Sometimes we need to work on Linux environment during development specially on Linux box hosting the server.As we know Linux is bundled with lots of useful commadline features, file handling is one of them.Here is small list of commands which I feel very useful while working on Linux.
Note : Command syntax/example given below are based on requirements/assignment I worked upon.Every command below may have multiple options,which can be used in different combination based on scenarios(requirement).For example I am redirecting output to a file which can also be displayed on console.
1. Secure File Copy.
Using this feature you can securely copy file from one machine to another machine without login into any of the machine.
Syntax : scp user1@machine1:Path of source file user2@machine2:Path of the destination directory
Example :scp admin@192.168.0.101:/opt/file/Test.jar jboss@192.168.0.109:/opt/jboss/app/lib
2. Fetching the specific line range from file and write result to another file.
Syntax : sed -n 'startLineNumber,EndLineNumberp' fileToBeSearch > resultFile
Example : sed -n '1,500p' Data.csv > SmallData.csv
3. Fetching the line containing given text from file.
Syntax :grep searchText SourceFile > FileContainingResultData
Example : Search For single String
grep nike BrandData.csv > NikeData.csv
Example : Search For 2 Strings with OR operation
grep 'nike\|adidas' BrandData.csv > NikeORAdidasData.csv
Example : Search For 2 Strings with AND operation
grep nike BrandData.csv | grep shoe > NikeANDShoeData.csv
4. Changing file or directory (folder) permissions.
Sometimes it required to change the permissions of an file or directory in order to perform certain operations.
Syntax : chmod permissionOctalCode fileOrDirectoryName
Example : chmod 777 dataSyntax : chmod permissionOctalCode fileOrDirectoryName
chmod 777 Record.csv
Note : Use -R option to recursively change the permission of the directory.
5. Searching file by name.
find command is very useful to search files.
Syntax : find directoryToSearch -name fileName
Example : find / -name 'eaccmd.sh'
6. Access environment as different user.
Using below command you can access the environment as an different user.Mostly it is used to access the environment as more privileged user(root).
Syntax : sudo su - userName
Example : sudo su - admin
7. Navigate to previous directory.
Using below command you can navigate to previous directory from where you have navigated to current directory.
Syntax : cd -
8. Create a zip file.
Using below command you can add single or multiple files to zip.
Syntax : zip nameOfZip.zip file1 file2 ...
Example : zip Log.zip server.log console.log
9. Unzip the zipped file.
Use below command to unzip the zipped file.
Syntax : unzip nameOfZip.zip
Example : unzip Log.zip
10. Display content of zip file without extracting it.
You can display the content of zip file without extracting it.
Syntax : unzip -l nameOfZip.zip
Example : unzip -l Log.zip
11. Delete all lines containing specific text from a file.Without opening the file.
You can delete all lines containing 'some string' from a file without opening it.
Syntax : sed --in-place '/some string/d' myfile
Example : sed --in-place '/nike/d' Brand.csv
For more detail on any of the above commands use man command(manual pages or man pages).
