.getc.chr doesn't work

ruby-talk
1

Hi!

I'm trying to read a file using ruby. Firsty I use readline twice,
then I wan't to read some part of data, but I don't get where I have a
mistake. Could you help me find it?

######## CUT HERE ########
#Constans
FS = 0x1c
RS = 0x1e

#Open file
f = File.new("abcdef", "r")

#Read a line, split it, and delete bad fields (last one)
tbl = f.readline(FS.chr).split(RS.chr) - [FS.chr]
#For each from tbl
tbl.each { |x|
   #Split field
   splitted = x.split("_")
   #The read loop
   tmp = String.new
   i=0
   while (i < splitted[2].to_i)
     tmp += f.getc.chr #Here I have an error...
   end
   #Save readed data
   f2 = File.new(s[0]+"-"+s[1]+".txt", "w")
   f2.write(tmp)
   f2.close
}

#Close file
f.close
######## CUT HERE ########

The test file in HEX (beacouse it have non-printable chars)
######## CUT HERE ########
31 37 31 5f 35 31 32 5f 31 32 1e 33 30 34 5f 35 31 32 5f 39 1e 1c 61
62 63 64 65 66 67 68 69 6a 6b 6c 30 31 32 33 34 35 36 37 38
######## CUT HERE ########

with greetings
Procek

2

I'm not sure exactly what you are trying to do, but I have a guess. I
wouldn't really use readline or getc for this...

FS = 0x1c
RS = 0x1e

#your hex string
hex = "31 37 31 5f 35 31 32 5f 31 32 1e 33 30 34 5f 35 31 32 5f 39 /
1e 1c 61 62 63 64 65 66 67 68 69 6a 6b 6c 30 31 32 33 34 35 36 37 38"

#change it to your real data
s = hex.split.map {|i| i.to_i(16).chr}.join
#=> "171_512_12\036304_512_9\036\034abcdefghijkl012345678"

info, data = s.split(FS.chr)
lengths = info.split(RS.chr).map {|i| i.split(/_/).last}
data_array =
lengths.each {|len| data_array << data.slice!(0, len.to_i)}

p data_array

...Your test file isn't long enough for me to establish the actual
layout, so I had to make educated guesses. When reading a file you
can wrap your code up like...

File.open( 'my_file', 'r') do |f|
  #parsing code in here
end

hth,
Todd

···

On Sun, Sep 28, 2008 at 7:59 PM, Procek <proc.procek@gmail.com> wrote:

Hi!

I'm trying to read a file using ruby. Firsty I use readline twice,
then I wan't to read some part of data, but I don't get where I have a
mistake. Could you help me find it?

######## CUT HERE ########
#Constans
FS = 0x1c
RS = 0x1e

#Open file
f = File.new("abcdef", "r")

#Read a line, split it, and delete bad fields (last one)
tbl = f.readline(FS.chr).split(RS.chr) - [FS.chr]
#For each from tbl
tbl.each { |x|
  #Split field
  splitted = x.split("_")
  #The read loop
  tmp = String.new
  i=0
  while (i < splitted[2].to_i)
    tmp += f.getc.chr #Here I have an error...
  end
  #Save readed data
  f2 = File.new(s[0]+"-"+s[1]+".txt", "w")
  f2.write(tmp)
  f2.close
}

#Close file
f.close
######## CUT HERE ########

The test file in HEX (beacouse it have non-printable chars)
######## CUT HERE ########
31 37 31 5f 35 31 32 5f 31 32 1e 33 30 34 5f 35 31 32 5f 39 1e 1c 61
62 63 64 65 66 67 68 69 6a 6b 6c 30 31 32 33 34 35 36 37 38
######## CUT HERE ########

3

Hi,

At Mon, 29 Sep 2008 09:59:18 +0900,
Procek wrote in [ruby-talk:316286]:

   i=0
   while (i < splitted[2].to_i)
     tmp += f.getc.chr #Here I have an error...
   end

This is an inifinite loop.

    splitted[2].to_i.times do
    end

or

    tmp = f.read(splitted[2].to_i)

work.

  FS = "\x1c"
  RS = "\x1e"

  File.open("abcdef", "rb") do |f|
    f.gets(FS).chomp(FS).split(RS).each do |x|
      s = x.split("_")
      tmp = f.read(s[2].to_i)
      File.open(s[0]+"-"+s[1]+".txt", "w") {|f2| f2.write(tmp)}
    end
  end

···

--
Nobu Nakada