Linux - Dinlenen portlar

netstat -tupln | grep ':5000'

Linux port açma

iptables -I INPUT -p tcp --dport 5000 -j ACCEPT

Bash - Komut çıktısını değişkene atamak

dir=$(pwd)

Sed - Dosyanın her satırına prepend etmek

text.txt | sed "s/^/[prepend1] /"

colrm - linux

echo "123456" | colrm -4

Sed - Boş satırları silmek

sed '/^$/d' input.txt > output.txt

Linux - tar.bz2 dosyasını açmak

tar jxf file.tar.bz2

Linux kabuk değişkenleri

$$ = The PID number of the process executing the shell.
$? = Exit status variable.
$0 = The name of the command you used to call a program.
$1 = The first argument on the command line.
$2 = The second argument on the command line.
$n = The nth argument on the command line.
$* = All the arguments on the command line.
$# The number of command line arguments.

Linux - Koşullar

There is a function provided by bash called test which returns a true or false value depending on the result of the tested expression. Its syntax is:

test expression

It can also be implied as follows:

[ expression ]

The tests below are test conditions provided by the shell:

-b file = True if the file exists and is block special file.
-c file = True if the file exists and is character special file.
-d file = True if the file exists and is a directory.
-e file = True if the file exists.
-f file = True if the file exists and is a regular file
-g file = True if the file exists and the set-group-id bit is set.
-k file = True if the files' "sticky" bit is set.
-L file = True if the file exists and is a symbolic link.
-p file = True if the file exists and is a named pipe.
-r file = True if the file exists and is readable.
-s file = True if the file exists and its size is greater than zero.
-s file = True if the file exists and is a socket.
-t fd = True if the file descriptor is opened on a terminal.
-u file = True if the file exists and its set-user-id bit is set.
-w file = True if the file exists and is writable.
-x file = True if the file exists and is executable.
-O file = True if the file exists and is owned by the effective user id.
-G file = True if the file exists and is owned by the effective group id.
file1 –nt file2 = True if file1 is newer, by modification date, than file2.
file1 ot file2 = True if file1 is older than file2.
file1 ef file2 = True if file1 and file2 have the same device and inode numbers.
-z string = True if the length of the string is 0.
-n string = True if the length of the string is non-zero.
string1 = string2 = True if the strings are equal.
string1 != string2 = True if the strings are not equal.
!expr = True if the expr evaluates to false.
expr1 –a expr2 = True if both expr1 and expr2 are true.
expr1 –o expr2 = True is either expr1 or expr2 is true.
The syntax is :

arg1 OP arg2



where OP is one of –eq, -ne, -lt, -le, -gt, or –ge. Arg1 and arg2 may be positive or negative integers or the special expression "-l string" which evaluates to the length of string.

Unix shell scripting - Log yazma fonsiyonu

Log-function

---

In a private message, I was asked how the log-function worked that I described above. Since this might be helpful to other people too, I'm answering the question in public.

First of all, I use Bash, don't know if this trick works in other Shells.

Content of script:

Code:

#!/bin/bash
. lib/functions.conf # mind the SPACE between the DOT and the path/filename!!! 
logfile=scheduler.log
func_eventlog "STARTING ABG JOB"
-=script runs some more, but that's irrelevant, the example is clear=-

Content of file: lib/functions.conf which by the way is executable :

Code:

################################################
#                                              #
# Log functie                                  #
#                                              #
# Usage:                                       #
#                                              #
# func_eventlog "Dit wil ik loggen"            #
#                                              #
# Variabelen:                                  #
#                                              #
# $logfile (logfile inclusief pad)             #
#                                              #
################################################

func_eventlog()
{
 echo -e "`date` - $1" >> $logfile
}

So whenever I want something logged, I just use:

func_eventlog "Send this text to logfile"

and I never ever have to worry about accidentally overwriting my logs instead of appending to them. 

Linux - CGI shell scripti web üzerinden çağırmak

http://www.cyberciti.biz/faq/how-do-i-find-the-url-for-my-cgi-bin/


http://www.xappsoftware.com/wordpress/2013/06/17/how-to-run-a-shell-script-from-a-web-page/?goback=%2Egde_4232349_member_250408628

Awk - Boş satırları silmek

awk /./ dosya.txt

Awk - linux swap colunms

awk 'BEGIN {FS=OFS=":"} {temp=$1; $1=$2; $2=temp} {print}' input.txt

Grep alfanümerik içeren satırlar

grep -Ei '[[:alnum:]]'

AWK - Sonraki her n satırı birleştir

awk '{printf("%s%s", $0, (NR%3 ? "," : "\n"))}' details.txt

Raspberry - Boot'ta ssh'ı açmak

ssh'ı kurmak
sudo apt-get install ssh


ssh dinlemeye başlamak
sudo /etc/init.d/ssh start


tek sefere mahsus boot ile dinlemeyi öğretmek

sudo update-rc.d ssh defaults

 
reboot
sudo reboot

Raspberry - Network bilgileri

/sbin/ifconfig

Linux - Sed ile Satır başındaki boşlukları silmek

sed -e 's/^[ \t]*//'

Raspbian - Sistem dilini değiştirmek

sudo dpkg-reconfigure locales

Raspbian - Klavye dilini değiştirmek

sudo vi /etc/default/keyboard