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:
Code:
awk ' ##Starting awk program from here.
BEGIN{ ##Starting BEGIN section of this awk code here.
FS=OFS="|" ##Setting FS and OFS as pipe here.
}
FNR==NR{ ##Checking condition if FNR==NR which will be TRUE when first time Input_file is being read.
b[$1]=length($3)>a[$1]?$3:b[$1] ##Creating array b with index $1 and checking if value of length of $3 is grater than value of a[$3] then keep value of length of $3 else keep OLD Value in it.
a[$1]=length($3)>a[$1]?length($3):a[$1] ##Creating array a with index $1 and checking condition if length of $3 is grater than a[$1] then save value as length($3) or keep the OLD value to it. This array a is basically has length in integer form value with index $1 to be used later in condition.
next ##next will skip all further statements from here,
}
length($3)<a[$1]{ ##Checking condition if length of 3rd field is lesser than value of array a with index $1 then
$3=b[$1] ##Setting current $3 to value of array b with index of $1 here.
}
1 ##1 will print edited/non-edited values of current line.
' Input_file Input_file ##Mentioning Input_file 2 times here.
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:
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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
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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 PHP
pg_field_name
PG_FIELD_NAME(3)PG_FIELD_NAME(3)pg_field_name - Returns the name of a fieldSYNOPSIS
string pg_field_name (resource $result, int $field_number)
DESCRIPTION pg_field_name(3) returns the name of the field occupying the given $field_number in the given PostgreSQL $result resource. Field numbering
starts from 0.
Note
This function used to be called pg_fieldname(3).
PARAMETERS
o $result
- PostgreSQL query result resource, returned by pg_query(3), pg_query_params(3) or pg_execute(3) (among others).
o $field_number
- Field number, starting from 0.
RETURN VALUES
The field name, or FALSE on error.
EXAMPLES
Example #1
Getting information about fields
<?php
$dbconn = pg_connect("dbname=publisher") or die("Could not connect");
$res = pg_query($dbconn, "select * from authors where author = 'Orwell'");
$i = pg_num_fields($res);
for ($j = 0; $j < $i; $j++) {
echo "column $j
";
$fieldname = pg_field_name($res, $j);
echo "fieldname: $fieldname
";
echo "printed length: " . pg_field_prtlen($res, $fieldname) . " characters
";
echo "storage length: " . pg_field_size($res, $j) . " bytes
";
echo "field type: " . pg_field_type($res, $j) . "
";
}
?>
The above example will output:
column 0
fieldname: author
printed length: 6 characters
storage length: -1 bytes
field type: varchar
column 1
fieldname: year
printed length: 4 characters
storage length: 2 bytes
field type: int2
column 2
fieldname: title
printed length: 24 characters
storage length: -1 bytes
field type: varchar
SEE ALSO pg_field_num(3).
PHP Documentation Group PG_FIELD_NAME(3)