Commands by axelabs

Commands by axelabs (11)

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Use the builtin ':' bash command to increment variables

I just found another use for the builtin ':' bash command. It increments counters for me in a loop if a certain condition is met... : [arguments] No effect; the command does nothing beyond expanding arguments and performing any specified redirections. A zero exit code is returned. Show Sample Output
This is sample output - yours may be different.
```
1
```
2

[ $V ] || : $((V++)) && echo $V

axelabs · 2012-06-15 16:48:03 0
Synchronize directory copy

rsync will copy the source directory into destination and any subsequent run will synchronize only the changes from the source. Show Sample Output
This is sample output - yours may be different.
```
building file list ... done
src/
src/modified
src/newfile

sent 271 bytes  received 70 bytes  682.00 bytes/sec
total size is 30  speedup is 0.09
```
0

rsync -avz ~/src ~/des/

axelabs · 2012-06-01 15:08:12 2
Time conversion/format using the date command

Show Sample Output
This is sample output - yours may be different.
```
epoch: 1323946029 or format: 2011/12/15
```
1

date -d '2011-12-15 05:47:09' +"epoch: %s or format: %Y/%m/%d"

axelabs · 2011-12-16 18:43:36 0
Identifying Xorg video driver in use

The above one liner can be used to determine what card/driver is Xorg currently using. For additional information, see http://goo.gl/mDnWu Show Sample Output
This is sample output - yours may be different.
```
[    27.597] (II) RADEON(0): PCIE card detected
[    27.638] (II) RADEON(0): Output LVDS connected
```
-1

egrep -i " connected|card detect|primary dev" /var/log/Xorg.0.log

axelabs · 2011-02-24 18:04:04 0
Use tee to process a pipe with two or more processes

Tee can be used to split a pipe into multiple streams for one or more process to work it. You can add more " >()" for even more fun. Show Sample Output
This is sample output - yours may be different.
```
tee can split a pipe in two
tee_can_split_a_pipe_in_two
owt ni epip a tilps nac eet
```
33

echo "tee can split a pipe in two"|tee >(rev) >(tr ' ' '_')

axelabs · 2010-08-14 20:38:59 3
Sed can refference parts of the pattern in the replacement:

Show Sample Output
This is sample output - yours may be different.
```
me=swap
2=1
```
2

echo -e "swap=me\n1=2"|sed 's/$.*$=$.*$/\2=\1/g'

axelabs · 2010-01-16 22:01:37 0
Watch number of lines being processed on a clear screen

awk can clear the screen while displaying output. This is a handy way of seeing how many lines a tail -f has hit or see how many files find has found. On solaris, you may have to use 'nawk' and your machine needs 'tput' Show Sample Output
This is sample output - yours may be different.
```
13164
```
0

cat /dev/urandom|awk 'BEGIN{"tput cuu1" | getline CursorUp; "tput clear" | getline Clear; printf Clear}{num+=1;printf CursorUp; print num}'

axelabs · 2009-07-13 07:30:51 0
Randomize lines in a file

This appends a random number as a first filed of all lines in SOMEFILE then sorts by the first column and finally cuts of the random numbers.
This is sample output - yours may be different.
4

awk 'BEGIN{srand()}{print rand(),$0}' SOMEFILE | sort -n | cut -d ' ' -f2-

axelabs · 2009-05-29 01:20:50 4
lsof equivalent on solaris

Report fstat(2) and fcntl(2) information for all open files in each process.
This is sample output - yours may be different.
4

/usr/proc/bin/pfiles $PID

axelabs · 2009-03-05 17:26:57 2
Print text string vertically, one character per line.

Show Sample Output
This is sample output - yours may be different.
```
P
r
i
n
t
 
t
e
x
t
 
v
e
r
t
i
c
a
l
l
y
```
8

echo Print text vertically|sed 's/$.$/\1\n/g'

axelabs · 2009-03-04 23:58:02 6
check if commandlinefu.com got a better domain

It would be nice if commandlinefu.com had a better domain name. Will they pick one of the above; We'll see. Show Sample Output
This is sample output - yours may be different.
```
No whois server is known for this kind of object.
No match for "CMDFU.COM".
```
-11

whois cmd.fu;whois cmdfu.com|grep -i cmdfu

axelabs · 2009-02-19 08:57:50 3

What's this?

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Kill any lingering ssh processes

Find the package that installed a command

List your MACs address

Know SELinux status

Usefule to check whether SELinux is in force or disabled. Though you need to be superuser while execute this command.

Show all LISTENing and open server connections, with port number and process name/pid

Renames all files in the current directory such that the new file contains no space characters.

This is a better version, as it does no command piping, uses for instead of while loops, which allows for a list of files in the current working directory to be natively processed. It also uses the -v/verbose option with mv to let you know what the command is doing. While the command does exactly the same in a better way, I would modify the sed option to replace spaces with underscores instead, or dashes. Please note that you'll receive errors with this command as it tries to rename files that don't even have spaces. This is an alternative to: http://www.commandlinefu.com/commands/view/8761/renames-all-files-in-the-current-directory-such-that-the-new-file-contains-no-space-characters.

Show GCC-generated optimization commands when using the "-march=native" or "-mtune=native" switches for compilation.

You can tell GCC to automatically select optimization commands and produce optimized code for the local machine (the one compiling the code), but you can't normally see what switches have been selected and used unless you append a "-v" and pause compilation.

Burn CD/DVD from an iso, eject disc when finished.

cdrecord -scanbus will tell you the (x,y,z) value of your cdr (for example, mine is 3,0,0)

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" }

Get sunrise and sunset times

This will get the sunrise and sunset times of a specific location. To be able to determine $l you need to first go to http://weather.yahoo.com/ and look up your location. The last numbers in the URL will be the $l Instead of forecastrss?w=$l you can also use forecastrss?p=$l and use the RSS link of the city you found. Also see http://developer.yahoo.com/weather/ for more information

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