There are few commands which are frequently used and we stuck for those command.
I have listed some of the basic commands used frequently.1) Search string or word in a file in a specified directory:
find /path/to/dir -type f -exec grep -l yourstring {} \;
2)
Find files by name
a) locate -i filename :This command searches in database.here -i is ignorecase.(This is Fast)b) find filename : It searches the file system.(This is slow)
3) Find process and kill particular process.
a) ps -ef | grep tomcat : Shows running tomcat process details.
command explanation : -e stands for list all process and f formats output view.Output of ps -ef
is given to grep command which search given string in the given output.
b) kill pid : This command will kill the process. If process still not stopped then use kill -9 pid
command.
4) Check the available space on disk:
df -h : Outputs total space utilized and free space available. -h stands for human readable
format e.g. mb,gb etc.
5) Check the size of file or directory in linux
du -ah path : Display the size of directory. “-a” stands for show file along with size and “h”
for human readable format like mb,gc etc.
6) How to send mail in Linux
mailx -s "Subject line" me@you.com <message.txt : Before firing this command check
sendmail is running with command service sendmail status.
7) Installing software in linux is based on different linux flavours
a)RedHat,Fedora,CentOs : yum install software name e.g yum install sendmail. yum
command is for rpm packages
b)Ubuntu : apt -get software name e.g apt -get sendmail. apt command is used for debian
packages.
8) How start service in linux
service start servicename :Starts the tomcat service e.g service start tomcat
service status servicename : Check status of service.
service stop servicename : Stops the service.
9) Change permission of file or directory in linux:
Below is good link for understanding file permission. Tead it once so concept will be clear
forever.
http://www.comptechdoc.org/os/linux/usersguide/linux_ugfilesp.html
10) Cut paste file from one location to other (move file from one dir to other)
a) mv file.txt directorypath/ : Move file.txt to given directory path
b) mv file1.txt directorypath/file1.txt : Move file.txt to directory path and rename it to
file1.txt
11) Renaming file in linux : same mv command is used for renaming file.
mv file.txt file1.txt : As path file.txt and file1.txt is in the same directory mv utility will
understand it’s a renaming file not moving.
12) Deleting file and folder in linux:
rm -f filename : Delete file . -f option tell that don’t prompt message like “are you sure you
want to delete this file?”.
rm -rf directorypath : This command delete directory. -r will delete subdirectories as well
-f is explain above.
rm -f ./*.log : This command will delete all the files in current directory with extension .log.
Also check below links :
