Feature #4477

Updated by mrkn (Kenta Murata) over 8 years ago

 From documentation and common sense, I would expect that Kernel:exec and backtick (`) work for _all_ kind of system commands. This is currently not the case. 

 ~$ cat test1 
 echo success 
 ~$ cat test2 
 echo success 
 ~$ chmod a+x test? 
 ~$ ruby1.8 -e 'p `test1`' 
 -e:1: command not found: test1 
 ~$ ruby1.9 -e 'p `test1`' 
 -e:1:in ``': Exec format error - test1 (Errno::ENOEXEC) 
         from -e:1:in `<main>' 
 ~$ ruby1.8 -e 'p `test2`' 
 ~$ ruby1.9 -e 'p `test2`' 

 This problem has been reported before (#3856: strange Kernel#exec behavior with bash's source command). As a workaround, it has been suggested to append a semikolon to the system command: 

 ~$ ruby1.8 -e 'p `test1;`' 
 ~$ ruby1.9 -e 'p `test1;`' 

 The report #3856 has been closed with the decision "not a bug". 

 This I cannot accept. For many years, I got used to run system commands through `<cmd>`. When it failed, I spent painfully long time to search for a bug in my Ruby code and in the system command before I realized the problem was due to an unexpected restriction of Ruby's exec/backtick.