Help with simplifying file parsing program?

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

hi,
good morning,

I've done one program to read this file, please refer as below:

NAME   SUM   ITEMS_A         ITEMS_B    ITEMS_C
BAA     1    1348396499      134000 
BAA     10   1333333333      002333     
ITC     9    1340014296      181818      
ITC    10    1349999999      134110
BAA    29    1346512572      181919   
BAA   100    1349990990      *
FAC     3    1346048490      134795    122233
FAC    10    1346666655      181919    130303
BAB     9    1345100000      181919
...
[download]

But, there are too long and not very good. So, anybody knows how to make it easier and simple. The program algorithm are:

If NAME =~ /BAA/
   if ITEMS_A =~ /^134/ AND ITEMS_B =~ /^134/ THEN
   TBAA+=SUM
   a++;
   elsif ITEMS_A =~ /^134/ AND ITEMS_B !~ /^(134|00)/ THEN
   OBAA+=SUM
  b++; 
   elsif ITEMS_A =~ /^134/ AND ITEMS_B =~ /^00/ THEN
   IBAA+=SUM
   ab++; 
   else
   EBAA+=SUM
   c++;
elsif NAME =~ /ITC/
   if ITEMS_A =~ /^134/ AND ITEMS_B =~ /^134/ THEN
   TITC+=SUM
    d++;
   elsif ITEMS_A =~ /^134/ AND ITEMS_B !~ /^134/ THEN
   OITC+=SUM
   e++;
   else
   EITC+=SUM
   f++;
elsif NAME =~ /FAC/
   if ITEMS_A =~ /^134/ AND ITEMS_B =~ /^134/ THEN
     if ITEMS_C !~ /130303/ THEN
        TFAC+=SUM
        g++;
     else
        TXFAC+=SUM
        h++
   elsif ITEMS_A =~ /^134/ AND ITEMS_B !~ /^134/ THEN
      if ITEMS_C !~ /130303/ THEN
        TYFAC+=SUM
        i++;
     else
        TZFAC+=SUM
        j++
else
   if ITEMS_A =~ /^134/ AND ITEMS_B =~ /^134/ THEN
   UNK+=SUM
    k++;
   elsif ITEMS_A =~ /^134/ AND ITEMS_B !~ /^134/ THEN
   UNK2+=SUM
   l++;
   else
   UNK3+=SUM
   m++;
[download]

finally, print all the result by following the NAME, as example:

NAME               TOTAL_SUM     TOTAL
BAA (134->134)     140            5
    (134->other)   123            4
    (134->00???)    20            1
    (134->unknown)  0             0

ITC (134->134)     100            10
    (134->other)   30             4
    (134->unknown)  0             0

FAC  (134->134->130303)   30      3
     (134->134->other)    90      4
     (134->other->130303) 60      2
     (134->other->other)   1      1 

OTH 
      (134->134)     10         1
      (134->other)    9         1
      (134->unknown)  1         1
[download]

20030717 Edit by jeffa: Changed title from 'how to make it easier ?'

Comment on Help with simplifying file parsing program? Select or Download Code

Replies are listed 'Best First'.
Re: Help with simplifying file parsing program? by robartes (Priest) on Jul 17, 2003 at 05:58 UTC
Since this does indeed smell of homework (and I'm lazy), I'll not provide a shrink wrapped solution (it is supposed to be homework after all). But have a look at pack to parse the lines and have a closer look than you have before at perlre to interpret them. Also, a book like Learning Perl or yea, even an extended stroll through this very site, will help you even more. Good luck! CU Robartes-	[reply]
Re: Re: Help with simplifying file parsing program? by johndageek (Hermit) on Jul 17, 2003 at 14:07 UTC
Why is it that now I only have work work, homework looks fun? I would look at arrays and sorting as possibilities, or if you feel daring hashes. have fun! John	[reply]
Re: Help with simplifying file parsing program? by waswas-fng (Curate) on Jul 17, 2003 at 05:22 UTC
Do I get credit in your class for doing it for you? =) -Waswas	[reply]
Re: Help with simplifying file parsing program? by Skeeve (Parson) on Jul 17, 2003 at 06:03 UTC
You could outfactor(?) the combined ifs: `If NAME =~ /BAA/ if ITEMS_A =~ /^134/ if ITEMS_B =~ /^134/ THEN TBAA+=SUM a++; elsif ITEMS_B !~ /^(134\|00)/ THEN OBAA+=SUM b++; elsif ITEMS_B =~ /^00/ THEN IBAA+=SUM ab++; else EBAA+=SUM c++; # AFAICS this will never be reached. # Either ITEMS_B starts wit 134 or 00 or something # else. The last case is targeted by your second # ITEMS_B-if` [download] To shorten it, or at least make it more switch-like, in perl you could use the aliasing to $_ or "for": `SWITCH: for ($ITEMS_B) { /^134/ && do { # see above last SWITCH; }; !/^(134\|00)/ && do { # see above last SWITCH; }; /^00/ && do { # see above last SWITCH; }; # else do { #see above last SWITCH; } }` [download]	[reply] [d/l] [select]