Commands by unefunge

Commands by unefunge (19)

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Backup a file with a date-time stamp

even shorter (infix) version. Show Sample Output
This is sample output - yours may be different.
```
$ buf() { cp -v $1 ${1/${1%%.*}/$f-$(date +"%Y%m%d_%H%M%S")};}
$ buf a.txt
`a.txt' -> `a-20101215_131256.txt'
$ buf a.txt.gz
`a.txt.gz' -> `a-20101215_131305.txt.gz'
```
0

buf() { cp -v $1 ${1/${1%%.*}/$f-$(date +"%Y%m%d_%H%M%S")};}

unefunge · 2010-12-15 12:16:03 2
Do one ping to a URL, I use this in a MRTG gauge graph to monitor connectivity
This is sample output - yours may be different.
2

ping -q -c 1 www.google.com|awk -F/ 'END{print $5}'

unefunge · 2010-12-15 11:01:10 5
Backup a file with a date-time stamp

"infix" version in bash (4.x+) Remove -v to make it silent. BTW: The OP forgot to use "cat" and "nmap" ;-) I had a good laugh though. Show Sample Output
This is sample output - yours may be different.
```
$ buf a.txt
`a.txt' -> `a-20101215_104638.txt'
$ buf a.txt.gz
`a.txt.gz' -> `a-20101215_104647.txt.gz'
```
0

buf() { f=${1%%.*};e=${1/$f/};cp -v $1 $f-$(date +"%Y%m%d_%H%M%S")$e;}

unefunge · 2010-12-15 09:50:04 2
Backup a file with a date-time stamp

1. you don't need to prepend the year with 20 - just use Y instead of y 2. you may want to make your function a bit more secure: buf () { cp ${1?filename not specified}{,$(date +%Y%m%d_%H%M%S)}; }
This is sample output - yours may be different.
3

buf () { cp $1{,$(date +%Y%m%d_%H%M%S)}; }

unefunge · 2010-12-14 14:02:03 2
Function to split a string into an array

Show Sample Output
This is sample output - yours may be different.
```
read -a ARR <<<'world domination now!'; echo ${ARR[2]};
now!

IFS=":" read -a ARR <<<"$PATH"; echo ${ARR[2]};
/usr/local/bin
```
10

read -a ARR <<<'world domination now!'; echo ${ARR[2]};

unefunge · 2010-12-03 16:27:03 4
Binary clock

cryptic version Show Sample Output
This is sample output - yours may be different.
```
...#
..#.
..#.
..##
```
2

read -a A <<<"8 9 5 10 6 0 3 11 7 4";B='.*.**..*....***';for C in $(date +"%H%M"|fold -w1);do echo "${B:${A[C]}:4}";done

unefunge · 2010-11-26 11:29:23 4
Binary clock

Lightweight alternative with case Show Sample Output
This is sample output - yours may be different.
```
...*
...*
.*.*
.**.
```
0

for a in $(date +"%H%M"|cut -b1,2,3,4 --output-delimiter=" ");do case "$a" in 0)echo "....";;1)echo "...*";;2)echo "..*.";;3)echo "..**";;4)echo ".*..";;5)echo ".*.*";;6)echo ".**.";;7)echo ".***";;8)echo "*...";;9)echo "*..*";;esac;done

unefunge · 2010-11-26 10:58:22 3
Monitor a file with tail with timestamps added
This is sample output - yours may be different.
3

tail -f file |xargs -IX printf "$(date -u)\t%s\n" X

unefunge · 2010-11-25 11:23:13 4
Find which service was used by which port number
This is sample output - yours may be different.
2

getent services <port_number>

unefunge · 2010-11-25 08:30:35 3
Find which service was used by which port number

I used 110 as the port number in examples for clarity. backslash+lessthan or backslash+b marks 'edge of the word'. Show Sample Output
This is sample output - yours may be different.
```
pop3            110/tcp    # Post Office Protocol - Version 3
pop3            110/udp    # Post Office Protocol - Version 3
```
0

grep '\<110/' /etc/services; grep '\b110/' /etc/services

unefunge · 2010-11-25 08:29:42 3
Binary clock

displays current time in "binary clock" format (loosely) inspired by: http://www.thinkgeek.com/homeoffice/lights/59e0/ "Decoding": 8421 .... - 1st hour digit: 0 *..* - 2nd hour digit: 9 (8+1) .*.. - 1st minutes digit: 4 *..* - 2nd minutes digit: 9 (8+1) Prompt-command version: PROMPT_COMMAND='echo "10 i 2 o $(date +"%H%M"|cut -b 1,2,3,4 --output-delimiter=" ") f"|dc|tac|xargs printf "%04d\n"|tr "01" ".*"' Show Sample Output
This is sample output - yours may be different.
```
....
....
.*..
...*
```
3

echo "10 i 2 o $(date +"%H%M"|cut -b 1,2,3,4 --output-delimiter=' ') f"|dc|tac|xargs printf "%04d\n"|tr "01" ".*"

unefunge · 2010-11-24 23:49:21 5
get function's source

no need to reinvent the wheel. Thanks to the OP for the "obsolete" hint. 'declare' may come in pretty handy on systems paranoid about "up-to-dateness" Show Sample Output
This is sample output - yours may be different.
```
$ typeset -f startx
startx () 
{ 
    test -x /usr/bin/startx || { 
        echo "No startx installed" 1>&2;
        return 1
    };
    /usr/bin/startx ${1+"$@"} 2>&1 | tee $HOME/.xsession-errors
}
```
3

typeset -f <function name>; declare -f <function name>

unefunge · 2010-11-24 15:59:42 10
Annoying PROMPT_COMMAND animation

unset PROMPT_COMMAND to disable. Show Sample Output
This is sample output - yours may be different.
```
$                                                                              @
```
2

PROMPT_COMMAND='seq $COLUMNS | xargs -IX printf "%Xs\r" @'

unefunge · 2010-11-24 14:34:21 37
Generate MD5 hash for a string
This is sample output - yours may be different.
10

md5sum <<<"test"

unefunge · 2010-11-24 12:04:41 14

Used it on daily basis, not sure if it's any better than the OPs version, tho' One advantage is - you can replace 'bash' at the end of the line with eg. cat - to check if the generated command is OK. Show Sample Output

-1

mailq |awk '/MAILER-DAEMON/{gsub("*","");printf("postsuper -d %s\n",$1)}'|bash

unefunge · 2010-11-24 11:42:54 11

Fibonacci numbers with awk

recursive version, "pure" AWK Show Sample Output
This is sample output - yours may be different.
```
0
1
1
2
3
5
8
13
21
34
55
89
144
233
377
610
987
1597
2584
4181
6765
10946
17711
28657
```
5

awk 'func f(n){return(n<2?n:f(n-1)+f(n-2))}BEGIN{while(a<24){print f(a++)}}'

unefunge · 2010-11-24 10:40:08 5
Directory bookmarks

pushd and popd are your friends, but sometimes they're just incompatible with the way one works... Two shell functions: bm bookmarkname - "bookmarks" the current directory, just 'cd $BMbookmarkname' to return to it. forget bookmarkname - unsets the 'bookmarkname' variable. It isn't mandatory, they cease to exist when the session ends. Show Sample Output
This is sample output - yours may be different.
```
$ cd /home/user/very/complicated-and-quirky/dir.ectory/name/foo
$ bm foo
$ cd /var/log/apache2
$ pwd
/var/log/apache2
$ # many commands and cd's later...
$ cd $BMf<Tab>oo # you can use bash's autocompletion mechanism
$ pwd 
/home/user/very/complicated-and-quirky/dir.ectory/name/foo
$
```
2

bm() { export BM${1?"bookmark name missing"}="$PWD" ; }; forget() { unset BM${1?"bookmark name missing"} ; }

unefunge · 2010-11-19 12:15:11 4
Generate trigonometric/log data easily
This is sample output - yours may be different.
2

echo "e("{1..8}");" | bc -l

unefunge · 2010-11-18 21:18:22 1
Bash: escape '-' character in filename
This is sample output - yours may be different.
4

mv -- -filename filename

unefunge · 2010-11-17 12:52:36 5

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Copy a file using dc3dd and watch its progress (very nice alternative to dd)

Requires the dc3dd package - available at http://dc3dd.sourceforge.net

command line calculator

simple function , floating point number is supported.

Convert seconds to [DD:][HH:]MM:SS

Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

set your ssd disk as a non-rotating medium

if you still get a permissions error using sudo, then nano the file: sudo nano -w /sys/block/sdb/queue/rotational and change 1 to 0 this thread: http://www.ocztechnologyforum.com/forum/showpost.php?p=369836&postcount=15 says that this will "help the block layer to optimize a few decisions"

To have only unique lines in a file

Insert a line at the top of a text file without sed or awk or bash loops

Yet another way to add a line at the top a of text file with the help of the tac command (reverse cat).

Decreasing the cdrom device speed

Decreasing the cdrom device speed may be more comfortable to watch films (for example)

Renaming a file without overwiting an existing file name

Sometimes in a hurry you may move or copy a file using an already existent file name. If you aliased the cp and mv command with the -i option you are prompted for a confirmation before overwriting but if your aliases aren't there you will loose the target file! The -b option will force the mv command to check if the destination file already exists and if it is already there a backup copy with an ending ~ is created.

Avoids ssh timeouts by sending a keep alive message to the server every 60 seconds

ssh_config is the system-wide configuration file for ssh. For per-user configuration, which allows for different settings for each host: $echo 'ServerAliveInterval 60' >> ~/.ssh/ssh_config On OSX: $echo 'ServerAliveInterval 60' >> ~/.ssh/config or $echo 'ServerAliveInterval 60' >> ~/etc/ssh_config

shows the full path of shell commands

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