29 Top Linux Commands You Need Hands-on

Daily Use Linux Commands

1. cat – display or concatenate files
2. cd – change directory
3. chmod – change the permissions on a file or directory
4. compress – compress a file
5. cp – copy a file
6. date – display the current date and time
7. diff – display differences between text files
8. echo – echo arguments to the standard
9. output file – determine the type of a file
10. find – find files of a specified name or type
11. finger – display information about a user
12. ftp – file transfer program
13. grep – searches files for a specified string or expression
14. kill – kill a process
15. lpr – print out a file l
16. s – list names of files in a directory
17. man – display an on-line manual page
18. mkdir – make a directory
19. more – scan through a text file page by page
20. mv – move or rename files or directories
21. nice – change the priority at which a job is being run
22. passwd – change your password ps – list processes
23. pwd – display the name of your current directory
24. quota – disk quota and usage
25. rm – remove files or directories
26. rmdir – remove a directory
27. sort – sort and collate lines
28. talk – talk to another user
29. wc – display a count of lines, words and characters

How to Get Two Top Duplicate Records

I have been asked the same question in an interview. How to get 2 top duplicate records?

Sort file1 |unique -d | head -2

What this command does…

• Sorts File
• Display duplicate records
• Top 2 duplicate records

Count Number of Lines in a List of Files Using For Loop

#!/bin/bash 
if [ $# -lt 1 ]
then
echo "Usage: $0 file ..."
exit 1
fi

echo "$0 counts the lines of code"
l=0
n=0
s=0
for f in $*
do
l=wc -l $f | sed 's/^\([0-9]*\).*$/\1/'
echo "$f: $l"
n=$[ $n + 1 ]
s=$[ $s + $l ]
done

echo "$n files in total, with $s lines in total"

Related Posts