The OpenD Programming Language

expandTilde

Performs tilde expansion in paths on POSIX systems. On Windows, this function does nothing.

There are two ways of using tilde expansion in a path. One involves using the tilde alone or followed by a path separator. In this case, the tilde will be expanded with the value of the environment variable HOME. The second way is putting a username after the tilde (i.e. ~john/Mail). Here, the username will be searched for in the user database (i.e. /etc/passwd on Unix systems) and will expand to whatever path is stored there. The username is considered the string after the tilde ending at the first instance of a path separator.

Note that using the ~user syntax may give different values from just ~ if the environment variable doesn't match the value stored in the user database.

When the environment variable version is used, the path won't be modified if the environment variable doesn't exist or it is empty. When the database version is used, the path won't be modified if the user doesn't exist in the database or there is not enough memory to perform the query.

This function performs several memory allocations.

@safe nothrow
string
expandTilde
(
return scope const string inputPath
)

Parameters

inputPath string

The path name to expand.

Return Value

Type: string

inputPath with the tilde expanded, or just inputPath if it could not be expanded. For Windows, expandTilde merely returns its argument inputPath.

Examples

void processFile(string path)
{
    // Allow calling this function with paths such as ~/foo
    auto fullPath = expandTilde(path);
    ...
}
version (Posix)
{
    import std.process : environment;

    auto oldHome = environment["HOME"];
    scope(exit) environment["HOME"] = oldHome;

    environment["HOME"] = "dmd/test";
    assert(expandTilde("~/") == "dmd/test/");
    assert(expandTilde("~") == "dmd/test");
}

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