FILE:
hello
world
foo
bar
How can when remove all the empty new lines in this FILE?
Output of command:
FILE:
hello
world
foo
bar
views:
582answers:
3
+7
A:
grep . FILE
(And if you really want to do it in sed, then: sed -e /^$/d FILE)
(And if you really want to do it in awk, then: awk /./{print} FILE)
DigitalRoss
2009-10-23 07:08:10
as simple as it gets
Brian Rasmussen
2009-10-23 07:10:29
Sweet! TY for the other commands as well - but looks like grep is my new best friend.
2009-10-23 07:15:13
grep . FILE doesn't work for me. It's probably better to stick with grep for searching file contents, and sed for editing file contents.
Michael Dillon
2009-10-23 08:27:20
a minor "issue" with grep . FILE is that if a space represents and blank line, then grep will grab that blank line as well.
ghostdog74
2009-10-23 10:26:04
`sed -ne/./p` works too, and `awk /./` is shorter (action is `{print}` if left unspecified). @ghostdog74: `grep '[^[:space:]]'` then.
ephemient
2009-10-23 16:33:56
this has the same effect as grep . FILE in that a space as a blank line will get grabbed.
ghostdog74
2009-10-23 10:27:14
"grep" looks for any line that matches the pattern. "." matches any character. "grep . FILE" matches any line with at least 1 character. Whereas "grep -v" excludes lines matching the pattern. OP said "remove all the empty new lines". If you want to exclude lines with just spaces, "grep -v '^ *$'". The "*" will match zero or more of the preceding pattern, in this case a space. Though you might prefer to match and exclude other whitespace characters (tabs, form-feeds, etc) too.
Mr.Ree
2009-10-23 23:44:52
+2
A:
with awk, just check for number of fields. no need regex
$ more file
hello
world
foo
bar
$ awk 'NF' file
hello
world
foo
bar
ghostdog74
2009-10-23 10:24:06
Doesn't need quotes. This trick is found in `awk1line.txt` -- then again, so are most awk tricks :)
ephemient
2009-10-23 16:35:22
its just my good practice to put quotes, since you are running it from shell.. for composite awk statements, you still have to put quotes. so why not cultivate this habit.
ghostdog74
2009-10-23 23:59:16