[Tutor] Cmd line not correctly interpreted

[Steven D'Aprano]

On Fri, Jun 03, 2016 at 06:01:48PM -0700, Alan Outhier wrote:
> I'm working on a Python script to call "sox" to convert ;ogg files to .mp3s.
> 
> In the following segment...:
> 
> *1    outname=fname+".mp3"2    fname=ReSpace(fname)   # substitute " " with
> "\ "3    outname=ReSpace(outname)4    cmdline="sox " + fname + " "
> +outname5    print cmdline6    rtncode=os.system(cmdline)7    if rtncode <>
> 0:8        print "Bad return code (" + str(rtncode) + ") from sox
> command"9        sys.exit()*

Your code is a mess. Try sending plain text instead of "rich text". When 
you send rich text, your mail client will mangle the line breaks and put 
them where ever it sees fit.

Also, there's no need for line numbers. Especially not when there are 
only nine lines.


> ...I DO get the error trap (every time). Line 5 causes the following (for
> example) to be printed:
> 
> 
> *sox Carnegie\ Hall\ Jazz\ Band/Carnegie\ Hall\ Jazz\ Band/Frame\ for\ the\
> Blues Carnegie\ Hall\ Jazz\ Band/Carnegie\ Hall\ Jazz\ Band/Frame\ for\
> the\ Blues.mp3*
> *Bad return code (512) from sox command *

According to the sox man page, it will only return 0, 1 or 2, not 512:

    Exit status is 0 for no error, 1 if there is a problem with 
    the command-line parameters, or 2 if an error occurs during
    file processing.

http://sox.sourceforge.net/sox.html#DIAGNOSTICS

but I think that is a lie, as I can reproduce your error, without even 
using spaces:

py> os.system("sox ab cd")
sox: Can't open input file 'ab': No such file or directory
512

I'm surprised that you don't see the error message printed by sox. Are 
you redirecting stderr to a file or something? If so, please check the 
file.

You are using a relative path starting with "Carnegie\ Hall...". You 
probably should use an absolute path.



-- 
Steve