3

How do I print all complete lines of a file? By 'complete' I mean only the ones that end with newline character. grep treats EOF as line delimiter, so grep '^.*$' file will print the last line even if there's no newline at the end of file.

The whole problem comes from parsing log files: we need to somehow be sure that the last entry was completely logged - i.e. it ends with newline.

7

A simple approach is to use perl:

perl -ne '/\n/ && print' file

If you just want to check that the last character of a file is a newline, you can do:

tail -c1 file | grep -q '^$' && echo yes || echo no

But the -c option is not POSIX, so it isn't portable.

1

read (at least in Bourne shell) requires a line to be terminated with newline:

# /bin/sh -c 'echo -e "foo\nbar\c" | while read line; do echo $line; done'
foo
#

So you could use something like:

#!/bin/sh
while read line
    do echo $line
done < logfile.txt

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.