This question already has answers here:
Editing/Replacing content in multiple files in Unix AIX without opening it
(2 answers)
Closed 6 years ago.
I wonder know if there is a way to edit a conf file without getting in the file and changing the lines?
In my case, I need to edit zabbix-agent conf file (located in /etc/zabbix/zabbix_agentd.conf) and there are some parameters in the file that I need to change, such as Server Name, DebugLevel, and others.
Normally I edit the file using vim and change the lines, but my idea is to edit the file directly from bash, but I don`t know if this is possible.
For example, if I need to change the parameter DebugLevel, at bash I would run:
# /etc/zabbix/zabbix_agentd.conf.DebugLevel=3
This actually doesn`t works, but I would like something like this for my problem...
Does anyone knows??
I tested what David said, but it didn`t solved my problem... There are some lines in the file that is commented and I need to uncomment them, and there are some lines that I just need to change.
For example, the line above:
# DebugLevel=3
I need to change to:
DebugLevel=3
And this line:
Server=127.0.0.1
I need to change for the IP of zabbix server name, like this:
Server=172.217.28.142
Is there any other way?
If I understand your question correctly, then you want sed -i (the -i option allows sed to edit the file in place, and -i.bak will do the same but create a backup of the original file with the .bak extension)
To change DebugLevel=3 to DebugLevel=4 in file /etc/zabbix/zabbix_agentd.conf, you can do:
# sed -i.bak "/DebugLevel/s/[0-9][0-9]*$/4/" /etc/zabbix/zabbix_agentd.conf
If I misinterpreted your question, please let me know.
To Change Values at the End
Example Input File
$ cat file.txt
DebugLevel=3
Example Use
$ sed -i "/DebugLevel/s/[0-9][0-9]*$/4/" file.txt
$ cat file.txt
DebugLevel=4
To Remove Comments
You can do virtually the same thing to uncomment the parameters of interest, for example:
# sed -i.bak "/DebugLevel/s/^#//" /etc/zabbix/zabbix_agentd.conf
In each case, sed is searching for the label in the first set of forward slashes /.../, next the substitute command is called s and then the expression between the next set of forward slashes, e.g. /^#/ (^ match at the beginning), if matched, is replaced by what follows in the next set // (nothing in the remove comment case).
You will need to adjust the values as required to match each parameter you need to find and replace. Let me know if you have further problems and exactly what the problem is.
Related
This question already has answers here:
Find and replace in file and overwrite file doesn't work, it empties the file
(12 answers)
Closed 6 years ago.
I am working on a bash script and running into a problem with sed leaving the file that I am using it to clean blank.
Here is the blocks that define the file and the function that I created to clean the file:
# Define Review Log file
reviewlog=/home/serverreview-$(date +%d%^b%y).txt
# Bleachs the Review Log of the color customization
bleach ()
{
sed -r "s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]//g" $reviewlog >> $reviewlog
}
Using the >> it does append the info to the bottom of the file as it is supposed to. However if I use:
bleach ()
{
sed -r "s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]//g" $reviewlog > $reviewlog
}
It leaves the output file totally blank
This is normal as sed reads as it writes. The first write will truncate the file. This ends reading and leaves an empty file.
In some condition when a tool reads a buffer before writing it would work for small inputs. But this is nothing you dont want to depend on. so if the tool does not have a in-place overwrite option don't use it.
You can write to a temp outfile and rename it over the infile or rename the in-file (or open the in-file, then delete it) and then write to the expected location. Otherwise you have to ensure to read everything into memory.
sed -i with and without extension does work the same. See for example https://robots.thoughtbot.com/sed-102-replace-in-place which describes the -i variations.
I'm trying to remove an ID number from a text file using a series of commands (using terminal), but they don't seem to be working. I need to remove the number and the associated "ID" text
Text in File:
{"id":"098765432"}
Commands I've been using (but don't seem to be working):
sed -i.bak 's/"id":[0-9]\{1,\},//g' ./Filename.txt
sed -i.bak 's/"id":"[0-9]\{1,\}",//g' ./Filename.txt
sed -i.bak 's/"id":"[0-9]\{9,\}",//g' ./Filename.txt
sed -i.bak 's/"id":[0-9]\{9,\},//g' ./Filename.txt
sed -i.bak 's/"[0-9]\{1,\}",//g' ./Filename.txt
Thanks for the help :)
As #Wintermute already noted in the comment, the problem is in the comma before //. However, I am going to explain the whole line, just so the others may understand it completely, in case something is not clear to those who come across this question later.
So, the proper command that will satisfy your requirement is:
sed -i.bak 's/"id":"[0-9]\{1,\}"//g' ./Filename.txt
sed is the command that calls stream editor.
Flag -i is the flag used to represent editing files in place (it makes backup if extension is supplied). In this case, extension written is .bak and indeed the backup file (containing initial context of our file) is created with the original name + the extension provided.
Argument 's/"id":"[0-9]{1,}"//g' is the argument given to the sed command.
Since this argument (regular expression in it) was the cause of the problem, I am going to explain it in detail.
First part we should notice is that its structure is s/Regex/Replacement/g where
Regex = "id":"[0-9]{1,}"
Replacement = nothing (literally nothing, not even blank space)
So basically, as described by Bruce Barnett, s stands for substitution. Regex is the part we will replace with the Replacement. At the end, letter g means that we will change more than just one occurrence of this regex per line (without g, it would replace just the first occurrence in every line, no matter how many are there).
And at the end we have ./Filename.txt, which is the source file we are applying this command on (./ means that the file is in the same directory from where we are running this command).
About the regex used ("id":"[0-9]{1,}"):
It starts with the literals ("id":") and this part will match literally any part in the file which is exactly the same as this one. Next, we have ([0-9]{1,}), which means that we want to, in addition to the first part, look for the at least one occurrence of a number (but it can be more of them, as the matched example from the question shows).
Now you may understand why comma caused this problem. There is no comma in the original text in the file. Thus, none of the commands tried (since all of them contain comma) worked. Of course, some of them have even more reasons.
EDIT: As #ghoti pointed out, replacement is not a regex. It is the string we will put at the place(s) that are found by our regex expression. So in this case, our replacement is blank string (since we want to delete the specified part).
I am essentially trying to use sed to remove a few lines within a text document. To clean it up. But I'm not getting it right at all. Missing something and I have no idea what...
#!/bin/bash
items[0]='X-Received:'
items[1]='Path:'
items[2]='NNTP-Posting-Date:'
items[3]='Organization:'
items[4]='MIME-Version:'
items[5]='References:'
items[6]='In-Reply-To:'
items[7]='Message-ID:'
items[8]='Lines:'
items[9]='X-Trace:'
items[10]='X-Complaints-To:'
items[11]='X-DMCA-Complaints-To:'
items[12]='X-Abuse-and-DMCA-Info:'
items[13]='X-Postfilter:'
items[14]='Bytes:'
items[15]='X-Original-Bytes:'
items[16]='Content-Type:'
items[17]='Content-Transfer-Encoding:'
items[18]='Xref:'
for f in "${items[#]}"; do
sed '/${f}/d' "$1"
done
What I am thinking, incorrectly it seems, is that I can setup a for loop to check each item in the array that I want removed from the text file. But it's simply not working. Any idea. Sure this is basic and simple and yet I can't figure it out.
Thanks,
Marek
Much better to create a single sed script, rather than generate 19 small scripts in sequence.
Fortunately, generating a script by joining the array elements is moderately easy in Bash:
regex=$(printf '\|%s' "${items[#]}")
regex=${regex#'\|'}
sed "/^$regex/d" "$1"
(Notice also the addition of ^ to the final regex -- I assume you only want to match at beginning of line.)
Properly, you should not delete any lines from the message body, so the script should leave anything after the first empty line alone:
sed "1,/^\$/!b;/$regex/d" "$1"
Add -i if you want in-place editing of the target file.
I've just been writing some code, that renders a locale property redundant. Because of that, I'd like it to be able to remove that property from every locale file of the project, but I simply couldn't find a way of doing that, and I ended up doing it by hand in vim.
Now, I'm no UNIX black-belt, but I know that there must be a pretty simple solution to such a trivial problem, probably hidden in the depths of sed or awk. So I managed to match the property (the property being no_outline):
sed -e '/no_outline=/d' l10n/*/viewer.properties
But this only prints out the contents of each file, without the no_outline line. Isn't it possible to write the "result" of the sed command to the same file as it was executed on?
you could:
sed -i '/no_outline=/d' l10n/*/viewer.properties
from man page:
-i[SUFFIX], --in-place[=SUFFIX]
edit files in place (makes backup if SUFFIX supplied)
i have a template, with a var LINK
and a data file, links.txt, with one url per line
how in bash i can substitute LINK with the content of links.txt?
if i do
#!/bin/bash
LINKS=$(cat links.txt)
sed "s/LINKS/$LINK/g" template.xml
two problem:
$LINKS has the content of links.txt without newline
sed: 1: "s/LINKS/http://test ...": bad flag in substitute command: '/'
sed is not escaping the // in the links.txt file
thanks
Use some better language instead. I'd write a solution for bash + awk... but that's simply too much effort to go into. (See http://www.gnu.org/manual/gawk/gawk.html#Getline_002fVariable_002fFile if you really want to do that)
Just use any language where you don't have to mix control and content text. For example in python:
#!/usr/bin/env python
links = open('links.txt').read()
template = open('template.xml').read()
print template.replace('LINKS', links)
Watch out if you're trying to force sed solution with some other separator - you'll get into the same problems unless you find something disallowed in urls (but are you verifying that?) If you don't, you already have another problem - links can contain < and > and break your xml.
You can do this using ed:
ed template.xml <<EOF
/LINKS/d
.r links.txt
w output.txt
EOF
The first command will go to the line
containing LINKS and delete it.
The second line will insert the
contents of links.txt on the current
line.
The third command will write the file
to output.txt (if you omit output.txt
the edits will be saved to
template.xml).
Try running sed twice. On the first run, replace / with \/. The second run will be the same as what you currently have.
The character following the 's' in the sed command ends up the separator, so you'll want to use a character that is not present in the value of $LINK. For example, you could try a comma:
sed "s,LINKS,${LINK}\n,g" template.xml
Note that I also added a \n to add an additional newline.
Another option is to escape the forward slashes in $LINK, possibly using sed. If you don't have guarantees about the characters in $LINK, this may be safer.