Top Linux Commands

#linux #commands #unix

Linux is one of the most popular operating systems with an extensive user-base around the world, most commonly programmers and developers. The open-source Unix-like operating system (OS) is rooted from the Linux kernel - an operating system developed by Linus Torvalds.

The Linux operating system has countless commands but today we are only going to look at top linux commands that are frequently used by programmers. The best part of it is that it makes it easy to complete any task.

ls Directory listing
ls -al Formatted listing with hidden files
ls -lt Sorting the Formatted listing by time modification
cd dir Change directory to dir
cd Change to home directory
pwd Show current working directory
mkdir dir Creating a directory dir
cat >file Places the standard input into the file
more file Output the contents of the file
head file Output the first 10 lines of the file
tail file Output the last 10 lines of the file
tail -f file Output the contents of file as it grows,starting with the last 10 lines
touch file Create or update file
rm file Deleting the file
rm -r dir Deleting the directory
rm -f file Force to remove the file
rm -rf dir Force to remove the directory dir
cp file1 file2 Copy the contents of file1 to file2
cp -r dir1 dir2 Copy dir1 to dir2;create dir2 if not present
mv file1 file2 Rename or move file1 to file2,if file2 is an existing directory
ln -s file link Create symbolic link link to file

Process management commands

ps To display the currently working processes
top Display all running process Unix/Linux Command Reference
kill pid Kill the process with given pid
killall proc Kill all the process named proc
pkill pattern Will kill all processes matching the pattern
**bg List stopped or background jobs, resume a stopped job in the background
fg Brings the most recent job to the foreground
fg n Brings job n to the foreground

File permission commands

chmod octal file Change the permission of file to octal,which can be found separately for user,group,world by adding, • 4-read(r) • 2-write(w) • 1-execute(x)

Searching commands

grep pattern file Search for pattern in file
grep -r pattern dir Search recursively for pattern in dir
command | grep pattern Search pattern in the output of a command
locate file Find all instances of file
find . -name filename Searches in the current directory (represented by a period) and below it, for files and directories with names starting with a filename
pgrep pattern Searches for all the named processes , that matches with the pattern and, by default, returns their ID

System Info Commands

date Show the current date and time
cal Show this month's calender
uptime Show current uptime
w Display who is on line
whoami Who you are logged in as Unix/Linux Command Reference
finger user Display information about user
uname -a Show kernel information
cat /proc/cpuinfo Cpu information
cat proc/meminfo Memory information
man command Show the manual for command
df Show the disk usage
du Show directory space usage
free Show memory and swap usage
whereis app Show possible locations of app
which app Show which applications will be run by default

Compression Commands

tar cf file.tar file Create tar named file.tar containing file
tar xf file.tar Extract the files from file.tar
tar czf file.tar.gz files Create a tar with Gzip compression
tar xzf file.tar.gz Extract a tar using Gzip
tar cjf file.tar.bz2 Create tar with Bzip2 compression
tar xjf file.tar.bz2 Extract a tar using Bzip2
gzip file Compresses file and renames it to file.gz
gzip -d file.gz Decompresses file.gz back to file

Network Commands

ping host Ping host and output results
whois domain Get whois information for domains
dig domain Get DNS information for domain
dig -x host Reverse lookup host
wget file Download file
wget -c file Continue a stopped download

The article covers most of the basic Linux commands that one will come across. There are various other commands, but commonly the above listed 50 Linux commands will do the job.