Fallocate() Command Equivalent in Os X

fallocate() command equivalent in OS X?

What about using:

mkfile -n 1m test.tmp

It's not the same command but serves the same purpose.

Note that fallocate uses decimal multipliers, whereas mkfile uses binary multipliers.

mkfile man

Quickly create a large file on a Mac OS X system?

macOS has the command mkfile to achieve the same:

mkfile -n 10g temp_10GB_file

Syntax:

mkfile [ -nv ] size[b|k|m|g] filename ...

And here's the related manual page for mkfile

Cross Platform Alternative (Unix including macOS):

As an alternative you could also you the Unix util dd:

dd if=/dev/zero of=temp_10GB_file bs=1 count=0 seek=10G

Note that on macOS you need to use a lowercase for the unit as follow:

dd if=/dev/zero of=temp_10GB_file bs=1 count=0 seek=10g

And here's the related manual page for dd

How do you pre-allocate space for a file in C/C++ on Windows?

Programatically, on Windows you have to use Win32 API functions to do this:

SetFilePointerEx() followed by SetEndOfFile()

You can use these functions to pre-allocate the clusters for the file and avoid fragmentation. This works much more efficiently than pre-writing data to the file. Do this prior to doing your fopen().

If you want to avoid the Win32 API altogether, you can also do it non-programatically using the system() function to issue the following command:

fsutil file createnew filename filesize

How to create a file with a given size in Linux?

For small files:

dd if=/dev/zero of=upload_test bs=file_size count=1

Where file_size is the size of your test file in bytes.

For big files:

dd if=/dev/zero of=upload_test bs=1M count=size_in_megabytes

Preallocate storage with fcntl doesn't work as expected

If your goal is a contiguous space only you should should call fcntl with F_ALLOCATECONTIG flag and fail if ret == -1.

The second call to fcntl in your code (without F_ALLOCATECONTIG flag set) will try to preallocate non-contiguous space (as contiguous allocation failed).

ftruncate call is needed on darwin to have file size reported correctly. Without the call space is being reserved, but file size reported is still zero. Read this article that states that:

It appears that the posix_fallocate equivalent [on OS X] is to the fnctl
followed by a truncate() call (which actually forces data to be
written to the file)

translating a linux vimrc function to one that will work in cygwin

Okay, for CYGWIN, you do NEED to install "busybox"

Then, in my .vimrc file, change:

let my_command = "lsof | grep '" . fname . ".swp' | grep " . $USER . " | sed -n 's/^vim\\? \\+\\([0-9]\\+\\).*$/\\1/p' "

to:

let my_command = "busybox lsof | grep '" . fname . ".swp' | cut -f1 "

As there are no users listed, and the PID comes first, not after the process name.

Secondly, change:

let my_cmd2 = "cat /proc/" . result . "/environ | xargs -0 echo | sed -n 's/.*WINDOW=\\([0-9]*\\).*/\\1/p' "

to:

let my_cmd2 = "cat /proc/" . result . "/environ | xargs -0 echo | busybox sed -n 's/.*WINDOW=\\([0-9]*\\).*/\\1/p' "

Automatic Event Wiring in Global.asax

The ASP.Net runtime uses reflection to dynamically look for methods with names like "Application_Start", "Session_Start" etc. and then binds them to the corresponding events on the HttpApplication class. You can effectively bind to any of the HttpApplication events simply by including a method in Global.asax.cs whose name is "Application_" followed by the name of the event. For example, to utilize the EndRequest event, add this to your Global.asax.cs file:

    protected void Application_EndRequest(object sender, EventArgs e)
    {
        // Your code here
    }

See this Blog Entry from Rick Strahl for a bunch of helpful information on how this is done.

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