Re: io.popen Run command with spaces in argument filename, and get the result

[Andrew Gierth <andrew@...>]

>>>>> "v" == v  <v19930312@gmail.com> writes:

 >> No it doesn't, it turns into:
 >> 
 >> otfinfo -p 'somefile\'\'';rm -rf /*;echo \'\'''
 >> 
 >> Note that \ is not an escape character inside '...' so this is
 >> correct.
 >> 
 >> Perhaps you misunderstood what the [[ ]] do, you certainly didn't try
 >> running the actual code.

 v> Oops, my bad - I've misunderstood how shell matches tick braces (and
 v> still a little confused about that as of right now, actually).

The reason for using '...' here is exactly because it has the _simplest_
quoting rules: the character ' itself may not appear within '...' (i.e.
any ' character terminates the quote) and every other character, without
exception, is quoted (there are no escape characters). So in this
example the input breaks down into the following 5 sequences (with no
characters between them, so they are concatenated into one single word):

'somefile\'
\'
';rm -rf /*;echo \'
\'
''

Since \' outside of any quoting construct is itself just a quoted '
character, then when these are reassembled with the quoting removed we
get a word with:

somefile\';rm -rf /*;echo \'

which was the original string.

BTW, you can use a command like  printf '[%s]' blahblah  or similar to
test argument splitting/dequoting in the shell.

-- 
Andrew.