# File Save Question **URL:** \ **Category:** ruby-talk\ **Created:** [5 November 2007 21:49 UTC](https://rubytalk.org/t/file-save-question/41931 "2007-11-05T21:49:23Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![12345678\_123456789](https://avatars.discourse-cdn.com/v4/letter/1/3ec8ea/32.png) [@12345678\_123456789](https://rubytalk.org/u/12345678_123456789)\ **Post date:** [5 November 2007 21:49 UTC](https://rubytalk.org/t/file-save-question/41931/1 "2007-11-05T21:49:23Z")
Hello! I've created a program that will run and update the array storing the information within that program. When the program is over, I would like the file to save, so th next time I run it, the same information is in the array and it will be able to start back where it left off; if that makes sense. I've tried google-ing it, but can't find any helpful information. > **···** > > -- > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). ---
**Author:** ![Drew\_Olson](https://avatars.discourse-cdn.com/v4/letter/d/c67d28/32.png) [@Drew\_Olson](https://rubytalk.org/u/Drew_Olson)\ **Post date:** [5 November 2007 21:53 UTC](https://rubytalk.org/t/file-save-question/41931/2 "2007-11-05T21:53:11Z")
Tj Superfly wrote: > Hello! > > I've created a program that will run and update the array storing the > information within that program. When the program is over, I would like > the file to save, so th next time I run it, the same information is in > the array old\_array = [1,2,3,4] File.open("array.yaml","w") do |out|   out \<\< old\_array.to\_yaml end new\_array = YAML.load(File.open("array.yaml")) puts new\_array.inspect > **···** > > -- > Posted via [http://www.ruby-forum.com/\](http://www.ruby-forum.com/%5C). ---
**Author:** ![Michael\_Guterl1](https://avatars.discourse-cdn.com/v4/letter/m/e47c2d/32.png) [@Michael\_Guterl1](https://rubytalk.org/u/Michael_Guterl1)\ **Post date:** [5 November 2007 22:53 UTC](https://rubytalk.org/t/file-save-question/41931/3 "2007-11-05T22:53:11Z")
Try googling "ruby serialization" that will give you more information on the topic. The two main classes you want to look at are Marshal and YAML. Brief synopsis: Marshal is fast, but unreadable, and is not guaranteed to work across different versions of ruby. YAML is human readable, works across all versions of ruby and even other programming languages that support it. Michael Guterl > **···** > > On 11/5/07, Tj Superfly \ wrote: > > > Hello! > > > > I've created a program that will run and update the array storing the > > information within that program. When the program is over, I would like > > the file to save, so th next time I run it, the same information is in > > the array and it will be able to start back where it left off; if that > > makes sense. > > > > I've tried google-ing it, but can't find any helpful information. > > -- > > Posted via [http://www.ruby-forum.com/\](http://www.ruby-forum.com/%5C). ---
**Author:** ![7stud](https://avatars.discourse-cdn.com/v4/letter/7/57b2e6/32.png) [@7stud](https://rubytalk.org/u/7stud)\ **Post date:** [5 November 2007 23:27 UTC](https://rubytalk.org/t/file-save-question/41931/4 "2007-11-05T23:27:34Z")
Tj Superfly wrote: > Hello! > > I've created a program that will run and update the array storing the > information within that program. When the program is over, I would like > the file to save, so th next time I run it, the same information is in > the array and it will be able to start back where it left off; if that > makes sense. You can't. You have to save the data to a file and then read the data back from the file. One approach would be to write each item in the array to a file. Then, the next time your program runs, you could read each item back in from the file and insert it in an array. However, each item you read back will be a string, so if the original item was a number, you have to convert to the string back to a number. That's kind of a hassle to do all that. The ruby standard library yaml will do that all for you. It allows you to write the whole array to the file and then read the whole array back in one shot. One problem you are going to encounter is what to do when you run the program the first time. You can either create the file beforehand and leave it blank, e.g. $touch my\_array.yaml #creates a blank file and then do this: arr = YAML.load\_file("my\_array.yaml") if !arr   arr = end Or, you can have your program create the file if it doesn't exist, something like this: require 'yaml' begin   arr = YAML.load\_file("my\_array.yaml") rescue Errno::ENOENT #error type is from the error message                                     #when you open a file that doesn't exit   #The first time the program is run you will   #get an error saying the file doesn't exist   #which will make execution jump into here.   #By putting this rescue block here,   #the error won't cause your program to   #terminate. end if !arr #then the file didn't exist   arr = end p arr #Your program then adds items to arr, e.g.: arr \<\< 10 \<\< 12.5 \<\< "hello" #At end of program, write array to file: File.open("my\_array.yaml", "w") do |file|   YAML.dump(arr, file) end If you run that a few times, you will see that the data keeps getting added to the array. > **···** > > -- > Posted via [http://www.ruby-forum.com/\](http://www.ruby-forum.com/%5C). ---
**Author:** ![James\_Britt](https://avatars.discourse-cdn.com/v4/letter/j/22d042/32.png) [@James\_Britt](https://rubytalk.org/u/James_Britt)\ **Post date:** [6 November 2007 00:28 UTC](https://rubytalk.org/t/file-save-question/41931/5 "2007-11-06T00:28:33Z")
If you don't want to use YAML or other methods, you can also save the array's data in an even simpler format, like CSV (comma separated values) It can be a lot simpler and can be sent of to other apps like Excel or whatever. Just another option. You can then load it back from the CSV file into an array. ---
**Author:** ![12345678\_123456789](https://avatars.discourse-cdn.com/v4/letter/1/3ec8ea/32.png) [@12345678\_123456789](https://rubytalk.org/u/12345678_123456789)\ **Post date:** [6 November 2007 00:36 UTC](https://rubytalk.org/t/file-save-question/41931/6 "2007-11-06T00:36:37Z")
I seem to have everything working with the YAML, so all is good. Thank you all for your help. 😃 > **···** > > -- > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/).