I have thousands of files named 1.txt 2.txt and so on. Some of those files are missing. Which would be the easiest way to find out which files are missing?
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Are those files all in the same directory? And how far will the seqence go? Is the naming convention always the same 1.txt for the first one 105.txt for the 105th one?– chaosOct 14, 2015 at 17:39
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4 Answers
ub=1000 # Replace this with the largest existing file's number.
seq "$ub" | while read -r i; do
[[ -f "$i.txt" ]] || echo "$i.txt is missing"
done
You can easily find the proper value for ub by doing ls | sort -n or similar. This relies on the files being in the format output by seq, notably here without leading zeroes.
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Thanks! I created a function for this on my .bashrc. You just saved my day :) Oct 14, 2015 at 18:09
$ ls
1.txt 3.txt
$ seq 1 10 | xargs -I {} ls {}.txt >/dev/null
ls: cannot access 2.txt: No such file or directory
ls: cannot access 4.txt: No such file or directory
ls: cannot access 5.txt: No such file or directory
ls: cannot access 6.txt: No such file or directory
ls: cannot access 7.txt: No such file or directory
ls: cannot access 8.txt: No such file or directory
ls: cannot access 9.txt: No such file or directory
ls: cannot access 10.txt: No such file or directory
$
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@DennisWilliamson Thats worthy of an answer and probably would be the best one :)– heemaylOct 15, 2015 at 1:23
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1@heemayl except that with "thousands of files" there's a good chance you'll blow the argument count and/or argument size limit on your system, hence the use of
xargs.– nneonneoOct 15, 2015 at 1:46 -
@DennisWilliamson: short, clear, simple, should be the best answer! Thanks.– TerDaleJan 5, 2021 at 13:33
This is the function I will be using
missing () {
#ub gets the largest sequential number
ub=$(ls | sort -n | tail -n 1 | xargs basename -s .txt)
seq "$ub" | while read -r i; do
[[ -f "$i.jpg" ]] || echo "$i.txt is missing"
done
}
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1
Another (bash):
comm -23 <(printf '%d.txt\n' {1..1000} | sort) <(ls *.txt |sort)
