Proposal: Add showCommandForUser to process:System.Process

[Isaac Dupree]

On 09/12/10 08:24, Ian Lynagh wrote:
>
> Add showCommandForUser to process:System.Process
> http://hackage.haskell.org/trac/ghc/ticket/4305
>
> There are many programs (e.g. ghc and Cabal) which run other programs,
> and when run with -v want to show the user what they are running. The
> user then often wants to run the command by hand, in order to debug a
> problem, but this can be tricky when the command or its arguments
> include spaces or other characters treated specially by shells.

*Which* shells, though, can it run in?

My particular example is I use "fish" shell on Linux, which has similar 
but not identical quoting-and-special-character rules to Bash.

The convention in the Linux/Unix world these days, I believe (on the 
internet and otherwise) is to post commands in a format that works in 
Bash / POSIX sh / whatever works in most/all default Unix shells that 
currently exist.

It looks like the patch's method of single-quoting everything and adding 
the usual trick to quote single-quotes ( '\'' ) should work fine for 
shell compatibility as well as user-readability.  (Ignoring Windows 
conventions I'm not familiar with.)  ( Csh/Tcsh looks somewhat hopeless 
to add compatibility with: e.g. even in single-quotes in scripts, '!' 
needs to be backslash-escaped*. Switching to using backslashes for 
everything instead of single-quotes would be way too ugly.
* 
http://www.mpi-inf.mpg.de/~uwe/lehre/unixffb/quoting-guide.html#para:csh-tcsh 
)

...So, at least from the Linux side of things, +1.

-Isaac