Find files on certain directory for excluding files certain permission

Why is this useful? When your directory contains thousands of files.
Yes, CHMOD is slow and surprisingly very I/O taxing.
So being able to use 'find' command first to only CHMOD certain files
that needs to be CHMODED is useful.


find /your_directory ! -perm 0777

-OR-

find /your_directory \! \( -perm 0777 -o -perm 0775 \)

Check if file or directory exists using bash or shell script sh

if [ -f file_path_name.ext ]

then

echo "file exists"

else

echo "file does not exists"

fi

if [ -d directory_path ]

then

echo "dir exists"

else

echo "dir does not exists"

fi

Send HUP hangup hang-up signal to linux process to re-read configuration file

kill -HUP $( cat /var/run/nginx.pid )

Find inodes where it is being used inside directories

This command will show inodes being used in directories recursively:

find {{{starting directory}}} -xdev -printf '%h\n' | sort | uniq -c | sort -k 1 -n

Quick and Easy Send Test E-mail using mail from linux command line (CLI)

echo "My message body" | mail -s "Test Email Subject" somebody@somedomain.com

Quick and dirty bash shell script to find issues on your linux server

I usually would place this file in my home directory and name it 'find_issues.sh'

cd ~
nano find_issues.sh
chmod +x find_issues.sh

content of find_issues.sh:

#!/bin/bash

read -sn 1 -p "Press any key to check keyword 'error'";echo
tail -n 1000 /var/log/messages | grep error

read -sn 1 -p "Press any key to check keyword 'fail'";echo
tail -n 1000 /var/log/messages | grep fail

read -sn 1 -p "Press any key to check keyword 'panic'";echo
tail -n 1000 /var/log/messages | grep panic

read -sn 1 -p "Press any key to check keyword 'fault'";echo
tail -n 1000 /var/log/messages | grep fault

read -sn 1 -p "Press any key to check keyword 'timeout'";echo
tail -n 1000 /var/log/messages | grep timeout

Check if directory exists using bash or linux shell script

if [ -d directory_path ]
then
   echo "dir exists"
else
   echo "dir does not exists"
fi