Here's some ways to remove empty or blank lines from a file in Unix. Simple but definitely useful.
In Vi editor, in escape mode type
$ grep -v '^$' file.txt $ grep '.' file.txt $ sed '/^$/d' file.txt $ sed -n '/^$/!p' file.txt $ awk NF file.txt $ awk '/./' file.txt
In Vi editor, in escape mode type
:g/^$/ dRelated posts:
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2 comments:
Another way..
$ grep . file.txt
sed '/./!d' file.txt
within the VI editor, we can do
:v/./d
Note that awk NF file.txt awk '/./' file.txt are not exactly equivalent.
awk NF will not print lines that have only space/TAB characters since the
field splitting by awk would ensure that they are canceled out. Whilst the
awk '/./' will print truly nonempty lines. We can also say:
awk 'length > 0' file.txt
perl -lne 'length&&print' file.txt
perl -lne '/./&&print' file.txt
sed -e 's/.*/[&]/' file.txt | dc -e "
[p]sp [q]sq
[? z 0 =q d Z 0 !=p c l?x]s?
l?x
"
while IFS= read -r line; do case $line in ?*) printf '%s\n' "$line";; esac; done < file.txt
cat file.txt | while IFS= read -r line; do
expr "$line" : '.*' 1>/dev/null && printf '%s\n' "$line"
done
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