# Rescuing a 'require' **URL:** \ **Category:** Ruby\ **Created:** [September 1, 2006, 4:41am UTC](https://www.ruby-forum.com/t/rescuing-a-require/67161 "2006-09-01T04:41:44Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Garance\_A\_Drosehn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/ccd318/32.png) [@Garance\_A\_Drosehn](https://www.ruby-forum.com/u/Garance_A_Drosehn)\ **Post date:** [September 1, 2006, 4:41am UTC](https://www.ruby-forum.com/t/rescuing-a-require/67161/1 "2006-09-01T04:41:44Z")
I wanted to use Socket.gethostname to get the current hostname without executing a unix command. So: require ‘socket’ $this\_host = Socket.gethostname I have to run this code on several platforms, and it turned out that some of them do not have ‘socket’. So, my first idea was change it to: begin require ‘socket’ $this\_host = Socket.gethostname rescue $this\_host = `hostname`.chomp end but the require still caused the script to terminate on the platforms which didn’t have ‘socket’. I already have an alternate solution for this specific case, but I’m wondering if there was something that I missed. Is there any way to catch errors from a require command? ---
**Author:** ![Garance\_A\_Drosehn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/ccd318/32.png) [@Garance\_A\_Drosehn](https://www.ruby-forum.com/u/Garance_A_Drosehn)\ **Post date:** [September 1, 2006, 5:13am UTC](https://www.ruby-forum.com/t/rescuing-a-require/67161/2 "2006-09-01T05:13:52Z")
On Aug 31, 2006, at 10:39 PM, Garance A Drosehn wrote: > begin begin require ‘foo’ rescue LoadError puts “You need foo for this!” end ---
**Author:** ![Garance\_A\_Drosehn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/ccd318/32.png) [@Garance\_A\_Drosehn](https://www.ruby-forum.com/u/Garance_A_Drosehn)\ **Post date:** [September 1, 2006, 5:14am UTC](https://www.ruby-forum.com/t/rescuing-a-require/67161/3 "2006-09-01T05:14:45Z")
Garance A Drosehn wrote: > I wanted to use Socket.gethostname to get the current hostname > without executing a unix command. So: > > require ‘socket’ > $this\_host = Socket.gethostname > > I have to run this code on several platforms, and it turned out that > some of them do not have ‘socket’. So, my first idea was change > it to: > > begin > require ‘socket’ > $this\_host = Socket.gethostname > rescue rescue LoadError > ``` > $this_host = `hostname`.chomp > > ``` > > end > > but the require still caused the script to terminate on the platforms > which didn’t have ‘socket’. I already have an alternate solution for > this specific case, but I’m wondering if there was something that I > missed. Is there any way to catch errors from a require command? You need to give the exception class; rescue by itself only catches subclasses of StandardError. ---
**Author:** ![Garance\_A\_Drosehn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/ccd318/32.png) [@Garance\_A\_Drosehn](https://www.ruby-forum.com/u/Garance_A_Drosehn)\ **Post date:** [September 1, 2006, 5:17am UTC](https://www.ruby-forum.com/t/rescuing-a-require/67161/4 "2006-09-01T05:17:52Z")
On 8/31/06, Garance A Drosehn [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > begin > require ‘socket’ > $this\_host = Socket.gethostname > rescue > $this\_host = `hostname`.chomp > end > > but the require still caused the script to terminate on the platforms > which didn’t have ‘socket’. I already have an alternate solution for > this specific case, but I’m wondering if there was something that I > missed. Is there any way to catch errors from a require command? irb(main):006:0\> begin irb(main):007:1\* require ‘foo’ irb(main):008:1\> rescue LoadError irb(main):009:1\> puts “caught it” irb(main):010:1\> end caught it =\> nil ## rescue without a specific exception or exceptions only catches subclasses of StandardError. LoadError is a subclass of ScriptError which in turn is a subclass of Exception. Rick DeNatale My blog on Ruby [http://talklikeaduck.denhaven2.com/](http://talklikeaduck.denhaven2.com/) IPMS/USA Region 12 Coordinator [http://ipmsr12.denhaven2.com/](http://ipmsr12.denhaven2.com/) Visit the Project Mercury Wiki Site [http://www.mercuryspacecraft.com/](http://www.mercuryspacecraft.com/) ---
**Author:** ![Garance\_A\_Drosehn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/ccd318/32.png) [@Garance\_A\_Drosehn](https://www.ruby-forum.com/u/Garance_A_Drosehn)\ **Post date:** [September 1, 2006, 5:49am UTC](https://www.ruby-forum.com/t/rescuing-a-require/67161/5 "2006-09-01T05:49:55Z")
Ah, answers in three-part harmony. On 8/31/06, Rick DeNatale [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) … On 8/31/06, Eero S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) … On 8/31/06, Logan C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) … … all wrote > You gotta rescue LoadError – Rick DeNatale My blog on Ruby [http://talklikeaduck.denhaven2.com/](http://talklikeaduck.denhaven2.com/) ---
**Author:** ![Garance\_A\_Drosehn](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/ccd318/32.png) [@Garance\_A\_Drosehn](https://www.ruby-forum.com/u/Garance_A_Drosehn)\ **Post date:** [September 2, 2006, 10:41pm UTC](https://www.ruby-forum.com/t/rescuing-a-require/67161/6 "2006-09-02T22:41:10Z")
On 8/31/06, Rick DeNatale [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Ah, answers in three-part harmony. > > On 8/31/06, Rick DeNatale [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) … > On 8/31/06, Eero S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) … > On 8/31/06, Logan C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) … > > … all wrote > > > You gotta rescue LoadError Ah. Very good. I figured it was something simple that I was missing. It makes a lot of sense now. It’s nice to receive answers in such harmony! 🙂