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 MOJAVE
join
JOIN(1) BSD General Commands Manual JOIN(1)NAME
join -- relational database operator
SYNOPSIS
join [-a file_number | -v file_number] [-e string] [-o list] [-t char] [-1 field] [-2 field] file1 file2
DESCRIPTION
The join utility performs an ``equality join'' on the specified files and writes the result to the standard output. The ``join field'' is
the field in each file by which the files are compared. The first field in each line is used by default. There is one line in the output
for each pair of lines in file1 and file2 which have identical join fields. Each output line consists of the join field, the remaining
fields from file1 and then the remaining fields from file2.
The default field separators are tab and space characters. In this case, multiple tabs and spaces count as a single field separator, and
leading tabs and spaces are ignored. The default output field separator is a single space character.
Many of the options use file and field numbers. Both file numbers and field numbers are 1 based, i.e., the first file on the command line is
file number 1 and the first field is field number 1. The following options are available:
-a file_number
In addition to the default output, produce a line for each unpairable line in file file_number.
-e string
Replace empty output fields with string.
-o list
The -o option specifies the fields that will be output from each file for each line with matching join fields. Each element of list
has the either the form 'file_number.field', where file_number is a file number and field is a field number, or the form '0' (zero),
representing the join field. The elements of list must be either comma (',') or whitespace separated. (The latter requires quoting
to protect it from the shell, or, a simpler approach is to use multiple -o options.)
-t char
Use character char as a field delimiter for both input and output. Every occurrence of char in a line is significant.
-v file_number
Do not display the default output, but display a line for each unpairable line in file file_number. The options -v 1 and -v 2 may be
specified at the same time.
-1 field
Join on the field'th field of file 1.
-2 field
Join on the field'th field of file 2.
When the default field delimiter characters are used, the files to be joined should be ordered in the collating sequence of sort(1), using
the -b option, on the fields on which they are to be joined, otherwise join may not report all field matches. When the field delimiter char-
acters are specified by the -t option, the collating sequence should be the same as sort(1) without the -b option.
If one of the arguments file1 or file2 is ``-'', the standard input is used.
EXIT STATUS
The join utility exits 0 on success, and >0 if an error occurs.
COMPATIBILITY
For compatibility with historic versions of join, the following options are available:
-a In addition to the default output, produce a line for each unpairable line in both file 1 and file 2.
-j1 field
Join on the field'th field of file 1.
-j2 field
Join on the field'th field of file 2.
-j field
Join on the field'th field of both file 1 and file 2.
-o list ...
Historical implementations of join permitted multiple arguments to the -o option. These arguments were of the form
'file_number.field_number' as described for the current -o option. This has obvious difficulties in the presence of files named
'1.2'.
These options are available only so historic shell scripts do not require modification. They should not be used in new code.
LEGACY DESCRIPTION
The -e option causes a specified string to be substituted into empty fields, even if they are in the middle of a line. In legacy mode, the
substitution only takes place at the end of a line.
Only documented options are allowed. In legacy mode, some obsolete options are re-written into current options.
For more information about legacy mode, see compat(5).
SEE ALSO awk(1), comm(1), paste(1), sort(1), uniq(1), compat(5)STANDARDS
The join command conforms to IEEE Std 1003.1-2001 (``POSIX.1'').
BSD July 5, 2004 BSD