Re: [Help-bash] play audio-CD in consol

[Mart Frauenlob]

On 29.01.2013 01:13, Gerard ROBIN wrote:
> Hello,
> the dvd burner of my laptop died and I replaced it with a external dvd burner,
> but now cdcd can not play the cd audio. It sees the tracks but no sound.
> alsaplayer-text works and I have written a bash script to simulate cdcd (not 
> very professional).
> Can someone help me to improve it?
> It is there: http://dl.free.fr/ibSYXRaTe

I don't speak french, but I managed to download your file :p

> thanks in advance.
>
> #!/bin/bash
>
> title="ALSAPLAYER-TEXT"
> frame="==============="
> center="\t\t\t\t"
> cpt=0
>
> function prompt { echo -n "alsaplayer> " ;}
>
> echo -e "\n"$center$frame"\n" $center$title"\n"$center$frame
>
> echo -e "\n\tListen to audio CDs with alsaplayer (http://www.alsaplayer.org/)"
> echo -e "\n\tFirst of all you must edit the ~/.alsaplayer/config
> \tComplement or add the following lines:
> \n\t 1 cdda.cddb_servername=freedb.freedb.org
> \t 2 cdda.cddb_serverport=8880
> \t 3 cdda.device=/dev/sr0 # replace /dev/sr0 by the good path of your box.
> \t 4 cdda.do_cddb_lookup=true"
>
> echo -e "\n\t\tTo play a CD, type: play, then Enter
> \t\tTo exit alsaplayer, keep playing, type exit and Enter
> \t\tTo stop the CD, if it is playing, type stop and Enter
> \t\tEnter ? for more help"

hard to read, I'd prefer printf, or here-document redirection here.

> file -s /dev/sr0 &>/dev/null
> if [ $? -eq 0 ]; then
>         echo -e "\n\t\t\e[1;31mSORRY NO AUDIO CD IN THE DRIVE\e[0m"
>         exit;
> fi

why not:
if command; then ...
fi

> prompt

The variable PROMPT_COMMAND might be handy, you don't need to call 
'prompt' every time.

> while read  anwser

you don't need the variable 'answer'. if you don't split the reply into 
several variables, but omit them completely, the input is put into the 
variable REPLY.

> do
>         ps -C alsaplayer &>/dev/null
>         if [ $? -eq 0 ] ;then run=0 ;else run=1 ;fi
you use #!/bin/bash, so...
if (($?)); then
        greater_zero_commands
else
        is_zero_commands
fi
but again, easier in this case:
if command; then ...else ...fi
                
>         
>         case $anwser in
>
>                 \?) echo -e " ?, play/stop, exit, prev/next, pause/unpause, 
> status"
>                         prompt ;;
>
>                 exit)   exit;;
>
>                 stop)   cpt=0
>                         alsaplayer --quit
>                         prompt;;
>
>                 play)   >/dev/null
>                         if [ $cpt -eq 0 ] && [ $run -eq 1 ]  ; then
>                                 cpt=$(( $cpt+1 ))

if ((cpt == 0 && run == 1)); then
or:
if ((! cpt && run)); then
let cpt+=1
or
((++cpt))
shorter, nicer imho

or to make you crazy:
if ! ((! cpt && run ? ++cpt : 0)); then
        alsaplayer ...
fi

>                                 alsaplayer -q CD.cdda &> /dev/null &
>                                 prompt
>                         else
>                                 echo "Alsaplayer is playing a CD"
>                                 prompt
>                         fi;;
>                 prev)   alsaplayer --prev
>                         prompt;;
>
>                 next)   alsaplayer --next
>                         prompt;;
>
>                 pause) alsaplayer --pause
>                         prompt;;
>
>                 unpause) alsaplayer --start
>                           prompt;;
>
>                 status) alsaplayer --status
>                         prompt;;
>
>                 *) if [ "$anwser" = "" ]; then

using #!/bin/bash:

if [[ $answer ]]; then....

>                         prompt
>                   else
>                         echo "unknown command  $anwser"
>                         prompt
>                   fi ;;
>         esac
> done

Best regards

Mart