The time-related fields of struct stat are as follows, man lstat:

• atime: Time when file data last accessed.
• mtime: Time when file data last modified.
• ctime: Time when file status was last changed
• birthtime or btime: Time of file creation. Only set once when the file is created.

1. To modify access time (atime):
   touch -a -t CCYYMMDDhhmm.SS file.txt (example: 201811251820.52 = 25 novembre 2018 à 18 h 20 min 52 s)

2. To modify modification time (mtime) and time of file creation (btime):
   touch -m -t CCYYMMDDhhmm.SS file.txt

3. To modify only the time of creation/birth (btime):
   SetFile -d "11/25/2018 18:20:52" file.txt

• touch
• SetFile

Reconstruire l’index des boîtes aux lettres de Mail

You may encounter an alert from Mail app telling you that the mailbox must be repaired, but you can also do this manually. This is particularly helpful if the search functions of the Mail app have become unreliable.

1. Quit out of Mail app and go to the Finder
2. Hit Command+Shift+G and go to the following path: ~/Library/Mail/
3. Open the latest V# folder (V9, V8, V7, V6, V4 etc), then open the “MailData” folder in that directory
4. Delete every file that begins with “Envelope Index(-shm/-wal)” (optional but recommended: back up these files to the desktop just in case something goes awry)
5. Close the MailData window, then relaunch Mail app to force reindexing