Temporary Files And Directories in D Programming Language

Throughout program execution, we often want to create data that isn’t needed after the program exits. Temporary files and directories are useful for this purpose since they don’t pollute the file system over time.

import std.stdio;
import std.file;
import std.path;
import std.exception;

void check(string msg)
{
    enforce(msg is null, msg);
}

void main()
{
    // The easiest way to create a temporary file is by
    // using std.file.tempFile. It creates a file and
    // opens it for reading and writing. We provide an
    // empty string as the first argument, so tempFile will
    // create the file in the default location for our OS.
    auto f = File.tmpfile();
    writeln("Temp file name: ", f.name);

    // Clean up the file after we're done. The OS is
    // likely to clean up temporary files by itself after
    // some time, but it's good practice to do this
    // explicitly.
    scope(exit) remove(f.name);

    // We can write some data to the file.
    f.rawWrite([1, 2, 3, 4]);

    // If we intend to write many temporary files, we may
    // prefer to create a temporary directory.
    // std.file.tempDir's arguments are similar to
    // tempFile's, but it returns a directory name
    // rather than an open file.
    string dname = tempDir("sampledir");
    writeln("Temp dir name: ", dname);

    // Clean up the directory after we're done
    scope(exit) rmdirRecurse(dname);

    // Now we can synthesize temporary file names by
    // prefixing them with our temporary directory.
    string fname = buildPath(dname, "file1");
    std.file.write(fname, [1, 2]);
}

To run the program, save it as temp_files_and_dirs.d and use the D compiler (dmd, ldc, or gdc) to compile and run:

$ dmd -run temp_files_and_dirs.d
Temp file name: /tmp/fileXXXXXX
Temp dir name: /tmp/sampledirXXXXXX

Note that the exact names of the temporary files and directories will vary, as they are generated uniquely for each run.

In this D version:

We use std.file.tempFile() instead of os.CreateTemp() to create a temporary file.
std.file.tempDir() is used to create a temporary directory, similar to os.MkdirTemp().
The check function is implemented using D’s enforce function from std.exception.
We use D’s scope(exit) feature for cleanup, which is similar to Go’s defer.
File operations are done using D’s std.file module.
Path joining is done with std.path.buildPath().

The overall structure and functionality remain the same as the original example, adapted to D’s syntax and standard library.

Command Line Subcommands in D Programming Language

Logging in D Programming Language

Learn X By Example

Title here

Temporary Files And Directories in D Programming Language