commandlinefu.com is the place to record those command-line gems that you return to again and again.
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Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.
Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):
Subscribe to the feed for:
Show only the subdirectories in the current directory. In the example above, /lib has 135 files and directories. With this command, the 9 dirs jump out.
Sort a list of IPV4 addresses in numerical order. Great as a filter, or within vim using !}
Often, when sorting you want the sort to ignore extraneous characters. The b, d, and f tell sort to ignore leading blanks, use 'dictionary order' (ignore punctuation), and ignore (fold) case. Add a "u" if you only want one copy of duplicate lines.
This is a great command to use within vim to sort lines of text, using !}sort -bdf
Finds the string in every file in an entire directory and all its subdirectories and replaces it with a new string. Especially useful when changing a machine's IP address or hostname - run it on /etc.
Old snapshots can cause problems. It's best to remove them when finished. I use this script to remove all snapshots. The "while read" command is necessary because my vm names contain spaces. The "time" command reports how long the process runs.
I use this command on my machines running VMware Server to print out the state of all registered Virtual machines.
rpm, sometimes, is not wildcard friendly. To search files installed from package this could be useful.
change PACKAGENAME to any package do you want to search
Create a persistent SSH connection to the host in the background. Combine this with settings in your ~/.ssh/config:
All the SSH connections to the machine will then go through the persisten SSH socket. This is very useful if you are using SSH to synchronize files (using rsync/sftp/cvs/svn) on a regular basis because it won't create a new socket each time to open an ssh connection.
Run this in / in a chroot to get your own proc there.
Might match "ping 192.168.0.1" and then run it.
Works for most distributions, tested on Ubuntu, Fedora, CentOS, Gentoo, SUSE, RedHat.
Debian and Slackware:
fold wraps text at 80 characters wide, and with the -s flag, only causes wrapping to occur between words rather than through them.
Creates a full snapshot of your current vim session, including tabs, open buffers, cursor positions, everything. Can be resumed with vim -S . Useful for those times when you HAVE to close vim, but you don't want to lose all your hard-opened buffers and windows. The ! will cause vim to overwrite the file if it already exists. It is not necessary, but useful if you frequently save to the same file (like session.vim or something).
Symlinks all files in the base directory to the target directory then lists all of the created symlinks.
* Adjust the find command to your own filters.
* The -P flag forces to keep absolute paths in the tarball, so that you can be sure that the exact same file hierarchy will be created on the second machine.
Opens or closes the cdrom device.
Useful to archive files once a day:
cp file file.$(date --iso)
Displays a list of all the basic keyboard shortcuts in screen.