Login or Register to Ask a Question and Join Our Community


Shell Programming and Scripting

sed to replace a line with modified line in same file

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting sed to replace a line with modified line in same file
# 1  
Old 11-29-2011
sed to replace a line with modified line in same file
i have few lines in a file... i am reading them in a while loop so a particular line is held is $line1.. consider a modified line is held in $line2.... i want to replace $line1 with $line2 in the same file... how to do it..?
i have come up till the below code
Code:
 sed "s/$line1/$line2/g" tmpfile.sql

the code replaces fine but its not replaced in same file..it just displays it, i could direct to another temporary file but i wast the replacement to be in same file... plz help..
# 2  
Old 11-29-2011
sed -i, or use a temporary file and move it afterwards.
This User Gave Thanks to CarloM For This Post:
vivek d r
# 3  
Old 11-29-2011
cat input:
Code:
hello
world

Code:
sed -i 's/world/earth/g' input

cat input:
Code:
hello
earth

# 4  
Old 11-29-2011
thanks it worked :-)

---------- Post updated at 05:56 PM ---------- Previous update was at 05:39 PM ----------

oh am sorry it dint work....
here what i tried...
contents of tmpfile.sql is
Code:
CREATE TABLE `ZoneVoiceRecorderVoiceRecordersMap` (
  `zoneId` int(11) DEFAULT NULL,
  `voiceRecordersId` int(11) DEFAULT NULL,
  `lastModified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  UNIQUE KEY `zoneId` (`zoneId`,`voiceRecordersId`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

the code which i used is
Code:
while read line1
do
 if [[ `expr match "$line1" ".*DEFAULT NULL.*"` != "0" ]]; then
                line2="blah blah blah"
                sed -i 's/$line1/$line2/g' tmpfile.sql
        fi
done < tmpfile.sql

i am not getting any error but when i open tmpfile.sql its not changed....
# 5  
Old 11-29-2011
Use double quotes with sed if you have variables inside...
Code:
sed -i "s/$line1/$line2/g" tmpfile.sql

--ahamed
This User Gave Thanks to ahamed101 For This Post:
vivek d r
# 6  
Old 11-29-2011
Oh thanks.. its working now... :-)
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

sed replace to rename each line a file

Have a file in this format This is line one ; line_one This is line two ; line_two This is line three ; line_three This is line four ; line four. I'm trying to make each line a new file called line_one line_two line_three line_four. Tried using split -1 but then I'm back needing to rename... (3 Replies)
Discussion started by: jimmyf
3 Replies

2. Shell Programming and Scripting

Replace values in script reading line by line using sed

Hi all, Let's say I have a script calling for the two variables PA_VALUE and PB_VALUE. for pa in PA_VALUE blah blah do for pb in PB_VALUE blah blah do I have a text file with two columns of values for PA and PB. 14.5 16.7 7.8 9.5 5.6 3.6 etc etc I would like to read this... (7 Replies)
Discussion started by: crimsonengineer
7 Replies

3. Shell Programming and Scripting

sed command to replace a line in a file using line number from the output of a pipe.

Sed command to replace a line in a file using line number from the output of a pipe. Is it possible to replace a whole line piped from someother command into a file at paritcular line... here is some basic execution flow.. the line number is 412 lineNo=412 Now i have a line... (1 Reply)
Discussion started by: vivek d r
1 Replies

4. Shell Programming and Scripting

Multiple line search, replace second line, using awk or sed

All, I appreciate any help you can offer here as this is well beyond my grasp of awk/sed... I have an input file similar to: &LOG &LOG Part: "@DB/TC10000021855/--F" &LOG &LOG &LOG Part: "@DB/TC10000021852/--F" &LOG Cloning_Action: RETAIN &LOG Part: "@DB/TCCP000010713/--A" &LOG &LOG... (5 Replies)
Discussion started by: KarmaPoliceT2
5 Replies

5. Shell Programming and Scripting

sed command to replace a line at a specific line number with some other line

my requirement is, consider a file output cat output blah sdjfhjkd jsdfhjksdh sdfs 23423 sdfsdf sdf"sdfsdf"sdfsdf"""""dsf hellow there this doesnt look good et cetc etc etcetera i want to replace a line of line number 4 ("this doesnt look good") with some other line ... (3 Replies)
Discussion started by: vivek d r
3 Replies

6. Shell Programming and Scripting

I need to know how to replace a line after a pattern match with an empty line using SED

Hi How Are you? I am doing fine! I need to go now? I will see you tomorrow! Basically I need to replace the entire line containing "doing" with a blank line: I need to the following output: Hi How Are you? I need to go now? I will see you tomorrow! Thanks in advance.... (1 Reply)
Discussion started by: sags007_99
1 Replies

7. Shell Programming and Scripting

sed to replace a line with 2 or more different lines in same file

i have something like this... cat filename.txt <complexType name="abc"> bklah vlah blah blha blha blah blha </complexType > <complexType name="def"> bklah vlah blah blha blha blah blha </complexType > . . .and so on.. its a very large file (11 Replies)
Discussion started by: vivek d r
11 Replies

8. Shell Programming and Scripting

sed replace characters in next line with input from a file

Hi, I have a set of strings in filea. I want to search string xyz in fileb and replace next line in file b with the content from filea. #cat filea abc def ghi #cat fileb asdkjdslka sajljskdjoi xyzjjjjkko aaaaaaaa bbbbbbbb cccccccc xyzsdsajd dddddddd eeeeeeee (2 Replies)
Discussion started by: anilvk
2 Replies

9. Shell Programming and Scripting

Replace a line in a file with sed

Hi, I am trying to write a script that will replace "PermitEmptyPasswords yes" with "PermitEmptyPasswords no". The following does not seem to work: - sed 's!/"PermitEmptyPasswords yes"/!/"PermitEmptyPasswords no"/!' Appreciate any ideas. Thanks (2 Replies)
Discussion started by: mtech3
2 Replies

10. Shell Programming and Scripting

sed - Replace Line which contains the Pattern match with a new line

I need to replace the line containing "STAGE_DB" with the line "STAGE_DB $DB # database that contains the table being loaded ($workingDB)" Here $DB is passed during the runtime. How can I do this? Thanks, Kousikan (2 Replies)
Discussion started by: kousikan
2 Replies
Login or Register to Ask a Question