sed help


 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers sed help
# 1  
Old 12-08-2004
sed help

I have to search and replace a string in a file and I am using the following command in a script.

sed "s/a/b/g" file

All the occurances of a are getting replaced by b except the last line since it does not have a return character at the end of line. If I enter space at the end of last last and
then use the above sed command then it works fine.

I want to know if there is a way I can replace all occurances. Else What is the command that I need to include in my script before the sed command so that I can get that extra space at the end of last line
# 2  
Old 12-08-2004
use line numbers anyway instead of g...
ex ,. try
1,$s/a/b/
if not
use
1,(n)s/a/b/
that should work.. then you need to figure out why the g flag is not working.. it may be that you are not using sed according to the file syntax... it could be you need to do something like this s/\<a\>/b/ i can't see the file so I can't tell you.. try this site for help
http://sed.sourceforge.net
moxxx68
# 3  
Old 12-08-2004
i do some like this ...

echo "" >> file1 puts the new line at the end of the file.



$ cat abcd.txt
abcde
abdcrewuroewr
abababbaaba
abbabbaba$ echo "" >> abcd.txt
$ cat abcd.txt
abcde
abdcrewuroewr
abababbaaba
abbabbaba
$ sed '${$a \ }' abcd.txt
$ sed 's/a/b/g/ abcd.txt
>
$ sed 's/a/b/g' abcd.txt
bbcde
bbdcrewuroewr
bbbbbbbbbbb
bbbbbbbbb
$
# 4  
Old 12-08-2004
Sry for the disordered previous post

$ cat abcd.txt
abcde
abdcrewuroewr
abababbaaba
abbabbaba$ echo "" >> abcd.txt
$ cat abcd.txt
abcde
abdcrewuroewr
abababbaaba
abbabbaba
$ sed 's/a/b/g' abcd.txt
bbcde
bbdcrewuroewr
bbbbbbbbbbb
bbbbbbbbb
# 5  
Old 12-08-2004
Some utilities, like sed, are line-based, i.e they only work on complete lines. So, either add a newline to the last line, as bhargav suggests, but if you only want to do simple character translation, then consider using tr, which works on any file, e.g...

tr 'a' 'b' < file1 > file2
# 6  
Old 12-08-2004
Thanks buddies. Really appreciate your help. Both the suggestions; appending space and tr command work fine for me.
 
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

I am learning regular expression in sed,Please help me understand the use curly bracket in sed,

I am learning SED and just following the shell scripting book, i have trouble understanding the grep and sed statement, Question : 1 __________ /opt/oracle/work/antony>cat teledir.txt jai sharma 25853670 chanchal singhvi 9831545629 anil aggarwal 9830263298 shyam saksena 23217847 lalit... (7 Replies)
Discussion started by: Antony Ankrose
7 Replies

2. Shell Programming and Scripting

sed and awk giving error ./sample.sh: line 13: sed: command not found

Hi, I am running a script sample.sh in bash environment .In the script i am using sed and awk commands which when executed individually from terminal they are getting executed normally but when i give these sed and awk commands in the script it is giving the below errors :- ./sample.sh: line... (12 Replies)
Discussion started by: satishmallidi
12 Replies

3. Shell Programming and Scripting

sed inside sed for replacing string

My need is : Want to change docBase="/something/something/something" to docBase="/only/this/path/for/all/files" I have some (about 250 files)xml files. In FileOne it contains <Context path="/PPP" displayName="PPP" docBase="/home/me/documents" reloadable="true" crossContext="true">... (1 Reply)
Discussion started by: linuxadmin
1 Replies

4. Shell Programming and Scripting

How to use sed to replace the a string in the same file using sed?

How do i replace a string using sed into the same file without creating a intermediate file? (7 Replies)
Discussion started by: gomes1333
7 Replies

5. UNIX for Dummies Questions & Answers

SED: Can't Repeat Search Character in SED Output

I'm not sure if the problem I'm seeing is an artifact of sed or simply a beginner's mistake. Here's the problem: I want to add a zero-width space following each underscore between XML tags. For example, if I had the following xml: <MY_BIG_TAG>This_is_a_test</MY_BIG_TAG> It should look like... (8 Replies)
Discussion started by: rhetoric101
8 Replies

6. Shell Programming and Scripting

deleting text records with sed (sed paragraphs)

Hi all, First off, Thank you all for the knowledge I have gleaned from this site! Deleting Records from a text file... sed paragraphs The following code works nearly perfect, however each time it is run on the log file it adds a newline at the head of the file, run it 5 times, it'll have 5... (1 Reply)
Discussion started by: Festus Hagen
1 Replies

7. Shell Programming and Scripting

sed has zeored my files. Help me with sed please

i made a script to update a lot of xml files. to save me some time. Ran it and it replaced all the the files with a 0kb file. The problem i was having is that I am using sed to change xml node <doc_root>. The problem with this is it has a / in the closing xml tag and the stuff inside will also have... (4 Replies)
Discussion started by: timgolding
4 Replies

8. Shell Programming and Scripting

sed over writes my original file (using sed to remove leading spaces)

Hello and thx for reading this I'm using sed to remove only the leading spaces in a file bash-280R# cat foofile some text some text some text some text some text bash-280R# bash-280R# sed 's/^ *//' foofile > foofile.use bash-280R# cat foofile.use some text some text some text... (6 Replies)
Discussion started by: laser
6 Replies

9. Shell Programming and Scripting

Issue with a sed one liner variant - sed 's/ ; /|/g' $TMP1 > $TMP

Execution of the following segment is giving the error - Script extract:- OUT=$DATADIR/sol_rsult_orphn.bcp TMP1=${OUT}_tmp1 TMP=${OUT}_tmp ( isql -w 400 $dbConnect_OPR <<EOF select convert(char(10), s.lead_id) +'|' + s.pho_loc_type, ";", s.sol_rsult_cmnt, ";", +'|'+ s.del_ind... (3 Replies)
Discussion started by: kzmatam
3 Replies

10. Shell Programming and Scripting

Sed Question 1. (Don't quite know how to use sed! Thanks)

Write a sed script to extract the year, rank, and stock for the most recent 10 years available in the file top10_mktval.csv, and output in the following format: ------------------------------ YEAR |RANK| STOCK ------------------------------ 2007 | 1 | Exxon... (1 Reply)
Discussion started by: beibeiatNY
1 Replies
Login or Register to Ask a Question