Can we do it using sed and if so how?
How to replace a entire line from a file which has a content /u02/app/oracle-1/product/12.2.0/db_1:N to /u01/app/oracle/product/12.2.0/db_1:Y using Sed
It is very easy with sed command. Use below sed command which will do it for you.
sed 's|'/u02/app/oracle-1/product/12.2.0/db_1:N'|'/u01/app/oracle/product/12.2.0/db_1:Y'|g' your_original_file > newfile
mv newfile your_original_file
In above example, first sed command will replace /u02/app/oracle-1/product/12.2.0/db_1:N with /u01/app/oracle/product/12.2.0/db_1:Y and modified text will be redirect to newfile. In the new file you can review the changes whether correct or not.
With mv command you can rename newfile to your_original_file. So above example is safe. But you can do so with a single command like below, but you should be careful here, because if anything wrong you will be in trouble :-)
sed -i.bak 's|'/u02/app/oracle-1/product/12.2.0/db_1:N'|'/u01/app/oracle/product/12.2.0/db_1:Y'|g' yourfile
After lot of trials got it done.
sudo sed -i.bak '/^G:/u01/app/oracle/product/12.2.0/db_1:/ s/N/Y/'
Related
I have a configuration file (gpsd.default) containing data with the following format:
# If you must specify a non-NMEA driver, uncomment and modify the next line
GPSD_SOCKET="/var/run/gpsd.sock"
GPSD_OPTIONS=""
GPS_DEVICES=""
I am making a change on the file with sed:
sed -i 's/^GPS_DEVICES="".*/GPS_DEVICES="dev/ttyUSB1"/' /etc/default/gpsd.default
or
sed -i '4s/^.*/GPS_DEVICES="dev/ttyUSB1"/' /etc/default/gpsd.default
The above sed command returns error:
sed: bad option in substitution expression
Because the new line contains "/" in its expression.
How to update my sed command to make it work?
This is because you are using a regex containing /, which is the same character sed uses as delimiter.
Just change the sed delimiter to another one, for example ~:
sed -i 's~^GPS_DEVICES="".*~GPS_DEVICES="dev/ttyUSB1"~' /etc/default/gpsd.default
By the way, since you are changing files in /etc, you may want to use -i.bak, so that the original file gets backed up. It is a good practice to prevent loss of important information.
You should update your sed command to this.
sed -i 's/^GPS_DEVICES=\"\".*/GPS_DEVICES=\"dev\/ttyUSB1\"/' /etc/default/gpsd.default
i'm trying to move a dynamic string from a file and append it to the second file with sed.
what I have tried so far:
sed -i -e '/To300/{w /home/test/test1.txt' -e 'd}' /home/test/test2.txt
where XXXXTo300 is the string I want to move. Its moving the string to the second file, but when the next string is moved, its overwriting the existing strings in the second file.
thanks
In general, this won't work, as sed overwrites the file each time you use the command. However, if you use GNU sed, you can work around this limitation by writing to stdout and redirecting:
sed -i -e '/To300/{w /dev/stdout' -e ';d }' oldfile >> newfile
I have to implement an application in shell programming (Unix/Linux).
I have to search a word from a text file and replace that word with my given word. I have a knowledge on shell and still learning.
I am not expecting source code. Can anybody help me or suggest me or give me some similar solution....
cat abc.txt | grep "pattern" | sed 's/"pattern"/"new pattern"/g'
The above command should work
Thanks,
Regards,
Dheeraj Rampally
Say you are looking for pattern in a file (input.txt) and want to replace it with "new pattern" in another (output.txt)
Here is the main idea, without UUOC:
<input.txt sed 's/"pattern"/"new pattern"/g' >output.txt
todo
Now you need to embed this line in your program. You may want to make it interactive, or a command that you could use with 3 parameters.
edit
I tried to avoid the use of output.txt as a temporary file with this:
<input.txt sed 's/"pattern"/"new pattern"/g' >input.txt
but it empties input.txt for a reason I can't understand. So I tried with a subshell, so:
echo $(<input.txt sed 's/pattern/"new pattern"/g')>input.txt
... but the echo command removes line breaks... still looking.
edit2
From https://unix.stackexchange.com/questions/11067/is-there-a-way-to-modify-a-file-in-place , it looks like writing to the very same file at once it not easy at all. However, I could do what I wanted with sed -i for linux only:
sed -i 's/pattern/"new pattern"/g' input.txt
From sed -i + what the same option in SOLARIS , it looks like there's no alternative, and you must use a temporary file:
sed 's/pattern/"new pattern"/g' input.txt > input.tmp && mv input.tmp input.txt
I want to edit a file from the command line, because opening it in vim or other editors takes forever (a large file). I want to add a string ('chr') to the beginning of every line that is not commented out with a #. The command I am using is this:
cat '/home/me/37.vcf' | sed s/^/chr/>'sp.vcf'
But it adds a chr to the beginning of EVERY line and a > to the END of every line. I don't want either of those things to occur.
Can anyone offer any suggestions to improve my results?
To apply the substitution to only the lines that don't start with a #:
sed '/^[^#]/s/^/chr/' file > output
Note: the command cat is for concatenating files, it is useless here.
You can syntax error in your sed command. Use this syntactically correct sed command:
sed -E 's/^([^#]|$)/chr/' /home/me/37.vcf > sp.vcf
OR on Linux:
sed -r 's/^([^#]|$)/chr/' /home/me/37.vcf > sp.vcf
This might work for you (GNU sed):
sed '/^\s*#/!s/^/chr/' file > new_file
I was doing some hands-on with the Unix sed command. I was trying out the substitution and append command, in a file. But the difficulty is, I have to create an intermediate file, and then do mv to rename it to the original file.
Is there any way to do it at one shot in the same file?
[root#dhcppc0 practice]# sed '1i\
> Today is Sunday
> ' file1 > file1
[root#dhcppc0 practice]# cat file1
[root#dhcppc0 practice]#
The file is deleted!
[root#dhcppc0 practice]# sed 's/director/painter/' file1 > file1
[root#dhcppc0 practice]# cat file1
The file is deleted!
Try this -
sed -i '' 's/originaltext/replacementtext/g' filename | cat filename
-i '' is meant for providing a backup file. If you are confident your replacement won't cause an issue you can put '' to pass no backup file
/g is for replacing globally. If you have more than one originaltext in one line then with /g option will replace all else it will only replace the first.
GNU sed knows an option -i which does in-place edit of the given files.
When doing an operation file1 > file1 what actually happens is, that the file is opened and truncated by the shell before the program (which gets it's name as argument) comes around reading anything from it.
Update:
sed's man page states the following on the -i option (thanks Delan for mentioning it):
-i[SUFFIX], --in-place[=SUFFIX]
edit files in place (makes backup if extension supplied)
sed -i.bak 's/director/painter/' file1
-i[SUFFIX], --in-place[=SUFFIX]
edit files in place (makes backup if extension supplied)