Having Ruby 1.8 decide on "File.open" or 'IO.popen'?

[Josef 'Jupp' Schugt]

Hi!

To write to (mbox) file I use "File.open('/var/spool/mail/jupp')". To
write to a (MDA) stream I would use "File.popen('/usr/bin/fetchmail')".
Is there an *existing* means that I can use for both purposes so that I
can code as follows?

SomeClass.open('/var/spool/mail/jupp')
SomeClass.open('| /usr/bin/fetchmail')

Or is there good reason *not* to do that?

Josef 'Jupp' Schugt

 

[Neil Stevens]

Hi!

To write to (mbox) file I use "File.open('/var/spool/mail/jupp')". To
write to a (MDA) stream I would use "File.popen('/usr/bin/fetchmail')".
Is there an *existing* means that I can use for both purposes so that I
can code as follows?

SomeClass.open('/var/spool/mail/jupp')
SomeClass.open('| /usr/bin/fetchmail')

Or is there good reason *not* to do that?

"| " are valid characters to start a filename, so how would you
distinguish what is intended?

 

[David G. Andersen]

Hi!

To write to (mbox) file I use "File.open('/var/spool/mail/jupp')". To
write to a (MDA) stream I would use "File.popen('/usr/bin/fetchmail')".
Is there an *existing* means that I can use for both purposes so that I
can code as follows?

SomeClass.open('/var/spool/mail/jupp')
SomeClass.open('| /usr/bin/fetchmail')

Kernel.open("/var/spool/mail/jupp")
Kernel.open("| /usr/bin/fetchmail")

Or is there good reason *not* to do that?

If there's any user-supplied data in the string and you want to
be certain you're opening a file. From a security standpoint,
File.open is better because it cannot spawn a sub-shell or invoke
other programs. This only matters in certain contexts, obviously.

-Dave

 

[Josef 'Jupp' Schugt]

"| " are valid characters to start a filename, so how would you
distinguish what is intended?

By means of quoting:

SomeClass.open('| /usr/bin/fetchmail') # Stream
SomeClass.open('\|\ /usr/bin/fetchmail') # File

Josef 'Jupp' Schugt