trouble with name increment

[jaaf]

Hi,
I am trying to write a script that records a window on my screen. No pb with that.
To go further I would like to choose an incremental fileName for output incrementing if the fileName already exist.
I have trouble doing it so before dealing with the incrementation itself, I want to check I can substitute the calculated name in the ffmpeg command.

filename="~/Bureau/essai" 

index=1 #I[B] will deal with the incrementation of index after this part works [/B]

mystring="${fileName}${index}.mkv" #omce I have a proper index I concatenate the name with index and name extension 

echo ${mystring} # gives ~/Bureau/essai1.mkv seems to be what I expect 

ffmpeg -f alsa .....  -y ${mystring}  # gives error message ~/Bureau/essai1.mkv: No such file or directory despite -y to force overwriting

I get this message

~/Bureau/essai1.mkv No such file or directory despite -y to force overwriting

However if I put the file name directly in the command like this


Code:

ffmpeg -f alsa .....  -y ~/Bureau/essai1.mkv

it works perfectly. My question is : "What is wrong ?"

 

[KenJackson]

Do you have a subdirectory in your home directory named Bureau?

If not, then that's the problem. Execute mkdir Bureau and then run the script again.

 

[jaaf]

Thanks for your answer.

Bureau is the French translation for Desktop and I*can CD to it from terminal. Moreover if the string

 ffmpeg  -f alsa .....  -y ~/Bureau/essai1.mkv

is written directly in the scipt it works fine.