CompTIA Linux+ XK0-006 (V8) Practice Question

The correct command is touch -c -r source.file app.log. The -r (--reference) option tells touch to use the timestamps from the specified reference file (source.file) instead of the current time. The -c (--no-create) option prevents touch from creating the file if it does not exist. The other options are incorrect because they either create the file if it's missing or perform an entirely different operation. touch -r source.file app.log would incorrectly create app.log if it didn't exist. touch -d "$(date -r source.file)" app.log also fails the no-create requirement. cp -p source.file app.log is incorrect because it copies the content of source.file to app.log, rather than just updating the timestamps of the existing app.log file.