how to execute command and log only the command to a file

Question

I'm trying to run a command and log only the command to a file. I've tried using exec 4>test|command >&4|exec 4>&- but doesnt' work. If I run the commands separately it works but only records the output of the command, the same with command | tee -a test. I also found this: command|& ts |tee -a test but I don't have admin rights so I can't install anything. Also I don't want to write a script or save the command history or the output, preferably I just want a one liner to record the command to a file and then execute it normally. This are some related questions: https://stackoverflow.com/questions/70677322/in-linux-how-to-save-only-the-command-into-file-without-output Record commands only to file

Answer 1

If it's in a shell scripting environment, you could make a function like so, which executes the given arguments:

log_and_execute_command() {
    printf '%(%FT%T%z)T\t%s\n' -1 "$*" >> my_logging_file
    "$@"
}

If we don't need to record timestamps, it gets a bit easier. This one uses the fact that if you pass commands in the standard input to the shell, it executes them:

printf '%s' 'my_command' | tee -a my_logging_file | sh

If you want to pipe something into ts but don't have it, a shell script like this can be used as a similar alternative:

#!/bin/bash
while read -r line; do
    printf '%(%FT%T%z)T\t%s\n' -1 "$line"
done