Category Archives: Linux

You got to love Linux. Not only that it is free, but it is also very strong, stable, and widely used.

List open or listening ports

MacOS 1lsof -nP -i4TCP RedHat/Centos7 1netstat -tulpn

Posted in Bash, Operating System | Leave a comment

CentOS 6 repo Settings

To fix repo settings in CentOS 6 1. make sure there is no proxy or funny settings in vi /etc/yum.conf 2. There are a couple of files within /etc/yum.repos.d/. Make sure the url are correct (accessible) and enabled=1 ll /etc/yum.repos.d/ … Continue reading

Posted in Linux | Leave a comment

Show Linux Partition Tree Mountpoint and If SSD

1lsblk -o TYPE,NAME,KNAME,UUID,MOUNTPOINT,SIZE,ROTA

Posted in Linux | Leave a comment

SELinux directory permission

To check SELinux directory permission you need to -z for example 1ls -Z /var/www/html If something is incorrect you can re-adjust some of the directory permission: 1chcon -R -t httpd_sys_content_t /var/www/html

Posted in Linux, Operating System | Leave a comment

RedHat / Centos Firewall

To add an exception to firewall In RedHat/CentOS 6 12345iptables –line -vnL iptables -A INPUT -p tcp –dport 80 -m state –state NEW,ESTABLISHED -j ACCEPT iptables -A INPUT -p tcp -s 192.168.0.0/16 -j ACCEPT iptables -D INPUT -p tcp -s … Continue reading

Posted in Linux, Operating System | Leave a comment

Bash string comparison

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465#!/bin/bash function test(){ echo "" echo "TEST $1" echo "VAR_1: $VAR_1 VAR_2: $VAR_2 " if [ "$VAR_1" = "false" ]; then echo " VAR_1 is false"; fi if [ "$VAR_2" = "false" ]; then echo " VAR_2 is false"; fi … Continue reading

Posted in Bash, Linux | Leave a comment

Crontab header

123456# minute (0-59), # |      hour (0-23), # |      |       day of the month (1-31), # |      |       |       month of the year (1-12), # … Continue reading

Posted in Bash, Linux | Leave a comment

Simple unit test is bash file

Consider the following 3 files: 1. shellTestFramework.sh 1234567891011121314151617181920212223242526272829303132333435363738394041424344454647#!/bin/bash # Copyright (c) Ronald Pringadi # Before each Test function setUpTest(){     #"Please overwrite this function on your unit test. Something that need to be done before each test"     … Continue reading

Posted in Bash | Leave a comment

Linux find files and total their size

1find ./ -type f -newerct "1 May 2015" ! -newerct "1 Jul 2015" -print0 | du –files0-from=- -hc| tail -n1

Posted in Bash, Linux | Leave a comment

Allowing a linux/unix user all sudo access without password

/etc/sudoers yourusername ALL=(ALL) NOPASSWD:ALL

Posted in Linux | Tagged , | Leave a comment