touch

Create an empty file or update timestamps

low risk

interactive breakdown — edit the command and press Explain
$ 
⚠ Risks & cautions
What it does

Creates the file if it does not exist, otherwise updates its modification time. Often used to create placeholders or reset mtime for make/rsync.

Common flags
FlagMeaning
-cDo not create missing files
-tSet a specific timestamp [[CC]YY]MMDDhhmm
-rCopy timestamps from another file
Examples
touch notes.txtCreate an empty file · explain & risk-check →
touch -r a.txt b.txtGive b.txt the same mtime as a.txt · explain & risk-check →
Related
stat mkdir
Open the full explainer →More in Files & Archives

Reference text is hand-written and may be incomplete — check man touch for your version. Test destructive commands on a non-production system first.