This question already has answers here:
How do I delete a matching line, the line above and the one below it, using sed?
(7 answers)
Closed 1 year ago.
I have a file named file.txt and it contains several lines containing string "NaN". How can I delete lines containing "Nan" and one line before and after it. I know sed －i '/pattern/d' file.txt can delete the matched line, but how can I delete neaby lines of the matched line.
Best regards
This is a most inelegant solution, but works. Perhaps, it will anger a UNIX guru to come and provide a real answer.
grep 'Nan' -n -C 1 target_file.txt | awk -F '[-:]' '{print $2}' | sed '2d' | paste -d, - - | sed 's/$/d/' > del_lines.sed && sed -f del_lines.sed target_file.txt > output_file.txt
fyi, The word "perticular" is misspelled, its "par-" like in golf!
Related
This question already has answers here:
How to use sed/grep to extract text between two words?
(14 answers)
Closed 4 years ago.
how to print text between two specific words using awk, sed ?
$ ofed_info | awk '/MLNX_OFED_LINUX/{print}'
MLNX_OFED_LINUX-4.1-1.0.2.0 (OFED-4.1-1.0.2):
$
Output required:-
4.1-1.0.2.0
Following awk may help you here.(considering that your input to awk will be same as shown sample only)
your_command | awk '{sub(/[^-]*/,"");sub(/ .*/,"");sub(/-/,"");print}'
Solution 2nd: With sed solution now.
your_command | sed 's/\([^-]*\)-\([^ ]*\).*/\2/'
Solution 3rd: Using awk's match utility:
your_command | awk 'match($0,/[0-9]+\.[0-9]+\-[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/){print substr($0,RSTART,RLENGTH)}'
You may use this sed:
echo 'MLNX_OFED_LINUX-4.1-1.0.2.0 (OFED-4.1-1.0.2):' |
sed -E 's/^[^-]*-| .*//g'
4.1-1.0.2.0
This sed command removes text till first hyphen from start or text starting with space towards end.
Try this:
ofed_info | sed -n 's/^MLNX_OFED_LINUX-\([^ ]\+\).*/\1/p'
The sed command only selects lines starting with the keyword and prints the version attached to it.
This question already has answers here:
Delete empty lines using sed
(17 answers)
Closed 6 years ago.
I tried to use 'sed' command to remove the empty lines.
sed -i '/^$/d' file.txt
My sample txt file looks likes this. The second line has space characters. sed command only removes the empty lines but not the lines with white space.
Sample text
Sample text
So is there away to accomplish this via bash.
My intended out put is
Sample text
Sample text
Use character class [:blank:] to indicate space or tab:
With sed:
sed -i '/^[[:blank:]]*$/ d' file.txt
With perl:
perl -ne 'print if !/^[[:blank:]]*$/' file.txt
With awk:
awk '!/^[[:blank:]]*$/' file.txt
With grep:
grep -v '^[[:blank:]]*$' file.txt
If the tool does not support editing in-place, leverage a temporary file e.g. for grep:
grep -v '^[[:blank:]]*$' file.txt >file.txt.tmp && mv file.txt{.tmp,}
sed -i '/^ *$/d' file.txt
or to also match other white space characters such as tabs, etc:
sed -i '/^[[:space:]]*$/d' file.txt
the * character matches 0 or more instances of preceding character
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 have an output that looks as below
- 0.1-1
- 0.1-2
- 0.1-3
- 0.1-6
- 0.1-7
- 0.1-9
How to use grep or something else so as to remove "-" and a space from the beginning.
0.1-1
0.1-2
0.1-3
0.1-6
0.1-7
0.1-9
With sed:
sed -e 's/^- //' input.txt
Or with GNU grep:
grep -oP '^- \K.*' input.txt
You may use grep also,
grep -oE '[0-9].*' file
With awk:
awk '{print $2}' file
You can use cut to remove the first two columns of every line:
cut -c3- input.txt
This question already has answers here:
Match two strings in one line with grep
(23 answers)
Closed 8 years ago.
Could you please help me how to grep two strings (or the whole lines) from one file and write them on the same line in output file?
grep -e "string1 string2" inputfile > output.txt doesn't work
for one string it works:
grep -e "string1" inputfile > output.txt
thx!
Change your grep command like below,
grep -o 'string1\|string2' file | paste - - > out.txt
This writes string1 string2 in a single line on out.txt
This question already has answers here:
Capturing multiple line output into a Bash variable
(7 answers)
Closed 3 years ago.
This code should read from wget2.html and output the links found. But it gives me output without line breaks.
How can I force cat to add line breaks?
chksitename=$(cat wget2.html | grep -e "$sitename" | sed -e "s/^.*\("$sitename".*jpg\).*$/\1/g" | sort | uniq)
echo $chksitename
The problem is not in the cat line but in the echo line. To get the line breaks, you need to use:
echo "$chksitename"
See also Capturing Multiple Line Output to a Bash Variable.
I think you can replace your cat/grep/sed with one sed:
sed -e -n "/$sitename/ s#^.*\("$sitename".*jpg\).*$#\1#pg" wget.html
And you can replace sort | uniq to sort -u.
You could try:
echo $chksitename | tr ' ' '\n'