for the entire website.

Is there any way to set a larger time out for individual pages?

Linq-to-SQL Timeout

I need to learn about the ELF file layout for a project I am working on and I noticed the existence of these tools.
Why do all Linux distributions include both readelf and objdump? Do these tools complement one another? When would i prefer to use one over another?

readelf vs. objdump: why are both needed

<p>I need to learn about the ELF file layout for a project I am working on and I noticed the existence of these tools.
Why do all Linux distributions include both readelf and objdump? Do these tools complement one another? When would i prefer to use one over another?</p>


I want to kill all processes that I get by:

    ps aux | grep my_pattern

How to do it?

This does not work:

    pkill my_pattern

 

How to kill all processes with a given partial name?

I&#39;m trying to get `psql` to format nicely and am following the docs [here](http://www.postgresql.org/docs/9.0/static/app-psql.html). Right now, whenever I do a query on tables with lots of columns, no matter how big I make my screen each line overflows into the next line and producing a whole screen of unreadable junk.

The docs (link is above) say there&#39;s a way to align columns nicely for more readable output.

Normally, to start `psql`, I just type:

&gt; psql

and hit *Enter*. Now I&#39;m trying:

&gt; psql \pset format aligned

And getting an error:

    could not change directory to &quot;/root&quot;
    psql: warning: extra command-line argument &quot;aligned&quot; ingored
    psql: FATAL: Indent authentication failed for user &quot;format&quot;

Any ideas as to how I could get these command-line args to work for me?

PostgreSQL psql terminal command

Let&#39;s say I wanted to benchmark two programs: foo.py and bar.py.

Are a couple thousand runs and the respective averages of `time python foo.py` and `time python bar.py` adequate enough for profiling and comparing their speed?
&lt;br/&gt;&lt;br /&gt;&lt;br /&gt;
&lt;b&gt;Edit:&lt;/b&gt; Additionally, if the execution of each program was sub-second (assume it wasn&#39;t for the above), would `time` still be okay to use?

Is the UNIX `time` command accurate enough for benchmarks?

How do I go about enabling GD Support in a CentOS Installation?

CentOS: Enabling GD Support in PHP Installation

I am trying to rsync directory A of server1 with directory B of server2.

Sitting in the directory A of server1, I ran the following commands.

    rsync -av * server2::sharename/B

but the interesting thing is, it synchronizes all files and directories except .htaccess or any hidden file in the directory A. Any hidden files within subdirectories get synchronized.

I also tried the following command:

    rsync -av --include=&quot;.htaccess&quot; * server2::sharename/B

but the results are the same.

Any ideas why hidden files of A directory are not getting synchronized and how to fix it. I am running as root user.

thanks



rsync not synchronizing .htaccess file

How do I install GCC (the GNU Compiler Collection) piece by piece, using the current version,  
using the correct versions of dependencies, not using a package manager (like yum, rpm, apt, dpkg), and not using shared libraries?

Typical developers will likely want to install GCC the typical way, use your package manager (yum, rpm, apt, dpkg, port, brew, etc.) or follow the instructions here (http://gcc.gnu.org/wiki/InstallingGCC).

My question is how to install GCC piece by piece, without shared libraries.

* I want a fully-independent GCC that can be moved around my system without using any shared libraries, and without creating any shared libraries.
* This is what GCC calls &quot;the difficult way&quot; and it is not recommended for typical users.

GCC depends on:

  * GMP: GNU Multiple Precision Arithmetic Library
  * MPFR: GNU Multiple-precision floating-point rounding library
  * MPC: GNU Multiple-precision C library
  * ELF: Executable and Linkable Format library
  * PPL: Parma Polyhedra Library (optional, for memory optimizations)


How to install GCC piece by piece with GMP, MPFR, MPC, ELF, without shared libraries?

I am trying to build a simple C program for two different Linux environments. On one device the program runs fine, on the other device the program generates a floating point exception. The program does nothing but return 0 from main which leads me to believe there is some incompatibility with the start-up code perhaps ABI?

The program is compiled with gcc with the following build specs:

&gt; Using built-in specs. Target: i386-redhat-linux Configured with:
&gt; ../configure --prefix=/usr --mandir=/usr/share/man
&gt; --infodir=/usr/share/info --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-libgcj-multifile --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --disable-plugin --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic --host=i386-redhat-linux Thread model: posix gcc version 4.1.2 20080704 (Red Hat 4.1.2-52)


The program source is the following:

    int main()
    {
            return(0);
    }

On the Celeron device this program generates the following under GDB:

    [root@n00200C30AA2F jrn]# /jrn/gdb fail GNU gdb Red Hat Linux (5.3post-0.20021129.18rh) (gdb) run Starting program: /jrn/fail 
    
    Program received signal SIGFPE, Arithmetic exception. 0x40001cce in ?? () (gdb) bt
    #0  0x40001cce in ?? ()
    #1  0x4000c6b0 in ?? ()
    #2  0x40000cb5 in ?? ()

Below are the details that I can think to gather to help find out what is happening:

&lt;!-- language: none --&gt;

    CELERON:  ( fails on this device )
    2.6.8 #21 Mon Oct 1 11:41:47 PDT 2007 i686 i686 i386 GNU/Linux
    ============
    [root@n00200C30AA2F proc]# cat cpuinfo 
    processor       : 0
    vendor_id       : GenuineIntel
    cpu family      : 6
    model           : 9
    model name      : Intel(R) Celeron(R) M processor          600MHz
    stepping        : 5
    cpu MHz         : 599.925
    cache size      : 512 KB
    fdiv_bug        : no
    hlt_bug         : no
    f00f_bug        : no
    coma_bug        : no
    fpu             : yes
    fpu_exception   : yes
    cpuid level     : 2
    wp              : yes
    flags           : fpu vme de pse tsc msr mce cx8 sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 tm pbe
    bogomips        : 1179.64
    
    GNU C Library stable release version 2.3.2, by Roland McGrath et al.
    Compiled by GNU CC version 3.2.2 20030222 (Red Hat Linux 3.2.2-5).
    Compiled on a Linux 2.4.20 system on 2003-03-13.
    Available extensions:
            GNU libio by Per Bothner
            crypt add-on version 2.1 by Michael Glad and others
            linuxthreads-0.10 by Xavier Leroy
            BIND-8.2.3-T5B
            libthread_db work sponsored by Alpha Processor Inc
            NIS(YP)/NIS+ NSS modules 0.19 by Thorsten Kukuk
    
    ATOM:  ( works fine on this device )
    2.6.35 #25 SMP Mon Mar 12 09:02:45 PDT 2012 i686 i686 i386 GNU/Linux
    ==========
    [root@n00E04B36ECE5 ~]# cat /proc/cpuinfo 
    processor       : 0
    vendor_id       : GenuineIntel
    cpu family      : 6
    model           : 28
    model name      : Genuine Intel(R) CPU N270   @ 1.60GHz
    stepping        : 2
    cpu MHz         : 1599.874
    cache size      : 512 KB
    fdiv_bug        : no
    hlt_bug         : no
    f00f_bug        : no
    coma_bug        : no
    fpu             : yes
    fpu_exception   : yes
    cpuid level     : 10
    wp              : yes
    flags           : fpu vme de tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc up arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl est tm2 ssse3 xtpr pdcm movbe lahf_lm
    bogomips        : 3199.74
    clflush size    : 64
    cache_alignment : 64
    address sizes   : 32 bits physical, 32 bits virtual
    power management:
    
    
    GNU C Library stable release version 2.5, by Roland McGrath et al.
    Compiled by GNU CC version 4.1.2 20080704 (Red Hat 4.1.2-44).
    Compiled on a Linux 2.6.9 system on 2009-09-02.
    Available extensions:
            The C stubs add-on version 2.1.2.
            crypt add-on version 2.1 by Michael Glad and others
            GNU Libidn by Simon Josefsson
            GNU libio by Per Bothner
            NIS(YP)/NIS+ NSS modules 0.19 by Thorsten Kukuk
            Native POSIX Threads Library by Ulrich Drepper et al
            BIND-8.2.3-T5B
            RT using linux kernel aio
    Thread-local storage support included.


What can I do to determine what is causing this problem?
How about trying to statically link against a certain version of libc?

After failure occurs under GDB I execute:

&gt;     (gdb) x/1i $eip
&gt;     0x40001cce:     divl   0x164(%ecx)
&gt; 

    (gdb) info reg
    eax            0x6c994f 7117135
    ecx            0x40012858       1073817688
    edx            0x0      0
    ebx            0x40012680       1073817216
    esp            0xbffff740       0xbffff740
    ebp            0xbffff898       0xbffff898
    esi            0x8049580        134518144
    edi            0x400125cc       1073817036
    eip            0x40001cce       0x40001cce
    eflags         0x10246  66118
    cs             0x73     115
    ss             0x7b     123
    ds             0x7b     123
    es             0x7b     123
    fs             0x0      0
    gs             0x0      0
    (gdb) x/1wx 0x164+$ecx
    0x400129bc:     0x00000000
    (gdb) 


Based on the help I&#39;ve received it appears that for some reason the libc startup code is dividing by 0. 

The question now is, what is causing this obviously bad behavior? Something must be incompatible with something else? 

**Assembly output:**

    [jrn@localhost ~]$ more fail.s
            .file   &quot;fail.c&quot;
            .text
    .globl main
            .type   main, @function
    main:
            leal    4(%esp), %ecx
            andl    $-16, %esp
            pushl   -4(%ecx)
            pushl   %ebp
            movl    %esp, %ebp
            pushl   %ecx
            movl    $0, %eax
            popl    %ecx
            popl    %ebp
            leal    -4(%ecx), %esp
            ret
            .size   main, .-main
            .ident  &quot;GCC: (GNU) 4.1.2 20080704 (Red Hat 4.1.2-52)&quot;
            .section        .note.GNU-stack,&quot;&quot;,@progbits

  




Floating point exception ( SIGFPE ) on &#39;int main(){ return(0); }&#39;

I have an old executable that&#39;s scheduled for the scrap heap, but it&#39;s not there yet. It relies on some libs that have been removed from my environment, but I have some stub libs someplace where it works fine. Id like to point this executable to these stub libs. Yes, i could set LD_LIBRARY_PATH, but this executable is called from many scripts, and many users and I&#39;d love to fix it in one spot.

I don&#39;t have source for this, and would be hard to get it. I was thinking - can I edit this file, using an ELF aware editor, and add a simple PATH to rpath to have it hit the new libs? Is this possible, or once you create an ELF binary, you fix things to locations and they can&#39;t be moved?

Can I change &#39;rpath&#39; in an already compiled binary?

From wiki [Executable and Linkable Format](https://en.wikipedia.org/wiki/Executable_and_Linkable_Format):

&gt; The segments contain information that is necessary for runtime execution of the file, while sections contain important data for linking and relocation. Any byte in the entire file can be owned by at most one section, and there can be orphan bytes which are not owned by any section.

But what is the difference between section and segment? 
In an executable ELF file, does a segment contain one or more sections?

What&#39;s the difference of section and segment in ELF file format

I&#39;m working on a nodejs project for school.
I wasn&#39;t able to install bcrypt with npm so i installed bcrypt-nodejs and the project worked fine yesterday.
But today, when I do a &quot;node app&quot; i have this error :


    /.../node_modules/bcrypt/node_modules/bindings/bindings.js:79
            throw e
                  ^
    Error: /.../node_modules/bcrypt/build/Release/bcrypt_lib.node: invalid ELF header
        at Module.load (module.js:356:32)
        at Function.Module._load (module.js:312:12)
        at Module.require (module.js:364:17)
        at require (module.js:380:17)
        at bindings (/.../node_modules/bcrypt/node_modules/bindings/bindings.js:74:15)
        at Object.&lt;anonymous&gt; (/.../node_modules/bcrypt/bcrypt.js:1:97)
        at Module._compile (module.js:456:26)
        at Object.Module._extensions..js (module.js:474:10)
        at Module.load (module.js:356:32)
        at Function.Module._load (module.js:312:12)
        at Module.require (module.js:364:17)
        at require (module.js:380:17)

my package.json file looks like this:


    {
      &quot;name&quot;: &quot;Supinfarm&quot;,
      &quot;version&quot;: &quot;0.0.0&quot;,
      &quot;env&quot;: {
                  &quot;PYTHON&quot;: &quot;/usr/bin/python2.6&quot;
            },
      &quot;dependencies&quot;: {
        &quot;express&quot;: &quot;3.1.0&quot;,
        &quot;connect-flash&quot;: &quot;*&quot;,
        &quot;jade&quot;: &quot;*&quot;,
        &quot;stylus&quot;: &quot;*&quot;,
        &quot;passport&quot;: &quot;*&quot;,
        &quot;passport-local&quot;: &quot;*&quot;,
        &quot;mongoose&quot;: &quot;*&quot;,
        &quot;bcrypt&quot;: &quot;*&quot;
      }
    }

I&#39;m on Linux ubuntu 10.04 LTS
I&#39;ve tried to find a solution on google without success...
Can somebody help me?


bcrypt invalid elf header when running node app

How can I tell `objdump` to emit assembly in Intel Syntax rather than the default AT&amp;T syntax?

How can objdump emit intel syntax

I&#39;ve got a binary installed on my system, and would like to look at the disassembly of a given function. Preferrably using `objdump`, but other solutions would be acceptable as well.

From [this questions][1] I&#39;ve learned that I might be able to disassemble part of the code if I only know the boundary addresses. From [this answer][2] I&#39;ve learned how to turn my split debug symbols back into a single file.

But even operating on that single file, and even disassembling all the code (i.e. without start or stop address, but plain `-d` parameter to `objdump`), I still don&#39;t see that symbol anywhere. Which makes sense insofar as the function in question is static, so it isn&#39;t exported. Nevertheless, `valgrind` will report the function name, so it has to be stored somewhere. 

Looking at the details of the debug sections, I find that name mentioned in the `.debug_str` section, but I don&#39;t know a tool which can turn this into an address range.


  [1]: https://stackoverflow.com/q/6441721/1468366
  [2]: https://stackoverflow.com/a/17599967/1468366

Content Type	Original Author	Original Content on Stackoverflow
Question	zr.	View Question on Stackoverflow
Solution 1 - Linux	synthesizerpatel	View Answer on Stackoverflow

readelf vs. objdump: why are both needed

Linux Problem Overview

Linux Solutions

Solution 1 - Linux

Linq-to-SQL Timeout

Oracle timestamp data type

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