marshalling and serialiing to IO problem

[Junkone]

hello
i am trying to serialise a object to file. i have errors when i try to
restore the object. any ideas

for eg
irb(main):009:0> a=Hash.new
=> {}
irb(main):010:0> a[1]='key'
=> "key"
irb(main):011:0> a[1]='kew'
=> "kew"
irb(main):016:0> a=> {1=>"kew"}
irb(main):022:0> f=File.new("c:\\temp\\log",File::CREAT|File::TRUNC|
File::RDWR)
=> #<File:c:\temp\log>
irb(main):023:0> data=Marshal.dump(a,f)
=> #<File:c:\temp\log>
irb(main):024:0> f.close
=> nil
irb(main):025:0> f1=File.open("c:\\temp\\log",File::NONBLOCK|
File::RDONLY)
=> #<File:c:\temp\log>
irb(main):026:0> Z=Marshal.load(f1)
IOError: not opened for reading from (irb):26:in `getc'
from (irb):26:in `load'
from (irb):26

 

[Robert Klemme]

hello
i am trying to serialise a object to file. i have errors when i try to
restore the object. any ideas

for eg
irb(main):009:0> a=Hash.new
=> {}
irb(main):010:0> a[1]='key'
=> "key"
irb(main):011:0> a[1]='kew'
=> "kew"
irb(main):016:0> a=> {1=>"kew"}
irb(main):022:0> f=File.new("c:\\temp\\log",File::CREAT|File::TRUNC|
File::RDWR)
=> #<File:c:\temp\log>
irb(main):023:0> data=Marshal.dump(a,f)
=> #<File:c:\temp\log>
irb(main):024:0> f.close
=> nil
irb(main):025:0> f1=File.open("c:\\temp\\log",File::NONBLOCK|
File::RDONLY)
=> #<File:c:\temp\log>
irb(main):026:0> Z=Marshal.load(f1)
IOError: not opened for reading from (irb):26:in `getc'
from (irb):26:in `load'
from (irb):26

Works for me. Why do you open in nonblocking mode? That might cause
issues on your system and it's not needed. Also, why do you open in RW
mode when you want to write only?

Here's what I usually do

irb(main):001:0> a={1=>2}
=> {1=>2}
irb(main):002:0> File.open("foo","wb") {|io| Marshal.dump(a,io)}
=> #<File:foo (closed)>

irb(main):007:0> File.open("foo","rb") {|io| Marshal.load io}
=> {1=>2}

If you prefer boolean flags:

irb(main):009:0> File.open("foo", File::WRONLY | File::BINARY) {|io|
Marshal.dump(a,io)}
=> #<File:foo (closed)>
irb(main):010:0> File.open("foo", File::RDONLY | File::BINARY) {|io|
Marshal.load io}
=> {1=>2}

Cheers

robert