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Shell Execution in Ruby
# Ways to execute a shell script in Ruby
# Example Script - Joseph Pecoraro
cmd = "echo 'hi'" # Sample string that can be used
# 1. Kernel#` - commonly called backticks - `cmd`
# This is like many other languages, including bash, PHP, and Perl
# Returns the result of the shell command
# Docs:
value = `echo 'hi'` # or uglier but valid => Kernel.`("echo 'hi'")
value = `#{cmd}` # or uglier but valid => Kernel.`("#{cmd}")
# 2. Built-in syntax, %x( cmd )
# Following the ``x'' character is a delimiter, which can be any character.
# If the delimiter is one of the characters ``('', ``['', ``{'', or ``<'',
# the literal consists of the characters up to the matching closing delimiter,
# taking account of nested delimiter pairs. For all other delimiters, the
# literal comprises the characters up to the next occurrence of the
# delimiter character. String interpolation #{ ... } is allowed.
# Returns the result of the shell command, just like the backticks
# Docs:
value = %x( echo 'hi' )
value = %x[ #{cmd} ]
# 3. Kernel#system
# Executes the given command in a subshell
# Return: true if the command was found and ran successfully, false otherwise
# Docs:
wasGood = system( "echo 'hi'" )
wasGood = system( cmd )
# 4. Kernel#exec
# Replaces the current process by running the given external command.
# Return: none, the current process is replaced and never continues
# Docs:
exec( "echo 'hi'" )
exec( cmd ) # Note: this will never be reached beacuse of the line above
# Extra Advice
# $? which is the same as $CHILD_STATUS (if you require 'english')
# Accesses the status of the last system executed command if
# you use the backticks, system() or %x{}.
# You can then access the ``exitstatus'' and ``pid'' properties
# More Reading

awesome summary - thanks!


Liked the extra advice :)


Just Awsesome


Thank you!


Very useful , Thx!


Thanks, very helpful !


In case you need to drop the ball when the command fails,


thanks man!


I'd suggest you to check if you are having memory/latency issues when executing shell commands.


thanks man!


Awesome man!


Thanks man, very interesting and useful :+1:

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