Deleting a Column name from file

lazy has asked for the wisdom of the Perl Monks concerning the following question:

how to delete a column name from file actual file would be like this i'm using Tie::File to write it as an array of columns, columns are written seperately and so the data

col1,col2,col3,col4,col5,col6

33,12dxc,fvgdf,dfgv,sdfvd

22,12cvb,gfbsd,fddg,fdvdf

expected is

col1,col2,col3,col4,col5

33,12dxc,fvgdf,dfgv,sdfvd

22,12cvb,gfbsd,fddg,fdvdf

 open (MYFILE, "$filename");
$ColumnNames = <MYFILE>;
$array[0] = $ColumnNames;
[download]

Comment on Deleting a Column name from file Download Code

Replies are listed 'Best First'.
Re: Deleting a Column name from file by hippo (Archbishop) on Jul 16, 2014 at 08:52 UTC
perlrun explains the runtime switches and in this case it is likely that `-i` and `-p` could prove useful. You'll probably also want to look at the `s///` operator as explained in perlop. Have you tried writing out what you want to acheive as an algorithm instead of just the starting and ending datasets? This exercise will usually prove helpful.	[reply] [d/l] [select]
Re: Deleting a Column name from file by Anonymous Monk on Jul 16, 2014 at 08:52 UTC
A question true to your username, so here's a very lazy answer: `perl -i.orig -pe 's/,col6//' FILENAME` It does what you specified by clobbering all instances of ",col6" in the file. If you want more, read and follow this: How do I post a question effectively?	[reply] [d/l]
Re: Deleting a Column name from file by Anonymous Monk on Jul 16, 2014 at 08:55 UTC
you don't need perl for this, its one line in one file :)	[reply]
Re^2: Deleting a Column name from file by lazy (Novice) on Jul 16, 2014 at 13:13 UTC
thanks for the replies... actually i write this file using perl using module Tie::File ! which runs fast but writing last column takes longer time! so just placed another column name it ran fast, now i have a prob of removing column name so i just posted. i have no clue why it writes so slow i shuffled coulmns but everytime the last column written in file is v slow. i tried it for 1 million records ! i use the following code to fetch the column names, i need to delete that last column (dummy) to be deleted while writing it in file `$ColumnNames = <MYFILE>;`	[reply] [d/l]
Re^3: Deleting a Column name from file by Anonymous Monk on Jul 16, 2014 at 21:06 UTC
That sounds like a very strange problem worth its own thread. But since it might not be so easy to debug, please make sure to regard How do I post a question effectively?	[reply]
Re: Deleting a Column name from file by Anonymous Monk on Jul 16, 2014 at 16:38 UTC
You are going to massive amounts of unnecessary effort. This file can be read one line at a time, each line `split` by comma, then the resulting array `splice`d to remove the column before `join`ing it again by comma. There are no brownie-points for needless complexity.	[reply]