删除shell中一行的最后一个单词

Question

I'm looking for how to delete the last word of a line in shell ! I use sed but I only found the way how delete the lase word of every line, but not a specify line. For exemple: I have a file test.db

key1 value1
key2 value2
key3 value3

And I just want to delete value3

sed -i s/'\w*$'// test.db

This line just delete the last word of every line !

Answer 1

试试这个 ：

sed -i '1{s/[^ ]\+\s*$//}' file test.db

Answer 2

If you want to delete the last word only off of the last line, then you can use:

sed -i '$s/\w*$//' test.db

If you want to delete the last word from the line for key3 :

sed -i '/key3/s/\w*$//' test.db

Answer 3

Here is an awk to remove last field:

echo "one two three" | awk '{$NF="";sub(/[ \t]+$/,"")}1'
one two

Answer 4

Deleting the last word of your line

since you are targeting the line key3 value3

  sed -i '/key3 value3/s/\S*$//' test.db

where \\S is represents a digit that is not a space or whitespace.

Deleting the last word of a particular line (General rule)

   sed -i '/line pattern/s/\S*$//' test.db

line pattern represents a pattern that is found on the line that you want to target

Answer 5

This might work for you (GNU sed):

sed -r '$s/(\s*)\S+(\s*)$/\1\2/' file

this removes the last non-space token from the last line (keeping any surrounding white space).

To remove surrounding white space as well use:

sed -r '$s/\s*\S+\s*$//' file