10 Most Frequently Used Linux Commands
Are you starting out on the Linux command line? Are you having a hard time remembering those commands? Not to worry. Here's a list of some of the most common and most basic commands that are used on Linux, along with some examples explaining there usage
- tar command
The following command creates a new tar archive:
tar cvf archive_name.tar dirname/
Use this when you need to extract from an existing archive:
tar xvf archive_name.tar
This is the command that is used to view a tar archive:
tar tvf archive_name.tar
- grep command
This command searches for a given string within a file:
grep -i "the" demo_file
This command prints a matched line and three lines after it:
grep -A 3 -i "example" demo_text
Recursively search for a string in all files:
grep -r "ramesh" *
- find command
Use this to find files when the filename is known:
find -iname "MyCProgram.c"
This command is used to execute command on files that have been found using find:
find -iname "MyCProgram.c" -exec md5sum {} \;
Empty files in the directory:
find ~ -empty
- ssh command
This command allows you to login to a remote host.
ssh -l jsmith remotehost.example.com
Use this to debug ssh clients:
ssh -v -l jsmith remotehost.example.com
For displaying the ssh client version:
ssh -V
- sed command
Convert the DOS file format into Unix format:
sed 's/.$//' filename
Print the contents of a file in reverse order:
sed -n '1!G;h;$p' thegeekstuff.txt
Add a line number for the non-empty lines in a particular file
sed '/./=' thegeekstuff.txt | sed 'N; s/\n/ /'
- awk command
Remove duplicate lines:
awk '!($0 in array) { array[$0]; print }' temp
Print all lines from a file , which have the same uid and gid:
awk -F ':' '$3==$4' passwd.txt
Printing specific fields from a particular file:
awk '{print $2,$5;}' employee.txt
- vim command
Go to the file's 143rd line.
vim +143 filename.txt
Go to the first found match of the file specified:
vim +/search-term filename.txt
- diff command
Ignoring white spaces when comparing files:
diff -w name_list.txt name_list_new.txt
- sort command
Ascending order:
sort names.txt
Descending order:
sort -r names.txt
Sort a file (passwd) the third field:
sort -t: -k 3n /etc/passwd | more
- export command
Use this for viewing oracle related environment variables:
export | grep ORACLE declare -x ORACLE_BASE="/u01/app/oracle" declare -x ORACLE_HOME="/u01/app/oracle/product/10.2.0" declare -x ORACLE_SID="med" declare -x ORACLE_TERM="xterm"
Export environment variable:
export ORACLE_HOME=/u01/app/oracle/product/10.2.0
Comments
Post a Comment