How to use 2 variable for "for" statement in Shell Script

Question

I want to use f and v for variable. f *.mkv and v *.mp3

for f in *.mkv v in *.mp3; do 
   ffmpeg -i "$f" -i "$v" -vcodec copy merge_"$f"
done

I dont know how to do it properly. I am still new with bash shell scripting.

I hope someone can help me.

Do the mkv and mp3 files have common names? Are you trying to pair up files? — Etan Reisner
– Etan Reisner, Commented Jul 9, 2015 at 19:49
Did you look at: stackoverflow.com/questions/11215088/… might be similar or duplicate. — Rakholiya Jenish
– Rakholiya Jenish, Commented Jul 9, 2015 at 19:53

Eugeniu Rosca · Accepted Answer · 2015-07-09 20:05:35Z

5

If the *.mp3 and *.mkv basenames are the same:

for f in *.mkv; do
    mp3name="${f%.mkv}.mp3"
    ffmpeg -i "$f" -i "$mp3name" -vcodec copy "merge_${f}"
done

answered Jul 9, 2015 at 19:53

Eugeniu Rosca

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Comments

Jahid · Accepted Answer · 2015-07-09 20:37:38Z

1

If you are looking for a way to loop through the variables the way it is expected to loop through with your original code, you can do this:

f=(*.mkv)
v=(*.mp3)
for((i=0;i<${#f[@]};i++));do
echo "${f[$i]} ${v[$i]}"
done

General assumption is, you have the same number of files for both mkv and mp3.

Or if the files have identical basenames, you can do this:

for f in *.mkv;do
v="${f/%mkv/mp3}"
echo "$f $v"
done

In "${f/%mkv/mp3}" mkv is being replaced by mp3 at the end.

answered Jul 9, 2015 at 20:29

Jahid

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