murex Shell Docs

Command Reference: tmp

Create a temporary file and write to it


tmp creates a temporary file, writes the contents of STDIN to it then returns its filename to STDOUT.

You can optionally specify a file extension, for example if the temporary file needs to be read by open or an editor which uses extensions to define syntax highlighting.


<stdin> -> tmp [ file-extension ] -> <stdout>


» out: "Hello, world!" -> set: tmp

» out: $tmp

» open: $tmp
Hello, world!


The temporary file name is a base64 encoded md5 hash of the time plus murex function ID with murex process ID appended:

package io

import (


func init() {
    lang.DefineMethod("tmp", cmdTempFile, types.Any, types.String)

func cmdTempFile(p *lang.Process) error {

    ext, _ := p.Parameters.String(0)
    if ext != "" {
        ext = "." + ext

    fileId := time.Now().String() + ":" + strconv.Itoa(int(p.Id))

    h := md5.New()
    _, err := h.Write([]byte(fileId))
    if err != nil {
        return err

    name := consts.TempDir + hex.EncodeToString(h.Sum(nil)) + "-" + strconv.Itoa(os.Getpid()) + ext

    file, err := os.Create(name)
    if err != nil {
        return err

    defer file.Close()

    _, err = io.Copy(file, p.Stdin)
    if err != nil {
        return err

    _, err = p.Stdout.Write([]byte(name))
    return err

This should should provide enough distance to run tmp in parallel….should you ever want to.

tmp files are also located inside a unique per-process murex temp directory which itself is located in the appropriate temp directory for the host OS (eg $TMPDIR on macOS).

See Also

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Last built on Mon Feb 13 09:18:06 UTC 2023 against commit f339958f33995895c1d997efcdbb8408d2c8d45f8b5f934.

Current version is which has been verified against 13950 tests cases.