Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: sed command - substitue first instance
Top Forums Shell Programming and Scripting sed command - substitue first instance Post 302070497 by matrixmadhan on Wednesday 5th of April 2006 10:52:41 AM
Old 04-05-2006
Quote:
Originally Posted by vgersh99
Code:
sed -e 's/pattern/REPLACEMENT/1' <INPUTFILE

i tried with this one and it didnot work,
Code:
>cat filename
swap
swap1
swap2
swap
swap

ur command
Code:
sed -e 's/swap/newswap/1' < filename

and this is the output of ur command
Code:
newswap
newswap1
newswap2
newswap
newswap

try this command,
Code:
awk 'BEGIN{x=0} /swap/ {if (x==0) { print "replace"; x=1} else { print } }' filename

and this is the output,
Code:
replace
swap1
swap2
swap
swap


Is this what you were expecting?
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

sed replace 2nd instance

Hello, I want to replace 2nd instance of "foo" in a file use sed. Any suggestions? (2 Replies)
Discussion started by: katrvu
2 Replies

2. Shell Programming and Scripting

Sed on first instance only

Hi, I've been trying to figure this one out and found a post about this on the forum here but the solution didn't seem to work for me. Basically what I have is a file that looks something like: stuff morestuff 0 otherthing 0 etc I want to substitute for the 0 but what I want to... (9 Replies)
Discussion started by: eltinator
9 Replies

3. Shell Programming and Scripting

sed appending needed only after first instance

Hi, Here is my piece of code used with sed in shell script: sed -i '/<falsemodule-option>/ a\<LdapLogin>' myxmlfile The problem that i am facing with the above is that in 'myxml' file i have mulitple instances of <falsemodule-option> so when i execute the above sed command, it is appending... (10 Replies)
Discussion started by: sunrexstar
10 Replies

4. Shell Programming and Scripting

sed: how to limit pattern search to first instance only

I need to reduce a file's size below 50MB by deleting chucks of text. The following sed does this. sed '/^begpattern/,/endpattern/d' myfile However, it's possible that the file size can get below 50MB by just deleting the first instance of the pattern. How do I code that into sed? Or can awk... (8 Replies)
Discussion started by: mariod1049
8 Replies

5. Homework & Coursework Questions

Bash Scripting - sed (substitue)

1. The problem statement, all variables and given/known data: I have been asked to create a bash script to delete comments from another file but in the file they have an echo command with this inside of it /* this is an echo */\ so obviously they want to keep this one in the file. I have found... (5 Replies)
Discussion started by: syco__
5 Replies

6. Shell Programming and Scripting

Using sed can you specify the last instance of a character on a line?

I was told a way to do this with awk earlier today but is there a way with sed to specify the last instance of a character on a line? You will know what character you're looking for but there could be none or one hundred instances of it on a line say and you ONLY want to specify the last one for... (3 Replies)
Discussion started by: Bashingaway
3 Replies

7. Shell Programming and Scripting

sed command to print first instance of pattern in range

The following text is in testFile.txt: one 5 two 10 three 15 four 20 five 25 six 10 seven 35 eight 10 nine 45 ten 50 I'd like to use sed to print the first occurance of search pattern /10/ in a given range. This command is to be run against large log files, so to optimize efficiency,... (9 Replies)
Discussion started by: uschaafm
9 Replies

8. Shell Programming and Scripting

sed for first instance of a pattern

Hi Everyone, I have the below information from a log file: LOAD SUMMARY ============ WRT_8036 Target: TGT_1_TAB (Instance Name: ) WRT_8039 Inserted rows - Requested: 3929 Applied: 0 Rejected: 3929 Affected: 0 Mutated from update: 3929 WRT_8041 Updated rows ... (7 Replies)
Discussion started by: galaxy_rocky
7 Replies

9. Shell Programming and Scripting

sed to grab first instance of a range

Hi all, I'm new to the forum and also relatively new to sed and other such wonderfully epic tools. I'm attempting to grab a section of text between two words, but it seems to match all instances of the range instead of stopping at just the first. This occurs when I use: sed -n... (7 Replies)
Discussion started by: Lazarix
7 Replies

10. Shell Programming and Scripting

sed substitue whole file + 1 substitue with variables on one sed line?.

I'm trying to remove '--X' from the whole file and using variables replace $oldvar with $newvar. I have tried with double quotes but it doesn't seem to work. $newvar is set to /usr/bin/bash. Would appreciate some guidance. newvar=$(which bash) oldvar=/bin/bash sed... (1 Reply)
Discussion started by: itman73
1 Replies

LEARN ABOUT DEBIAN

nbdswapd

nbdswapd(8)															       nbdswapd(8)

NAME

       nbdswapd -- dynamically create swap files on request export with an nbd-server(1) instance

SYNOPSIS

       nbdswapd

DESCRIPTION

       nbdswapd  will  dynamically  create  a  swap  file  when it receives a request and export it using nbd-server(1). it is usually run from an
       inetd(8) instance.

EXAMPLE

       add the following lines to /etc/inetd.conf(5):

       9210	      stream  tcp     nowait  nobody /usr/sbin/tcpd /usr/sbin/nbdswapd

SEE ALSO

       nbd-server(1), inetd(8), inetd.conf(5), nbd-client(8).

AVAILABILITY

       nbdswapd is part of ltsp package and the latest versions are available in source form from https://launchpad.net/products/ltsp (link to URL
       https://launchpad.net/products/ltsp) .

AUTHOR

       copyright  2006	Vagrant  Cascadian  <vagrant@freegeek.org>, distributed under the terms of the GNU General Public License version 2 or any
       later version.

Vagrant Cascadian						     20061023							       nbdswapd(8)
All times are GMT -4. The time now is 10:24 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy