merging two column

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http://unix.stackexchange.com – input_file (columns are tab delimited, only column 4 contains spaces) A B C D;<>X;<>Y 0 C D E F;<>Z;<>X 1 Output_file A B C D;<>X;<>Y;<>apple=0 C D E F;<>Z;<>X;<>apple=1 I would like to merge the last column of input_file with the second last column and separate the value of last column with ";" and a tag "apple=" in second last column (just like in column number 4 of input_file). Hence that output_file has one less column. It is also necessary to keep the formatting output file to be intact.As all the columns are tab delimited (HowTos)