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# Print a random line from input
# Process arguments
BEGIN {
# Name self
self = "rndl"
# Seed the random number generator
"rnds 2>/dev/null" | getline seed
if (length(seed))
srand(seed + 0)
else
srand()
}
# Iterate over the lines, randomly assigning the first field of each one with a
# decreasing probability
rand() * NR < 1 { ln = $0 }
# Check and print
END {
# Check that we processed at least one line
if (!NR) {
printf "%s: No lines found on input\n", self | "cat >&2"
exit(1)
}
# Print the line
print ln
}
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