29 lines
616 B
Awk
29 lines
616 B
Awk
#!/bin/awk -f
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# use as: awk -f middle_three_digits.awk
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BEGIN {
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n = split("123 12345 1234567 987654321 10001 -10001 -123 -100 100 -12345 1 2 -1 -10 2002 -2002 0", arr)
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for (i=1; i<=n; i++) {
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if (arr[i] !~ /^-?[0-9]+$/) {
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printf("%10s : invalid input: not a number\n", arr[i])
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continue
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}
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num = arr[i]<0 ? -arr[i]:arr[i]
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len = length(num)
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if (len < 3) {
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printf("%10s : invalid input: too few digits\n", arr[i])
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continue
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}
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if (len % 2 == 0) {
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printf("%10s : invalid input: even number of digits\n", arr[i])
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continue
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}
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printf("%10s : %s\n", arr[i], substr(num, len/2, 3))
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}
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}
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