grep

 

---

 

1. Extract lines with phrase "Silver rocket"
   

   grep "Silver rocket" filename

    

2. List names of files that contain the word "hummingbird"
   

   grep -l hummingbird *.csv > filelist.txt &

    

3. Use grep as a filter
   

   ls -l | grep string

    

4. Grep for word "unix", irrespective of case
   

   grep -i unix *.html

    

5. Select all lines containing xyz followed by any 2 numbers
   

   grep 'xyz[0-9][0-9]' filename

    

6. Retrieve all lines that begin with a space
   

   grep '^ ' filename

    

7. Retrieve all lines that do not begin with a space
   

   grep '^[^ ]' filename

    

8. Search directories recursively
   

   grep -r string /directory/name

    

9. Search directories recursively, looking only in *PD files
   

   find /directory/name -name '*PD' -print | xargs grep string /dev/null

    

10. Retrieve all lines that begin with a number
    

    grep '^[1-9]' filename

     

11. Retrieve lines with string and the lines above and below string
    

    grep -C 2 'string' filename

     

12. Retrieve lines containing string with a leading dash (-)
    

    grep -e '-string' filename

     

13. Retrieve lines containing both string1 and string2
    

    /usr/xpg4/bin/grep -E 'string1|string2' tmp.out

     

14. Have grep return a status code (0 or 1) for testing
    

         if grep -s $1 $2 
         then 
            echo "Found it"     
         else 
            echo "Did not find it"     
         fi
    

     

15. Test if file exists and is readable:
    

         if test -r filename     
         then 
             grep $1 filename
         else 
             echo "ERROR!  Database file does not exist or is not readable".     
         fi