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

Issue

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.

Solution

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.

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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!

Answered By - fedorqui 'SO stop harming'

Answer Checked By - Candace Johnson (WPSolving Volunteer)