Get the application's path

In Java the calls

System.getProperty("user.dir")

and

new java.io.File(".").getAbsolutePath();

return the current working directory.

The call to

getClass().getProtectionDomain().getCodeSource().getLocation().getPath();

returns the path to the JAR file containing the current class, or the CLASSPATH element (path) that yielded the current class if you're running directly from the filesystem.

Example:

1. Your application is located at

    C:\MyJar.jar
   

2. Open the shell (cmd.exe) and cd to C:\test\subdirectory.

3. Start the application using the command java -jar C:\MyJar.jar.

4. The first two calls return 'C:\test\subdirectory'; the third call returns 'C:\MyJar.jar'.

When running from a filesystem rather than a JAR file, the result will be the path to the root of the generated class files, for instance

c:\eclipse\workspaces\YourProject\bin\

The path does not include the package directories for the generated class files.

A complete example to get the application directory without .jar file name, or the corresponding path to the class files if running directly from the filesystem (e.g. when debugging):

String applicationDir = getClass().getProtectionDomain().getCodeSource().getLocation().getPath(); 

if (applicationDir.endsWith(".jar"))
{
    applicationDir = new File(applicationDir).getParent();
}
// else we already have the correct answer

In .NET (C#, VB, …), you can query the current Assembly instance for its Location. However, this has the executable's file name appended. The following code sanitizes the path (using System.IO and using System.Reflection):

Directory.GetParent(Assembly.GetExecutingAssembly().Location)

Alternatively, you can use the information provided by AppDomain to search for referenced assemblies:

System.AppDomain.CurrentDomain.BaseDirectory

VB allows another shortcut via the My namespace:

My.Application.Info.DirectoryPath

In Windows, use the WinAPI function GetModuleFileName(). Pass in NULL for the module handle to get the path for the current module.

Python

path = os.path.dirname(__file__)

That gets the path of the current module.

Objective-C Cocoa (Mac OS X, I don't know for iPhone specificities):

NSString * applicationPath = [[NSBundle mainBundle] bundlePath];

In Java, there are two ways to find the application's path. One is to employ System.getProperty:

System.getProperty("user.dir");

Another possibility is the use of java.io.File:

new java.io.File("").getAbsolutePath();

Yet another possibilty uses reflection:

getClass().getProtectionDomain().getCodeSource().getLocation().getPath();

Delphi

In Windows applications:

Unit Forms;
path := ExtractFilePath(Application.ExeName);

In console applications:

Independent of language, the first command line parameter is the fully qualified executable name:

Unit System;
path := ExtractFilePath(ParamStr(0));

Libc
In *nix type environment (also Cygwin in Windows):

  #include <unistd.h>

   char *getcwd(char *buf, size_t size);

   char *getwd(char *buf); //deprecated

   char *get_current_dir_name(void);

See man page

In bash, the 'pwd' command returns the current working directory.

Unix

In unix one can find the path to the executable that was started using the environment variables. It is not necessarily an absolute path, so you would need to combine the current working directory (in the shell: pwd) and/or PATH variable with the value of the 0'th element of the environment.

The value is limited in unix though, as the executable can for example be called through a symbolic link, and only the initial link is used for the environment variable. In general applications on unix are not very robust if they use this for any interesting thing (such as loading resources). On unix, it is common to use hard-coded locations for things, for example a configuration file in /etc where the resource locations are specified.

in Ruby, the following snippet returns the path of the current source file:

path = File.dirname(__FILE__)

In CFML there are two functions for accessing the path of a script:

getBaseTemplatePath()
getCurrentTemplatePath()

Calling getBaseTemplatePath returns the path of the 'base' script - i.e. the one that was requested by the web server.
Calling getCurrentTemplatePath returns the path of the current script - i.e. the one that is currently executing.

Both paths are absolute and contain the full directory+filename of the script.

To determine just the directory, use the function getDirectoryFromPath( ... ) on the results.

So, to determine the directory location of an application, you could do:

<cfset Application.Paths.Root = getDirectoryFromPath( getCurrentTemplatePath() ) />

Inside of the onApplicationStart event for your Application.cfc

To determine the path where the app server running your CFML engine is at, you can access shell commands with cfexecute, so (bearing in mind above discussions on pwd/etc) you can do:

Unix:

<cfexecute name="pwd"/>

for Windows, create a pwd.bat containing text @cd, then:

<cfexecute name="C:\docume~1\myuser\pwd.bat"/>

(Use the variable attribute of cfexecute to store the value instead of outputting to screen.)