问题
I was trying to use sed to count all the lines based on a particular extension.
find -name '*.m' -exec wc -l {} \; | sed ...
I was trying to do the following, how would I include sed in this particular line to get the totals.
回答1:
You may also get the nice formatting from wc with :
wc `find -name '*.m'`
回答2:
Most of the answers here won't work well for a large number of files. Some will break if the list of file names is too long for a single command line call, others are inefficient because -exec starts a new process for every file. I believe a robust and efficient solution would be:
find . -type f -name "*.m" -print0 | xargs -0 cat | wc -l
Using cat in this way is fine, as its output is piped straight into wc so only a small amount of the files' content is kept in memory at once. If there are too many files for a single invocation of cat, cat will be called multiple times, but all the output will still be piped into a single wc process.
回答3:
You can cat all files through a single wc instance to get the total number of lines:
find . -name '*.m' -exec cat {} \; | wc -l
回答4:
On modern GNU platforms wc and find take -print0 and -files0-from parameters that can be combined into a command that count lines in files with total at the end. Example:
find . -name '*.c' -type f -print0 | wc -l --files0-from=-
回答5:
you could use sed also for counting lines in place of wc:
find . -name '*.m' -exec sed -n '$=' {} \;
where '$=' is a "special variable" that keep the count of lines
EDIT
you could also try something like sloccount
回答6:
Hm, solution with cat may be problematic if you have many files, especially big ones.
Second solution doesn't give total, just lines per file, as I tested.
I'll prefer something like this:
find . -name '*.m' | xargs wc -l | tail -1
This will do the job fast, no matter how many and how big files you have.
回答7:
sed is not the proper tool for counting. Use awk instead:
find . -name '*.m' -exec awk '{print NR}' {} +
Using + instead of \; forces find to call awk every N files found (like with xargs).
回答8:
For big directories we should use:
find . -type f -name '*.m' -exec sed -n '$=' '{}' + 2>/dev/null | awk '{ total+=$1 }END{print total}'
# alternative using awk twice
find . -type f -name '*.m' -exec awk 'END {print NR}' '{}' + 2>/dev/null | awk '{ total+=$1 }END{print total}'
来源：https://stackoverflow.com/questions/1412244/use-find-wc-and-sed-to-count-lines