mac 的 WC 命令显示少一个结果

Question

I have a text file which has over 60MB size. It has got entries in 5105043 lines, but when I am doing wc -l it is giving only 5105042 results which is one less than actual. Does anyone have any idea why it is happening?

Is it a common thing when the file size is large?

Answer 1

Last line does not contain a new line.

One trick to get the result you want would be:

sed -n '=' <yourfile> | wc -l

This tells sed just to print the line number of each line in your file which wc then counts. There are probably better solutions, but this works.

Answer 2

The last line in your file is probably missing a newline ending. IIRC, wc -l merely counts the number of newline characters in the file.

If you try: cat -A file.txt | tail cat -A file.txt | tail does your last line contain a trailing dollar sign ( $ )?

EDIT:

Assuming the last line in your file is lacking a newline character, you can append a newline character to correct it like this:

printf "\n" >> file.txt

The results of wc -l should now be consistent.

Answer 3

60 MB seems a bit big file but for small size files. One option could be

cat -n file.txt

OR

cat -n sample.txt | cut -f1 | tail -1