Temporary Files And Directories in Julia

Our first example demonstrates how to create temporary files and directories in Julia. These are useful for storing data that isn’t needed after the program exits, preventing unnecessary pollution of the file system over time.

using Random

# Function to check for errors
function check(e)
    if e !== nothing
        throw(e)
    end
end

# Create a temporary file
f = tempname()
open(f, "w") do io
    write(io, [1, 2, 3, 4])
end

println("Temp file name: ", f)

# Clean up the file after we're done
rm(f)

# Create a temporary directory
dname = mktempdir()
println("Temp dir name: ", dname)

# Clean up the directory after we're done
rm(dname, recursive=true)

# Create a file in the temporary directory
fname = joinpath(dname, "file1")
open(fname, "w") do io
    write(io, [1, 2])
end

In Julia, we use the tempname() function to create a temporary file. This function returns a path to a non-existent temporary file. We then use open() with a do-block to write to this file.

To create a temporary directory, we use the mktempdir() function. This creates a new temporary directory and returns its path.

We can then use joinpath() to create file paths within this temporary directory.

Note that in Julia, we don’t need to explicitly close files when using open() with a do-block, as it automatically closes the file when the block ends.

To clean up, we use rm() for both files and directories. For directories, we need to set recursive=true to remove the directory and all its contents.

When you run this script, you’ll see output similar to:

Temp file name: /tmp/jl_xyz123
Temp dir name: /tmp/jl_abc456

The exact names will be different each time you run the script, as they are randomly generated to ensure uniqueness.

Remember, it’s good practice to clean up temporary files and directories explicitly, even though the operating system will likely clean them up after some time.