Unix Handy Commands

These are the commands which i use on daily basis in Unix.I found these commands very useful

In point 2 and 6 it is not displaying pipe symbol due to some problem.Please use pipe between commands

1. Too see a particular line For example if you just want to see 180th line in file sed -n '180p' testfile.txt
2. To find a particular column in file cat testfile.txt awk -F"," '{print $2}'
3. To rename file with current date mv test test_`date +%Y-%m-%d
4. This command will take out all those lines which are having 8 at 17th position grep '^.\{16\}8' testfile.txt >testfile_new.txt
5. To remove nth line without openning file sed 'nd' file1>file2 to remove multiple lines sed -e 1d -e 5d
6. To find top 20 files with most spacels -ltrawk -F" " '{print $5 $9}' sort -ntail -20
7. To find record in first file not in second comm -13 testfile1.txt testfile2.txt
8. If you are looking from something that is contained in a file but you don't know which directory it is in do the following: find . -name "*" xargs grep -i something This will find all of the files in the directory and below and grep for the string something in those files!
9. Delete Files Delete all the files starting with name testfile find . -type f -name "testfile*" exec rm -f {} \;
10. Remove blank space from file sed -e "s/ *//g" testfile.txt >testfile.txt_wo_space