[Issue 13996] New: Function for returning a temporary file with a randomly generated name where the name can be accessed

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13996

          Issue ID: 13996
           Summary: Function for returning a temporary file with a
                    randomly generated name where the name can be accessed
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: Phobos
          Assignee: nobody at puremagic.com
          Reporter: issues.dlang at jmdavisProg.com

We need a function which creates a file with a temporary name where we have
access to the name and can close and reopen the file. We have
std.stdio.tmpfile, which calls the C tmpfile function and gives us a temporary
file, but we have no access to the name of the file, and it gets deleted when
its closed, which is completely useless for many situations, especially in unit
tests where you need to do something like write to a file, close it, and then
read from it.

POSIX's mkstemp does something similar to this, but on some systems, it doesn't
allow for very many file names (e.g. the windows implementation is restricted
to 26; some POSIX implementations have similar limitations), and it doesn't
provide any control over where the file is written to.

So, I propose that we create something like

    static File tempFile(string prefix = "", string dir = tempDir()) {...}

in std.stdio.File which allows for adding a prefix like mkstemp does but also
allows control over where the file goes and does not have the same limitations
on the number of randomly generated files as mkstemp sometimes does. And, of
course, it's a normal File which won't delete itself when being closed, so it
will be able to be used like any other File, unlike the one returned by
std.stdio.File.tmpfile.

And with that added, I'd suggest that we deprecate tmpfile, since IMHO it's
pretty useless, and it'll reduce confusion if there's only one function returns
a temporary file with a randomly generated name, but that's obviously up for
debate.

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