Searchin' through values

[MaroonBalloon]

I am searching through values from the command line, basically my ARGV[0] is my $search.

I am searching through sequences like: ASPASRRQLPGAASPRT for sequences like ASP. I have found that I can type in AS[P/R] and get the results for ASP AND ASR. Any idea how I can use "X" to mean "All characters" or..."F" to mean "Q,R, or G" ?

Thanks!
ER

[ikegami]

If you treat the arg as a regex pattern, "[P/R]" actually means "P", "/" or "R". You simply want "[PR]".

"." means any character

"[QRG]" will match one of those three characters.

---

And if you want to format you specified:

my $pat = '';
for ($ARGV[0]) {
   /\G ([A-EG-WYZ]+)            /xgc && do { $pat .= $1;       redo };
   /\G X                        /xgc && do { $pat .= '.';      redo };
   /\G F                        /xgc && do { $pat .= '[QRG]';  redo };
   /\G \[ ([A-Z]) \/ ([A-Z]) \] /xgc && do { $pat .= "[$1$2]"; redo };
   /\G \z                       /xgc && last;

   my $pos  = pos();
   my $next = substr($_, $pos, 1);
   die("Unrecognized character \"$next\" at pos $pos\n");
}

Update: Added missing /xgc.

[vitoco]

I found very interesting this piece of code as an example for the \G pattern, but I noticed that x modifier was missing on each regexp AFAIK, but then tested if there was anything else I'm not awared.

Just as it is, it returns nothing on $pat. Then added the x modifier and got an endless loop!

I thought it was related to a note in perlre: "It is worth noting that \G improperly used can result in an infinite loop.", but a small trace using print "($pat)\n"; just before each redo shows that \G is always at the beginning of the argument, not after what was already matched.

I tried again removing pos() to see if that function resets the pointer... No luck!

Am I doing something wrong?

[ikegami]

It's because 'x' wasn't the only missing modifier. 'g' (to make the engine pay attn to pos) and 'c' (to prevent the engine from resetting pos) were also missing. Fixed.

[desemondo]

huh? i don't understand... perhaps providing a snippit of your actual code would help clarify things...

you're using regex's aren't you? if not, read up on them here: perldoc re

sounds like you could probably use this or something similar depending on your actual source data...



m/ASP[a-z]/i
# thats a literal 'ASP'
# followed by a character class of 1 of any letter from a-z