Linux Commands

LinuxCommands

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'''UseFul Linux Command
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1. To take backup of a file or copy paste a file from one location to another
cp <Filepath/filename> <filepath/filename.bak>

2. To copy all the sub-directories also, use -r with cp command
cp -r <Filepath1/filename1> <filepath2/filename2>

3. TO find file or directory(case insensitive search)
find -iname "file or directory name"

4. To remove/Move file
mv <filename1> <path/filename2>

5. To check if Directory is present
if [[ -d DirectoryName ]]
  then "directory does exist"
fi

6. $# represents the command line arguments

7. not eqals is represented by ne
eg. to check if the commandl line arguments are equal to 14 or not
if [[ $# -ne 14 ]]
then
  echo "Commnad lines are not equal to 14"
else
  echo "Arguments are 14 in length"
fi

8. Command line arguments are represented by $1, $2, $3 and so on.
After $9 the arguments must be enclosed in brackets, for example, ${10}, ${11}, ${12}

9. To get the date in format of YYYYMMDD
date +%Y%m%d
eg date +%Y%m%d will print 20190924

10. To get the date in format of HourMinuteSecond
date +%H%M%S
eg date +%H%M%S will orint 122659