Linux cribsheet

This is a personal cribsheet intended for my own use. If it's useful to you, great, but it doesn't cover the subject exhaustively.

sudo shutdown -r now

sudo apt-get upgrade

grep files like '*.haystack' for 'needle'
grep -iHn needle *.haystack
- grep -i = case-insensitive
- grep -H = print out the name of the file before the matching line
- grep -n = print out the number of the matching line
Find files like '*.haystack' modified in the last five days and grep them for 'needle':
find . -name '*.haystack' -mtime -5 -exec grep -iHn needle {} \;
- the dot after find is where to start, i.e. the current working directory
- the pattern '*.haystack' has to be quote-enclosed to stop the shell expanding the wildcard
- -mtime -5 means 'modification time less than five days ago. For files more than five days old, use -mtime +5
- -exec has to be semi-colon terminated to tell find where the command ends, but the semi-colon has to be escaped to stop the shell treating it as the end of find
Find files exeeding a certain size:
find . -type f -size +1M
- find files of size 1MB or greater
Find files modified in the last day:
find . -type f -mtime -1 | grep -v ./.git
- the grep -v is because you probably aren't interested in repo transactions

Reboot