Commands by hkyeakley

Commands by hkyeakley (2)

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Remove blank lines from a file

To save the result, redirect the output to another file. grep -v "^$" file1 > file2
This is sample output - yours may be different.
-1

grep -v "^$" file

hkyeakley · 2009-02-19 18:11:58 3
Quick glance at who's been using your system recently

This command takes the output of the 'last' command, removes empty lines, gets just the first field ($USERNAME), sort the $USERNAMES in reverse order and then gives a summary count of unique matches. Show Sample Output
This is sample output - yours may be different.
```
1 wtmp
      2 reboot
     31 oracle
     15 jsmith
    142 jdoe
      3 root
```
15

last | grep -v "^$" | awk '{ print $1 }' | sort -nr | uniq -c

hkyeakley · 2009-02-18 16:38:59 1

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Easily run a program in the background without losing output

This function runs a program in the background, and logs all output to an automatically created logfile. That way, you can still get at the output without it clogging up your terminal. Tip: Throw fork() and this: $for prog in firefox kate konqueror ;do alias $prog="fork $prog";done into your bashrc, so that they'll automatically run out of the way.

Ring the system bell after finishing a long script/compile

This will ring the system bell once if your script exits successfully and twice if it fails. So you can go look at something else and it will alert you when done. Don't forget to use 'xset b [vol [pitch [duration]]]' to get the bell to sound the way you want.

list folders containing less than 2 MB of data

Just shortened the awk a bit and removed sed. Edit: I'm assuming there are no spaces in the path. To support white space in pathname try: $ awk '($1 < 2048) {sub(/^[0-9]+[ \t]+/,""); print $0}'

Test I/O performance by timing the writing of 100Mb to disk

Write 200 blocks of 512k to a dummy file with dd, timing the result. The is useful as a quick test to compare the performance of different file systems.

Shell recorder with replay

If you provide the option -t to the script command and redirect stderr into a file, the timing information on what is going on on the terminal, is also stored. You can replay the session via the scriptreplay command, where you can also provide a speedup factor (see the man page for details). Great for demonstration purposes ...

python2 -m CGIHTTPServer

In case you need to test some CGI scripts this does the job. It also has the functionality of a http server. Enjoy!

Url Encode

get a random command

This command will show an random command. this is useful if you want to explore various random commands.

Easily decode unix-time (funtion)

A shell function using perl to easily convert Unix-time to text. Put in in your ~/.bashrc or equivalent. Tested on Linux / Solaris Bourne, bash and zsh. using perl 5.6 and higher. (Does not require GNU date like some other commands)

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