# Strange ruby problem **URL:** \ **Category:** Ruby\ **Created:** [September 24, 2008, 4:21pm UTC](https://www.ruby-forum.com/t/strange-ruby-problem/149411 "2008-09-24T16:21:11Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [September 24, 2008, 4:21pm UTC](https://www.ruby-forum.com/t/strange-ruby-problem/149411/1 "2008-09-24T16:21:11Z")
So i’ve cut the program down to about 4 lines to give the idea of whats going on: num = ARGV[0] num2 = ARGV[1] puts " #{num} #{num2} \n" line = gets if i give the program some input from the command line it fails and sais " gets: No such file or directory -1" yet if i supply no input the program goes straight to gets. This seems fairly strange to me. Though when I did this: num = ARGV[0] num2 = ARGV[1] puts " #{num} #{num2} \n" STDOUT.flush line = STDIN.gets everything works normal. Why is this and whats going on? Thanks in advance Sincerely, Chris Dancy ---
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [September 24, 2008, 4:30pm UTC](https://www.ruby-forum.com/t/strange-ruby-problem/149411/2 "2008-09-24T16:30:35Z")
try without the last line, line = gets On Wed, Sep 24, 2008 at 7:49 PM, removed\_email\_address@domain.invalid \< ---
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [September 24, 2008, 4:43pm UTC](https://www.ruby-forum.com/t/strange-ruby-problem/149411/3 "2008-09-24T16:43:31Z")
The program is trying to read from ARGV[0] , and there is no file with the name ARGV[0] that you have given. On Wed, Sep 24, 2008 at 7:49 PM, removed\_email\_address@domain.invalid \< ---
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [September 24, 2008, 6:35pm UTC](https://www.ruby-forum.com/t/strange-ruby-problem/149411/4 "2008-09-24T18:35:45Z")
On Sep 24, 10:18 am, “removed\_email\_address@domain.invalid” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > yet if i supply no input the program goes straight to gets. This seems > fairly strange to me. Though when I did this: > > num = ARGV[0] > num2 = ARGV[1] > puts " #{num} #{num2} \n" > STDOUT.flush > line = STDIN.gets > > everything works normal. Why is this and whats going on? Thanks in > advance I think we need to see your command-line arguments and whether you’re putting them before the name of the Ruby script or after. Are you invoking the script like: ``` ruby script.rb arg1 arg2 ``` or: ``` ruby arg1 arg2 script.rb ``` because the first is what you should be doing. Alternatively, do you have RUBYOPT set or do you invoke any arguments on your #! line (if you’re on a Unix-like system). Eric ==== [LearnRuby.com](http://LearnRuby.com) offers Rails & Ruby hands-on public & on-site workshops. Ruby Fundamentals Workshop Oct 8-10 Ann Arbor, Mich. (Note: Great Lakes Ruby Bash in Ann Arbor on Oct. 11; attend both!) Please visit [http://LearnRuby.com](http://LearnRuby.com) for all the details. ---
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [September 24, 2008, 8:31pm UTC](https://www.ruby-forum.com/t/strange-ruby-problem/149411/5 "2008-09-24T20:31:46Z")
On 24.09.2008 16:18, removed\_email\_address@domain.invalid wrote: > sais " gets: No such file or directory -1" > advance > As others have said: arguments are the problem. “gets” tries to read > from ARGF which is basically all ARGV values interpreted as files and > concatenated as streams. You typically use this for poor man’s cat: ruby -e ‘ARGF.each {|line| puts line}’ foo bar baz You can avoid the issue by doing num = ARGV.shift num2 = ARGV.shift puts num, num2 line = gets Cheers robert ---
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [September 24, 2008, 11:58pm UTC](https://www.ruby-forum.com/t/strange-ruby-problem/149411/6 "2008-09-24T23:58:57Z")
On Wed, Sep 24, 2008 at 1:29 PM, Robert K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > num2 = ARGV.shift > puts num, num2 > line = gets > > Cheers > > ``` > robert > > ``` As robert says. I ran into this just the other day. ARGV has to be clear (empty), for stdin to work for gets. (Pickaxe 2nd Ed., p. 180) Todd ---
**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\ **Post date:** [September 25, 2008, 1:55am UTC](https://www.ruby-forum.com/t/strange-ruby-problem/149411/7 "2008-09-25T01:55:33Z")
On Sep 24, 9:18 am, “removed\_email\_address@domain.invalid” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > yet if i supply no input the program goes straight to gets. This seems > > Sincerely, > Chris Dancy Arguments on the command line are assumed to be files to be read by “gets”. E:\>echo First line of file \> temp.txt E:\>ruby -e “p gets” temp.txt “First line of file \n” Correct programs: num = ARGV.shift num2 = ARGV.shift puts " #{num} #{num2}" line = gets num = ARGV[0] num2 = ARGV[1] puts " #{num} #{num2}" line = $stdin.gets