[Scons-users] Printing after command

[William Blevins]

Eric,

Probably not what you are looking for but you "could" use a post action.
AddPostAction(target, action) , env.AddPostAction(target, action)

Arranges for the specified action to be performed after the specified target
has been built. The specified action(s) may be an Action object, or
anything that can be converted into an Action object (see below).

When multiple targets are supplied, the action may be called multiple
times, once after each action that generates one or more targets in the
list.
V/R,
William

On Tue, Jan 3, 2017 at 5:30 PM, Eric Lunderberg <eric.lunderberg at gmail.com>
wrote:

> I am attempting to improve the readability of the messages being printed
> to screen.  I've used the *COMSTR variables before to customize what gets
> printed before a command is run.  I would like to add a message that gets
> printed after the command as well, summarizing the results of the command
> (i.e. ok, warning, or error).
>
> With make, I can do this by printing a before-run status message, running
> the command with the output piped to a file, printing an after-run status
> message, then printing the contents of the piped file.  The overall effect
> is shown in this gif <https://i.stack.imgur.com/ndiin.gif>.  This way, I
> can visually distinguish which file produced warning and error messages,
> especially with the different colors for each.  I haven't found a way to
> replicate these status messages with scons.
>
> I can get fairly close to a solution by replacing env['SPAWN'] in the
> environment.  From there, I can run the command, printing before and after
> running the command.  There are two main difficulties that I ran into.
> First, the spawn function is passed only the command to be run, and not the
> description of the command, as formed from the comstr.  As far as I can
> tell, that information is only present in the SCons.Action._ActionAction.
>
> I can get a little bit closer by also replacing the command action
> (CXXCOM, SHCXXCOM, etc) with a custom function.  That custom function can
> generate the string to be printed, based on the appropriate COMSTR.  It can
> run the command, using the custom SPAWN function to grab the output of the
> command, then print it afterward.
>
> However, while replacing env['CXXCOM'] allows me to call my custom
> function, the COMSTR is still being printed twice.  As far as I can tell,
> this is done in the action defined in Defaults.py, before control ever gets
> passed to my function.  I would like some way to silence this printing, but
> cannot find a way to do so.  As it stands, my best attempt to reproduce the
> behavior from the makefile is shown in this gif
> <http://i.imgur.com/ITE8ber.gif>.  Note that the COMSTR has been printed
> twice.
>
> The relevant parts of the SConstruct in order to produce this behavior are
> shown below.  Any advice on fixing the double-printing would be most
> appreciated.
>
> import sys
>
> class BufferSpawn(object):
>     def __init__(self):
>         self.stdout = ''
>
>     def __call__(self, sh, escape, cmd, args, spawnenv):
>         asciienv = {key:str(value) for key,value in spawnenv.items()}
>
>         # Call a subprocess, grabbing all output
>         p = subprocess.Popen(
>             ' '.join(args),
>             shell=True,
>             env=asciienv,
>             stdout=subprocess.PIPE,
>             stderr=subprocess.STDOUT,
>             universal_newlines=True)
>         stdout,stderr = p.communicate()
>
>         self.stdout = stdout
>
>         return p.returncode
>
> class CommandWrapper(object):
>     _null = SCons.Action._null
>
>     def __init__(self, env, com, comstr):
>         self.overrides = {com:env[com],
>                           comstr:env[comstr],
>                           }
>         self.action = SCons.Action.Action('$'+com, '$'+comstr)
>         self.pad_to = 50
>
>     def __call__(self, target, source, env,
>                                exitstatfunc=_null,
>                                presub=_null,
>                                show=_null,
>                                execute=_null,
>                                chdir=_null,
>                                executor=None):
>
>         # Generate the environment for the subordinate action
>         overrides = self.overrides.copy()
>         spawn = BufferSpawn()
>         overrides['SPAWN'] = spawn
>         env = env.Override(overrides)
>
>         # Generate the status message to be printed
>         try:
>             to_print = self.action.strfunction(target, source, env,
> executor)
>         except TypeError:
>             to_print = self.action.strfunction(target, source, env)
>
>         to_print = to_print.ljust(self.pad_to)
>
>         # Print the before-command status
>         print to_print + '\r',
>         sys.stdout.flush()
>
>         # Run the command, without printing anything.
>         show = False
>         retval = self.action(target, source, env, exitstatfunc,
>                              presub, show, execute, chdir, executor)
>
>         # Figure out the change to the status message
>         if retval:
>             print_result = '[ERROR]'
>         elif spawn.stdout:
>             print_result = '[WARNING]'
>         else:
>             print_result = '[OK]'
>
>         # Print the after-command status, and the stdout, if any
>         print to_print + print_result
>         if spawn.stdout:
>             print spawn.stdout
>         sys.stdout.flush()
>
> env['CXXCOMSTR'] = 'Compiling C++ object $TARGETS'
> env['CXXCOM'] = CommandWrapper(env, 'CXXCOM','CXXCOMSTR')
>
> _______________________________________________
> Scons-users mailing list
> Scons-users at scons.org
> https://pairlist4.pair.net/mailman/listinfo/scons-users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://pairlist4.pair.net/pipermail/scons-users/attachments/20170103/1978f055/attachment-0001.html>