How to find the last field using cut

Question

Without using sed or awk  only cut  how do I get the last field when the number of fields are unknown or change with every line

User · Answer

This is the only solution possible for using nothing but cut:

echo "s.t.r.i.n.g." | cut -d'.' -f2- [repeat_following_part_forever_or_until_out_of_memory:] | cut -d'.' -f2-

Using this solution, the number of fields can indeed be unknown and vary from time to time. However as line length must not exceed LINE_MAX characters or fields, including the new-line character, then an arbitrary number of fields can never be part as a real condition of this solution.

Yes, a very silly solution but the only one that meets the criterias I think.

User · Answer

If your input string doesn t contain forward slashes then you can use basename and a subshell     basename    echo  maps google com    tr             This doesn t use sed or awk but it also doesn t use cut either  so I m not quite sure if it qualifies as an answer to the question as its worded   This doesn t work well if processing input strings that can contain forward slashes   A workaround for that situation would be to replace forward slash with some other character that you know isn t part of a valid input string   For example  the pipe     character is also not allowed in filenames  so this would work     basename    echo  maps google com some url things    tr           tr             tr

User · Answer

the following implements A friend s suggestion     bin bash rcut       nu     echo  1   cut -d  DELIM  -f 2-       if     nu       1      then     rcut   nu    else     echo   nu    fi      export DELIM     rcut a b c d d

User · Answer

Adding an approach to this old question just for the fun of it     cat input file   file containing input that needs to be processed a b c d e 1 2 3 4 5 no delimiter here 124 adsf 15454 foo bar is null info    cat tmp sh   showing off the script to do the job    bin bash delim     while read -r line  do       while      line       delim      do         line   cut -d  delim  -f 2-  lt  lt  lt   line       done     echo   line  done  lt  input file      tmp sh   output of above script processed input file e 5 no delimiter here 15454 info   Besides bash  only cut is used  Well  and echo  I guess

User · Answer

You could try something like this   echo  maps google com    rev   cut -d    -f 1   rev   Explanation   rev reverses  maps google com  to be moc elgoog spam cut uses dot  ie      as the delimiter  and chooses the first field  which is moc lastly  we reverse it again to get com

User · Answer

If you have a file named filelist txt that is a list paths such as the following  c  dir1 dir2 file1 h c  dir1 dir2 dir3 file2 h  then you can do this  rev filelist txt   cut -d    -f1   rev

User · Answer

It is not possible using just cut  Here is a way using grep   grep -o            Replace the comma for other delimiters

User · Answer

Use a parameter expansion  This is much more efficient than any kind of external command  cut  or grep  included   data foo bar baz qux last   data        See BashFAQ  100 for an introduction to native string manipulation in bash

User · Answer

I realized if we just ensure a trailing delimiter exists  it works  So in my case I have comma and whitespace delimiters  I add a space at the end      ans  a  b    ans       echo   ans    tr           tr -s       cut -d    -f2 b

User · Answer

There are multiple ways  You may use this too   echo  Your string here   tr       n    tail -n1  gt  here   Obviously  the blank space input for tr command should be replaced with the delimiter you need

User · Answer

Without awk       But it s so simple with awk   echo  maps google com    awk -F    print  NF     AWK is a way more powerful tool to have in your pocket  -F if for field separator NF is the number of fields  also stands for the index of the last

User · Answer

An alternative using perl would be  perl -pe  s             2   file  where you may change  t for whichever the delimiter of file is

[linux] How to find the last field using 'cut'

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