I need to pass some variable in the following awk cmd,
awk -F, 'NR==FNR{a[\$0]++;next}!(a[\$6])' "file1" "file2" > output
Instead of providing the value 6, I need to pass it as a variable?
Here's an example using -v to pass a variable to awk. Also note that if you use single quotes around the awk program, you don't want to escape the $s.
$ cat file1.txt
1
4
$ cat file2.txt
1,2
3,4
$ awk -F, -v i=1 'NR==FNR{a[$0]++;next} !(a[$i])' file1.txt file2.txt
3,4
$ awk -F, -v i=2 'NR==FNR{a[$0]++;next} !(a[$i])' file1.txt file2.txt
1,2
Related
This question already has answers here:
Compare two files line by line and generate the difference in another file
(14 answers)
Closed 2 years ago.
FILE1:
cat
dog
house
tree
FILE2:
dog
cat
tree
I need to be printed only:
house
$ cat file1
cat
dog
house
tree
$ cat file2
dog
cat
tree
$ grep -vF -f file2 file1
house
The -v flag only shows non-matches, -f is for a filename to use as a filter, and -F is for exact matches (doesn't slow it down with any pattern matching).
Using awk
awk 'FNR==NR{arr[$0]=1; next} !($0 in arr)' FILE2 FILE1
First build an associative array with words from FILE2 and than loop over FILE1 and only print those.
Using comm
comm -2 -3 <(sort FILE1) <(sort FILE2)
-2 suppresses lines unique to FILE2 and -3 suppresses lines found in both.
If you want just the words, you can sort the files, diff them, then use sed to filter out diff's symbols:
diff <(sort file1) <(sort file2) | sed -n '/^</s/^< //p'
Awk is an option here:
awk 'NR==FNR { arr[$1]="1" } NR != FNR { if (arr[$1] == "") { print $0 } } ' file2 file1
Create an array called arr, using the contents of file2 as indexes. Then with file1, look at each entry and check to see if an entry in the array arr exists. If it doesn't, print.
I have a file with thousands of rows. I want to print the rows which do not contain a period.
awk '{print$2}' file.txt | head
I have used this to print the column I am interested in, column 2 (The file only has two columns).
I have removed the head and then did
awk '{print$2}' file.txt | grep -v "." | head
But I only get blank lines not any actual values which is expected, I think it has included the spaces between the rows but I am not sure.
Is there an alternative command?
As suggested by Jim, I did-
awk '{print$2}' file.txt | grep -v "\." | head
However the number of lines is greater than before, is this expected? Also, my output is a list of numbers but with spaces in between them (Vertical), is this normal?
file.txt example below-
120.4 3
270.3 7.9
400.8 3.9
200.2 4
100.2 8.7
300.2 3.4
102.3 6
49.0 2.3
38.0 1.2
So the expected (and correct) output would be 3 lines, as there is 3 values in column 2 without the period:
$ awk '{print$2}' file.txt | grep -v "\." | head
3
4
6
However, when running the code as above, I instead get 5, which is also counting the spaces between the rows I think:
$ awk '{print$2}' file.txt | grep -v "\." | head
3
4
6
You seldom need to use grep if you're already using awk
This would print the second column on each line where that second column doesn't contain a dot:
awk '$2 !~ /\./ {print $2}'
But you also wanted to skip empty lines, or perhaps ones where the second column is not empty. So just test for that, too:
awk '$2 != "" && $2 !~ /\./ {print $2}'
(A more amusing version would be awk '$2 ~ /./ && $2 !~ /\./ {print $2}' )
As you said, grep -v "." gives you only blank lines. That's because the dot means "any character", and with -v, the only lines printed are those that don't contain, well, any characters.
grep is interpreting the dot as a regex metacharacter (the dot will match any single character). Try escaping it with a backslash:
awk '{print$2}' file.txt | grep -v "\." | head
If I understand well, you can try this sed
sed ':A;N;${s/.*/&\n/};/\n$/!bA;s/\n/ /g;s/\([^ ]*\.[^ ]* \)//g' file.txt
output
3
4
6
I have a text file /tmp/some.txt with below values
JOHN YES 6 6 2345762
SHAUN NO 6 6 2345748
I want to create a csv file with below format (i.e based on rows. NOT based on columns).
JOHN,YES,6,6,2345762
SHAUN,NO,6,6,2345748
i tried below code
for i in `wc -l /tmp/some.txt | awk '{print $1}'`
do
awk 'NR==$i' /tmp/some.txt | awk '{print $1","$2","$3","$4","$5}' >> /tmp/some.csv
done
here wc -l /tmp/some.txt | awk '{print $1}' will get the value as 2 (i.e 2 rows in text file).
and for each row awk 'NR==$i' /tmp/some.txt | awk '{print $1","$2","$3","$4","$5}' will print the 5 fields into some.csvfile which is separated by comma.
when i execute each command separately it will work. but when i make it as a shell script i'm getting empty some.csv file.
#Kart: Could you please try following.
awk '{$1=$1;} 1' OFS=, Input_file > output.csv
I hope this helps you.
I suggest:
sed 's/[[:space:]]\+/,/g' /tmp/some.txt
You almost got it. awk already process the file row by row, so you don't need to iterate with the for loop.
So you just need to run:
awk '{print $1","$2","$3","$4","$5}' /tmp/some.txt >> /tmp/some.csv
With tr, squeezing (-s), and then transliterating space/tab ([:blank:]):
tr -s '[:blank:]' ',' <file.txt
With sed, substituting one or more space/tab with ,:
sed 's/[[:blank:]]\+/,/g' file.txt
With awk, replacing one ore more space/tab with , using gsub() function:
awk 'gsub("[[:blank:]]+", ",", $0)' file.txt
Example
% cat foo.txt
JOHN YES 6 6 2345762
SHAUN NO 6 6 2345748
% tr -s '[:blank:]' ',' <foo.txt
JOHN,YES,6,6,2345762
SHAUN,NO,6,6,2345748
% sed 's/[[:blank:]]\+/,/g' foo.txt
JOHN,YES,6,6,2345762
SHAUN,NO,6,6,2345748
% awk 'gsub("[[:blank:]]+", ",", $0)' foo.txt
JOHN,YES,6,6,2345762
SHAUN,NO,6,6,2345748
How can I find lines that contain a double tab and then \N
It should match, for example, \N abcd
I've tried
grep $'\t'$'\t''\N' file1.txt
grep $'\t\t''\N' file1.txt
grep $'\t\t\N' file1.txt
The following works for me:
RHEL:
$ grep $'\t\t''\\N' file1.txt
OSX:
$ grep '\t\t\\N' file1.txt
I want to find the last appearance of a string in a text file with linux commands. For example
1 a 1
2 a 2
3 a 3
1 b 1
2 b 2
3 b 3
1 c 1
2 c 2
3 c 3
In such a text file, i want to find the line number of the last appearance of b which is 6.
I can find the first appearance with
awk '/ b / {print NR;exit}' textFile.txt
but I have no idea how to do it for the last occurrence.
cat -n textfile.txt | grep " b " | tail -1 | cut -f 1
cat -n prints the file to STDOUT prepending line numbers.
grep greps out all lines containing "b" (you can use egrep for more advanced patterns or fgrep for faster grep of fixed strings)
tail -1 prints last line of those lines containing "b"
cut -f 1 prints first column, which is line # from cat -n
Or you can use Perl if you wish (It's very similar to what you'd do in awk, but frankly, I personally don't ever use awk if I have Perl handy - Perl supports 100% of what awk can do, by design, as 1-liners - YMMV):
perl -ne '{$n=$. if / b /} END {print "$n\n"}' textfile.txt
This can work:
$ awk '{if ($2~"b") a=NR} END{print a}' your_file
We check every second file being "b" and we record the number of line. It is appended, so by the time we finish reading the file, it will be the last one.
Test:
$ awk '{if ($2~"b") a=NR} END{print a}' your_file
6
Update based on sudo_O advise:
$ awk '{if ($2=="b") a=NR} END{print a}' your_file
to avoid having some abc in 2nd field.
It is also valid this one (shorter, I keep the one above because it is the one I thought :D):
$ awk '$2=="b" {a=NR} END{print a}' your_file
Another approach if $2 is always grouped (may be more efficient then waiting until the end):
awk 'NR==1||$2=="b",$2=="b"{next} {print NR-1; exit}' file
or
awk '$2=="b"{f=1} f==1 && $2!="b" {print NR-1; exit}' file