perl script to extract string

ge1 · 07-05-2011, 03:00 PM

hii all.

i'm writing a perl script, by searching the net and understanding the functionality of it.

the requirement is that i should create a file by using a perl scipt which should contain something like this.
struct regread ge1[] {
{"string","offset","shift,"mask"},
{... },
{... },
}

so, the file from which i should read contains something like this

Code:

#define SPIRO_TX_EB_ADDR_LOW_OFFSET  0xc00

#define SPIRO_TX_EB_ADDR_LOW_SHIFT    	   0x00

#define SPIRO_TX_EB_ADDR_LOW_MASK    	   0xFFFFFFFF



#define SPIRO_TX_EB_ADDR_HIGH_OFFSET  0xc04

#define SPIRO_TX_EB_ADDR_HIGH_SHIFT    	   0x00

#define SPIRO_TX_EB_ADDR_HIGH_MASK    	   0xFFFFFFFF

so i have to 1.extract string
2.eliminate #define
3.extract string from (offset,shift,mask) and write that in the string
4.for offset the respective address should be in "offset" of the structure similarly for mask, and shift.

i came to a stage and stuck i need your help in extracting the spiro_tx_eb_addr_high and separating from (offset,mask,shift)
my code is

Code:

#!usr/bin/perl

open IN, "/home/ge1/Documents/c_files/gmac_dma.h" or die "Can not open in.txt for reading : $!";			#opening the file

while ( my $line = <IN> ) {		#openig each line in file
	#print "$line";		
my @list = split ' ' , $line;		#spliting the line on spaces,storing
#print "string:$list[1]\t\taddress:$list[2]\n";	#printing the wanted stuff
@string=$list[1]=~ m/OFFSET/g;
print "@string";

}

close IN or die "Can not close file : $!";

i hope you understood what i was expecting, if so please help. I'm not asking you to give me code, just tell how to do.

chrism01 · 07-05-2011, 07:14 PM

A few tips

1. amend top of prog to

Code:

#!usr/bin/perl -w
use strict;

2. Good links
http://perldoc.perl.org/
http://www.perlmonks.org/?node=Tutorials

3. 3 arg open() is best practice

Code:

open(INFILE, "<", $file) or die "Unable to open $file: $!\n";

4. tidier version of while loop

Code:

while ( defined ( $rec = <IN_FILE> ) )
{
    chomp($rec);
    ($var1, $var2) = (split(/:/, $rec));
    print  "$var1, $var2\n";
}

note use of defined() & chomp().
For a small amt of vars, you can specify target vars directly; using an array is optional; your call.

5. I think I'd like to see an example of the desired output before going any further.

samratk1230 · 07-06-2011, 12:33 AM

Really nice.

ge1 · 07-07-2011, 09:45 AM

sir, the output pattern is also mentioned in my above post.

the requirement is to read from a file, and create another file which should contain a structure.

the prototype of it is in my previous post.

thank you for answering.

markush · 07-07-2011, 12:14 PM

Hello ge1,

first of all you should use the "Report"-button at your post and ask a Moderator to move this thread to the Programming forum of LQ, http://www.linuxquestions.org/questions/programming-9/ because this is a programming-question.

To your program, the structure of your data will be fine represented by a "hash of hashes".
If you have a hash named %datahash it could look like

Code:

%datahash = ( SPIRO_TX_EB_ADDR_LOW => { offset => 0xc00, shift => 0x00, mask => 0xFFFFFFFF } 
... and so on ...
)

look here http://docstore.mik.ua/orelly/perl/prog3/ch09_04.htm

Markus