Shell Programming and Scripting

Originally Posted by Don Cragun

There is no test for 0. It is not necessarily the second line with a given value for the 1st three fields that is saved in the array; it is the last line with a given value for the 1st three fields that is saved. If there is one line with 900, -, and 1000 as the 1st three fields on the line, respectively, a[$1, $2, $3]'s value (or in this case a["900", "-", "1000"]'s value) will be that entire line. If there is more one line with 900, -, and 1000 as the 1st three fields on the line, respectively, a[$1, $2, $3]'s value will be the last line starting with those three values.

When processing an array with:

Code:

for(i in a)

the elements are processed in a random order (not necessarily the order in which they were found in the input file). This is why aia used sort -n to print the output in the same order as the (sorted) input file.