how to use script with sed command in linux? - sed

How can I use the sed command (in Linux) to find the 1000th line in a file with 10000 lines and replace just that one line with another?
Thanks in advance!

Like this:
sed '1000 s/foo/bar/' file.txt

Related

Add string to file at certain line number

I want to add a string to file at certain line number in Linux. I searched and found a command like:
sed "5i helloworld" test.txt
to add helloworld at line 5, but I got an error:
sed: command garbled.
I am testing in RedHat here. Is there any other command I can use here? Any other ways?
Older seds are a bit pickier with how you type commands like i, a and c. Try an actual line continuation:
sed '5i\
helloworld' test.txt
The i text syntax is a GNU extension. POSIX sed only know about the i\ version with linebreak.
Also, notice that there is a difference between the sed i command1 (insert text) and the -i option (in-place editing).
1 Or "function".
Here is awk solution:
awk 'NR==5{1;print "Hey there this is new text added on line 5"}1' inputfile

Sed Remove 3 last digits from string

27211;18:05:03479;20161025;0;0;0;0;10991;0;10991;000;0;0;000;1000000;0;0;000;0;0;0;82
Second string after ; is time. gg:mm:sssss:. I just want to be gg:mm:ss:
Like so:
27211;18:05:03;20161025;0;0;0;0;10991;0;10991;000;0;0;000;1000000;0;0;000;0;0;0;82
I tried with cut but it deletes everything after n'th occurance of character, and for now I am stuck, please help.
give this one liner a try:
awk -F';' -v OFS=";" 'sub(/...$/,"",$2)+1' file
It removes the last 3 chars from column 2.
update with sed one liner
If you are a fan of sed:
sed -r 's/(;[^;]*)...;/\1;/' file
With sed:
sed -r 's/^([^;]+;[^;]+)...;/\1;/' file
(Or)
sed -r 's/^([^;]+;[0-9]{2}:[0-9]{2}:[0-9]{2})...;/\1;/' file
It also can be something like sed 's/(.*)([0-9]{2}\:){2}([0-9]{3})[0-9]*\;(.*)/\1\2\3\4/g'
It is not very clean, but at least is more clear for me.
Regards
I'd use perl for this:
perl -pe 's/(?<=:\d\d)\d+(?=;)//' file
That removes any digits between "colon-digit-digit" and the semicolon (first match only, not globally in the line).
If you want to edit the file in-place: perl -i -pe ...
With sed:
sed -E 's/(:[0-9]{2})[0-9]{3}/\1/' file
or perl:
perl -pe's/:\d\d\B\K...//' file

Inserting numbers with sed in Linux?

I have the following line in cmdline
sed -e '1s/^/\\documentstyle\[11pt\]\{article\}\n/' -e 's/[0-9]//g' test.txt
My desired output is something like this
\documentstyle[11pt]{article}
rest of the file
However I only get this
\documentstyle[pt]{article}
rest of the file
I can't seem to find a way to insert numbers. I tried backslashing. Solution might be simple, but I'm a newbie with sed.
Note that sed has more commands than just s///. To insert a line at the top of a file:
sed -e '1i\
\\\documentstyle[11pt]{article}' -e 's/[0-9]//g' file
(frustratingly, the number of backslashes to achieve a backslash in the output was found by trial and error)
The bonus is that does not affect your goal to remove numbers.
My second command was removing numbers, working as intended indeed, but I was just trying to do it all at once. Credits to Jonathan Leffler.

Add text at the end of each line

I'm on Linux command line and I have file with
127.0.0.1
128.0.0.0
121.121.33.111
I want
127.0.0.1:80
128.0.0.0:80
121.121.33.111:80
I remember my colleagues were using sed for that, but after reading sed manual still not clear how to do it on command line?
You could try using something like:
sed -n 's/$/:80/' ips.txt > new-ips.txt
Provided that your file format is just as you have described in your question.
The s/// substitution command matches (finds) the end of each line in your file (using the $ character) and then appends (replaces) the :80 to the end of each line. The ips.txt file is your input file... and new-ips.txt is your newly-created file (the final result of your changes.)
Also, if you have a list of IP numbers that happen to have port numbers attached already, (as noted by Vlad and as given by aragaer,) you could try using something like:
sed '/:[0-9]*$/ ! s/$/:80/' ips.txt > new-ips.txt
So, for example, if your input file looked something like this (note the :80):
127.0.0.1
128.0.0.0:80
121.121.33.111
The final result would look something like this:
127.0.0.1:80
128.0.0.0:80
121.121.33.111:80
Concise version of the sed command:
sed -i s/$/:80/ file.txt
Explanation:
sed stream editor
-i in-place (edit file in place)
s substitution command
/replacement_from_reg_exp/replacement_to_text/ statement
$ matches the end of line (replacement_from_reg_exp)
:80 text you want to add at the end of every line (replacement_to_text)
file.txt the file name
How can this be achieved without modifying the original file?
If you want to leave the original file unchanged and have the results in another file, then give up -i option and add the redirection (>) to another file:
sed s/$/:80/ file.txt > another_file.txt
sed 's/.*/&:80/' abcd.txt >abcde.txt
If you'd like to add text at the end of each line in-place (in the same file), you can use -i parameter, for example:
sed -i'.bak' 's/$/:80/' foo.txt
However -i option is non-standard Unix extension and may not be available on all operating systems.
So you can consider using ex (which is equivalent to vi -e/vim -e):
ex +"%s/$/:80/g" -cwq foo.txt
which will add :80 to each line, but sometimes it can append it to blank lines.
So better method is to check if the line actually contain any number, and then append it, for example:
ex +"g/[0-9]/s/$/:80/g" -cwq foo.txt
If the file has more complex format, consider using proper regex, instead of [0-9].
You can also achieve this using the backreference technique
sed -i.bak 's/\(.*\)/\1:80/' foo.txt
You can also use with awk like this
awk '{print $0":80"}' foo.txt > tmp && mv tmp foo.txt
Using a text editor, check for ^M (control-M, or carriage return) at the end of each line. You will need to remove them first, then append the additional text at the end of the line.
sed -i 's|^M||g' ips.txt
sed -i 's|$|:80|g' ips.txt
sed -i 's/$/,/g' foo.txt
I do this quite often to add a comma to the end of an output so I can just easily copy and paste it into a Python(or your fav lang) array

Delete first and last line or record from file using sed

I want to delete first and last line from the file
file1 code :
H|ACCT|XEC|1|TEMP|20130215035845|
849002|48|1208004|1
849007|28|1208004|1
T|2
After delete the output should be
849002|48|1208004|1
849007|28|1208004|1
I have tried below method but has to run it 2 times, I want one liner solution to remove both in one go!
sed '1,1d' file1.txt >> file1.out
sed '$d' file1.out >> file2
Please suggest one liner code....
You could use ;
sed '1d; $d' file
Use Command Separator
In sed, you can separate commands using a semicolon. For example:
sed '1d; $d' /path/to/file
How about:
sed '$d' < file1.txt | sed "1d"
Try sed -i '1d;$d' /path/to/file
awk 'NR>2{print v}{v=$0}'
Starting with line 3, print the previous line each time. This means the first and last lines will not be printed.