Commands by StefanLasiewski (6)

  • Use GNU info with a pager

    This command is similar to the above, but is much simpler to remember. Sure, it's isn't as precise as the parent command, but most people aren't going to remember those --flags anyways unless you stick it into your .bashrc on every single system that you manage. Show Sample Output


    0
    info foo |less
    StefanLasiewski · 2013-09-12 16:49:08 0
  • Find Man pages for everything in your $PATH

    If I type 'man something', I want it to find the manpage in the same order as my PATH. You can add something like this to your .bashrc # # Add my MacPorts, my personal utilities and my company utilities to my PATH. export PATH=$PATH:/opt/local/bin:$HOME/bin:/our_company_utils/bin/ # Now set the manpath based on the PATH, after man(1) parses man.conf # - No need to modify man.conf or manually modify MANPATH_MAP # - Works on Linux, FreeBSD & Darwin, unlike /etc/manpaths.d/ # Must unset MANPATH first. MANPATH is set on some systems automatically (Mac), # which causes manpath to ignore the values of PATH like /opt/local/bin (MacPorts). # Also MANPATH may be deprecated. See "SEARCH PATH FOR MANUAL PAGES" in man(1) unset MANPATH # manpath acts differently on Solaris, FreeBSD, MacOSX & GNU. This works everywhere. manpath >/dev/null # Note that MacOSX, FreeBSD & Linux have fancier ways to do some of this. (e.g. 'man --path' or 'man -q'), but this command is more universal and should work everywhere. Show Sample Output


    0
    unset MANPATH; manpath >/dev/null
    StefanLasiewski · 2010-07-02 19:45:27 0
  • Don't spam root. Log your cronjob output to syslog

    This command will log the output of your simple cronjobs to syslog, and syslog will take it from there. Works great for monitoring scripts which only produce simple output. Advantages: * This can be used by regular users, without modifying system files like /etc/syslog.conf * Reduce cron spam to root@localhost (Please stop spaming the sysadmins) * Uses common tools like syslog (and logrotate) so that you don't need to maintain yet another krufty logfile. * Still ensures that the output is logged somewhere, for posterity. Perhaps it's stored the secure, central syslog server, for example. * Seems to work fine on Ubuntu, CentOS, FreeBSD & MacOSX Show Sample Output


    6
    */5 * * * * root /usr/local/nagios/sbin/nsca_check_disk 2>&1 |/usr/bin/logger -t nsca_check_disk
    StefanLasiewski · 2010-07-02 00:47:05 2
  • Print a date from 3 days ago

    This command prints the Date (Not time) from 3 days ago (72 hours ago). This works on systems without GNU date (MacOSX , Solaris, FreeBSD). Show Sample Output


    4
    TZ=PST8PDT+72 date '+%Y_%m_%d'
    StefanLasiewski · 2010-07-02 00:29:27 6
  • Delete the previous entry in your history

    I rarely need this, but I have a hard time remembering the command when I need it. Admit it. This has happened to you. Yes this is bad, and you better clean up now. Borrowed from http://thoughtsbyclayg.blogspot.com/2008/02/how-to-delete-last-command-from-bash.html Show Sample Output


    0
    alias histdel='history -d $((HISTCMD-2)) && history -d $((HISTCMD-1))'
    StefanLasiewski · 2010-07-02 00:20:44 3
  • Read info(1) pages using 'less' instead of GNU Texinfo

    I like man pages, and I like using `less(1)` as my pager. However, most GNU software keeps the manual in the 'GNU Texinfo' format, and I'm not a fan of the info(1) interface. Just give me less. This command will print out the info(1) pages, using the familiar interface of less! Show Sample Output


    1
    info gpg |less
    StefanLasiewski · 2010-07-01 23:44:15 2

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Check These Out

List your installed Chromium extensions (with url to each page)
Gives you a list for all installed chrome (chromium) extensions with URL to the page of the extension. With this you can easy add a new Bookmark folder called "extensions" add every URL to that folder, so it will be synced and you can access the names from every computer you are logged in. ------------------------------------------------------------------------------------------------------------------ Only tested with chromium, for chrome you maybe have to change the find $PATH.

Read and write to TCP or UDP sockets with common bash tools
Ever needed to test firewalls but didn't have netcat, telnet or even FTP? Enter /dev/tcp, your new best friend. /dev/tcp/(hostname)/(port) is a bash builtin that bash can use to open connections to TCP and UDP ports. This one-liner opens a connection on a port to a server and lets you read and write to it from the terminal. How it works: First, exec sets up a redirect for /dev/tcp/$server/$port to file descriptor 5. Then, as per some excellent feedback from @flatcap, we launch a redirect from file descriptor 5 to STDOUT and send that to the background (which is what causes the PID to be printed when the commands are run), and then redirect STDIN to file descriptor 5 with the second cat. Finally, when the second cat dies (the connection is closed), we clean up the file descriptor with 'exec 5>&-'. It can be used to test FTP, HTTP, NTP, or can connect to netcat listening on a port (makes for a simple chat client!) Replace /tcp/ with /udp/ to use UDP instead.

archlinux: shows list of files installed by a package
Shows the files which the package, for example gvim, installed on your system.

get a mysqldump with a timestamp in the filename and gzip it all in one go
Performs a mysqldump and gzip-compresses the output file with a timestamp in the resulting dump file. Inspect the file for integrity or fun with this command afterward, if you desire: $ zcat mysqldump-2009-06-12-07.41.01.tgz | less

Get current Xorg resolution via xrandr
Not sure if it works the same on any shell.

Encode png's into blu-ray format
This command takes a set of images (from a render, for example), and converts them into a format conforming to the Blu-ray spec, or at least the version on the Wikipedia page.

Delete all empty lines from a file with vim
This command delete all the empty lines (include the lines with space) from a file. g = global command \S = non-whitespace character; !\S the opposite d = delete a range

Test file system performance
You need bonnie++ package for this. More detail than a simple hdparm -t /dev/sda would give you. the -d is the directory where it performs writes/reads for example I use /tmp/scratch with 777 permissions Bonnie++ benchmarks three things: data read and write speed, number of seeks that can be performed per second, and number of file metadata operations that can be performed per second.

bash/ksh function: given a file, cd to the directory it lives
fcd : file change directory A bash function that takes a fully qualified file path and cd's into the directory where it lives. Useful on the commadline when you have a file name in a variable and you'd like to cd to the directory to RCS check it in or look at other files associated with it. Will run on any ksh, bash, likely sh, maybe zsh.

ssh autocomplete
Add to your bash profile to minimize carpal tunnel syndrome. Doesn't work with user@hostname but appending "-l user" works fine if needed. Works for ping as well.. complete -W "$(echo `cat ~/.ssh/known_hosts | cut -f 1 -d ' ' | sed -e s/,.*//g | uniq | grep -v "\["`;)" ping

Stay in the loop…

Follow the Tweets.

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.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

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: