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Zwetan Kjukov edited this page Jan 2, 2016 · 2 revisions

Implementation Of Program

TODO

Shell

Program.shell returns the full path of the default system shell

under Linux / Mac OS X it will be /bin/bash
same as the env var SHELL

under Windows it will be C:\Windows\system32\cmd.exe
same as the env var %COMSPEC%

C/C++

TODO

see

Windows

We require to have Cygwin installed to run command-line programs under Windows but there are still subtleties to understand.

The default command prompt (or console) under Windows is cmd.exe
when running Cygwin our console shell will become /bin/bash

Here some special cases

  • system( "cmd" ) from C.stdlib
    block the current process
    call the default system shell as child of the current process
    execute the cmd and wait for it to return
  • popen() from C.stdio
    call the default system shell as child of the current process
    and give you control over the input or output file stream
    returns the input or output FILE
  • Program.open()
    call the default system shell as child of the current process
    works like popen() but only control the output stream
    and returns the output stream as a String
  • exec() from
    replace the current process with a new process
  • fork() TODO
  • wait() TODO
  • spawn() TODO
  • pipe() TODO

TODO

With cmd.exe you can execute the ver command
C:\> ver
output Microsoft Windows [Version 6.3.9600]

Cygwin shell can not execute such commands
$ ver
output -bash: ver: command not found

You need to call cmd.exe from the Bash shell
$ cmd /c ver
output Microsoft Windows [Version 6.3.9600]

But if you use system(), popen() or Program.open()
you can directly use the ver command even if you are under Cygwin

#!/usr/bin/as3shebang -- 

import shell.*;

var str:String = Program.open( "ver" );
trace( str );

$ ./test_version
output Microsoft Windows [Version 6.3.9600]

But the inverse is not true,
Program.open( "ls -la" ) will work from a Bash shell
but it will not work from cmd.exe

If you need to run the Bash shell from cmd.exe
you will need to add its location to the %PATH%

test.as

import shell.*;

var str:String = Program.open( "ls -la" );
trace( str );

from cmd.exe
C:\> redshell.exe test.as
you will obtain

'ls' is not recognized as an internal or external command,
operable program or batch file.

to make it work you need to modify the PATH env var
C:\> set PATH=%PATH%;c:\cygwin\bin
and then C:\> redshell.exe test.as will work

also you can run bash in different ways
Program.open( "ls -la" )
Program.open( "bash -c 'ls -la'" )
Program.open( "bash.exe -c 'ls -la'" )

Another way to do it is to directly modify the env vars from the script

import shell.*;
import C.stdlib.*;

var PATH:String = getenv( "PATH" );
putenv( "PATH=" + PATH + ";C:\\cygwin\\bin" );

var str:String = Program.open( "ls -la" );
trace( str );

C:\> redshell.exe test.as will work directly
with the advantage that the %PATH% was modified only
in the redshell process and is not changed for cmd.exe itself

Another thing to know is that cmd.exe will run only what he knows
.exe, .bat, etc. and so it will not run your AS3 shell scripts
but there is a way ;)

with Program.open( "bash -c '/path/to/shellscript'" ) you can
if for example you have test_sysinfo in the current directory

test_sysinfo

#!/usr/bin/as3shebang -- 

import shell.*;

var p:Array = [ "api", "apiVersion" , "architecture",
				"description", "endian", "platform",
				"redtamarin", "swfVersion", "version" ];

for( var i:uint = 0; i < p.length; i++ )
{
	var m:String = p[i];
	trace( "Runtime." + m + " = " + Runtime[m] );
}

to run that shell script from cmd.exe
use var str:String = Program.open( "bash -c './test_sysinfo'" );
and you will get the output of the script in your cmd.exe prompt

see

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