Sys-Admin

Introduction

Sed is used to search and modify string.

Substitute string Get number of word About in the dista.xml documents.

cat /root/dista.xml | grep About | wc -l

Replace the word About with ResCF.

sed -i -e 's/About/ResCF/g' /root/dista.xml

's/About/ResCF/g'

• s - search and replace.
• About - word to search.
• ResCF - word to replace with.
• g - should be global search and replace.

Options

• -i or --in-place.

• -e

• Make global and case-insensitive you would need both g (global) and I (case-insensitive):

  sed 's/About/ResCF/gI' /root/dista.xml
  

• Substitute With a Regex Pattern: sed 's/[0-9]/#/g' file.txt Replaces all digits with #.

• Replace Only on Specific Line(s): sed '3s/old/new/' file.txt Replaces “old” with “new” only on line 3.

• Print Matching Lines: sed -n '/pattern/p' file.txt Only prints lines that match the given pattern.

• Replace Only on Specific Line(s): sed '3s/old/new/' file.txt Replaces “old” with “new” only on line 3.

• Insert/Append Lines: sed '2i\This is a new line' file.txt: Inserts “This is a new line” before line 2.

  sed '2a\This is a new line' file.txt Appends “This is a new line” after line 2.

There is some data on Nautilus App Server 3 in Stratos DC. Data needs to be altered in some of the files. On Nautilus App Server 3, alter the /home/BSD.txt file as per details given below.

a. Delete all lines containing the word following and save the results in /home/BSD_DELETE.txt file. (Please be aware of case sensitivity)

b. Replace all occurrences of the word and (look for the exact match) with their and save the results in /home/BSD_REPLACE.txt file.

Note: Let’s say you are asked to replace the word to with from. In that case, make sure not to alter any words containing the string itself, for example; upto, contributor etc.

sed -n '/following/!p' /home/BSD.txt > /home/BSD_DELETE.txt

sed 's/\band\b/their/g' /home/BSD.txt > /home/BSD_REPLACE.txt