From the manual: -N or –LINE-NUMBERS Causes a line number to be displayed at the beginning of each line in the display. You can also toggle line numbers without quitting less by typing -N. It is possible to toggle any of less’s command line options in this way.
Might not be one that 99% of Vim users don’t know about, but it’s something I use daily and that any Linux+Vim poweruser must know. Basic command, yet extremely useful. :w !sudo tee % I often forget to sudo before editing a file I don’t have write permissions on. When I come to save that … Read more
Use the shell globbing syntax: grep pattern -r –include=\*.cpp –include=\*.h rootdir The syntax for –exclude is identical. Note that the star is escaped with a backslash to prevent it from being expanded by the shell (quoting it, such as –include=”*.cpp”, would work just as well). Otherwise, if you had any files in the current working … Read more
You would have to run this as root, but: for user in $(cut -f1 -d: /etc/passwd); do crontab -u $user -l; done will loop over each user name listing out their crontab. The crontabs are owned by the respective users so you won’t be able to see another user’s crontab w/o being them or root. … Read more
Underneath the file system, files are represented by inodes. (Or is it multiple inodes? Not sure.) A file in the file system is basically a link to an inode. A hard link, then, just creates another file with a link to the same underlying inode. When you delete a file, it removes one link to … Read more
Short answer: $ ssh-keygen -p This will then prompt you to enter the keyfile location, the old passphrase, and the new passphrase (which can be left blank to have no passphrase). If you would like to do it all on one line without prompts do: $ ssh-keygen -p [-P old_passphrase] [-N new_passphrase] [-f keyfile] Important: … Read more
Real, User and Sys process time statistics One of these things is not like the other. Real refers to actual elapsed time; User and Sys refer to CPU time used only by the process. Real is wall clock time – time from start to finish of the call. This is all elapsed time including time … Read more