Hi, all
I need to get fields in a line that are separated by commas, some of the fields are enclosed with double quotes, and they are supposed to be treated as a single field even if there are commas inside the quotes.
sample input:
for this line, 5 fields are supposed to be extracted, they... (8 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)
First, thanks for the help in previous posts... couldn't have gotten where I am now without it!
So here is what I have, I use AWK to match $1 and $2 as 1 string in file1 to $1 and $2 as 1 string in file2. Now I'm wondering if I can extend this AWK command to incorporate the following:
If $1... (4 Replies)
Using awk, print all the lines where field 8 is equal to x
I really did try, but this awk thing is really hard to figure out.
file1.txt"Georgia","Atlanta","2011-11-02","x","","","",""
"California","Los Angeles","2011-11-03","x","","","",""... (2 Replies)
Hello experts
I have a file with paragraphs begining with a keeping date and ending with "END":
20120301 num num
John num num A keepnum1 num num
kathrin num num A keepnum1 num num
kathrin num num B keepnum2 num num
Pete num num A keepnum1 num num
Jacob num... (2 Replies)
I am trying to parse the input in awk to include the |gc= in $4 but am not able to. The below is close:
awk so far:
awk '{sub(/\|]+]++/, ""); print }' input.txt Input
chr1 955543 955763 AGRN-6|pr=2|gc=75 0 +
chr1 957571 957852 AGRN-7|pr=3|gc=61.2 0 +
chr1 970621 ... (7 Replies)
We have a csv file as mentioned below and the requirement is to change the date format in file as mentioned below.
Current file (file.csv)
----------------------
empname,date_of_join,dept,date_of_resignation
ram,08/09/2015,sales,21/06/2016
"akash,sahu",08/10/2015,IT,21/07/2016
... (6 Replies)
I am trying to output a tab-delimited result that uses the data from a tab-delimited file to combine and subtract specific lines.
If $4 matches in each line then the first matching sequential $6 value is added to $2, unless the value is 1, then the original $2 is used (like in the case of line... (3 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,
So awk is driving me crazy on this one. I have searched everywhere and read man, docs and every related post Google can find and still no luck. The actual files I need to run this on are sensitive in nature, but it is the same thing as if I needed to calculate weighted grades for multiple... (15 Replies)
Discussion started by: cotilloe
15 Replies
LEARN ABOUT X11R4
perldbmfilter
PERLDBMFILTER(1) Perl Programmers Reference Guide PERLDBMFILTER(1)NAME
perldbmfilter - Perl DBM Filters
SYNOPSIS
$db = tie %hash, 'DBM', ...
$old_filter = $db->filter_store_key ( sub { ... } );
$old_filter = $db->filter_store_value( sub { ... } );
$old_filter = $db->filter_fetch_key ( sub { ... } );
$old_filter = $db->filter_fetch_value( sub { ... } );
DESCRIPTION
The four "filter_*" methods shown above are available in all the DBM modules that ship with Perl, namely DB_File, GDBM_File, NDBM_File,
ODBM_File and SDBM_File.
Each of the methods work identically, and are used to install (or uninstall) a single DBM Filter. The only difference between them is the
place that the filter is installed.
To summarise:
filter_store_key
If a filter has been installed with this method, it will be invoked every time you write a key to a DBM database.
filter_store_value
If a filter has been installed with this method, it will be invoked every time you write a value to a DBM database.
filter_fetch_key
If a filter has been installed with this method, it will be invoked every time you read a key from a DBM database.
filter_fetch_value
If a filter has been installed with this method, it will be invoked every time you read a value from a DBM database.
You can use any combination of the methods from none to all four.
All filter methods return the existing filter, if present, or "undef" in not.
To delete a filter pass "undef" to it.
The Filter
When each filter is called by Perl, a local copy of $_ will contain the key or value to be filtered. Filtering is achieved by modifying the
contents of $_. The return code from the filter is ignored.
An Example -- the NULL termination problem.
DBM Filters are useful for a class of problems where you always want to make the same transformation to all keys, all values or both.
For example, consider the following scenario. You have a DBM database that you need to share with a third-party C application. The C appli-
cation assumes that all keys and values are NULL terminated. Unfortunately when Perl writes to DBM databases it doesn't use NULL termina-
tion, so your Perl application will have to manage NULL termination itself. When you write to the database you will have to use something
like this:
$hash{"$key "} = "$value ";
Similarly the NULL needs to be taken into account when you are considering the length of existing keys/values.
It would be much better if you could ignore the NULL terminations issue in the main application code and have a mechanism that automati-
cally added the terminating NULL to all keys and values whenever you write to the database and have them removed when you read from the
database. As I'm sure you have already guessed, this is a problem that DBM Filters can fix very easily.
use strict;
use warnings;
use SDBM_File;
use Fcntl;
my %hash;
my $filename = "filt";
unlink $filename;
my $db = tie(%hash, 'SDBM_File', $filename, O_RDWR|O_CREAT, 0640)
or die "Cannot open $filename: $!
";
# Install DBM Filters
$db->filter_fetch_key ( sub { s/ $// } );
$db->filter_store_key ( sub { $_ .= "