Using ls command (ls) to sort file names by number.

If you work with a lot of files, you often save the files with numbers for each system.

For example, 

1sample.out

2sample.out

3sample.out

4sample.out

......

......

......

......

10sample.out

11sample.out

12sample.out

.......

.......

Nsample.out

Suppose, you want to extract some information from these files in order from 1sample in order. If you type 'ls', the file 10sample.out will be listed first. You will get list as follow. So the extracted info will be different from what you expect as follow.

10sample.out

11sample.out

12sample.out

...... 

......

15sample.out

1sample.out

2sample.out

.....

.....

Nsample.out

To order file names based on the numbers in the file, use 'ls -v"

Now, the files will be ordered properly.

So, to list the files based on the numbers, use:

ls -v *.out    [to list files with extension .out]

This is a series of post on the "Efficient use of Linux" as well as "Linux Tips for beginners" series. To see all the post, click the link on the right side. 

Using ls command to list all the files in the current directory recursively:

Use:

ls -R

This will list all the files int he current directory recursively.

The 'ls' command in Linux/Unix

The 'ls' command in a Linux system can be used as follows.

To list only the files with no extension
ls !(*.*)              current all the subdirectories
ls -d !(*.*)         only in the current directory
ls -d !(*.tar)         only in the current directory
ls --ignore='*.tar'       without *.tar extension files

ls -I '*.*'

ls | grep -v  "\."      (using grep)

For a comprehensive list of bash commands usage, see here.