File System Commands in Unix: ls, cat, cp, mv, pwd, cd, mkdir, rmdir, touch, dirname, tar
This article aims to familiarize with the basic file system commands in Unix that helps to work with files and directories. ls command in Unix, cat command in Unix, cp command in Unix, mv command in Unix, pwd command in Unix, cd command in Unix, mkdir command in Unix, rmdir command in Unix, touch command in Unix,dirname command in Unix, tar command in Unix etc. are some of the commonly used File System commands in Unix.
In this article we will discuss about below Unix commands:
ls command in Unix
It is a command line utility that lists the content/files listed in a particular Unix directory. ls command with no parameters the command displays the files listed in your current working directory. With ls command, you can add one or more modifiers to get additional information.
-
- List contents of a directoryÂ
- ls is a command to list computer files in Unix
  Syntax:
 ls [option] [filenames]
| Command | Use |
ls -aÂ
|
Displays all files including hidden files |
ls -l
|
Long listing- The default output of the ls command shows only the names of the files and directories. The -l option shows files in a long listing format with details like file type, file permissions,Number of hard links to the file,file owner, file group, file size, Date and Time, file name. |
ls -i
|
Displays list of directory contents with inode number |
ls -r
|
Lists directory contents in reverse order. |
ls -t
|
Sort the data by modification date |
Here is an example:
ls -l /etc/hosts-rw-r--r-- 1 root root 317 Dec 4 11:31 /etc/hosts  cat command in Unix
The cat (“concatenate“) command is one of the most frequently used command in Unix. cat command allows us to create single or multiple files, view content of file, concatenate files and redirect output in terminal or files.
-
- Concatenate and display filesÂ
- It reads data from the file and gives their content as output.Â
Syntax:
cat [option...] [file ...]
| Command | Description |
$ cat filename
|
To view a single file. It will show content of given filename |
$ cat file1 file2
|
View multiple files. Shows the content of file1 and file2. |
$ cat -n filename
|
Shows contents of a file preceding with line numbers |
$ cat > new1
|
Create file named new1 |
$ cat [sourceFile] > [destFile]
|
Copy the contents of one file to another file. The content will be copied to the destination file. |
$ cat -s filename
|
Suppress repeated empty lines from the file. |
$ cat file1 >> file2
|
Append the contents of one file to the end of another file |
$ cat "file1" "file2" "file3" > "mergedFile"
|
Merge the contents of multiple files |
Examples of the cat command in Unix are:
1. Create a File with cat Command
2. Copy Content of a file to another with cat Command and view the file
cp command in Unix
Unix command used to copy files and directories
-
-
- Copy filesÂ
- It creates an exact image of a file on a disk with a different name.
-
Syntax:
cp [option] [file1] [file2]
command contains two file names, copies the contents of  file1 to the  file2. If the 2nd file doesn’t exist, then first it creates one and then content is copied to it.
cp [option] [file1] [file2][directory]
Command copies file1 and file2 to directoryÂ
   Examples of the cat command in Unix are:
make directory dir1 using mkdir command
Copy test1 and test2 files into this directory.
Change to dir1 using cd command
Check directory dir1 content
mv command in Unix
mv command in Unix is used to move files or directories from one place to another.
- Move or rename filesÂ
- mv is used to move one or more files or directories from one place to another.
Syntax:
mv [option] [sourceFile] [destFile]If the destination file doesn’t exist, it will be created.
If the destination file exist, then it will be overwrite and the source file will be deleted
    pwd command in Unix
Displays the present working directory
Syntax:
pwd    cd command in Unix
Change Working directory or change the current working to some other folder.
Syntax:
Command | Description |
$cd ./myData | Change current directory to myData |
$cd .. | Change current directory to parent directory |
$cd /home/base/myData | Change current directory to dir1 |
$cd -Â | Changes to last directory (from where you came)Â Can be used to toggle between two directories |
$cd | Changes to user’s home directory Home directory is referred by ~ character |
 Â
Example of cd command in Unix are:
change directory from home(~) to mydata
change directory to parent directory using cd..
Change to home directory using cd command
 mkdir command in Unix
- Create new directories
Syntax:
 mkdir [options] DirectoryNames  rmdir command in Unix
- Remove directories
Syntax:
rmdir [options] DirectoryNames   rm command in Unix
- Remove files or directories .For more details on this click hereÂ
Syntax:
 rm [option...] filelist