sed doubt - search and substitute string from variable.

Login or Register for Dates, Times and to Reply

Thread Tools Search this Thread
Top Forums Shell Programming and Scripting sed doubt - search and substitute string from variable.
# 1  
MySQL sed doubt - search and substitute string from variable.

trying to learn more abt sed Smilie

i want to substitute a variable(a) with other variable(b) appended.

Read.txt contains:

input.txt contains:
make test "home/test1/none"version="1.3"
wt's wrong test "home/test2/abc"version="1.0"
make save "home/test/root1"version="1.2"
make try "home/test3/user1"version="1.4"

code tried:
a=`cat read.txt`
for i in $a
sed -e "/$a/s///$a/$b/" input.txt

expected output:
make test "home/test1/none"version="1.3"
wt's wrong test "home/test2/abc_EDITED"version="1.0"
make save "home/test/root1_EDITED"version="1.2"
make try "home/test3/user1"version="1.4"

Thanks in advance Smilie

Last edited by dragon.1431; 09-22-2010 at 07:05 PM.. Reason: removed extra code tags
# 2  
#!/usr/bin/env ruby"read.txt").split("\n")"input.txt").each do |x|
  a.each{|i| x.gsub!(/#{i}/,"#{i}_EDITED") }
  puts x

# 3  
hi kurumi,
Thanks for ur solution.
I would like to go with sed only, i noticed typo error .sed address pattern shd be $i in my previous post .
still i didnt get the expected output.
# 4  
try this,


cp input.txt temp_forum.txt
a=`cat read.txt`

for i in $a
if [ -f temp1_forum.txt ]
cp temp1_forum.txt temp_forum.txt
c=$(echo $i | sed 's/\//\\\//g')
sed  '/'$c'/s//'$c$b'/' temp_forum.txt > temp1_forum.txt
cat temp1_forum.txt
rm temp_forum.txt temp1_forum.txt

This User Gave Thanks to pravin27 For This Post:
# 5  

while read i
  sed "s!$i!$i$b!" input.txt > temp
  mv temp input.txt
done < read.txt

If your sed version supports the -i option:

while read i
  sed -i "s!$i!$i$b!" input.txt
done < read.txt

This User Gave Thanks to Franklin52 For This Post:
# 6  
awk 'NR==FNR{a[$1];next} {for (i in a) {if ($0~i) sub(i,i "_EDITED")}}1' Read.txt input.txt

This User Gave Thanks to rdcwayx For This Post:
# 7  

thanks to everyone.
i have tested pravin & franklin solution.It worked . i hope other two solutions also works.

I will be more happy if you could explain how it works ?
sed -e "/$a/s///$a/$b/"

Am i not saying address & search pattern are same and substitute where $a is found with $a$b.

Thanks a lot in advance for explaining your sed code logic Smilie

Last edited by dragon.1431; 09-23-2010 at 07:54 AM.. Reason: added information about code test
Login or Register for Dates, Times and to Reply

Previous Thread | Next Thread
Thread Tools Search this Thread
Search this Thread:
Advanced Search

Test Your Knowledge in Computers #155
Difficulty: Easy
Defense Advanced Research Projects Agency (DARPA) initiated the ARPANET, the precursor to the Internet, in 1969.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Search for string in column using variable: awk

I'm interested to match column pattern through awk using an external variable for data: -9 1:751343:T:A -9 0 T A 0.726 -5.408837e-03 9.576603e-03 7.967536e-01 5.722312e-01 -9 1:751756:T:C -9 0 T C 0.727 -5.360458e-03 9.579447e-03 7.966977e-01 5.757858e-01... (7 Replies)
Discussion started by: genome
7 Replies

2. Shell Programming and Scripting

[sed]: Substitute a string with a multiline value

Dear all, I try to replace a string of characters in a file (MyFile.txt) by a multiline value of the variable "Myvar": $ cat MyFile.txt DESCRIPTION '@TargetTable SCHEMA' ( @InputFlowDef ); $ The content of Myvar: $ echo "$Myvar" col1 , col2 , col3 $ (4 Replies)
Discussion started by: dae
4 Replies

3. Shell Programming and Scripting

Search for 2 string in 2 lines with sed ?

Hi ! I want to search a string in all lines with sed. If that string is there, i want to look for an other string in the next line.If that string is there i want to put an other line under it. eg: aaa bbb ccc ddd cat bla.txt | sed -e '/aaa/a\' -e ' \!!!' in the upper case, i would... (6 Replies)
Discussion started by: fugitivus
6 Replies

4. Shell Programming and Scripting

String search between patterns using sed

Hi, I am trying to find a way to get sed/awk/grep to help me find a string in a log file that exists between two datestamps and then print the preceding datestamp up to the next datestamp. Here is an example of my logfile: +++ 2013/03/28 17:01:37.085 SIGNALING HIGH ACTIVE Failure Response... (5 Replies)
Discussion started by: raytx
5 Replies

5. Shell Programming and Scripting

How to substitute variable in sed for special character?

Hi , I have input file like below Hi this is "vinoth". Hi happy to work with 'unix' USA(united states of America) My script variables are below : Dquote=Ộ Squote=&#$567 Obrac=&^986 Cbrac=&^745 I want to read the variables in my SED command to replace the double quote,single... (9 Replies)
Discussion started by: vinothsekark
9 Replies

6. Shell Programming and Scripting

replace (sed?) a string in file with multiple lines (string) from variable

Can someone tell me how I can do this? e.g: a=$(echo -e wert trewt ertert ertert ertert erttert erterte rterter tertertert ert) How do i replace the STRING with $a? I try this: sed -i 's/STRING/'"$a"'/g' filename.ext but this don' t work (2 Replies)
Discussion started by: jforce
2 Replies

7. Shell Programming and Scripting

Trying to use a variable pulled from a for statement in a search string

Guys I am having trouble trying to pull some data from a file using a value returned from a for statement. Any help would greatly be apprecaited. I can't seem to get my script to pass the variable. I am trying to pull the 2 lines below the line that has the "pool name" so that i can get the... (5 Replies)
Discussion started by: scottzx7rr
5 Replies

8. Shell Programming and Scripting

Using sed to replace a string in file with a string in a variable that contains spaces

Hi, i call my shell like: my_shell "my project name" my script: #!/bin/bash -vx projectname=$1 sed s/'PROJECT_NAME ='/'PROJECT_NAME = '$projectname/ <test_config_doxy >temp cp temp test_config_doxy the following error occurres: sed s/'PROJECT_NAME ... (2 Replies)
Discussion started by: vivelafete
2 Replies

9. Shell Programming and Scripting

search a string in a line and save it in a variable

Hi I want to read a file line by line and search for a particular string in each line(say for example string containing @ )and save that string into a variable. Can someone suggest me the way to implement it.I am using K- shell Thanks Ishita (5 Replies)
Discussion started by: Ishita
5 Replies

10. Shell Programming and Scripting

Search for string in a file and extract another string to a variable

Hi, guys. I have one question: I need to search for a string in a file, and then extract another string from the file and assign it to a variable. For example: the contents of the file (group) is below: ... ftp:x:23: mail:x:34 ... testing:x:2001 sales:x:2002 development:x:2003 ...... (6 Replies)
Discussion started by: daikeyang
6 Replies

Featured Tech Videos