linux get specific fields from several files - linux

I have several files starting with the string "file" then a number (file1, file2, etc).
The content of these files is similar and looks like this
file1:
$xx_ at 10.0 "$elt_(0) coordinates 636.46 1800.37 9.90"
$xx_ at 10.0 "$elt_(1) coordinates 367.78 1263.63 7.90"
For each file, I want only keep the index of the element and the 2 numeric fields just after coordinates (in the same file or in another file):
file1:
0 636.46 1800.37
1 367.78 1263.63
What I tried to do is like this (but It is not correct)
find . -name "file*"|while read fname; do
echo "$fname"
for line in $(cat "$fname") do
FS="[_() ]"
print $7 "\t" $10 "\t" $11 > $fname
done
done

This is the perfect use of awk.
With awk you can simply print specific words.
If the index is the line number you can use this:
cat -n ./file1 | awk '{print $1 -1 " " $7 " " $8}' this simply prints the files with line numbers and prints the first, seventh and eighth word.
If the index is the $elt_(0) number in parenthese you can use sed like this:
cat ./file1 | awk '{print $4 " " $7 " " $8}' | sed 's/"$elt_(//g' | sed 's/)//g' | sed 's/"//g'
output:
1 636.46 1800.37
2 367.78 1263.63
Link to awk
Link to sed

Related

Print lines not containg a period linux

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

how to use awk/sed to deal with these two files to get a result that I want

I want to use awk/sed to deal with two files(a.txt and b.txt) below and get the result
cat a.txt
a UK
b Japan
c China
d Korea
e US
And cat b.txt results
c Russia
e Canada
The result that I want is as below:
a UK
b Japan
c Russia
d Korea
e Canada
With awk:
First fill aray/hash a with complete row ($0) and use first column ($1) from this row as index. Finally, print all elements of array/hash a with a loop.
awk '{a[$1]=$0} END{for(i in a) print a[i]}' file1 file2
Output:
a UK
b Japan
c Russia
d Korea
e Canada
try:
awk 'FNR==NR{A[$1]=$NF;next} {printf("%s %s\n",$1,$1 in A?A[$1]:$NF)}' b.txt a.txt
Checking here condition FNR==NR which will be TRUE only when first file(b.txt) is being read. Then creating an array named A whose index is $1 and have the value last column. Then using printf for printing 2 strings where first string is $1 and another is if $1 of a.txt is present in array A then print array A's value whose index is $1 else print last column of a.tzt itself.
EDIT: as OP had carriage characters into Input_files so please remove them by following too.
tr -d '\r' < b.txt > temp_b.txt && mv temp_b.txt b.txt
You can use the below one-liner:
join -a 1 -a 2 a.txt <( awk '{print $1, "--", $0, "--"}' < b.txt ) | sed 's/ --$//' | awk -F ' -- ' '{print $NF}'
We use awk to prefix each line in b.txt with a key and -- to give us a split point later:
<( awk '{print $1, "--", $0, "--"}' < b.txt )
Use the join command to join the files on common keys. The -a 1 option tells the command to
join -a 1 -a 2 a.txt <( awk '{print $1, "--", $0, "--"}' < b.txt )
Use sed to remove the -- parts that are on some end of lines:
sed 's/ --$//'
Use awk to print the last item on each line:
awk -F ' -- ' '{print $NF}'
$ awk 'NR==FNR{b[$1]=$2;next} {print $1, ($1 in b ? b[$1] : $2)}' b.txt a.txt
a UK
b Japan
c Russia
d Korea
e Canada

Linux command (Calculating the sum)

I have a .txt file with the following content:
a 3
a 4
a 5
a 6
b 1
b 3
b 5
c 9
c 10
I am wondering if there is any command (no awk if possible) that can read the .txt file and give the following output (Sorted by the second column):
c 19
a 18
b 9
You can use awk piped to sort:
awk '{sums[$1] += $2} END {for (i in sums) print i, sums[i]}' file | sort -rnk2
c 19
a 18
b 9
sums[$1] += $2 is adding value of $2 in an array sums that is indexed by field #1 ($1).
sort -rnk2 is reverse sorting numerically output of awk on field 2
Use can use this code:
cat 1.txt | awk '{arr[$1]+=$2}END{for (var in arr) print var," ",arr[var]}' | sort -rnk 2
Explanation:
cat 1.txt - read 1.txt file with content
awk - is a language very useful for data manipulation
{arr[$1]+=$2} for each line in content file increase array item with key first field with value of second field. Field separator by default is space.
END{for (var in arr) print var," ",arr[var]}' - after all line is proceeded, print array content
sort -rnk 2 - reverse numeric sort on field 2
Non-awk solutions.
perl
perl -lane '
$sum{$F[0]} += $F[1]
} END {
$, = " ";
print $_, $sum{$_} for reverse sort {$sum{$a} <=> $sum{$b}} keys %sum
' file.txt
bash version 4
declare -A sum
while read key val; do (( sum[$key] += $val )); done < file.txt
for key in "${!sum[#]}"; do echo "$key ${sum[$key]}"; done | sort -rn -k2
non-awk challenge accepted
vars=$(cut -d" " -f1 nums | uniq); paste <(echo "$vars") <(cat <(sed -e 's/ /+=/' nums) <(echo "$vars" | sed 's/$/;/') | bc) | sort -k2,2nr
c 19
a 18
b 9

linux command to get the last appearance of a string in a text file

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

deleting lines from a text file with bash

I have two sets of text files. First set is in AA folder. Second set is in BB folder. The content of ff.txt file from first set(AA folder) is shown below.
Name number marks
john 1 60
maria 2 54
samuel 3 62
ben 4 63
I would like to print the second column(number) from this file if marks>60. The output will be 3,4. Next, read the ff.txt file in BB folder and delete the lines containing numbers 3,4. How can I do this with bash?
files in BB folder looks like this. second column is the number.
marks 1 11.824 24.015 41.220 1.00 13.65
marks 1 13.058 24.521 40.718 1.00 11.82
marks 3 12.120 13.472 46.317 1.00 10.62
marks 4 10.343 24.731 47.771 1.00 8.18
awk 'FNR == NR && $3 > 60 {array[$2] = 1; next} {if ($2 in array) next; print}' AA/ff.txt BB/filename
This works, but is not efficient (is that matter?)
gawk 'BEGIN {getline} $3>60{print $2}' AA/ff.txt | while read number; do gawk -v number=$number '$2 != number' BB/ff.txt > /tmp/ff.txt; mv /tmp/ff.txt BB/ff.txt; done
Of course, the second awk can be replaced with sed -i
For multi files:
ls -1 AA/*.txt | while read file
do
bn=`basename $file`
gawk 'BEGIN {getline} $3>60{print $2}' AA/$bn | while read number
do
gawk -v number=$number '$2 != number' BB/$bn > /tmp/$bn
mv /tmp/$bn BB/$bn
done
done
I didn't test it, so if there is a problem, please comment.

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