Line differences with element location in shell script - shell

Input:
file1.txt
abc 1 2 3 4
file2.txt
abc 1 2 5 6
Expected output:
differences is
3
5
at location 3
I am able to track the differences using:
comm -3 file1.txt file2.txt | uniq -c | awk '{print $4}' | uniq
But not able to track the element location.
Could you guys please suggest the shell script to track the element location?

With perl, and Path::Class from CPAN for convenience
perl -MPath::Class -MList::Util=first -e '
#f1 = split " ", file(shift)->slurp;
#f2 = split " ", file(shift)->slurp;
$idx = first {$f1[$_] ne $f2[$_]} 0..$#f1;
printf "difference is\n%s\n%s\nat index %d\n", $f1[$idx], $f2[$idx], $idx;
' file{1,2}.txt
difference is
3
5
at index 3

Related

how to find maximum and minimum values of a particular column using AWK [duplicate]

I'm using awk to deal with a simple .dat file, which contains several lines of data and each line has 4 columns separated by a single space.
I want to find the minimum and maximum of the first column.
The data file looks like this:
9 30 8.58939 167.759
9 38 1.3709 164.318
10 30 6.69505 169.529
10 31 7.05698 169.425
11 30 6.03872 169.095
11 31 5.5398 167.902
12 30 3.66257 168.689
12 31 9.6747 167.049
4 30 10.7602 169.611
4 31 8.25869 169.637
5 30 7.08504 170.212
5 31 11.5508 168.409
6 31 5.57599 168.903
6 32 6.37579 168.283
7 30 11.8416 168.538
7 31 -2.70843 167.116
8 30 47.1137 126.085
8 31 4.73017 169.496
The commands I used are as follows.
min=`awk 'BEGIN{a=1000}{if ($1<a) a=$1 fi} END{print a}' mydata.dat`
max=`awk 'BEGIN{a= 0}{if ($1>a) a=$1 fi} END{print a}' mydata.dat`
However, the output is min=10 and max=9.
(The similar commands can return me the right minimum and maximum of the second column.)
Could someone tell me where I was wrong? Thank you!
Awk guesses the type.
String "10" is less than string "4" because character "1" comes before "4".
Force a type conversion, using addition of zero:
min=`awk 'BEGIN{a=1000}{if ($1<0+a) a=$1} END{print a}' mydata.dat`
max=`awk 'BEGIN{a= 0}{if ($1>0+a) a=$1} END{print a}' mydata.dat`
a non-awk answer:
cut -d" " -f1 file |
sort -n |
tee >(echo "min=$(head -1)") \
> >(echo "max=$(tail -1)")
That tee command is perhaps a bit much too clever. tee duplicates its stdin stream to the files names as arguments, plus it streams the same data to stdout. I'm using process substitutions to filter the streams.
The same effect can be used (with less flourish) to extract the first and last lines of a stream of data:
cut -d" " -f1 file | sort -n | sed -n '1s/^/min=/p; $s/^/max=/p'
or
cut -d" " -f1 file | sort -n | {
read line
echo "min=$line"
while read line; do max=$line; done
echo "max=$max"
}
Your problem was simply that in your script you had:
if ($1<a) a=$1 fi
and that final fi is not part of awk syntax so it is treated as a variable so a=$1 fi is string concatenation and so you are TELLING awk that a contains a string, not a number and hence the string comparison instead of numeric in the $1<a.
More importantly in general, never start with some guessed value for max/min, just use the first value read as the seed. Here's the correct way to write the script:
$ cat tst.awk
BEGIN { min = max = "NaN" }
{
min = (NR==1 || $1<min ? $1 : min)
max = (NR==1 || $1>max ? $1 : max)
}
END { print min, max }
$ awk -f tst.awk file
4 12
$ awk -f tst.awk /dev/null
NaN NaN
$ a=( $( awk -f tst.awk file ) )
$ echo "${a[0]}"
4
$ echo "${a[1]}"
12
If you don't like NaN pick whatever you'd prefer to print when the input file is empty.
late but a shorter command and with more precision without initial assumption:
awk '(NR==1){Min=$1;Max=$1};(NR>=2){if(Min>$1) Min=$1;if(Max<$1) Max=$1} END {printf "The Min is %d ,Max is %d",Min,Max}' FileName.dat
A very straightforward solution (if it's not compulsory to use awk):
Find Min --> sort -n -r numbers.txt | tail -n1
Find Max --> sort -n -r numbers.txt | head -n1
You can use a combination of sort, head, tail to get the desired output as shown above.
(PS: In case if you want to extract the first column/any desired column you can use the cut command i.e. to extract the first column cut -d " " -f 1 sample.dat)
#minimum
cat your_data_file.dat | sort -nk3,3 | head -1
#this fill find minumum of column 3
#maximun
cat your_data_file.dat | sort -nk3,3 | tail -1
#this will find maximum of column 3
#to find in column 2 , use -nk2,2
#assing to a variable and use
min_col=`cat your_data_file.dat | sort -nk3,3 | head -1 | awk '{print $3}'`

how to sort values of 1st column and print only corresponding values of third column using awk

I tried to sort the file using awk '{print $0|"sort -t',' -nk1 "}' but I want to print only the third column of sorted file. Input file:
1 4 7 9
9 7 4 1
4 6 8 9
1 2 3 4
5 4 5 2
the expected output:
3
7
8
5
4
Try this -
sort file|awk '{print $3}'
3
7
8
5
4
Two simple ways "to print only the third column of sorted file":
with tr + cut command:
sort -n file | tr -s ' ' | cut -d' ' -f3
with awk:
sort -n file | awk '{print $3}'
Well, since I already started doing it using Gnu awk's asorti:
$ awk '
{ a[$1 "," $3]=$3 } # get the data to a hash (*)
END { n=asorti(a) # sort a by the index
for(i=1;i<=n;i++) { # for each ordered index
split(a[i],b,",") # split and
print b[2] # print the latter part
}
}' file
3
7
8
5
4
(*) If using only $1 as the key there will be a collision when $1=1. For this data using $1 "," $3 won't produce a collision and will sort the $3 as well. However, there could be a collision. The correct way would be to keep a count of the keys and have a sub for loop to print those out (or have keys and values in different arrays indexed with NR). That will be left as an exersize.

Piped input for `bc` division generates random numbers

I've got two files formatted in this way:
File1:
word token occurence
File2:
token occurence
What I want is a third file with this output:
word token occurrence1/occurence2
This is my code:
while read token pos count
do
#get pos counts
poscount=$(grep "^$pos" $2 | cut -f 2)
#calculate probability
prob=$(echo "scale=5;$count / $poscount" | bc -l)
#print token, pos-tag & probability
echo -e "$token\t$pos\t$prob"
done < $1
The problem is that my output is something like this:
- : .25000
: : .75000
' '' 1.00000
0 CD .00396
1000 CD .00793
13 CD .00793
13th JJ .00073
36
29
16 CD .00396
17 CD .00396
There are lines with numbers that I don't know where they come from, they are not in the previous files.
Why do these numbers appear? Is there a way to remove those lines?
Thanks in advance!
Method using paste, cut, & dc:
echo "5 k $(paste file[12] | cut -f 3,5) / p" | dc | \
paste file1 - | cut --complement -f 3
Method using bash, paste & dc:
paste <(join -1 2 file1 -2 1 file2 -o 1.1,1.2) \
<(echo "5 k $(join -1 2 file1 -2 1 file2 -o 1.3,2.2) / p" | dc)

awk: find minimum and maximum in column

I'm using awk to deal with a simple .dat file, which contains several lines of data and each line has 4 columns separated by a single space.
I want to find the minimum and maximum of the first column.
The data file looks like this:
9 30 8.58939 167.759
9 38 1.3709 164.318
10 30 6.69505 169.529
10 31 7.05698 169.425
11 30 6.03872 169.095
11 31 5.5398 167.902
12 30 3.66257 168.689
12 31 9.6747 167.049
4 30 10.7602 169.611
4 31 8.25869 169.637
5 30 7.08504 170.212
5 31 11.5508 168.409
6 31 5.57599 168.903
6 32 6.37579 168.283
7 30 11.8416 168.538
7 31 -2.70843 167.116
8 30 47.1137 126.085
8 31 4.73017 169.496
The commands I used are as follows.
min=`awk 'BEGIN{a=1000}{if ($1<a) a=$1 fi} END{print a}' mydata.dat`
max=`awk 'BEGIN{a= 0}{if ($1>a) a=$1 fi} END{print a}' mydata.dat`
However, the output is min=10 and max=9.
(The similar commands can return me the right minimum and maximum of the second column.)
Could someone tell me where I was wrong? Thank you!
Awk guesses the type.
String "10" is less than string "4" because character "1" comes before "4".
Force a type conversion, using addition of zero:
min=`awk 'BEGIN{a=1000}{if ($1<0+a) a=$1} END{print a}' mydata.dat`
max=`awk 'BEGIN{a= 0}{if ($1>0+a) a=$1} END{print a}' mydata.dat`
a non-awk answer:
cut -d" " -f1 file |
sort -n |
tee >(echo "min=$(head -1)") \
> >(echo "max=$(tail -1)")
That tee command is perhaps a bit much too clever. tee duplicates its stdin stream to the files names as arguments, plus it streams the same data to stdout. I'm using process substitutions to filter the streams.
The same effect can be used (with less flourish) to extract the first and last lines of a stream of data:
cut -d" " -f1 file | sort -n | sed -n '1s/^/min=/p; $s/^/max=/p'
or
cut -d" " -f1 file | sort -n | {
read line
echo "min=$line"
while read line; do max=$line; done
echo "max=$max"
}
Your problem was simply that in your script you had:
if ($1<a) a=$1 fi
and that final fi is not part of awk syntax so it is treated as a variable so a=$1 fi is string concatenation and so you are TELLING awk that a contains a string, not a number and hence the string comparison instead of numeric in the $1<a.
More importantly in general, never start with some guessed value for max/min, just use the first value read as the seed. Here's the correct way to write the script:
$ cat tst.awk
BEGIN { min = max = "NaN" }
{
min = (NR==1 || $1<min ? $1 : min)
max = (NR==1 || $1>max ? $1 : max)
}
END { print min, max }
$ awk -f tst.awk file
4 12
$ awk -f tst.awk /dev/null
NaN NaN
$ a=( $( awk -f tst.awk file ) )
$ echo "${a[0]}"
4
$ echo "${a[1]}"
12
If you don't like NaN pick whatever you'd prefer to print when the input file is empty.
late but a shorter command and with more precision without initial assumption:
awk '(NR==1){Min=$1;Max=$1};(NR>=2){if(Min>$1) Min=$1;if(Max<$1) Max=$1} END {printf "The Min is %d ,Max is %d",Min,Max}' FileName.dat
A very straightforward solution (if it's not compulsory to use awk):
Find Min --> sort -n -r numbers.txt | tail -n1
Find Max --> sort -n -r numbers.txt | head -n1
You can use a combination of sort, head, tail to get the desired output as shown above.
(PS: In case if you want to extract the first column/any desired column you can use the cut command i.e. to extract the first column cut -d " " -f 1 sample.dat)
#minimum
cat your_data_file.dat | sort -nk3,3 | head -1
#this fill find minumum of column 3
#maximun
cat your_data_file.dat | sort -nk3,3 | tail -1
#this will find maximum of column 3
#to find in column 2 , use -nk2,2
#assing to a variable and use
min_col=`cat your_data_file.dat | sort -nk3,3 | head -1 | awk '{print $3}'`

Counting equal lines in two files

Say, I have two files and want to find out how many equal lines they have. For example, file1 is
1
3
2
4
5
0
10
and file2 contains
3
10
5
64
15
In this case the answer should be 3 (common lines are '3', '10' and '5').
This, of course, is done quite simply with python, for example, but I got curious about doing it from bash (with some standard utils or extra things like awk or whatever). This is what I came up with:
cat file1 file2 | sort | uniq -c | awk '{if ($1 > 1) {$1=""; print $0}}' | wc -l
It does seem too complicated for the task, so I'm wondering is there a simpler or more elegant way to achieve the same result.
P.S. Outputting the percentage of common part to the number of lines in each file would also be nice, though is not necessary.
UPD: Files do not have duplicate lines
To find lines in common with your 2 files, using awk :
awk 'a[$0]++' file1 file2
Will output 3 10 15
Now, just pipe this to wc to get the number of common lines :
awk 'a[$0]++' file1 file2 | wc -l
Will output 3.
Explanation:
Here, a works like a dictionary with default value of 0. When you write a[$0]++, you will add 1 to a[$0], but this instruction returns the previous value of a[$0] (see difference between a++ and ++a). So you will have 0 ( = false) the first time you encounter a certain string and 1 ( or more, still = true) the next times.
By default, awk 'condition' file is a syntax for outputting all the lines where condition is true.
Be also aware that the a[] array will expand every time you encounter a new key. At the end of your script, the size of the array will be the number of unique values you have throughout all your input files (in OP's example, it would be 9).
Note: this solution counts duplicates, i.e if you have:
file1 | file2
1 | 3
2 | 3
3 | 3
awk 'a[$0]++' file1 file2 will output 3 3 3 and awk 'a[$0]++' file1 file2 | wc -l will output 3
If this is a behaviour you don't want, you can use the following code to filter out duplicates :
awk '++a[$0] == 2' file1 file2 | wc -l
with your input example, this works too. but if the files are huge, I prefer the awk solutions by others:
grep -cFwf file2 file1
with your input files, the above line outputs
3
Here's one without awk that instead uses comm:
comm -12 <(sort file1.txt) <(sort file2.txt) | wc -l
comm compares two sorted files. The arguments 1,2 suppresses unique lines found in both files.
The output is the lines they have in common, on separate lines. wc -l counts the number of lines.
Output without wc -l:
10
3
5
And when counting (obviously):
3
You can also use comm command. Remember that you will have to first sort the files that you need to compare:
[gc#slave ~]$ sort a > sorted_1
[gc#slave ~]$ sort b > sorted_2
[gc#slave ~]$ comm -1 -2 sorted_1 sorted_2
10
3
5
From man pages for comm command:
comm - compare two sorted files line by line
Options:
-1 suppress column 1 (lines unique to FILE1)
-2 suppress column 2 (lines unique to FILE2)
-3 suppress column 3 (lines that appear in both files)
You can do all with awk:
awk '{ a[$0] += 1} END { c = 0; for ( i in a ) { if ( a[i] > 1 ) c++; } print c}' file1 file2
To get the percentage, something like this works:
awk '{ a[$0] += 1; if (NR == FNR) { b = FILENAME; n = NR} } END { c = 0; for ( i in a ) { if ( a[i] > 1 ) c++; } print b, c/n; print FILENAME, c/FNR;}' file1 file2
and outputs
file1 0.428571
file2 0.6
In your solution, you can get rid of one cat:
sort file1 file2| uniq -c | awk '{if ($1 > 1) {$1=""; print $0}}' | wc -l
How about keeping it nice and simple...
This is all that's needed:
cat file1 file2 | sort -n | uniq -d | wc -l
3
man sort:
-n, --numeric-sort -- compare according to string numerical value
man uniq:
-d, --repeated -- only print duplicate lines
man wc:
-l, --lines -- print the newline counts
Hope this helps.
EDIT - one fewer process (credit martin):
sort file1 file2 | uniq -d | wc -l
One way using awk:
awk 'NR==FNR{a[$0]; next}$0 in a{n++}END{print n}' file1 file2
Output:
3
The first answer by Aserre using awk is good but may have the undesirable effect of counting duplicates - even if the duplicates exist in only ONE of the files, which is not quite what the OP asked for.
I believe this edit will return only the unique lines that exist in BOTH files.
awk 'NR==FNR{a[$0]=1;next}a[$0]==1{a[$0]++;print $0}' file1 file2
If duplicates are desired, but only if they exist in both files, I believe this next version will work, but will only report duplicates in the second file that exist in the first file. (If the duplicates exist in the first file, only the those that also exist in file2 will be reported, so file order matters).
awk 'NR==FNR{a[$0]=1;next}a[$0]' file1 file2
Btw, I tried using grep, but it was painfully slow on files with a few thousand lines each. Awk is very fast!
UPDATE 1 : new version ensures intra-file duplicates are excluded from count, so only cross-file duplicates would show up in the final stats :
mawk '
BEGIN { _*= FS = "^$"
} FNR == NF { split("",___)
} ___[$_]++<NF { __[$_]++
} END { split("",___)
for (_ in __) {
___[__[_]]++ } printf(RS)
for (_ in ___) {
printf(" %\04715.f %s\n",_,___[_]) }
printf(RS) }' \
<( jot - 1 999 3 | mawk '1;1;1;1;1' | shuf ) \
<( jot - 2 1024 7 | mawk '1;1;1;1;1' | shuf ) \
<( jot - 7 1295 17 | mawk '1;1;1;1;1' | shuf )
3 3
2 67
1 413
===========================================
this is probably waaay overkill, but i wrote something similar to this to supplement uniq -c :
measuring the frequency of frequencies
it's like uniq -c | uniq -c without wasting time sorting. The summation and % parts are trivial from here, with 47 over-lapping lines in this example. It avoids spending any time performing per row processing, since the current setup only shows the summarized stats.
If you need to actual duplicated rows, they're also available right there serving as the hash key for the 1st array.
gcat <( jot - 1 999 3 ) <( jot - 2 1024 7 ) |
mawk '
BEGIN { _*= FS = "^$"
} { __[$_]++
} END { printf(RS)
for (_ in __) { ___[__[_]]++ }
for (_ in ___) {
printf(" %\04715.f %s\n",
_,___[_]) } printf(RS) }'
2 47
1 386
add another file, and the results reflect the changes (I added <( jot - 5 1295 5 ) ):
3 9
2 115
1 482

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