Commands by abcde

Commands by abcde (10)

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change ownership en masse of files owned by a specific user, including files and directories with spaces

In the example, uid 0 is root. foo:foo are the user:group you want to make owner and group. '.' is the "current directory and below." -print0 and -0 indicate that filenames and directories "are terminated by a null character instead of by whitespace."
This is sample output - yours may be different.
1

find . -uid 0 -print0 | xargs -0 chown foo:foo

abcde · 2009-05-27 19:52:13 6
Use -t when using find and cp

-t, --target-directory=DIRECTORY (copy all SOURCE arguments into DIRECTORY).
This is sample output - yours may be different.
1

find . -name "*.pdf" -print0 | xargs -0 cp -t downloads/

abcde · 2009-03-13 03:15:27 6
Press ctrl+r in a bash shell and type a few letters of a previous command

In the sample output, I pressed ctrl+r and typed the letters las. I can't imagine how much typing this has saved me. Show Sample Output
This is sample output - yours may be different.
```
(reverse-i-search)`las': last -a | head
```
15

^r in bash begins a reverse-search-history with command completion

abcde · 2009-02-19 18:17:54 35
Find public IP when behind a random router (also see description)

Depends on GET. You can also replace GET with curl, or `wget -qO -` if GET isn't available.
This is sample output - yours may be different.
1

alias pubip='GET http://www.whatismyip.com/automation/n09230945.asp && echo'

abcde · 2009-02-13 04:38:19 8
Exclude grep from your grepped output of ps (alias included in description)

Surround the first letter of what you are grepping with square brackets and you won't have to spawn a second instance of grep -v. You could also use an alias like this (albeit with sed): alias psgrep='ps aux | grep $(echo $1 | sed "s/^$.$/[\1]/g")'
This is sample output - yours may be different.
10

ps aux | grep [h]ttpd

abcde · 2009-02-10 02:59:20 18
Split and join with split and cat.

`split -b 1k file` splits files into 1k chunks. Rejoin them with `cat x* > file`.
This is sample output - yours may be different.
2

split -b 1k file ; cat x* > file

abcde · 2009-02-08 23:10:18 11
seq can produce the same thing as Perl's ... operator.

Optionally, one can use {1..50} instead of seq. E.g. for i in {1..50} ; do echo Iteration $i ; done Show Sample Output
This is sample output - yours may be different.
```
Iteration 1
Iteration 2
Iteration 3
Iteration 4
Iteration 5
etc..
```
8

for i in $(seq 1 50) ; do echo Iteration $i ; done

abcde · 2009-02-08 23:03:31 13
E-mail a traditional Berkeley mbox to another recipient as individual e-mails.
This is sample output - yours may be different.
1

formail -Y -s /usr/sbin/sendmail bar@example.com < /var/mail/foo

abcde · 2009-02-06 23:37:24 11
Make a thumbnail image of first page of a PDF.

convert is included in ImageMagick. Don't forget the [X] (where X is the page number). [0] is the first page of the PDF.
This is sample output - yours may be different.
5

convert -resize 200 -sharpen 40 some_file.pdf[0] some_file.jpg

abcde · 2009-02-06 23:12:01 15
rot13 simple substitution cipher via command line

E.g. Useful for hiding spoilers in reviews, etc. Show Sample Output
This is sample output - yours may be different.
```
~% echo Command-line-fu | rot13
Pbzznaq-yvar-sh
~% echo Pbzznaq-yvar-sh | rot13
Command-line-fu
```
3

alias rot13='perl -pe "y/A-Za-z/N-ZA-Mn-za-m/;"'

abcde · 2009-02-06 14:22:43 14

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Create a mirror of a local folder, on a remote server

Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

fetch all revisions of a specific file in an SVN repository

Manages everything through one sed script instead of pipes of greps and awks. Quoting of shell variables is generally easier within a sed script.

Url Encode

Converts reserved characters in a URI to their percent encoded counterparts. Alternate python version: $ echo "$url" | python -c 'import sys,urllib;print urllib.quote(sys.stdin.read().strip())'

external projector for presentations

i spent way too many hours trying to fiddle with /etc/X11/xorg.conf trying to hook up various external projectors. too bad i didn't know this would solve all my problems.

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

set a reminder for 5 days in the future

setup for reminder in 5 days, added the date in the future. To run a job at 4pm three days from now, you would do at 4pm + 3 days, to run a job at 10:00am on July 31, you would do at 10am Jul 31 and to run a job at 1am tomorrow, you would do at 1am tomorrow.

Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

Rename files in batch

Edit a file inside a compressed archive without extracting it

If you vim a compressed file it will list all archive content, then you can pickup any of them for editing and saving. There you have the modified archive without any extra step. It supports many file types such as tar.gz, tgz, zip, etc.

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