On 01/24/2015 09:13 AM, Mike wrote:
Which is generally considered the best practice way of executing
system commands from within a Perl program?
Should I use backticks or qx//, system(), or exec()?
Or is there no "best way" and it's just a matter of what you want to
return?
even though those are all related they are very different animals. the
choice of system vs backticks is a classic newbie trap. they both run a
subprocess but backticks collects the stdout of the process and returns
it. system just lets stdout of the process be output to the existing
stdout (usually the terminal). qx// and backticks are the exact same
operation but with different syntax. it is like qq// is the same as
double quotes but you can select the delimiter.
exec is rarely needed in general coding and even more rarely needed by
newbies. it runs another process but that one REPLACES the current one
which is usually what you don't want. exec is usually called in pairing
with fork which will created a new child process. backticks and system
both do a fork/exec call internally for you. if you think you need to
call exec, you are likely wrong in choosing it. like with other
dangerous perl things (symrefs, string eval), it is only to be used when
you know when you should not use it. existing functions (as mentioned
above) and some modules use exec correctly so use those first before you
ever contemplate using exec.
uri
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