Find count of files matching a pattern in a directory in linux
bash, find, linux, ls, regex
Solution
It might be better to use `find` for this:
find . -name "pattern_*" -printf '.' | wc -m
In your specific case:
find . -maxdepth 1 -name "20061101-20131101_kh5x7tte9n_2010_*" -printf '.' | wc -m
`find` will return a list of files matching the criteria. `-maxdepth 1` will make the search to be done just in the path, no subdirectories (thanks Petesh!). `-printf '.'` will print a dot for every match, so that names with new lines won't make `wc -m` break.
Then `wc -m` will indicate the number of characters which will match the number of files.
Performance comparation of two possible options:
Let's create 10 000 files with this pattern:
$ for i in {1..10000}; do touch 20061101-20131101_kh5x7tte9n_201_$i; done
And then compare the time it takes to get the result with `ls -1 ...` or `find ...`:
$ time find . -maxdepth 1 -name "20061101-20131101_kh5x7tte9n_201_*" | wc -m
10000
real 0m0.034s
user 0m0.017s
sys 0m0.021s
$ time ls -1 | grep 20061101-20131101_kh5x7tte9n_201 | wc -m
10000
real 0m0.254s
user 0m0.245s
sys 0m0.020s
`find` is x5 times faster! But if we use `ls -1f` (thanks Petesh again!), then `ls` is even faster than `find`:
$ time ls -1f | grep 20061101-20131101_kh5x7tte9n_201 | wc -m
10000
real 0m0.023s
user 0m0.020s
sys 0m0.012s
Problem
I am new to linux. I have a directory in linux with approx 250,000 files I need to find count of number of files matching a pattern. I tried using following command : ``` ls -1 20061101-20131101_kh5x7tte9n_2010_* | wc -l ``` I got the following error message: ``` -bash: /bin/ls: Argument list too long 0 ``` Please help. Thanks in advance