I'm trying to write a bash shell script, that opens a certain file CATALOG.dat, containing the following lines, made of both characters and numbers:
event_0133_pk.gz
event_0291_pk.gz
event_0298_pk.gz
event_0356_pk.gz
event_0501_pk.gz
What I wanna do is print the numbers (only the numbers) inside a new file NUMBERS.dat, using something like > ./NUMBERS.dat, to get:
0133
0291
0298
0356
0501
My problem is: how do I extract the numbers from the text lines? Is there something to make the script read just the number as a variable, like event_0%d_pk.gz in C/C++?
A grep solution:
grep -oP '[0-9]+' CATALOG.dat >NUMBERS.dat
A sed solution:
sed 's/[^0-9]//g' CATALOG.dat >NUMBERS.dat
And an awk solution:
awk -F"[^0-9]+" '{print $2}' CATALOG.dat >NUMBERS.dat
There are many ways that you can achieve your result. One way would be to use awk:
awk -F_ '{print $2}' CATALOG.dat > NUMBERS.dat
This sets the field separator to an underscore, then prints the second field which contains the numbers.
Awk
awk 'gsub(/[^[:digit:]]/,"")' infile
Bash
while read line; do echo ${line//[!0-9]}; done < infile
tr
tr -cd '[[:digit:]\n]' <infile
You can use grep command to extract the number part.
grep -oP '(?<=_)\d+(?=_)' CATALOG.dat
gives output as
0133
0291
0298
0356
0501
Or
much simply
grep -oP '\d+' CATALOG.dat
You don't need perl mode in grep for this. BREs can do this.
grep -o '[[:digit:]]\+' CATALOG.dat > NUMBERS.dat
I am trying to sort files in a directory, depending on the 'date string' attached in the file name, for example files looks as below
SSA_F12_05122013.request.done
SSA_F13_12142012.request.done
SSA_F14_01062013.request.done
Where 05122013,12142012 and 01062013 represents the dates in format.
Please help me in providing a unix shell script to sort these files on the date string present in their file name(in descending and ascending order).
Thanks in advance.
Hmmm... why call on heavyweights like awk and Perl when sort itself has the capability to define what exactly to sort by?
ls SSA_F*.request.done | sort -k 1.13,1.16 -k 1.9,1.10 -k 1.11,1.12
Each -k option defines a "sort key":
-k 1.13,1.16
This defines a sort key ranging from field 1, column 13 to field 1, column 16. (A field is by default delimited by whitespace, which your filenames don't have.)
If your filenames are varying in length, defining the underscore as field separator (using the -t option) and then addressing columns in the third field would be the way to go.
Refer to man sort for details. Use the -r option to sort in descending order.
one way with awk and sort:
ls -1|awk -F'[_.]' '{s=gensub(/^([0-9]{4})(.*)/,"\\2\\1","g",$3);print s,$0}'|sort|awk '$0=$NF'
if we break it down:
ls -1|
awk -F'[_.]' '{s=gensub(/^([0-9]{4})(.*)/,"\\2\\1","g",$3);print s,$0}'|
sort|
awk '$0=$NF'
the ls -1 just example. I think you have your way to get the file list, one per line.
test a little bit:
kent$ echo "SSA_F13_12142012.request.done
SSA_F12_05122013.request.done
SSA_F14_01062013.request.done"|awk -F'[_.]' '{s=gensub(/^([0-9]{4})(.*)/,"\\2\\1","g",$3);print s,$0}'|
sort|
awk '$0=$NF'
SSA_F13_12142012.request.done
SSA_F14_01062013.request.done
SSA_F12_05122013.request.done
ls -lrt *.done | perl -lane '#a=split /_|\./,$F[scalar(#F)-1];$a[2]=~s/(..)(..)(....)/$3$2$1/g;print $a[2]." ".$_' | sort -rn | awk '{$1=""}1'
ls *.done | perl -pe 's/^.*_(..)(..)(....)/$3$2$1$&/' | sort -rn | cut -b9-
this would do +
Say I have file - a.csv
ram,33,professional,doc
shaym,23,salaried,eng
Now I need this output (pls dont ask me why)
ram,doc,doc,
shayam,eng,eng,
I am using cut command
cut -d',' -f1,4,4 a.csv
But the output remains
ram,doc
shyam,eng
That means cut can only print a Field just one time. I need to print the same field twice or n times.
Why do I need this ? (Optional to read)
Ah. It's a long story. I have a file like this
#,#,-,-
#,#,#,#,#,#,#,-
#,#,#,-
I have to covert this to
#,#,-,-,-,-,-
#,#,#,#,#,#,#,-
#,#,#,-,-,-,-
Here each '#' and '-' refers to different numerical data. Thanks.
You can't print the same field twice. cut prints a selection of fields (or characters or bytes) in order. See Combining 2 different cut outputs in a single command? and Reorder fields/characters with cut command for some very similar requests.
The right tool to use here is awk, if your CSV doesn't have quotes around fields.
awk -F , -v OFS=, '{print $1, $4, $4}'
If you don't want to use awk (why? what strange system has cut and sed but no awk?), you can use sed (still assuming that your CSV doesn't have quotes around fields). Match the first four comma-separated fields and select the ones you want in the order you want.
sed -e 's/^\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\)/\1,\4,\4/'
$ sed 's/,.*,/,/; s/\(,.*\)/\1\1,/' a.csv
ram,doc,doc,
shaym,eng,eng,
What this does:
Replace everything between the first and last comma with just a comma
Repeat the last ",something" part and tack on a comma. Voilà!
Assumptions made:
You want the first field, then twice the last field
No escaped commas within the first and last fields
Why do you need exactly this output? :-)
using perl:
perl -F, -ane 'chomp($F[3]);$a=$F[0].",".$F[3].",".$F[3];print $a."\n"' your_file
using sed:
sed 's/\([^,]*\),.*,\(.*\)/\1,\2,\2/g' your_file
As others have noted, cut doesn't support field repetition.
You can combine cut and sed, for example if the repeated element is at the end:
< a.csv cut -d, -f1,4 | sed 's/,[^,]*$/&&,/'
Output:
ram,doc,doc,
shaym,eng,eng,
Edit
To make the repetition variable, you could do something like this (assuming you have coreutils available):
n=10
rep=$(seq $n | sed 's:.*:\&:' | tr -d '\n')
< a.csv cut -d, -f1,4 | sed 's/,[^,]*$/'"$rep"',/'
Output:
ram,doc,doc,doc,doc,doc,doc,doc,doc,doc,doc,
shaym,eng,eng,eng,eng,eng,eng,eng,eng,eng,eng,
I had the same problem, but instead of adding all the columns to awk, I just used (to duplicate the 2nd column):
awk -v OFS='\t' '$2=$2"\t"$2' # for tab-delimited files
For CSVs you can just use
awk -F , -v OFS=, '$2=$2","$2'
How can I replace a column with its hash value (like MD5) in awk or sed?
The original file is super huge, so I need this to be really efficient.
So, you don't really want to be doing this with awk. Any of the popular high-level scripting languages -- Perl, Python, Ruby, etc. -- would do this in a way that was simpler and more robust. Having said that, something like this will work.
Given input like this:
this is a test
(E.g., a row with four columns), we can replace a given column with its md5 checksum like this:
awk '{
tmp="echo " $2 " | openssl md5 | cut -f2 -d\" \""
tmp | getline cksum
$2=cksum
print
}' < sample
This relies on GNU awk (you'll probably have this by default on a Linux system), and it uses openssl to generate the md5 checksum. We first build a shell command line in tmp to pass the selected column to the md5 command. Then we pipe the output into the cksum variable, and replace column 2 with the checksum. Given the sample input above, the output of this awk script would be:
this 7e1b6dbfa824d5d114e96981cededd00 a test
I copy pasted larsks's response, but I have added the close line, to avoid the problem indicated in this post: gawk / awk: piping date to getline *sometimes* won't work
awk '{
tmp="echo " $2 " | openssl md5 | cut -f2 -d\" \""
tmp | getline cksum
close(tmp)
$2=cksum
print
}' < sample
This might work using Bash/GNU sed:
<<<"this is a test" sed -r 's/(\S+\s)(\S+)(.*)/echo "\1 $(md5sum <<<"\2") \3"/e;s/ - //'
this 7e1b6dbfa824d5d114e96981cededd00 a test
or a mostly sed solution:
<<<"this is a test" sed -r 'h;s/^\S+\s(\S+).*/md5sum <<<"\1"/e;G;s/^(\S+).*\n(\S+)\s\S+\s(.*)/\2 \1 \3/'
this 7e1b6dbfa824d5d114e96981cededd00 a test
Replaces is from this is a test with md5sum
Explanation:
In the first:- identify the columns and use back references as parameters in the Bash command which is substituted and evaluated then make cosmetic changes to lose the file description (in this case standard input) generated by the md5sum command.
In the second:- similar to the first but hive the input string into the hold space, then after evaluating the md5sum command, append the string G to the pattern space (md5sum result) and using substitution arrange to suit.
You can also do that with perl :
echo "aze qsd wxc" | perl -MDigest::MD5 -ne 'print "$1 ".Digest::MD5::md5_hex($2)." $3" if /([^ ]+) ([^ ]+) ([^ ]+)/'
aze 511e33b4b0fe4bf75aa3bbac63311e5a wxc
If you want to obfuscate large amount of data it might be faster than sed and awk which need to fork a md5sum process for each lines.
You might have a better time with read than awk, though I haven't done any benchmarking.
the input (scratch001.txt):
foo|bar|foobar|baz|bang|bazbang
baz|bang|bazbang|foo|bar|foobar
transformed using read:
while IFS="|" read -r one fish twofish red fishy bluefishy; do
twofish=`echo -n $twofish | md5sum | tr -d " -"`
echo "$one|$fish|$twofish|$red|$fishy|$bluefishy"
done < scratch001.txt
produces the output:
foo|bar|3858f62230ac3c915f300c664312c63f|baz|bang|bazbang
baz|bang|19e737ea1f14d36fc0a85fbe0c3e76f9|foo|bar|foobar
I am looking for the easiest way to solve this problem. I have a huge data set that i cannot load into excel of this type of format
This is a sentence|10
This is another sentence|5
This is the last sentence|20
What I want to do is sort this from least to greatest based on the number.
cat MyDataSet.txt | tr "|" "\t" | ???
Not sure what the best way is to do this, I was thinking about using awk to switch the columns and the do a sort, but I was having trouble doing it.
Help me out please
sort -t\| -k +2n dataset.txt
Should do it. field separator and alternate key selection
You usually don't need cat to send the file to a filter. That said, you can use the sort filter.
sort -t "|" -k 2 -n MyDataSet.txt
This sorts the MyDataSet.txt file using the | character as field separator and sorting numerically according to the second field (the number).
have you tried sort -n
$ sort -n inputFile
This is another sentence|5
This is a sentence|10
This is the last sentence|20
you could switch the columns with awk too
$ awk -F"|" '{print $2"|"$1}' inputFile
10|This is a sentence
5|This is another sentence
20|This is the last sentence
combining awk and sort:
$ awk -F"|" '{print $2"|"$1}' inputFile | sort -n
5|This is another sentence
10|This is a sentence
20|This is the last sentence
per comments
if you have numbers in the sentence
$ sort -n -t"|" -k2 inputFile
This is another sentence|5
This is a sentence|10
This is the last sentence|20
this is a sentence with a number in it 2|22
and of course you could redirect it to a new file:
$ awk -F"|" '{print $2"|"$1}' inputFile | sort -n > outFile
Try this sort command:
sort -n -t '|' -k2 file.txt
Sort by number, change the separator and grab the second group using sort.
sort -n -t'|' -k2 dataset.txt