For your questions, why a[$1] didn't throw errors because if any variable is NOT initialized in awk and we are using it in any condition or etc then its value will be considered as NULL, hence NO ERRORS in it.
I am adding a detailed level of explanation here for my solution above:
These 2 Users Gave Thanks to RavinderSingh13 For This Post:
I will be performing a task on several directories, each containing a large number of files (2500+) that follow a regular naming convention:
YYYY_MM_DD_XX.foo_bar.A.B.some_different_stuff.EXT
What I would like to do is automatically discover the part of the filenames that are common to all... (1 Reply)
Hi!
I have a difficult problem, to step up a unknown version number in a text file, and save the file. It would be great to run script.sh and the version gets increased.
Example the content of the textfile.txt
hello
version = x
bye
This include three steps
1. First find the char after... (2 Replies)
Hello, I am using awk to match text in a tab separated field and am able to do so when matching the exact word. My problem is that I would like to match any sequence of text in the tab-separated field without having to match it all. Any help will be appreciated. Please see the code below.
awk... (3 Replies)
here is what i want to achieve... consider a file contains below contents. the file size is large about 60mb
cat dump.sql
INSERT INTO `table1` (`id`, `action`, `date`, `descrip`, `lastModified`) VALUES (1,'Change','2011-05-05 00:00:00','Account Updated','2012-02-10... (10 Replies)
I met a challenge to filter ~70 millions of sequence rows and I want using awk with conditions:
1) longest string of each pattern in column 2, ignore any sub-string, as the index;
2) all the unique patterns after 1);
3) print the whole row;
input:
1 ABCDEFGHI longest_sequence1
2 ABCDEFGH... (12 Replies)
Hi all !
I almost did it but got a small problem.
input:
cars red
cars blue
cars green
truck black
Wanted:
cars red-blue-green
truck black
Attempt:
gawk 'BEGIN{FS="\t"}{a = a (a?"-":"")$2; $2=a; print $1 FS $2}' input
But I also got the intermediate records... (2 Replies)
Hello gurus,
I have a database of possible primary signal strings
pp22
pt22dx
pp22dx
jty2234
Also I have a list of scrambled signals which has a shorter string and a longer string separated by // (double slash ). Always the shorter string of a scrambled signal will have the primary... (6 Replies)
In the awk below I am trying to set/update the value of $14 in file2 in
bold, using the matching NM_ in $12 or $9 in file2
with the NM_ in $2 of file1.
The lengths of $9 and $12 can be variable but what is consistent is the start pattern
will always be NM_ and the end pattern is always ;... (2 Replies)
Hi,
Wish to remove "DR-" from the string variable (var).
var="DR-SERVER1"
var=`echo $var | sed -e 's/DR-//g'`
echo "$var"
Expected Output:
However, I get the below error:
Can you please suggest. (4 Replies)
Discussion started by: mohtashims
4 Replies
LEARN ABOUT DEBIAN
plan9-join
JOIN(1) General Commands Manual JOIN(1)NAME
join - relational database operator
SYNOPSIS
join [ options ] file1 file2
DESCRIPTION
Join forms, on the standard output, a join of the two relations specified by the lines of file1 and file2. If one of the file names is the
standard input is used.
File1 and file2 must be sorted in increasing ASCII collating sequence on the fields on which they are to be joined, normally the first in
each line.
There is one line in the output for each pair of lines in file1 and file2 that have identical join fields. The output line normally con-
sists of the common field, then the rest of the line from file1, then the rest of the line from file2.
Input fields are normally separated spaces or tabs; output fields by space. In this case, multiple separators count as one, and leading
separators are discarded.
The following options are recognized, with POSIX syntax.
-a n In addition to the normal output, produce a line for each unpairable line in file n, where n is 1 or 2.
-v n Like -a, omitting output for paired lines.
-e s Replace empty output fields by string s.
-1 m
-2 m Join on the mth field of file1 or file2.
-jn m Archaic equivalent for -n m.
-ofields
Each output line comprises the designated fields. The comma-separated field designators are either 0, meaning the join field, or
have the form n.m, where n is a file number and m is a field number. Archaic usage allows separate arguments for field designators.
-tc Use character c as the only separator (tab character) on input and output. Every appearance of c in a line is significant.
EXAMPLES
sort /etc/passwd | join -t: -1 1 -a 1 -e "" - bdays
Add birthdays to the /etc/passwd file, leaving unknown birthdays empty. The layout of /adm/users is given in passwd(5); bdays con-
tains sorted lines like
tr : ' ' </etc/passwd | sort -k 3 3 >temp
join -1 3 -2 3 -o 1.1,2.1 temp temp | awk '$1 < $2'
Print all pairs of users with identical userids.
SOURCE
/src/cmd/join.c
SEE ALSO sort(1), comm(1), awk(1)BUGS
With default field separation, the collating sequence is that of sort -b -ky,y; with -t, the sequence is that of sort -tx -ky,y.
One of the files must be randomly accessible.
JOIN(1)