Have you ever wondered what the hell was dd command doing? well, there you have it... notice the -USR1 signal :)...

sudo when you mean it

ps aux | grep $USER

exit

# newline to space; the whack before dollar-underbar is required

alias nl2space="perl -ne 'push @F, \$_; END { chomp @F; print join(qq{ }, @F) , qq{\n};}' "

# newline to comma; the whack before dollar-underbar is required

alias nl2,="perl -ne 'push @F, \$_; END { chomp @F; print join(qq{,}, @F) , qq{\n};}' "

foo-001

foo-002

foo-003

foo-004

foo-005

foo-006

foo-007

foo-008

foo-009

foo-010

# 'tr' does not give a newline after it run. Makes a messy commandline.

foo-001 foo-002 foo-003 foo-004 foo-005 foo-006 foo-007 foo-008 foo-009 foo-010 $PROMPT> tr "\n" ' ' /tmp/foo

# 'tr' does not take arguements

tr: extra operand `/tmp/foo'

Try `tr --help' for more information.

# 'nl2space' is a filter and takes arguements, adds a newline after it runs.

foo-001 foo-002 foo-003 foo-004 foo-005 foo-006 foo-007 foo-008 foo-009 foo-010

foo-001 foo-002 foo-003 foo-004 foo-005 foo-006 foo-007 foo-008 foo-009 foo-010

xargs deals badly with special characters (such as space, ' and "). To see the problem try this:

touch important_file

touch 'not important_file'

ls not* | xargs rm

Parallel https://savannah.nongnu.org/projects/parallel/ does not have this problem.

-l for long list, -r for recursive, -a for display of hidden files, and -t for modification date

Get information pci All

-k, --keep-open will keep connection alive, and we could exclude using 'while true'

nc is such a powerful command, it could be used instead of any OS! :p

do it, disown it and exit without time for a mess

sudo when you mean it

ps aux | grep $USER

exit

The command will help to print the location of the pattern. Above command will print all the files which contain variable "$foo" along with line containing that pattern.

Specify pattern after "grep"

All folders, human-readable, no subfolder, with a total. Even shorter.

If you add the bookmarklet to your browser's bookmarks with like say, the keyword 'cfu', you can for example type 'cfu hello' in the location bar and the %s gets replaced with 'hello'.

The bookmarklet will convert the search text to base64 for use with the commandlinefu website and will take you there. Tested with Firefox.

remove all carriage return of a given file (or input, if used with | ) and replace them with a space (or whatever character is after %s)

Quick and easy way of validating a date format of yyyy-mm-dd and returning a boolean, the regex can easily be upgraded to handle "in betweens" for mm dd or to validate other types of strings, ex. ip address.

Boolean output could easily be piped into a condition for a more complete one-liner.

This command adds the numbers 10, 12, 14 to a bunch of mp3's in the current working directory. You can then run the command replacing the inital i=10 with i=11 to add 11,13,15 in another directory then mv the files together and the first files interweave with the second group of files. I used this to weave a backlog of a podcast with other podcast so I didn't get sick of one while I was catching up. I started at 10 because printf blows up with 0 padded numbers 08 and 09 which kind of makes the printf command redundant as it was used to pad numbers 1 - 9 so they would come first and not get sorted incorrectly