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digitalmars.D.announce - safeArg: Little CLI util to pass null-delimited list of cmdline args

reply Nick Sabalausky <SeeWebsiteToContactMe semitwist.com> writes:
https://github.com/Abscissa/safeArg
http://code.dlang.org/packages/safearg

This is a small command line tool that was inspired by this: 
http://stackoverflow.com/questions/30720364/honoring-quoting-in-reading-shell-arguments-from-a-file

To quote safeArg's readme:

-----------------------------------------
Using eval or command substitution to pass arguments to a program is 
error-prone, non-portable and a potential security risk:

     Error-Prone: Proper shell quoting/escaping rules can be complex and 
confusing. Ignoring proper quoting/escaping can cause your program to 
fail (or worse) on certain inputs (such as filepaths with spaces, or 
multi-line data).

     Non-Portable: Posix platforms and Windows have completely different 
shells, and not all Windows machines have a Posix-style shell installed. 
Even the various Posix shells may have differences, and knowing whether 
you're relying on an extension-specific feature isn't always obvious.

     Potential Security Risk: Specially-constructed arguments can give 
an attacker full shell access.

A recommended solution is to use a null-delimited stream for sending the 
output of one command to the command line of another. This completely 
bypasses the shell's command parsing, and thus can avoid the problems 
above. Unfortunately, using the shell to actually send a null-delimited 
stream of arguments to a program can still be non-trivial and 
platform-specific, so this cross-platform tool helps you out:

$ safearg program_to_run < INPUT

For example (Granted, this example is using tools that aren't built-in 
on Windows, but it's only an example for illustration. Safearg itself is 
cross-platform, and sticking to only cross-platform tools would still 
work fine):

$ printf "[%s]\n" abc 'hello world'   # Let's try doing this
[abc]
[hello world]

$ echo abc \'hello world\' >datafile  # Store in file: abc 'hello world'
$ printf "[%s]\n" $(<datafile)        # Fails?! Plus, a security risk :(
[abc]
['hello]
[world']

$ echo -n '[%s]\n' >datafile          # Store printf's first arg
$ printf "\0abc\0hello world" >>datafile # Append next two args
$ safearg printf <datafile            # Works! And safe!
[abc]
[hello world]
-----------------------------------------

I think it's cool that this program is only about 100 LOC. Yay D :)
Jun 08 2015
next sibling parent reply "Marc =?UTF-8?B?U2Now7x0eiI=?= <schuetzm gmx.net> writes:
This sounds like "xargs":
http://linux.die.net/man/1/xargs
Jun 09 2015
parent Nick Sabalausky <SeeWebsiteToContactMe semitwist.com> writes:
On 06/09/2015 05:45 AM, "Marc =?UTF-8?B?U2Now7x0eiI=?= 
<schuetzm gmx.net>" wrote:
 This sounds like "xargs":
 http://linux.die.net/man/1/xargs
Heh, Unix: The ORIGINAL "There's an app for that." ;) In any case, FWIW, safearg is simpler (which I suppose could be good or bad depending on use-case), and easier for D users to be able to rely on even in Windows due to dub support (Windows users rarely ever install GNU tools).
Jun 09 2015
prev sibling next sibling parent Nick Sabalausky <SeeWebsiteToContactMe semitwist.com> writes:
On 06/09/2015 02:16 AM, Nick Sabalausky wrote:
 https://github.com/Abscissa/safeArg
 http://code.dlang.org/packages/safearg

 This is a small command line tool that was inspired by this:
 http://stackoverflow.com/questions/30720364/honoring-quoting-in-reading-shell-arguments-from-a-file
Just tagged a small update, v0.9.2: https://github.com/Abscissa/safeArg/blob/master/CHANGELOG.md - Enhancement: Use --newline|-n to delimit with newlines (both \n and \r\n) instead of \0. - Enhancement: Use --delim=VALUE to use custom one-byte delimiter instead of \0. - Enhancement: Displays version number in help screen, and via new --version flag. - Change: Cleaned up internal directory structure. - Change: Documentation improvements.
Jun 13 2015
prev sibling next sibling parent Nick Sabalausky <SeeWebsiteToContactMe semitwist.com> writes:
On 06/09/2015 02:16 AM, Nick Sabalausky wrote:
 https://github.com/Abscissa/safeArg
 http://code.dlang.org/packages/safearg

 This is a small command line tool that was inspired by this:
 http://stackoverflow.com/questions/30720364/honoring-quoting-in-reading-shell-arguments-from-a-file
Another small update, v0.9.3: https://github.com/Abscissa/safeArg/blob/master/CHANGELOG.md - Enhancement: Allow extra "initial-arguments" to be specified on the command line (ex: safearg echo -n < WHATEVER). - Enhancement: Add --post|-p for "post"-arguments to be added to the end of the command line.
Jun 14 2015
prev sibling next sibling parent Nick Sabalausky <SeeWebsiteToContactMe semitwist.com> writes:
Yet another. Hopefully the last for now ;)

safeArg v0.9.4

https://github.com/Abscissa/safeArg/blob/master/CHANGELOG.md

- Fixed: Build failure for projects depending on safearg 
(gen-package-version was run from wrong directory).
Jun 14 2015
prev sibling next sibling parent Nick Sabalausky <SeeWebsiteToContactMe semitwist.com> writes:
Aaaand, one more...

safeArg v0.9.5

https://github.com/Abscissa/safeArg/blob/master/CHANGELOG.md

- Fixed: Correctly pass-thru all initial_arguments after program_to_run, 
instead of mistakenly trying to process them.

- Fixed: Fix a build issue for dub projects with a dependency on safearg 
by updating minimum gen-package-version to v0.9.3.
Jun 15 2015
prev sibling next sibling parent Nick Sabalausky <SeeWebsiteToContactMe semitwist.com> writes:
Another small update:

safeArg v0.9.6
https://github.com/Abscissa/safeArg/blob/master/CHANGELOG.md

One change:
- Enhancement: Add --verbose|-v to echo the generated command to stdout 
before running.
Jun 27 2015
prev sibling parent Nick Sabalausky <SeeWebsiteToContactMe semitwist.com> writes:
safeArg v0.9.7
https://github.com/Abscissa/safeArg/blob/master/CHANGELOG.md

- Fixed: Don't use a broken scriptlike release (v0.9.0), use v0.9.1 instead.
Jun 27 2015