What's an easy way to read random line from a file in Unix command line?
You can use shuf:
shuf -n 1 $FILEThere is also a utility called rl. In Debian it's in the randomize-lines package that does exactly what you want, though not available in all distros. On its home page it actually recommends the use of shuf instead (which didn't exist when it was created, I believe). shuf is part of the GNU coreutils, rl is not.
rl -c 1 $FILE
Another alternative:
head -$((${RANDOM} % `wc -l < file` + 1)) file | tail -1
sort --random-sort $FILE | head -n 1(I like the shuf approach above even better though - I didn't even know that existed and I would have never found that tool on my own)