Useful Linux commands

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diskutil[edit]

diskutil unmount /dev/disk1s2 [1]

rsync[edit]

--chown=USER:GROUP

This option forces all files to be owned by USER with group GROUP. This is a simpler interface than using --usermap and --groupmap directly, but it is implemented using those options internally, so you cannot mix them. If either the USER or GROUP is empty, no mapping for the omitted user/group will occur. If GROUP is empty, the trailing colon may be omitted, but if USER is empty, a leading colon must be supplied.[2]

chown[edit]

chown -R nobody:users /mnt/disk1/Download [3]

grep[edit]

grep -nr 'yourString*' .

The dot at the end searches the current directory. Meaning for each parameter:

-n            Show relative line number in the file
'yourString*' String for search, followed by a wildcard character
-r            Recursively search subdirectories listed
.             Directory for search (current directory)

How to grep ps output with headers [4][edit]

ps -ef | egrep "Download|PID"

FreeBSD[edit]

  • su:
     The su utility requests appropriate user credentials via PAM and switches
     to	that user ID (the default user is the superuser).  A shell is then
     executed.

pstree[edit]

  • shows a tree of processes! [5]

du -sh foldername[edit]

  • (h)uman readable (s)ummary for disk usage of foldername [6]

lsof -ad3-999 -c rsync[edit]

  • to see what files rsync currently has opened [7]

References[edit]