.getc.chr doesn't work

[Procek]

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

 

[Todd Benson]

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 ########

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

 

[Nobuyoshi Nakada]

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