Lum – How to combine contents of two files having the same value in a column

You want join (1), I guess:

For each pair of input lines with identical join fields, write a line to standard output. The default join field is the first, delimited by whitespace. When FILE1 or FILE2 (not both) is -, read standard input.

[0 1075 12:50:10] ~/temp/sx % join A B
1 kfjk 3243424
3 iefjk 21493402
8 kfkdlkf 309834
join: file 1 is not in sorted order

OK, so apparently you need to combine this with sort (1) to sort by alpha value (not numerical value, so 20 < 3)

join <(sort A) <(sort B) works for me, but that looks weird and might be a zsh extension. There's no harm in doing

sort A > A.tmp; sort B > B.tmp; join A.tmp B.tmp

(As usual, check the man pages for pitfalls.)

If order is not important, two passes of sort should do the trick. In the first pass, sort by field 1 followed by reverse-sorting by the numeric portion of field 3 (starting position 4). The -b modifier causes leading blanks to be ignored. Pipe this to a second sort that returns one record for every unique value in field 1, but this time specify the stable sort(-s) modifier to ensure that the record with the highest value in field 3 (which had bubbled up to the top for each value in field 1 courtesy the previous sort) is returned

sort -k1,1 -k3.4b,3nr file.txt | sort -k1,1 -s -u
apple   V$NFY_Q6_rc V=0.741
grapes  V$SP1_Q6_rc V=0.884
orange  V$SP4_Q5    V=0.747