In zabbix-agent.conf I have lines:
# Example: Server=127.0.0.1,192.168.1.0/24,::1,2001:db8::/32,zabbix.example.com
Server=127.0.0.1
I want to replace line
Server=127.0.0.1
with my
Server=zabbix.mydomain.com
But if I do
sed -i -e 's/Server=127.0.0.1/Server=zabbix.mydomain.com/g' /etc/zabbix/zabbix_agentd.conf
it found also line with commented example and replace string in it. I get:
#<----->Example: Server=zabbix.mydomain.com,192.168.1.0/24,::1,2001:db8::/32,zabbix.example.com
Server=zabbix.mydomain.com
How to replace only one line?
You need to
Match the text at the start of string
Escape the dots
Remove g flag since the match will only be found at the string start.
Also, you do not need the -e option, you can use
sed -i 's/^Server=127\.0\.0\.1/Server=zabbix.mydomain.com/' /etc/zabbix/zabbix_agentd.conf
See the online demo:
#!/bin/bash
s='# Example: Server=127.0.0.1,192.168.1.0/24,::1,2001:db8::/32,zabbix.example.com
Server=127.0.0.1'
sed 's/^Server=127\.0\.0\.1/Server=zabbix.mydomain.com/g' <<< "$s"
Output:
Example: Server=127.0.0.1,192.168.1.0/24,::1,2001:db8::/32,zabbix.example.com
Server=zabbix.mydomain.com
This might work for you (GNU sed):
sed -i '/^Server=127\.0\.0\.1/cServer=zabbix.mydomain.com' file
Change line beginning Server=127.0.0.1 to Server=zabbix.mydomain.com.
The other answers are almost fine but they would also replace a line like:
Server=127.0.0.10
A complete solution with any sed could be:
sed -i 's/^Server=127\.0\.0\.1$/Server=zabbix.mydomain.com/' /etc/zabbix/zabbix_agentd.conf
^ and $ anchor the string to the beginning and end of line, respectively. Dots need backslash escape, else they stand for any character.
Related
How can I use a cat and sed to read data from a file and insert it into another file under known line?
For example I have a file named script1.txt that contains a few hundred lines, one of the line has the value "COMMANDS="commands"
If I wanted use sed to insert a line under it, simply I can use sed as the command bellow.
sed -i '/^COMMANDS=.*/a NEW LINE HERE' script1.txt
But if I want to insert a multi lines and these lines inside a file, and these line changes every a few hours.. how can i do that ?
I tried:
DATA=$(cat data.txt)
sed -i '/^COMMANDS=.*/a '$DATA'' script1.txt
I got the error bellow.
sed: -e expression #1, char 1: unknown command: `"'
Is there a way other than sed to insert the data from file under known line with no issues?
This might work for you (GNU sed):
sed -i '/^COMMANDS=/r dataFile' file
This will append the contents of the file dataFile after the line beginning COMMANDS= and update file
If the data you want to append is multi-line, you might want to replace newlines with \n.
#!/bin/sh
DATA="$(awk '{gsub(/[]\/$*.^&[]/, "\\\\&");printf (FNR>1)?"\\n%s":"%s",$0}END{print ""}' data.txt)"
sed -i -e '/^COMMANDS=.*/a\' -e "$DATA" script1.txt
Here the awk command escapes sed special characters (for basic regular expressions), then prints "%s" for the first line, and "\\n%s" for the others. A newline is printed at the end, but it's somewhat pointless as $() strips it anyway.
The sed command is almost the same but multiple expressions are used which is equivalent to a multi-line sed script (The a text sed alternative syntax can act weirdly with leading spaces/backslashes).
I have a file file.txt and it has the lines below. I want the queuename to be converted to uppercase, like this: queuename=SP00245B
# Queue name
#
queuename=sp00245b
awk '$1 == "queuename" {$2 = toupper($2)}1' FS== OFS== input-file
Note that this will fail if there are 2 = in the line, and only the values between the first 2 = will be uppercased. If that's an issue, it's an easy fix (left as an exercise for the reader).
A simple Perl solution:
perl -i -pe 's/^\s*queuename=\K(.*)/\U$1/' file.txt
(Remove -i if you don't want to modify the file in place.)
With GNU sed:
sed -i 's/\(^[[:blank:]]*queuename=\)\(.*\)/\1\U\2/' file.txt
This uses two captures groups and the \U sequence to toggle uppercase substitution for the second group.
You can also use the sed conversion \U to convert the portions of the matched pattern with the substitution command to uppercase. To covert everything following the '=' sign you could use, e.g.
sed '/^queuename=/s/=.*$/\U&/' filename
To edit the file in-place, include the -i option, e.g.
sed -i '/^queuename=/s/=.*$/\U&/' filename
Example Use/Output
$ echo "queuename=sp00245b" | sed '/^queuename=/s/=.*$/\U&/'
queuename=SP00245B
I am trying to use sed to append the "^A" control character at the end of each line:
sed -i 's/$/^A/' testfile
I want the '\001' special character instead of the "^A" literal string.
Please suggest how to achieve this.
You can use \x01 for ^A i.e.:
sed -i.bak 's/$/\x01/' file
sed -i 's/$/^A/' file
when you press the ^A, just press in this way: Ctrl+(v+a together)
sed 's/$/'$'\01''/' testfile
Explanation
s/$/ — start the sed argument
$'\01' — let bash expand this
'/' — end the sed argument
(I recommend you start off without the rather dangerous -i flag and only add it once you're sure it does what you want.)
Unix command to remove dot at end of each line in file.
Sample rec in file
11234567 0.
23456789 5569.
34567810 1.
10162056 0.
Just use sed:
sed 's/\.$//' yourfile
Escape the special character . using \.
Put an achor $ to only remove it from the end.
To make infile changes use -i option of sed.
sed -e 's/\.$//'
done. (padding to make answer long enough. grumble)
sed -i 's/\.$//' /path/to/file
This will match a literal period that is anchored to the end of the line, and replace it with nothing. The -i tells sed to make the change inline.
I need to delete the same line in a large number of text files. I have been trying to use sed, but I cannot get it to delete the newline character at the end. The following successfully deletes the line, but not the newline:
sed -i -e 's/VERSION:1//' *.txt
I have tried using the following to delete the newline also, but it does not work:
sed -i -e 's/VERSION:1\n//' *.txt
Is there anyway to specify a newline in a sed substitute command OR is there any other command line tool I can use to achieve my goal? Thank you
You can use the sed command:
sed -i -e '/VERSION:1/d'
for this.
The following transcript gives an example:
pax> echo 'hello
> goodbye
> hello again' | sed '/oo/d'
hello
hello again
You should also check whether you want to match whole lines with, for example:
sed -i -e '/^VERSION:1$/d'
since, as it stands, that will also delete lines like the following:
VERSION:10
CONVERSION:1
sed '/VERSION:1/{:q;N;s/VERSION\n//g;t q}' file