Is possible to return after exec cmd?

Ruby
#1

Hi folks,
why doesn’t work command 5.times{exec “pwd”} like this 5.times{puts
“Hello”} ?

ollin

#2

On 7/11/06, Petr S. [email protected] wrote:

Hi folks,
why doesn’t work command 5.times{exec “pwd”} like this 5.times{puts
“Hello”} ?

ollin

exec() starts a new process in place of the current one, i.e. the ruby
interpreter. Use system() if you want to launch a child process and
return when it’s finished.

Regards,
Sean

#3

Petr S. wrote:

Hi folks,
why doesn’t work command 5.times{exec “pwd”} like this 5.times{puts
“Hello”} ?

Because ‘exec’ overwrites the current Ruby process, so when ‘pwd’
finishes there’s nothing left to run. What you are looking for is
‘system(“pwd”)’ or “pwd”.

Greets, Markus

#4

On 7/11/06, Petr S. [email protected] wrote:

Hi folks,
why doesn’t work command 5.times{exec “pwd”} like this 5.times{puts
“Hello”} ?

Because exec (as in the shell BTW) replaces your process with the
program
passed as argument. That is the ruby interpreter is replaced by pwd.
What you want is probably system
5.times{ system “pwd” }

Cheers
Robert

ollin

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#5

fr ollin:

why doesn’t work command 5.times{exec “pwd”} like this 5.times{puts

“Hello”} ?

since that is exec’s feature. exec replaces current process.

maybe you want system or `

irb(main):004:0> echo am still here
=> “am still here\n”
irb(main):005:0> system “echo am still here”
am still here
=> true

#6

Thanks to all,
example 5.times{ system “pwd” } works right.

… I’m beginer with ruby, command system is new sufficient way for me.

thnx

ollin

#7

since that is exec’s feature. exec replaces current process.

maybe you want system or `

irb(main):004:0> echo am still here

=> “am still here\n”

irb(main):005:0> system “echo am still here”

am still here

=> true

ok, ok, if you really want to run exec, you can do something this
stupid,

irb(main):012:0> ruby -e "exec 'pwd'"
=> “/root\n”
irb(main):014:0> system %q[ruby -e “exec ‘pwd’”]
/root
=> true

#8

On Jul 11, 2006, at 7:00 AM, Peña, Botp wrote:

ok, ok, if you really want to run exec, you can do something this
stupid,

irb(main):012:0> ruby -e "exec 'pwd'"
=> “/root\n”
irb(main):014:0> system %q[ruby -e “exec ‘pwd’”]
/root
=> true

That’s an impressively longwinded approach. I applaud you, sir :slight_smile:
-Mat