Data base Management

1
Data base Management

• awk
• grep
• ltlt
• bc

2
awk

• The name of the awk is derived from the names of
  the programmers who wrote it, Aho, Weinberger,
  and Kernighan
• The awk is useful for information retrieval, data
  manipulation, and report writing
• So awk utility can be used to select and print
  specific field e.g.,
• Who awk print 1

3
Select lines and print fields

• Awk can select record based on the presence of a
  specified pattern
• awk /string/ print 3 filename
• 0 denotes all fields of a record, I.e, the
  entire line
• awk /string/ print 0 filename

4
Changing the field delimiter

• awk F print 2 /etc/passwd

5
grep

• grep searches for lines containing target string
• grep string filename
• Search through all files
• grep string /
• List name of the files that contain matches
• grep l string /
• Ignore the case
• grep i string filename

6
grep

• Identify the line number for each match
• grep n string filename
• Reverse the sense display all lines without the
  string
• grep v string filename
• Select lines having a pattern at the beginning of
  the line
• grep string filename

7
Task 1

• 1. What command do you enter to print the fourth
  field of file1?
• 2. Using awk, write a command line that functions
  like the following grep command
• grep pattern file3

8
Here Document

• A term used for redirecting multiple lines
• cat gtgt /.profile ltltEND
• banner Welcome
• date
• END

9
Performing Arithmetic

• Basic Calculator
• bc ltentergt
• 57
• 12
• 57
• 35

10
Performing Arithmetic

• The (()) command
• echo ((57))
• 12
• echo ((57))
• 35