[Haskell] system command

[Duncan Coutts]

On Tue, 2006-07-04 at 11:22 +0200, J. E. Palomar wrote:
> Hi,
> 
> I am newbie in Haskell programing and need to launch 
> a shell command through a Haskell code.
> In other programing languages like C or Java I know how 
> carry out this task; for instance the code
> 
> system("ls -l ")
> 
> in C or
> 
> exec("ls -l") 
> 
> in Java  work fine and lists the working directory.
> I know that in interactive mode the Haskell command
> :! ls -l 
> is similar, but ¿It is possible something like in Haskell
> non-interactive mode?

The function you're looking for is called 'system' and is in the System
module.

System.system :: String -> IO ExitCode

it does just the same as the C and Java versions.

BTW, one way you could have found this out is to search using hoogle:

http://haskell.org/hoogle/

searching for 'system' gives the one we want as part of the search
results

http://haskell.org/hoogle/?q=system

and links to the detailed documentation:

http://haskell.org/ghc/docs/latest/html/libraries/base/System-Cmd.html#v
%3Asystem

Duncan