File printing

[NesPes]

I have a very basic question on deleting/printing from/to a file.

My input file is something like this:

A1:This is the first line
A2:Welcome to the first line
A3:haaaaaaaaaaaaaaaaaaaaa

A1:This is the first line
A2:Welcome to the second line
A3:heeeeeeeeeeeeeeeeeeeee

I want to first search for A2 and then look for "first" in the string. If i find it, i then want to remove the first set of A1,A2 and A3 lines from this file. Can somebody help me with this?

 

[travs69]

A stab..

use Tie::File;
tie @array, 'Tie::File', 'test.txt' or die "can't open test.txt: $!\n";;
#If the second line starts with A2 and contains first
if ($array[1] =~ /^A2/ && $array[1] =~ /first/) {
        #remove the first 3 lines of the array
	for (1..3) {
		pop @array;
	}
}
untie @array;

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Travis - Those who say it cannot be done are usually interrupted by someone else doing it; Give the wrong symptoms, get the wrong solutions;

 

[KevinADC]

Travis,

Did you mean to use "shift" instead of "pop"?

NesPes,

Is A1, A2 and A3 always the first three lines of the file?

------------------------------------------
- Kevin, perl coder unexceptional!

 

[travs69]

Um.. yep

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Travis - Those who say it cannot be done are usually interrupted by someone else doing it; Give the wrong symptoms, get the wrong solutions;

 

[NesPes]

Kevin

The input file always has multiple sets of A1,A2,A3 but all of them are in the same order as shown in the example.

 

[travs69]

Oh.. if it has multiple sets in one file don't use my code I'll try and re-write it in a bit if someone else hasn't posted a solution.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Travis - Those who say it cannot be done are usually interrupted by someone else doing it; Give the wrong symptoms, get the wrong solutions;

 

[KevinADC]

NesPes,

Have you tried to write some code?

------------------------------------------
- Kevin, perl coder unexceptional!

 

[MillerH]

[url=http://perldoc.perl.org/functions/use.html][black][b]use[/b][/black][/url] [green]Tie::File[/green][red];[/red]

[black][b]use[/b][/black] [green]strict[/green][red];[/red]

[url=http://perldoc.perl.org/functions/my.html][black][b]my[/b][/black][/url] [blue]$file[/blue] = [red]'[/red][purple]test.txt[/purple][red]'[/red][red];[/red]

[url=http://perldoc.perl.org/functions/tie.html][black][b]tie[/b][/black][/url] [black][b]my[/b][/black] [blue]@array[/blue], [red]'[/red][purple]Tie::File[/purple][red]'[/red], [blue]$file[/blue] or [url=http://perldoc.perl.org/functions/die.html][black][b]die[/b][/black][/url] [red]"[/red][purple]Can't open [blue]$file[/blue]: [blue]$![/blue][/purple][red]"[/red][red];[/red]

[maroon]LINE[/maroon][maroon]:[/maroon]
[olive][b]for[/b][/olive] [red]([/red][black][b]my[/b][/black] [blue]$i[/blue] = [fuchsia]0[/fuchsia][red];[/red] [blue]$i[/blue] <= [blue]$#array[/blue][red];[/red] [blue]$i[/blue]++[red])[/red] [red]{[/red]
	[olive][b]if[/b][/olive] [red]([/red][blue]$array[/blue][red][[/red][blue]$i[/blue][red]][/red] =~ [red]/[/red][purple]^A1[/purple][red]/[/red] && [blue]$array[/blue][red][[/red][blue]$i[/blue]+[fuchsia]1[/fuchsia][red]][/red] =~ [red]/[/red][purple]first[/purple][red]/[/red][red])[/red] [red]{[/red]
		[url=http://perldoc.perl.org/functions/splice.html][black][b]splice[/b][/black][/url] [blue]@array[/blue], [blue]$i[/blue], [fuchsia]3[/fuchsia][red];[/red]
		[olive][b]last[/b][/olive] LINE[red];[/red]
	[red]}[/red]
[red]}[/red]
[url=http://perldoc.perl.org/functions/untie.html][black][b]untie[/b][/black][/url] [blue]@array[/blue][red];[/red]

[tt]------------------------------------------------------------
Pragmas (perl 5.8.8) used :
[ul]
[li]strict - Perl pragma to restrict unsafe constructs[/li]
[/ul]
Core (perl 5.8.8) Modules used :
[ul]
[li]Tie::File - Access the lines of a disk file via a Perl array[/li]
[/ul]
[/tt]

- Miller

 

[travs69]

won't the 'last' stop the search through the array?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Travis - Those who say it cannot be done are usually interrupted by someone else doing it; Give the wrong symptoms, get the wrong solutions;

 

[MillerH]

Yep.

His specs are unclear. However, I'm pretty sure they expressed a single removal being the goal. If not, then the last should be a redo. But we can only work with what we're told.

- Miller

 

[travs69]

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Travis - Those who say it cannot be done are usually interrupted by someone else doing it; Give the wrong symptoms, get the wrong solutions;

 

[KevinADC]

Travis needs a haircut

------------------------------------------
- Kevin, perl coder unexceptional!