I suppose you meant `strace -fetrace=open`?

&lt;pre&gt;&lt;a href=&quot;https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man1/dtruss.1m.html&quot;&gt;dtruss&lt;/a&gt; -f -t open python myfile.py&lt;/pre&gt;

I tried to create a database diagramm with SQL Server 2008, but an error occurs:

&gt; Database diagram support objects
&gt; cannot be installed because this
&gt; database does not have a valid owner.
&gt; To continue, first use the Files page
&gt; of the Database Properties dialog box
&gt; or the ALTER AUTHORIZATION statement
&gt; to set the database owner to a valid
&gt; login, then add the database diagram
&gt; support objects.

Then I tried the following:

    EXEC sp_dbcmptlevel &#39;Ariha&#39;, &#39;90&#39;;
    GO
    ALTER AUTHORIZATION ON DATABASE::Ariha TO [WIN-NDKPHUPPNFL\Administrator]
    GO
    USE Ariha
    GO
    EXECUTE AS USER = N&#39;dbo&#39; REVERT
    GO
Next erorr pops up: 

&gt; Msg 15404, Level 16, State 11, Line 1
&gt; Could not obtain information about
&gt; Windows NT group/user
&gt; &#39;WIN-NDKPHUPPNFL\Administrator&#39;, error
&gt; code 0x534.

The Problem is the name of the PC has changed into &quot;DevPC&quot; I also changed this in the update script, but still the same error 15404. 

What can I do to fix this annoying error?

    

Database Diagram Support Objects cannot be Installed ... no valid owner

Given a date `MM-dd-yyyy` format, can someone help me get the first day of the week?

Get first day of week in PHP?

This is useful for debugging (hence programming related).  On linux, we can use the command

    strace -feopen python myfile.py

to figure out which python modules and shared objects are loaded.  Is there an equivalent one-liner on macOS X?



Equivalent of strace -feopen &lt; command &gt; on mac os X

<p>This is useful for debugging (hence programming related).  On linux, we can use the command</p>
<pre><code class="hljs">strace -feopen python myfile.py
</code></pre>
<p>to figure out which python modules and shared objects are loaded.  Is there an equivalent one-liner on macOS X?</p>


It&#39;s hard to find Mac-specific answers to this question on the web, so I&#39;m hoping someone out there can put this one to rest for me? My permissions are screwed up on my sites and I&#39;m not sure how to fix them without just slamming a recursive 777 on everything which is quite obviously incorrect.

Thanks!

Correct owner/group/permissions for Apache 2 site files/folders under Mac OS X?

Does OS X (Snow Leopard in particular) have an equivalent to (some versions of) Linux&#39;s `/dev/shm` , ie something where you can write to and read from a file without necessarily touching the hard drive?

Does OS X have an equivalent to /dev/shm?

I have MacVim installed and I am trying to set it up as the editor for Git (version control),  but I can&#39;t run &#39;mvim&#39; from the command line as it isn&#39;t recognised. How do I setup mvim so I can run it from Terminal?

How to run mvim (MacVim) from Terminal?

On Mac OS X, if I send SIGQUIT to my C program, it terminates, but there is no core dump file.

Do you have to manually enable core dumps on Mac OS X (how?), or are they written to somewhere else instead of the working directory?

Where are core dumps written on Mac?

Running &#39;`sudo gem list --local`&#39; and &#39;`gem list --local`&#39; give me differing results. My gem path is set to my home folder and only contains the gems from &#39;`gem list --local`&#39;.

It&#39;s probably not good to have gems installed in different directories on my computer, so should I have the gem path set differently, and should I always use `sudo` when installing something?

    my ~/.profile
    export PATH=/opt/local/bin:/opt/local/sbin:$PATH
    export PATH=&quot;/usr/local/bin:/usr/local/sbin:/usr/local/mysql/bin:$PATH&quot;

~/.bash_profile is empty.


&#39;sudo gem install&#39; or &#39;gem install&#39; and gem locations

Snow Leopard introduced many new methods to use NSURL objects to refer to files, not pathnames or Core Services&#39; FSRefs.

However, there&#39;s one task I can&#39;t find a URL-based method for: Testing whether a file exists. I&#39;m looking for a URL-based version of [-\[NSFileManager `fileExistsAtPath:`\]](http://developer.apple.com/mac/library/documentation/Cocoa/Reference/Foundation/Classes/NSFileManager_Class/Reference/Reference.html#//apple_ref/occ/instm/NSFileManager/fileExistsAtPath:). Like that method, it should return `YES` if the URL describes anything, whether it&#39;s a regular file, a directory, or anything else.

I could attempt to look up various [resource values](http://developer.apple.com/mac/library/documentation/Cocoa/Reference/Foundation/Classes/NSURL_Class/Reference/Reference.html#//apple_ref/occ/instm/NSURL/resourceValuesForKeys:error:), but none of them are explicitly guaranteed to not exist if the file doesn&#39;t, and some of them (e.g., [NSURLEffectiveIconKey](http://developer.apple.com/mac/library/documentation/Cocoa/Reference/Foundation/Classes/NSURL_Class/Reference/Reference.html#//apple_ref/doc/c_ref/NSURLEffectiveIconKey)) could be costly if it does.

I could just use NSFileManager&#39;s `fileExistsAtPath:`, but if there&#39;s a more modern method, I&#39;d prefer to use that.

Is there a simple method or function in Cocoa, CF, or Core Services that&#39;s guaranteed/documented to tell me whether a given file (or file-reference) URL refers to a file-system object that exists?


Testing file existence using NSURL

Though I&#39;m sure others have eventually managed to figure this out, I&#39;ve been following the various documentation out there and have been having a heck of a rough time of it.

http://www.phpunit.de/manual/current/en/installation.html

Makes it sound pretty easy.  However depending on your setup, you might be going down a rabbit hole.

PEAR for example must be of a version higher than 1.8.1.  I had 1.8.0 at the time, so I went to find out how to update PEAR

    PEAR upgrade-all

Gives an error.  No access.

    sudo PEAR upgrade-all

Works, but upgrades the PEAR install owned by the user &#39;sudo&#39; (and not your primary account... or something like that, short version is 5that it plain don&#39;t work)

    cd ~
    pico .bash_profile

add

    export PATH=/usr/local/bin:$PATH

give you the correct PEAR when you type PEAR, you&#39;re finally ready for step 1 of the install PHPUnit instructions.

    pear channel-discover pear.phpunit.de

Error.  You don&#39;t have access to /usr/local/temp

    sudo chmod 777 /usr/local/temp

Error. You don&#39;t have access to /usr/local/temp/channel.xml

    sudo chmod 777 /usr/local/temp/channel.xml
    pear channel-discover pear.phpunit.de

Error.

    Registry directory is not writeable by the current user

BUT I&#39;M ON A MAC!

    /sigh
    /facepalm
    /tears


I&#39;ve actually got a &quot;working copy&quot; of phpunit on my machine.  (YAY!) the odd problem is that 
 it only works when I type phpunit from one specific folder

    cd /usr/local/PEAR
    phpunit

^^ WORKS

    cd ~
    phpunit

^^ Returns 

    Warning: require_once(PHPUnit/Util/Filter.php): failed to open stream: No such file or directory in /usr/local/bin/phpunit on line 46

    Fatal error: require_once(): Failed opening required &#39;PHPUnit/Util/Filter.php&#39; (include_path=&#39;.:/usr/lib/php&#39;) in /usr/local/bin/phpunit on line 46

So close yet so far... I&#39;m wondering if anyone has some input on getting this guy working right?




Setting up PHPUnit on OSX

Double values store higher precision and are double the size of a float, but are Intel CPUs optimized for floats?

That is, are double operations just as fast or faster than float operations for +, -, *, and /?

Does the answer change for 64-bit architectures?


Is using double faster than float?

##The setup...
Trying to set up a clean Mac os X 10.6 install to develop python/django and I didn&#39;t remember running into this on 10.5.

After installing MySQL from the installer on `mysql-5.5.8-osx10.6-x86_64.dmg` I ran

    $ sudo pip install MySQL-python

and it seemed to go smoothly (output below)

    Downloading/unpacking MySQL-python
      Downloading MySQL-python-1.2.3.tar.gz (70Kb): 70Kb downloaded
      Running setup.py egg_info for package MySQL-python
        warning: no files found matching &#39;MANIFEST&#39;
        warning: no files found matching &#39;ChangeLog&#39;
        warning: no files found matching &#39;GPL&#39;
    Installing collected packages: MySQL-python
      Running setup.py install for MySQL-python
        building &#39;_mysql&#39; extension
        gcc-4.2 -fno-strict-aliasing -fno-common -dynamic -DNDEBUG -g -fwrapv -Os -Wall -Wstrict-prototypes -DENABLE_DTRACE -pipe -Dversion_info=(1,2,3,&#39;final&#39;,0) -D__version__=1.2.3 -I/usr/local/mysql/include -I/System/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6 -c _mysql.c -o build/temp.macosx-10.6-universal-2.6/_mysql.o -Os -g -fno-common -fno-strict-aliasing -arch x86_64
        In file included from _mysql.c:36:
        /usr/local/mysql/include/my_config.h:325:1: warning: &quot;SIZEOF_SIZE_T&quot; redefined
        In file included from /System/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6/Python.h:9,
                         from pymemcompat.h:10,
                         from _mysql.c:29:
        /System/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6/pymacconfig.h:33:1: warning: this is the location of the previous definition
        In file included from _mysql.c:36:
        /usr/local/mysql/include/my_config.h:419:1: warning: &quot;HAVE_WCSCOLL&quot; redefined
        In file included from /System/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6/Python.h:8,
                         from pymemcompat.h:10,
                         from _mysql.c:29:
        /System/Library/Frameworks/Python.framework/Versions/2.6/include/python2.6/pyconfig.h:803:1: warning: this is the location of the previous definition
        gcc-4.2 -Wl,-F. -bundle -undefined dynamic_lookup build/temp.macosx-10.6-universal-2.6/_mysql.o -L/usr/local/mysql/lib -lmysqlclient_r -lpthread -o build/lib.macosx-10.6-universal-2.6/_mysql.so -arch x86_64
        warning: no files found matching &#39;MANIFEST&#39;
        warning: no files found matching &#39;ChangeLog&#39;
        warning: no files found matching &#39;GPL&#39;
    Successfully installed MySQL-python
    Cleaning up...

after this I tried:

    $ python -c &quot;import MySQLdb&quot;

and it crapped out on me with:

    Traceback (most recent call last):
      File &quot;&lt;string&gt;&quot;, line 1, in &lt;module&gt;
      File &quot;/Library/Python/2.6/site-packages/MySQLdb/__init__.py&quot;, line 19, in &lt;module&gt;
        import _mysql
    ImportError: dlopen(/Library/Python/2.6/site-packages/_mysql.so, 2): Library not loaded: libmysqlclient.16.dylib
      Referenced from: /Library/Python/2.6/site-packages/_mysql.so
      Reason: image not found

##So on to my question...

What did I do wrong?/What else do I need to do?

Googling (and searching here) for this returns a lot of results getting this error message with Ruby not too many with Python tho.


Python: MySQLdb and &quot;Library not loaded: libmysqlclient.16.dylib&quot;

In my iPhone app, I have many ASCII arts which I need to insert into the database.

I am using the simulator and pasting the textpic in the textview to insert the ASCII art to database.

Here the clipboard of simulator once pastes the art properly but when I copy another art then too it pastes the previous art into textview. 

How to solve this problem? Is there a work around for this or any better approach?


Copy from Mac OS X does not copy to iPhone Simulator

OS X lacks linux&#39;s `strace`, but it has `dtrace` which is supposed to be so much better. 

However, I miss the ability to do simple tracing on individual commands. For example, on linux I can write `strace -f gcc hello.c ` to caputre all system calls, which gives me the  list of *all* the filenames needed by the compiler to compile my program (the excellent [memoize][1] script is built upon this trick)

  [1]: http://www.eecs.berkeley.edu/~billm/memoize.html

I want to port memoize on the mac, so I need some kind of `strace`. What I actually need is the list of files `gcc` reads and writes into, so what I need is more of a `truss`. Sure enough can I say `dtruss -f gcc hello.c` and get somewhat the same functionality, but then the compiler is run with root priviledges, which is obviously undesirable (apart from the massive security risk, one issue is that the `a.out` file is now owned by root :-)

I then tried `dtruss -f sudo -u myusername gcc hello.c`, but this feels a bit wrong, and does not work anyway (I get no `a.out` file at all this time, not sure why)

All that long story tries to motivate my original question: **how do I get `dtrace` to run my command with normal user privileges, just like `strace` does in linux ?**

Edit: is seems that I&#39;m not the only one wondering how to do this: question [#1204256][2] is pretty much the same as mine (and has the same suboptimal sudo answer :-) 

[2]: https://stackoverflow.com/questions/1204256/how-to-trace-a-program-from-its-very-beginning-without-running-it-as-root


How can I get dtrace to run the traced command with non-root priviledges?

It looks like in OS X 10.11 El Capitan, `dtruss` and `dtrace` can no longer do what they&#39;re meant to do. This is the error I get when I try to run `sudo dtruss curl ...`:

&gt; dtrace: failed to execute curl: dtrace cannot control executables signed with restricted entitlements

I&#39;ve come across people noticing this problem but so far no solutions.

Is there a way to fix this or work around this?

Is there a workaround for: &quot;dtrace cannot control executables signed with restricted entitlements&quot;?

How do I diagnose the cause of Docker on MacOS, specifically `com.docker.hyperkit` using 100% of CPU?

[![docker CPU usage][1]][1]

### Docker stats

Docker stats shows all the running containers have low CPU, memory, net IO and block IO.


[![docker stats output][2]][2]

### iosnoop

iosnoop shows that `com.docker.hyperkit` performs about 50 writes per second totaling 500KB per second to the file `Docker.qcow2`.  According to https://stackoverflow.com/questions/49887747/what-is-docker-qcow2, `Docker.qcow2` is a sparse file that&#39;s the persistent storage for all Docker containers.

In my case the file isn&#39;t that sparse. The physical size matches the logical size.

[![docker.qcow actual size][3]][3]


### dtrace (dtruss)

dtruss `sudo dtruss -p $DOCKER_PID` shows a large number of `psynch_cvsignal` and `psynch_cvwait` calls.

```
psynch_cvsignal(0x7F9946002408, 0x4EA701004EA70200, 0x4EA70100)          = 257 0
psynch_mutexdrop(0x7F9946002318, 0x5554700, 0x5554700)           = 0 0
psynch_mutexwait(0x7F9946002318, 0x5554702, 0x5554600)           = 89474819 0
psynch_cvsignal(0x10BF7B470, 0x4C8095004C809600, 0x4C809300)             = 257 0
psynch_cvwait(0x10BF7B470, 0x4C8095014C809600, 0x4C809300)               = 0 0
psynch_cvwait(0x10BF7B470, 0x4C8096014C809700, 0x4C809600)               = -1 Err#316
psynch_cvsignal(0x7F9946002408, 0x4EA702004EA70300, 0x4EA70200)          = 257 0
psynch_cvwait(0x7F9946002408, 0x4EA702014EA70300, 0x4EA70200)            = 0 0
psynch_cvsignal(0x10BF7B470, 0x4C8097004C809800, 0x4C809600)             = 257 0
psynch_cvwait(0x10BF7B470, 0x4C8097014C809800, 0x4C809600)               = 0 0
psynch_cvwait(0x10BF7B470, 0x4C8098014C809900, 0x4C809800)               = -1 Err#316
```

### Update: `top` on Docker host

From https://stackoverflow.com/a/58293240/30900:

```
docker run -it --rm --pid host busybox top
```

The CPU usage on docker embedded host is ~3%.  CPU usage on my MacBook was ~100%.  So, the docker embedded host isn&#39;t causing the CPU usage spike.

[![docker host top][4]][4]

### Update: running dtrace scripts of most common stack traces

Stack traces from the dtrace scripts in the answer below: https://stackoverflow.com/a/58293035/30900.

These kernel stack traces look innocuous.

```
              AppleIntelLpssGspi`AppleIntelLpssGspi::regRead(unsigned int)+0x1f
              AppleIntelLpssGspi`AppleIntelLpssGspi::transferMmioDuplexMulti(void*, void*, unsigned long long, unsigned int)+0x91
              AppleIntelLpssSpiController`AppleIntelLpssSpiController::transferDataMmioDuplexMulti(void*, void*, unsigned int, unsigned int)+0xb2
              AppleIntelLpssSpiController`AppleIntelLpssSpiController::_transferDataSubr(AppleInfoLpssSpiControllerTransferDataRequest*)+0x5bc
              AppleIntelLpssSpiController`AppleIntelLpssSpiController::_transferData(AppleInfoLpssSpiControllerTransferDataRequest*)+0x24f
              kernel`IOCommandGate::runAction(int (*)(OSObject*, void*, void*, void*, void*), void*, void*, void*, void*)+0x138
              AppleIntelLpssSpiController`AppleIntelLpssSpiDevice::transferData(IOMemoryDescriptor*, void*, unsigned long long, unsigned long long, IOMemoryDescriptor*, void*, unsigned long long, unsigned long long, unsigned int, AppleIntelSPICompletion*)+0x151
              AppleHSSPISupport`AppleHSSPIController::transferData(IOMemoryDescriptor*, void*, unsigned long long, unsigned long long, IOMemoryDescriptor*, void*, unsigned long long, unsigned long long, unsigned int, AppleIntelSPICompletion*)+0xcc
              AppleHSSPISupport`AppleHSSPIController::doSPITransfer(bool, AppleHSSPITransferRetryReason*)+0x97
              AppleHSSPISupport`AppleHSSPIController::InterruptOccurred(IOInterruptEventSource*, int)+0xf8
              kernel`IOInterruptEventSource::checkForWork()+0x13c
              kernel`IOWorkLoop::runEventSources()+0x1e2
              kernel`IOWorkLoop::threadMain()+0x2c
              kernel`call_continuation+0x2e
               53

              kernel`waitq_wakeup64_thread+0xa7
              pthread`__psynch_cvsignal+0x495
              pthread`_psynch_cvsignal+0x28
              kernel`psynch_cvsignal+0x38
              kernel`unix_syscall64+0x27d
              kernel`hndl_unix_scall64+0x16
               60

              kernel`hndl_mdep_scall64+0x4
              113

              kernel`ml_set_interrupts_enabled+0x19
              524

              kernel`ml_set_interrupts_enabled+0x19
              kernel`hndl_mdep_scall64+0x10
             5890

              kernel`machine_idle+0x2f8
              kernel`call_continuation+0x2e
            43395
```

The most common stack traces in user space over 17 seconds clearly implicate com.docker.hyperkit.  There 1365 stack traces in 17 seconds in which `com.docker.hyperkit` created threads which averages to 80 threads per second.

```
              com.docker.hyperkit`0x000000010cbd20db+0x19f9
              com.docker.hyperkit`0x000000010cbdb98c+0x157
              com.docker.hyperkit`0x000000010cbf6c2d+0x4bd
              libsystem_pthread.dylib`_pthread_body+0x7e
              libsystem_pthread.dylib`_pthread_start+0x42
              libsystem_pthread.dylib`thread_start+0xd
               19

              Hypervisor`hv_vmx_vcpu_read_vmcs+0x1
              com.docker.hyperkit`0x000000010cbd4c4f+0x2a
              com.docker.hyperkit`0x000000010cbd20db+0x174a
              com.docker.hyperkit`0x000000010cbdb98c+0x157
              com.docker.hyperkit`0x000000010cbf6c2d+0x4bd
              libsystem_pthread.dylib`_pthread_body+0x7e
              libsystem_pthread.dylib`_pthread_start+0x42
              libsystem_pthread.dylib`thread_start+0xd
               22

              Hypervisor`hv_vmx_vcpu_read_vmcs
              com.docker.hyperkit`0x000000010cbdb98c+0x157
              com.docker.hyperkit`0x000000010cbf6c2d+0x4bd
              libsystem_pthread.dylib`_pthread_body+0x7e
              libsystem_pthread.dylib`_pthread_start+0x42
              libsystem_pthread.dylib`thread_start+0xd
               34

              com.docker.hyperkit`0x000000010cbd878d+0x36
              com.docker.hyperkit`0x000000010cbd20db+0x42f
              com.docker.hyperkit`0x000000010cbdb98c+0x157
              com.docker.hyperkit`0x000000010cbf6c2d+0x4bd
              libsystem_pthread.dylib`_pthread_body+0x7e
              libsystem_pthread.dylib`_pthread_start+0x42
              libsystem_pthread.dylib`thread_start+0xd
               47

              Hypervisor`hv_vcpu_run+0xd
              com.docker.hyperkit`0x000000010cbd20db+0x6b6
              com.docker.hyperkit`0x000000010cbdb98c+0x157
              com.docker.hyperkit`0x000000010cbf6c2d+0x4bd
              libsystem_pthread.dylib`_pthread_body+0x7e
              libsystem_pthread.dylib`_pthread_start+0x42
              libsystem_pthread.dylib`thread_start+0xd
              135
```

### Related issues

Github - docker/for-mac: [com.docker.hyperkit 100% cpu usage is back again #3499
][5].  One comment suggests adding volume caching described here: https://www.docker.com/blog/user-guided-caching-in-docker-for-mac/.  I tried this and got a small ~10% reduction in CPU usage.


  [1]: https://i.stack.imgur.com/N0ftg.png
  [2]: https://i.stack.imgur.com/YhAui.png
  [3]: https://i.stack.imgur.com/aixXT.png
  [4]: https://i.stack.imgur.com/vkbdV.jpg
  [5]: https://github.com/docker/for-mac/issues/3499

Diagnosing high CPU usage on Docker for Mac

I&#39;m looking for a Windows equivalent of [Systrace][1] or at least [strace][2]. I&#39;m aware of 
[StraceNT][3], but wondering if there are any more alternatives out there. Specifically, I&#39;m looking for a specific way to programmatically enforce system call policies, though this can be after the fact rather than actively stopping them.

Is there a good way to do this currently?


  [1]: http://www.citi.umich.edu/u/provos/systrace/
  [2]: http://linux.die.net/man/1/strace
  [3]: http://www.intellectualheaven.com/default.asp?BH=projects&amp;H=strace.htm

Systrace for Windows

I used `strace` to attach to a process briefly. The process created 90 threads. When I found the offending thread, I had to tediously search for the parent thread, then the grandparent thread, and so on all the way to the root process.

Is there a trick or tool to quickly figure out which thread created another? Or better yet, print the tree of thread creations like `pstree`? 


How to track child process using strace?

I&#39;m trying to use strace to find out what commands a program executes using `execve`. Some of the arguments in these commands are quite long, and strace is abbreviating the arguments to `execve` (I see &quot;...&quot; after about 30 characters), preventing me from getting any useful information. How can I get the full text of each argument?

I&#39;ve read the [man page][1]. The -v option prints the environment, which is useful, but the arguments are still truncated.

    strace -f -e trace=execve -v -p 1234

I also tried passing verbose=all, but this just gives some extra information about SIGCHLD.

    strace -f -e verbose=all trace=execve -v -p 1234


  [1]: http://linux.die.net/man/1/strace

Prevent strace from abbreviating arguments?

I do know that `strace` uses `ptrace` to do the job,

but it needs to run the target process with `TRACE_ME` on,

which don&#39;t apply for the case of an already running process.

how does it work on an already running process?

Content Type	Original Author	Original Content on Stackoverflow
Question	Setjmp	View Question on Stackoverflow
Solution 1 - Macos	ephemient	View Answer on Stackoverflow

Equivalent of strace -feopen < command > on mac os X

Macos Problem Overview

Macos Solutions

Solution 1 - Macos

Get first day of week in PHP?

Database Diagram Support Objects cannot be Installed ... no valid owner

Attributions