remove white space from the end of line in linux [duplicate]

Question

i have file in which i want to remove white space from the end of line test.txt is as following (there is white space at the end of line.

ath-miRf10005-akr  ath-miRf10018-akr  ath-miRf10019-akr ath-miRf10020-akr  ath-miRf10023-akr ath-miRf10024-akr  

i used sed 's/$\s//' but it is not working.

Answer 1

Use either a simple blank * or [:blank:]* to remove all possible spaces at the end of the line:

sed 's/ *$//' file 

Using the [:blank:] class you are removing spaces and tabs:

sed 's/[[:blank:]]*$//' file 

Note this is POSIX, hence compatible in both GNU sed and BSD.

For just GNU sed you can use the GNU extension \s* to match spaces and tabs, as described in BaBL86's answer. See POSIX specifications on Basic Regular Expressions.

---

Let's test it with a simple file consisting on just lines, two with just spaces and the last one also with tabs:

$ cat -vet file hello   $ bye   $ ha^I  $     # there is a tab here 

Remove just spaces:

$ sed 's/ *$//' file | cat -vet - hello$ bye$ ha^I$       # tab is still here! 

Remove spaces and tabs:

$ sed 's/[[:blank:]]*$//' file | cat -vet - hello$ bye$ ha$         # tab was removed! 

Answer 2

Try this:

sed -i 's/\s*$//' youfile.txt 

On OS X:

sed -i '' 's/\s*$//' youfile.txt