If we have the following result:
Operating System,50
Operating System,40
Operating System,30
Operating System,23
Data Structure,87
Data Structure,21
Data Structure,17
Data Structure,8
Data Structure,3
Crypo,33
Crypo,31
C++,65
C Language,39
C Language,19
C Language,4
Java 1.6,16
Java 1.6,11
Java 1.6,10
Java 1.6,2
I only want to compare the first field (book name), and remove duplicate lines except the first line of each book, which records the largest number. So the result is as below:
Operating System,50
Data Structure,87
Crypo,33
C++, 65
C Language,39
Java 1.6,16
Can anyone help me out that how could I do using uniq, sort & cut command? May be using tr, head or tail?
Most elegant in this case would seem
rev input | uniq -f1 | rev
If your input is sorted, you can use GNU awk like this:
awk -F, '!array[$1]++' file.txt
Results:
Operating System,50
Data Structure,87
Crypo,33
C++,65
C Language,39
Java 1.6,16
If your input is unsorted, you can use GNU awk like this:
awk -F, 'FNR==NR { if ($2 > array[$1]) array[$1]=$2; next } !dup[$1]++ { if ($1 in array) print $1 FS array[$1] }' file.txt{,}
Results:
Operating System,50
Data Structure,87
Crypo,33
C++,65
C Language,39
Java 1.6,16
awk -F, '{if(P!=$1)print;p=$1}' your_file
This could be done in different ways, but I've tried to restrict myself to the tools you suggested:
cut -d, -f1 file | uniq | xargs -I{} grep -m 1 "{}" file
Alternatively, if you are sure that the words in the first column do not have more than 2 characters which are the same, you can simply use: uniq -w3 file. This tells uniq to compare no more than the first three characters.
Related
I'm trying to get a uniq -c output like the following:
100 a
99 b
45 c
etc...
To write to a file in csv format using only unix utils, with the ordering reversed:
a,100
b,99
c,45
etc...
I figure I can pipe the output into tr " " "," to get the csv format, but how do I get the order of the columns to be reversed, only using unix utils?
cat test.txt | awk '{print $2,$1}'
armnotstrong's is probably the simplest but you can also use sed
sed -r 's/(.+) (.+)/\2,\1/'
For these one liners in unix, i like to use perl.
uniq -c yourfile | perl -lne 's/^(\s*)(\d*)(\s*)(.*)/$4,$2/g; print $_'
Difference is how the "," gets included in the output. If done as per #armnotstrong, the result will just be a bunch of lines seperated by spaces.
bash
=> cat text
100 a
99 b
98 c
=> cat text | awk '{print $2","$1}'
a,100
b,99
c,98
The awk solutions don't work correctly if your text data contains spaces.
Based on #cbreezier's answer, I came up with this solution:
sed -r 's/ +([0-9]+) (.+)/\2,\1/'
I have a grep that gives as output a list of many strings with different lengths.
the issue is that i want a list of the same size with the character number.
example:
grep output => what I want
agdhetfy 8
ethfnsjkl 9
eynjfi 6
kjfdbgkasjdfk 13
I was trying
grep -o 'expresion' | wc -m > filename
and of course it didn't work and i dont want to do it with a for loop... but if there is no other way, I'll do it.
You can use an awk version that supports the length() function:
grep ... | awk '{ print $1, length($1) }'
I need to get the records from a text file in Unix. The delimiter is multiple blanks. For example:
2U2133 1239
1290fsdsf 3234
From this, I need to extract
1239
3234
The delimiter for all records will be always 3 blanks.
I need to do this in an unix script(.scr) and write the output to another file or use it as an input to a do-while loop. I tried the below:
while read readline
do
read_int=`echo "$readline"`
cnt_exc=`grep "$read_int" ${Directory path}/file1.txt| wc -l`
if [ $cnt_exc -gt 0 ]
then
int_1=0
else
int_2=0
fi
done < awk -F' ' '{ print $2 }' ${Directoty path}/test_file.txt
test_file.txt is the input file and file1.txt is a lookup file. But the above way is not working and giving me syntax errors near awk -F
I tried writing the output to a file. The following worked in command line:
more test_file.txt | awk -F' ' '{ print $2 }' > output.txt
This is working and writing the records to output.txt in command line. But the same command does not work in the unix script (It is a .scr file)
Please let me know where I am going wrong and how I can resolve this.
Thanks,
Visakh
The job of replacing multiple delimiters with just one is left to tr:
cat <file_name> | tr -s ' ' | cut -d ' ' -f 2
tr translates or deletes characters, and is perfectly suited to prepare your data for cut to work properly.
The manual states:
-s, --squeeze-repeats
replace each sequence of a repeated character that is
listed in the last specified SET, with a single occurrence
of that character
It depends on the version or implementation of cut on your machine. Some versions support an option, usually -i, that means 'ignore blank fields' or, equivalently, allow multiple separators between fields. If that's supported, use:
cut -i -d' ' -f 2 data.file
If not (and it is not universal — and maybe not even widespread, since neither GNU nor MacOS X have the option), then using awk is better and more portable.
You need to pipe the output of awk into your loop, though:
awk -F' ' '{print $2}' ${Directory_path}/test_file.txt |
while read readline
do
read_int=`echo "$readline"`
cnt_exc=`grep "$read_int" ${Directory_path}/file1.txt| wc -l`
if [ $cnt_exc -gt 0 ]
then int_1=0
else int_2=0
fi
done
The only residual issue is whether the while loop is in a sub-shell and and therefore not modifying your main shell scripts variables, just its own copy of those variables.
With bash, you can use process substitution:
while read readline
do
read_int=`echo "$readline"`
cnt_exc=`grep "$read_int" ${Directory_path}/file1.txt| wc -l`
if [ $cnt_exc -gt 0 ]
then int_1=0
else int_2=0
fi
done < <(awk -F' ' '{print $2}' ${Directory_path}/test_file.txt)
This leaves the while loop in the current shell, but arranges for the output of the command to appear as if from a file.
The blank in ${Directory path} is not normally legal — unless it is another Bash feature I've missed out on; you also had a typo (Directoty) in one place.
Other ways of doing the same thing aside, the error in your program is this: You cannot redirect from (<) the output of another program. Turn your script around and use a pipe like this:
awk -F' ' '{ print $2 }' ${Directory path}/test_file.txt | while read readline
etc.
Besides, the use of "readline" as a variable name may or may not get you into problems.
In this particular case, you can use the following line
sed 's/ /\t/g' <file_name> | cut -f 2
to get your second columns.
In bash you can start from something like this:
for n in `${Directoty path}/test_file.txt | cut -d " " -f 4`
{
grep -c $n ${Directory path}/file*.txt
}
This should have been a comment, but since I cannot comment yet, I am adding this here.
This is from an excellent answer here: https://stackoverflow.com/a/4483833/3138875
tr -s ' ' <text.txt | cut -d ' ' -f4
tr -s '<character>' squeezes multiple repeated instances of <character> into one.
It's not working in the script because of the typo in "Directo*t*y path" (last line of your script).
Cut isn't flexible enough. I usually use Perl for that:
cat file.txt | perl -F' ' -e 'print $F[1]."\n"'
Instead of a triple space after -F you can put any Perl regular expression. You access fields as $F[n], where n is the field number (counting starts at zero). This way there is no need to sed or tr.
I want to do something like this:
cat abcd.txt | cut -f 2,1
and I want the order to be 2 and then 1 in the output. On the machine I am testing (FreeBSD 6), this is not happening (its printing in 1,2 order). Can you tell me how to do this?
I know I can always write a shell script to do this reversing, but I am looking for something using the 'cut' command options.
I think I am using version 5.2.1 of coreutils containing cut.
This can't be done using cut. According to the man page:
Selected input is written in the same order that it is read, and is
written exactly once.
Patching cut has been proposed many times, but even complete patches have been rejected.
Instead, you can do it using awk, like this:
awk '{print($2,"\t",$1)}' abcd.txt
Replace the \t with whatever you're using as field separator.
Lars' answer was great but I found an even better one. The issue with his is it matches \t\t as no columns. To fix this use the following:
awk -v OFS=" " -F"\t" '{print $2, $1}' abcd.txt
Where:
-F"\t" is what to cut on exactly (tabs).
-v OFS=" " is what to seperate with (two spaces)
Example:
echo 'A\tB\t\tD' | awk -v OFS=" " -F"\t" '{print $2, $4, $1, $3}'
This outputs:
B D A
In order to use the uniq command, you have to sort your file first.
But in the file I have, the order of the information is important, thus how can I keep the original format of the file but still get rid of duplicate content?
Another awk version:
awk '!_[$0]++' infile
This awk keeps the first occurrence. Same algorithm as other answers use:
awk '!($0 in lines) { print $0; lines[$0]; }'
Here's one that only needs to store duplicated lines (as opposed to all lines) using awk:
sort file | uniq -d | awk '
FNR == NR { dups[$0] }
FNR != NR && (!($0 in dups) || !lines[$0]++)
' - file
There's also the "line-number, double-sort" method.
nl -n ln | sort -u -k 2| sort -k 1n | cut -f 2-
You can run uniq -d on the sorted version of the file to find the duplicate lines, then run some script that says:
if this_line is in duplicate_lines {
if not i_have_seen[this_line] {
output this_line
i_have_seen[this_line] = true
}
} else {
output this_line
}
Using only uniq and grep:
Create d.sh:
#!/bin/sh
sort $1 | uniq > $1_uniq
for line in $(cat $1); do
cat $1_uniq | grep -m1 $line >> $1_out
cat $1_uniq | grep -v $line > $1_uniq2
mv $1_uniq2 $1_uniq
done;
rm $1_uniq
Example:
./d.sh infile
You could use some horrible O(n^2) thing, like this (Pseudo-code):
file2 = EMPTY_FILE
for each line in file1:
if not line in file2:
file2.append(line)
This is potentially rather slow, especially if implemented at the Bash level. But if your files are reasonably short, it will probably work just fine, and would be quick to implement (not line in file2 is then just grep -v, and so on).
Otherwise you could of course code up a dedicated program, using some more advanced data structure in memory to speed it up.
for line in $(sort file1 | uniq ); do
grep -n -m1 line file >>out
done;
sort -n out
first do the sort,
for each uniqe value grep for the first match (-m1)
and preserve the line numbers
sort the output numerically (-n) by line number.
you could then remove the line #'s with sed or awk