Public bug reported:
Binary package hint: mplayer
Running mplayer in a loop is impossible because it consumes standard
input even when invoked just to batch convert a file.
Consider a script like:
find . -type f |
while read file; do
echo "# $file"
mplayer -vc null -vo null -ao pcm:file="$file.wav" "$file"
done
This will fail mysteriously with "No bind found for key 'O'" warnings
etc because apparently mplayer is eating some of the output from the
find command as if the user were using it interactively and pressing
keys to resize the display etc. As an additional symptom, the output
from the echo will mysteriously have chopped file names.
As a workaround, the small sample script above can be fixed by adding a
redirection </dev/null to the mplayer command line. Constructing the
loop differently (e.g. to run mplayer from within find with -exec) is
another possible workaround.
There are several threads about this in Google but none I have found
actually correctly diagnosed and corrected this problem.
There is a simple ioctl to find out when a program is invoked with
standard input connected to a terminal; the "test -t 0" command does
this in a shell script. mplayer should leave standard input alone if it
is not connected to a terminal.
e...@fsopti607:~$ lsb_release -rd
Description: Ubuntu 10.04.1 LTS
Release: 10.04
e...@fsopti607:~$ apt-cache policy mplayer
mplayer:
Installed: 2:1.0~rc3+svn20090426-1ubuntu16.1
Candidate: 2:1.0~rc3+svn20090426-1ubuntu16.1
Version table:
*** 2:1.0~rc3+svn20090426-1ubuntu16.1 0
500 http://mirrors.nic.funet.fi/ubuntu/ lucid-updates/multiverse
Packages
100 /var/lib/dpkg/status
2:1.0~rc3+svn20090426-1ubuntu16 0
500 http://mirrors.nic.funet.fi/ubuntu/ lucid/multiverse Packages
** Affects: mplayer (Ubuntu)
Importance: Undecided
Status: New
** Description changed:
Binary package hint: mplayer
Running mplayer in a loop is impossible because it consumes standard
input even when invoked just to batch convert a file.
Consider a script like:
find . -type f |
while read file; do
- echo "# $file"
- mplayer -vc null -vo null -ao pcm:file="$file.wav" "$file"
+ echo "# $file"
+ mplayer -vc null -vo null -ao pcm:file="$file.wav" "$file"
done
This will fail mysteriously with "No bind found for key 'O'" warnings
etc because apparently mplayer is eating some of the output from the
find command as if the user were using it interactively and pressing
keys to resize the display etc. As an additional symptom, the output
from the echo will mysteriously have chopped file names.
As a workaround, the small sample script above can be fixed by adding a
redirection </dev/null to the mplayer command line. Constructing the
loop differently (e.g. to run mplayer from within find with -exec) is
another possible workaround.
There are several threads about this in Google but none I have found
actually correctly diagnosed and corrected this problem.
There is a simple ioctl to find out when a program is invoked with
standard input connected to a terminal; the "test -t 0" command does
this in a shell script. mplayer should leave standard input alone if it
is not connected to a terminal.
+
+ e...@fsopti607:~$ lsb_release -rd
+ Description: Ubuntu 10.04.1 LTS
+ Release: 10.04
+
+ e...@fsopti607:~$ apt-cache policy mplayer
+ mplayer:
+ Installed: 2:1.0~rc3+svn20090426-1ubuntu16.1
+ Candidate: 2:1.0~rc3+svn20090426-1ubuntu16.1
+ Version table:
+ *** 2:1.0~rc3+svn20090426-1ubuntu16.1 0
+ 500 http://mirrors.nic.funet.fi/ubuntu/ lucid-updates/multiverse
Packages
+ 100 /var/lib/dpkg/status
+ 2:1.0~rc3+svn20090426-1ubuntu16 0
+ 500 http://mirrors.nic.funet.fi/ubuntu/ lucid/multiverse Packages
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https://bugs.launchpad.net/bugs/697655
Title:
Should not read standard input if not on a terminal
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