I try to duplicate a video file x times from the command line by using a for loop, I’ve tried it like this, but it does not work:
for i in {1..100}; do cp test.ogg echo "test$1.ogg"; done
Answers:
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Method 1
Your shell code has two issues:
- The
echoshould not be there. - The variable
$i(“dollar i”) is mistyped as$1(“dollar one”) in the destination file name.
To make a copy of a file in the same directory as the file itself, use
cp thefile thecopy
If you use more than two arguments, e.g.
cp thefile theotherthing thecopy
then it is assumed that you’d like to copy thefile and theotherthing into the directory called thecopy.
In your case with cp test.ogg echo "test$1.ogg", it specifically looks for a file called test.ogg and one named echo to copy to the directory test$1.ogg.
The $1 will most likely expand to an empty string. This is why, when you delete the echo from the command, you get “test.ogg and test.ogg are the same files”; the command being executed is essentially
cp test.ogg test.ogg
This is probably a mistyping.
In the end, you want something like this:
for i in {1..100}; do cp test.ogg "test$i.ogg"; done
Or, as an alternative
i=0 while (( i++ < 100 )); do cp test.ogg "test$i.ogg" done
Or, using tee:
tee test{1..100}.ogg <test.ogg >/dev/null
Note: This would most likely work for 100 copies, but for thousands of copies it may generate a “argument list too long” error. In that case, revert to using a loop.
Method 2
for i in {1..100}; do cp test.ogg "test_$i.ogg" ; done
Method 3
Short and precise
< test.ogg tee test{1..100}.ogg
or even better do
tee test{1..100}.ogg < test.ogg >/dev/null
see tee command usage for more help.
Update
as suggested by @Gilles, using tee has the defect of not preserving any file metadata. To overcome that issue, you might have to run below command after that:
cp --attributes-only --preserve Source Target
Method 4
You have not called variable i while copying
use below script . As tested it worked fine
for i in {1..10}; do cp -rvfp test.ogg test$i.ogg ;done
Method 5
The folowing command will copy file.a 5 times:
$ seq 5 | xargs -I AA cp file.a fileAA.a
If you prefer dd (not the same as cp!):
$ seq 5 | xargs -I AA dd if=file.a of=fileAA.a
All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0