How do I skip the first 7 lines (rows) and apply a script on the remaining lines? I tried the below script but unfortunately it removes everything in the file and makes it empty.
awk 'NR > 7 { $1="XD"$1}' file> temp && mv temp file
You are not far off the mark. Just append 1 to your script (this will cause the $0 to be printed):
awk 'NR > 7 { $1="XD"$1} 1' file> temp && mv temp file
skip number of lines
Use next statement in action to skip line
apply a script on the remaining
Your script does alter field value, but does not print it
Let file.txt content be
1 10 100
2 20 200
3 30 300
4 40 400
5 50 500
6 60 600
7 70 700
8 80 800
9 90 900
then
awk 'NR<=7{next}{$1="XD"$1;print}' file.txt
gives output
XD8 80 800
XD9 90 900
Observe that pattern-action pair with next is before other actions.
(tested in gawk 4.2.1)
full parameterized awk-based solution :::
# rows to skip "__"
string to prepend "___"
gawk '(__<NR) * ($_=___$_)^_' FS='^$' __=7 ___='XD' # gawk/nawk
mawk '(__<NR) * ($!_=___$_)^_' FS='^$' __=7 ___='XD' # any mawk
XD8 80 800
XD9 90 900
Related
Currently i am using a awk script to compare 2 files having random numbers in non sequential order.
It works perfect , but there is just one future condition i would like to fulfill.
Current awk function
awk '
{
$0=$0+0
}
FNR==NR{
a[$0]
next
}
($0 in a){
b[$0]
next
}
{ print }
END{
for(j in a){
if(!(j in b)){ print j }
}
}
' compare1.txt compare2.txt
What the the function accomplishes currently ?
It outputs list of all the numbers which are present in compare1 but not in compare 2 and vice versa
If any number has zero in its prefix, ignore zeros while comparing ( basically the absolute value of number must be different to be treated as a mismatch ) Example - 3 should be considered matching with 003 and 014 should be considered matching with 14, 008 with 8 etc
As required It also considers a number matched even if they are not necessarily on the same line in both files
Required additional condition
In its current form , this functions works in such a way that if a file has multiple occurances of a number and other file has even one occurance of that same number , it considers the number matched for both repetitions.
I need the awk function to be edited to output any additional occurrence of a number
cat compare1.txt
57
11
13
3
889
014
91
775
cat compare2.txt
003
889
13
14
57
12
90
775
775
Expected output
12
90
11
91
**775**
The number marked here at end is currently not being shown in output in my present awk function ( 2 occurances - 1 occurrence )
As mentioned at https://stackoverflow.com/a/62499047/1745001, this is the job that comm exists to do:
$ comm -3 <(awk '{print $0+0}' compare1.txt | sort) <(awk '{print $0+0}' compare2.txt | sort)
11
12
775
90
91
and to get rid of the white space:
$ comm -3 <(awk '{print $0+0}' compare1.txt | sort) <(awk '{print $0+0}' compare2.txt | sort) |
awk '{print $1}'
11
12
775
90
91
you just need to count the occurrences and account for it in matching...
$ awk '{k=$0+0}
NR==FNR {a[k]++; next}
!(k in a && a[k]-->0);
END {for(k in a) while(a[k]-->0) print k}' file1 file2
12
90
775
11
91
note that as in your original script there is no absolute value comparison, which you can add easily by just changing k in the first line.
I have a data file (data.txt) as shown below:
0 25 10 25000
1 25 7 18000
1 25 9 15000
0 20 9 1000
1 20 8 800
0 20 8 900
0 50 10 4000
0 50 5 2500
1 50 10 5000
I want to copy the rows with same value in the second column to separate files. I want to get following three files:
data.txt_25
0 25 10 25000
1 25 7 18000
1 25 9 15000
data.txt_20
0 20 9 1000
1 20 8 800
0 20 8 900
data.txt_50
0 50 10 4000
0 50 5 2500
1 50 10 5000
I have just started learning awk. I have tried the following bash script:
1 #!/bin/bash
2
3 for var in 20 25 50
4 do
5 awk -v var="$var" '$2==var { print $0 }' data.txt > data.txt_$var
6 done
While the bash script does what I want it to do, it is time consuming as I have to put the values of second column data in line 3 manually.
So I would like to do this using awk. How can I achieve this using awk ?
Thanks in advance.
Could you please try following, this considers that your 2nd column numbers are NOT in sorted form.
sort -k2 Input_file |
awk '
prev!=$2{
close(output_file)
output_file="data.txt_"$2
}
{
print > (output_file)
prev=$2
}'
In case your Input_file's 2nd column is sorted then no need to use sort you could directly use like:
awk '
prev!=$2{
close(output_file)
output_file="data.txt_"$2
}
{
print > (output_file)
prev=$2
}' Input_file
Explanation: Adding a detailed explanation for above.
sort -k2 Input_file | ##Sorting Input_file with respect to 2nd column then passing output to awk
awk ' ##Starting awk program from here.
prev!=$2{ ##Checking if prev variable is NOT equal to $2 then do following.
close(output_file) ##Closing output_file in back-end to avoid "too many files opened" errors.
output_file="data.txt_"$2 ##Creating variable output_file to data.txt_ with $2 here.
}
{
print > (output_file) ##Printing current line to output_file here.
prev=$2 ##Setting variable prev to $2 here.
}'
For the given sample, you can also use this:
awk -v RS= '{f = "data.txt_" $2; print > f; close(f)}' data.txt
-v RS= paragraph mode, empty lines are used to separate input records
f = "data.txt_" $2 construct filename using second column value (by default awk split input record on spaces/tabs/newlines)
print > f write input record contents to filename
close(f) close the file
I have many files that are of two column format with a label in the first column and a number in the second column. The number is positive (never zero):
AGS 3
KET 45
WEGWET 12
FEW 56
Within each file, the labels are not repeated.
I would like to concatenate these many files into one file with many+1 columns, such that the first column includes the unique set of all labels across all files, and the last five columns include the number for each label of each file. If the label did not exist in a certain file (and hence there is no number for it), I would like it to default to zero. For instance, if the second file contains this:
AGS 5
KET 14
KJV 2
FEW 3
then the final output would look like:
AGS 3 5
KET 45 14
WEGWET 12 0
KJV 0 2
FEW 56 3
I am new to Linux, and have been playing around with sed and awk, but realize this probably requires multiple steps...
*Edit note: I had to change it from just 2 files to many files. Even though my example only shows 2 files, I would like to do this in case of >2 files as well. Thank you...
Here is one way using awk:
awk '
NR==FNR {a[$1]=$0;next}
{
print (($1 in a)?a[$1] FS $2: $1 FS "0" FS $2)
delete a[$1]
}
END{
for (x in a) print a[x],"0"
}' file1 file2 | column -t
AGS 3 5
KET 45 14
KJV 0 2
FEW 56 3
WEGWET 12 0
You read file1 in to an array indexed at column 1 and assign entire line as it's value
For the file2, check if column 1 is present in our array. If it is print the value from file1 along with value from file2. If it is not present print 0 as value for file1.
Delete the array element as we go along to get only what was unique in file1.
In the END block print what was unique in file1 and print 0 for file2.
Pipe the output to column -t for pretty format.
Assuming that your data are in files named file1 and file2:
$ awk 'FNR==NR {a[$1]=$2; b[$1]=0; next} {a[$1]+=0; b[$1]=$2} END{for (x in b) {printf "%-15s%3s%3s\n",x,a[x],b[x]}}' file1 file2
KJV 0 2
WEGWET 12 0
KET 45 14
AGS 3 5
FEW 56 3
To understand the above, we have to understand an awk trick.
In awk, NR is the number of records (lines) that have been processed and FNR is the number of records that we have processed in the current file. Consequently, the condition FNR==NR is true only when we are processing in the first file. In this case, the associative array a gets all the values from the first file and associative array b gets placeholder, i.e. zero, values. When we process the second file, its values go in array b and we make sure that array a at least has a placeholder value of zero. When we are done with the second file, the data is printed.
More than two files using GNU Awk
I created a file3:
$ cat file3
AGS 3
KET 45
WEGWET 12
FEW 56
AGS 17
ABC 100
The awk program extended to work with any number of files is:
$ awk 'FNR==1 {n+=1} {a[$1][n]=$2} END{for (x in a) {printf "%-15s",x; for (i=1;i<=n;i++) {printf "%5s",a[x][i]};print ""}}' file1 file2 file3
KJV 2
ABC 100
WEGWET 12 12
KET 45 14 45
AGS 3 5 17
FEW 56 3 56
This code works creates a file counter. We know that we are in a new file every time that FNR is 1 and a counter, n, is incremented. For every line we encounter, we put the data in a 2-D array. The first dimension of a is the label and the second is the number of the file that we encountered it in. In the end, we just loop over all the labels and all the files, from 1 to n and print the data.
More than 2 files without GNU Awk
Without requiring GNU's awk, we can solve the problem using simulated two-dimensional arrays:
$ awk 'FNR==1 {n+=1} {b[$1]=1; a[$1,":",n]=$2} END{for (x in b) {printf "%-15s",x; for (i=1;i<=n;i++) {q=a[x,":",i]+0; printf "%5s",q};print ""}}' file1 file2 file3
KJV 0 2 0
ABC 0 0 100
WEGWET 12 0 12
KET 45 14 45
AGS 3 5 17
FEW 56 3 56
I have a text file with a series of numbers:
1 2 4 2 2 6 3 4 7 4 4 8 2 4 6 5 5 8
I need to have every third field multiplied by 3, so output would be:
1 2 12 2 2 18 3 4 21 4 4 24 2 4 18 5 5 24
Now, I've hammered out a solution already, but I know there's a quicker, more elegant one out there. Here's what I've gotten to work:
xargs -n1 < input.txt | awk '{printf NR%3 ? "%d " : $0*3" ", $1}' > output.txt
I feel that there must be an awk one-liner that can do this?? How can I make awk look at each field (instead of each record), thus not needing the call to xargs to put every field on a different line? Or maybe sed can do it?
Try:
awk '{for (i=3;i<=NF;i+=3)$i*=3; print}' input.txt > output.txt
I have not tested this yet (posted on my iPod). The print command without parameters should print out the whole (partially modified) line. You might have to set OFS=" " in the BEGIN section to get the blank as the separator in the output.
this line would work too:
awk -v RS="\\n| " -v ORS=" " '!(NR%3){$0*=3}7' file
I would like to calculate percentage of value in each line out of all lines and add it as another column.
Input (delimiter is \t):
1 10
2 10
3 20
4 40
Desired output with added third column showing calculated percentage based on values in second column:
1 10 12.50
2 10 12.50
3 20 25.00
4 40 50.00
I have tried to do it myself, but when I calculated total for all lines I didn't know how to preserve rest of line unchanged. Thanks a lot for help!
Here you go, one pass step awk solution -
awk 'NR==FNR{a = a + $2;next} {c = ($2/a)*100;print $1,$2,c }' file file
[jaypal:~/Temp] cat file
1 10
2 10
3 20
4 40
[jaypal:~/Temp] awk 'NR==FNR{a = a + $2;next} {c = ($2/a)*100;print $1,$2,c }' file file
1 10 12.5
2 10 12.5
3 20 25
4 40 50
Update: If tab is a required in output then just set the OFS variable to "\t".
[jaypal:~/Temp] awk -v OFS="\t" 'NR==FNR{a = a + $2;next} {c = ($2/a)*100;print $1,$2,c }' file file
1 10 12.5
2 10 12.5
3 20 25
4 40 50
Breakout of pattern {action} statements:
The first pattern is NR==FNR. FNR is awk's in-built variable that keeps track of number of records (by default separated by a new line) in a given file. So FNR in our case would be 4. NR is similar to FNR but it does not get reset to 0. It continues to grow on. So NR in our case would be 8.
This pattern will be true only for the first 4 records and thats exactly what we want. After perusing through the 4 records, we are assign the total to a variable a. Notice that we did not initialize it. In awk we don't have to. However, this would break if entire column 2 is 0. So you can handle it by putting an if statement in the second action statement i.e do the division only if a > 0 else say division by 0 or something.
next is needed cause we don't really want second pattern {action} statement to execute. next tells awk to stop further actions and move to the next record.
Once the four records are parsed, the next pattern{action} begins, which is pretty straight forward. Doing the percentage and print column 1 and 2 along with percentage next to them.
Note: As #lhf mentioned in the comment, this one-liner will only work as long as you have the data set in a file. It won't work if you pass data through a pipe.
In the comments, there is a discussion going on ways to make this awk one-liner take input from a pipe instead of a file. Well the only way I could think of was to store the column values in array and then using for loop to spit each value out along with their percentage.
Now arrays in awk are associative and are never in order, i.e pulling the values out of arrays will not be in the same order as they went in. So if that is ok then the following one-liner should work.
[jaypal:~/Temp] cat file
1 10
2 10
3 20
4 40
[jaypal:~/Temp] cat file | awk '{b[$1]=$2;sum=sum+$2} END{for (i in b) print i,b[i],(b[i]/sum)*100}'
2 10 12.5
3 20 25
4 40 50
1 10 12.5
To get them in order, you can pipe the result to sort.
[jaypal:~/Temp] cat file | awk '{b[$1]=$2;sum=sum+$2} END{for (i in b) print i,b[i],(b[i]/sum)*100}' | sort -n
1 10 12.5
2 10 12.5
3 20 25
4 40 50
You can do it in a couple of passes
#!/bin/bash
total=$(awk '{total=total+$2}END{print total}' file)
awk -v total=$total '{ printf ("%s\t%s\t%.2f\n", $1, $2, ($2/total)*100)}' file
You need to escape it as %%. For instance:
printf("%s\t%s\t%s%%\n", $1, $2, $3)
Perhaps there is better way but I would pass file twice.
Content of 'infile':
1 10
2 10
3 20
4 40
Content of 'script.awk':
BEGIN {
## Tab as field separator.
FS = "\t";
}
## First pass of input file. Get total from second field.
ARGIND == 1 {
total += $2;
next;
}
## Second pass of input file. Print each original line and percentage as third field.
{
printf( "%s\t%2.2f\n", $0, $2 * 100 / total );
}
Run the script in my linux box:
gawk -f script.awk infile infile
And result:
1 10 12.50
2 10 12.50
3 20 25.00
4 40 50.00