Grep -frt, how to sort the result by r, not t

Question

$ cat r
1
2
$ cat t
22
11
$ grep -f r t
22
11

The result is provided according to the sequence in t, how can I get a result sorted by r?

Answer 1

You can create a script that stores everything in memory, or you can apply the Schwartz transform. . Here is a brief attempt to do the latter.

Change the file rto a sedscript that prints the index number for each match:

/1/s/^/00001 /
/2/s/^/00002 /

Use sedinstead grepand sort by prefix; then cancel the prefix.

sed -f r t | sort -n | cut -d ' ' -f2- >output

sed script ; Awk script (, !)

awk '{ printf("/%s/s/^/%05i /\n", $0, NR) }' r >r.sed

, . , /foo/ \:foo:, , , , , , .

sed script ( , Linux sed ), ;

awk '{ printf("/%s/s/^/%05i /\n", $0, NR) }' r |
sed -f - t | sort -n | cut -d ' ' -f2- >output