Commands by ketil

Commands by ketil (3)

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Poor man's unsort (randomize lines)

If you need to randomize the lines in a file, but have an old sort commands that doesn't support the -R option, this could be helpful. It's easy enough to remember so that you can create it as a script and use that. It ain't real fast. It ain't safe. It ain't super random. Do not use it on untrusted data. It requires bash for the $RANDOM variable to work. Show Sample Output
This is sample output - yours may be different.
```
$ echo -e a\\nb\\nc | while read l; do echo $RANDOM "$l"; done | sort -n | cut -d " " -f 2-
c
a
b
```
0

while read l; do echo $RANDOM "$l"; done | sort -n | cut -d " " -f 2-

ketil · 2010-02-03 22:36:34 5
grep (or anything else) many files with multiprocessor power

xargs -P N spawns up to N worker processes. -n 40 means each grep command gets up to 40 file names each on the command line.
This is sample output - yours may be different.
4

find . -type f -print0 | xargs -0 -P 4 -n 40 grep -i foobar

ketil · 2009-08-05 23:18:44 8
Send email with one or more binary attachments

This command uses mutt to send the mail. You must pipe in a body, otherwise mutt will prompt you for some stuff. If you don't have mutt, it should be dead easy to install.
This is sample output - yours may be different.
11

echo "Body goes here" | mutt -s "A subject" -a /path/to/file.tar.gz recipient@example.com

ketil · 2009-08-05 23:06:25 10

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List the largest directories & subdirectoties in the current directory sorted from largest to smallest.

Share your terminal session (remotely or whatever)

Force the user you want to watch doing things into doing his things in a screen session. Then simply attach yourself to that session with the command shown above. Works only if you are on the same machine, of course

FizzBuzz in Perl

Just another FizzBuzz in Perl.

C function manual

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"

pass the output of some command to a new email in the default email client

This depends on 'stripansi' and 'urlencode' commands, which exist on my system as these aliases: $ alias stripansi='perl -ple "s/\033\[(?:\d*(?:;\d+)*)*m//g;"' $ alias urlencode='perl -MURI::Escape -ne "\$/=\"\"; print uri_escape \$_"' The `open` command handles URLs on a Mac. Substitute the equivalent for your system (perhaps gnome-open). I don't use system `mail`, so I have this aliased as `mail` and use it this way: $ git show head | mail

how to export a table in .csv file

Exports the result of query in a csv file

Edit all files found having a specific string found by grep

The grep switches eliminate the need for awk and sed. Modifying vim with -p will show all files in separate tabs, -o in separate vim windows. Just wish it didn't hose my terminal once I exit vim!!

Bitcoin prices from the command line

Combine cssh and shell expansion to execute commands on a large cluster

This will open an awful lot of little windows, but is quite useful if you want to quickly patch something on a cluster of servers.

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